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path: root/drivers/ntb/hw/idt/ntb_hw_idt.c
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Diffstat (limited to 'drivers/ntb/hw/idt/ntb_hw_idt.c')
-rw-r--r--drivers/ntb/hw/idt/ntb_hw_idt.c2712
1 files changed, 2712 insertions, 0 deletions
diff --git a/drivers/ntb/hw/idt/ntb_hw_idt.c b/drivers/ntb/hw/idt/ntb_hw_idt.c
new file mode 100644
index 000000000000..d44d7ef38fe8
--- /dev/null
+++ b/drivers/ntb/hw/idt/ntb_hw_idt.c
@@ -0,0 +1,2712 @@
+/*
+ * This file is provided under a GPLv2 license. When using or
+ * redistributing this file, you may do so under that license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright (C) 2016 T-Platforms All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, one can be found http://www.gnu.org/licenses/.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * IDT PCIe-switch NTB Linux driver
+ *
+ * Contact Information:
+ * Serge Semin <fancer.lancer@gmail.com>, <Sergey.Semin@t-platforms.ru>
+ */
+
+#include <linux/stddef.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/sizes.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/pci.h>
+#include <linux/aer.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/debugfs.h>
+#include <linux/ntb.h>
+
+#include "ntb_hw_idt.h"
+
+#define NTB_NAME "ntb_hw_idt"
+#define NTB_DESC "IDT PCI-E Non-Transparent Bridge Driver"
+#define NTB_VER "2.0"
+#define NTB_IRQNAME "ntb_irq_idt"
+
+MODULE_DESCRIPTION(NTB_DESC);
+MODULE_VERSION(NTB_VER);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("T-platforms");
+
+/*
+ * NT Endpoint registers table simplifying a loop access to the functionally
+ * related registers
+ */
+static const struct idt_ntb_regs ntdata_tbl = {
+ { {IDT_NT_BARSETUP0, IDT_NT_BARLIMIT0,
+ IDT_NT_BARLTBASE0, IDT_NT_BARUTBASE0},
+ {IDT_NT_BARSETUP1, IDT_NT_BARLIMIT1,
+ IDT_NT_BARLTBASE1, IDT_NT_BARUTBASE1},
+ {IDT_NT_BARSETUP2, IDT_NT_BARLIMIT2,
+ IDT_NT_BARLTBASE2, IDT_NT_BARUTBASE2},
+ {IDT_NT_BARSETUP3, IDT_NT_BARLIMIT3,
+ IDT_NT_BARLTBASE3, IDT_NT_BARUTBASE3},
+ {IDT_NT_BARSETUP4, IDT_NT_BARLIMIT4,
+ IDT_NT_BARLTBASE4, IDT_NT_BARUTBASE4},
+ {IDT_NT_BARSETUP5, IDT_NT_BARLIMIT5,
+ IDT_NT_BARLTBASE5, IDT_NT_BARUTBASE5} },
+ { {IDT_NT_INMSG0, IDT_NT_OUTMSG0, IDT_NT_INMSGSRC0},
+ {IDT_NT_INMSG1, IDT_NT_OUTMSG1, IDT_NT_INMSGSRC1},
+ {IDT_NT_INMSG2, IDT_NT_OUTMSG2, IDT_NT_INMSGSRC2},
+ {IDT_NT_INMSG3, IDT_NT_OUTMSG3, IDT_NT_INMSGSRC3} }
+};
+
+/*
+ * NT Endpoint ports data table with the corresponding pcie command, link
+ * status, control and BAR-related registers
+ */
+static const struct idt_ntb_port portdata_tbl[IDT_MAX_NR_PORTS] = {
+/*0*/ { IDT_SW_NTP0_PCIECMDSTS, IDT_SW_NTP0_PCIELCTLSTS,
+ IDT_SW_NTP0_NTCTL,
+ IDT_SW_SWPORT0CTL, IDT_SW_SWPORT0STS,
+ { {IDT_SW_NTP0_BARSETUP0, IDT_SW_NTP0_BARLIMIT0,
+ IDT_SW_NTP0_BARLTBASE0, IDT_SW_NTP0_BARUTBASE0},
+ {IDT_SW_NTP0_BARSETUP1, IDT_SW_NTP0_BARLIMIT1,
+ IDT_SW_NTP0_BARLTBASE1, IDT_SW_NTP0_BARUTBASE1},
+ {IDT_SW_NTP0_BARSETUP2, IDT_SW_NTP0_BARLIMIT2,
+ IDT_SW_NTP0_BARLTBASE2, IDT_SW_NTP0_BARUTBASE2},
+ {IDT_SW_NTP0_BARSETUP3, IDT_SW_NTP0_BARLIMIT3,
+ IDT_SW_NTP0_BARLTBASE3, IDT_SW_NTP0_BARUTBASE3},
+ {IDT_SW_NTP0_BARSETUP4, IDT_SW_NTP0_BARLIMIT4,
+ IDT_SW_NTP0_BARLTBASE4, IDT_SW_NTP0_BARUTBASE4},
+ {IDT_SW_NTP0_BARSETUP5, IDT_SW_NTP0_BARLIMIT5,
+ IDT_SW_NTP0_BARLTBASE5, IDT_SW_NTP0_BARUTBASE5} } },
+/*1*/ {0},
+/*2*/ { IDT_SW_NTP2_PCIECMDSTS, IDT_SW_NTP2_PCIELCTLSTS,
+ IDT_SW_NTP2_NTCTL,
+ IDT_SW_SWPORT2CTL, IDT_SW_SWPORT2STS,
+ { {IDT_SW_NTP2_BARSETUP0, IDT_SW_NTP2_BARLIMIT0,
+ IDT_SW_NTP2_BARLTBASE0, IDT_SW_NTP2_BARUTBASE0},
+ {IDT_SW_NTP2_BARSETUP1, IDT_SW_NTP2_BARLIMIT1,
+ IDT_SW_NTP2_BARLTBASE1, IDT_SW_NTP2_BARUTBASE1},
+ {IDT_SW_NTP2_BARSETUP2, IDT_SW_NTP2_BARLIMIT2,
+ IDT_SW_NTP2_BARLTBASE2, IDT_SW_NTP2_BARUTBASE2},
+ {IDT_SW_NTP2_BARSETUP3, IDT_SW_NTP2_BARLIMIT3,
+ IDT_SW_NTP2_BARLTBASE3, IDT_SW_NTP2_BARUTBASE3},
+ {IDT_SW_NTP2_BARSETUP4, IDT_SW_NTP2_BARLIMIT4,
+ IDT_SW_NTP2_BARLTBASE4, IDT_SW_NTP2_BARUTBASE4},
+ {IDT_SW_NTP2_BARSETUP5, IDT_SW_NTP2_BARLIMIT5,
+ IDT_SW_NTP2_BARLTBASE5, IDT_SW_NTP2_BARUTBASE5} } },
+/*3*/ {0},
+/*4*/ { IDT_SW_NTP4_PCIECMDSTS, IDT_SW_NTP4_PCIELCTLSTS,
+ IDT_SW_NTP4_NTCTL,
+ IDT_SW_SWPORT4CTL, IDT_SW_SWPORT4STS,
+ { {IDT_SW_NTP4_BARSETUP0, IDT_SW_NTP4_BARLIMIT0,
+ IDT_SW_NTP4_BARLTBASE0, IDT_SW_NTP4_BARUTBASE0},
+ {IDT_SW_NTP4_BARSETUP1, IDT_SW_NTP4_BARLIMIT1,
+ IDT_SW_NTP4_BARLTBASE1, IDT_SW_NTP4_BARUTBASE1},
+ {IDT_SW_NTP4_BARSETUP2, IDT_SW_NTP4_BARLIMIT2,
+ IDT_SW_NTP4_BARLTBASE2, IDT_SW_NTP4_BARUTBASE2},
+ {IDT_SW_NTP4_BARSETUP3, IDT_SW_NTP4_BARLIMIT3,
+ IDT_SW_NTP4_BARLTBASE3, IDT_SW_NTP4_BARUTBASE3},
+ {IDT_SW_NTP4_BARSETUP4, IDT_SW_NTP4_BARLIMIT4,
+ IDT_SW_NTP4_BARLTBASE4, IDT_SW_NTP4_BARUTBASE4},
+ {IDT_SW_NTP4_BARSETUP5, IDT_SW_NTP4_BARLIMIT5,
+ IDT_SW_NTP4_BARLTBASE5, IDT_SW_NTP4_BARUTBASE5} } },
+/*5*/ {0},
+/*6*/ { IDT_SW_NTP6_PCIECMDSTS, IDT_SW_NTP6_PCIELCTLSTS,
+ IDT_SW_NTP6_NTCTL,
+ IDT_SW_SWPORT6CTL, IDT_SW_SWPORT6STS,
+ { {IDT_SW_NTP6_BARSETUP0, IDT_SW_NTP6_BARLIMIT0,
+ IDT_SW_NTP6_BARLTBASE0, IDT_SW_NTP6_BARUTBASE0},
+ {IDT_SW_NTP6_BARSETUP1, IDT_SW_NTP6_BARLIMIT1,
+ IDT_SW_NTP6_BARLTBASE1, IDT_SW_NTP6_BARUTBASE1},
+ {IDT_SW_NTP6_BARSETUP2, IDT_SW_NTP6_BARLIMIT2,
+ IDT_SW_NTP6_BARLTBASE2, IDT_SW_NTP6_BARUTBASE2},
+ {IDT_SW_NTP6_BARSETUP3, IDT_SW_NTP6_BARLIMIT3,
+ IDT_SW_NTP6_BARLTBASE3, IDT_SW_NTP6_BARUTBASE3},
+ {IDT_SW_NTP6_BARSETUP4, IDT_SW_NTP6_BARLIMIT4,
+ IDT_SW_NTP6_BARLTBASE4, IDT_SW_NTP6_BARUTBASE4},
+ {IDT_SW_NTP6_BARSETUP5, IDT_SW_NTP6_BARLIMIT5,
+ IDT_SW_NTP6_BARLTBASE5, IDT_SW_NTP6_BARUTBASE5} } },
+/*7*/ {0},
+/*8*/ { IDT_SW_NTP8_PCIECMDSTS, IDT_SW_NTP8_PCIELCTLSTS,
+ IDT_SW_NTP8_NTCTL,
+ IDT_SW_SWPORT8CTL, IDT_SW_SWPORT8STS,
+ { {IDT_SW_NTP8_BARSETUP0, IDT_SW_NTP8_BARLIMIT0,
+ IDT_SW_NTP8_BARLTBASE0, IDT_SW_NTP8_BARUTBASE0},
+ {IDT_SW_NTP8_BARSETUP1, IDT_SW_NTP8_BARLIMIT1,
+ IDT_SW_NTP8_BARLTBASE1, IDT_SW_NTP8_BARUTBASE1},
+ {IDT_SW_NTP8_BARSETUP2, IDT_SW_NTP8_BARLIMIT2,
+ IDT_SW_NTP8_BARLTBASE2, IDT_SW_NTP8_BARUTBASE2},
+ {IDT_SW_NTP8_BARSETUP3, IDT_SW_NTP8_BARLIMIT3,
+ IDT_SW_NTP8_BARLTBASE3, IDT_SW_NTP8_BARUTBASE3},
+ {IDT_SW_NTP8_BARSETUP4, IDT_SW_NTP8_BARLIMIT4,
+ IDT_SW_NTP8_BARLTBASE4, IDT_SW_NTP8_BARUTBASE4},
+ {IDT_SW_NTP8_BARSETUP5, IDT_SW_NTP8_BARLIMIT5,
+ IDT_SW_NTP8_BARLTBASE5, IDT_SW_NTP8_BARUTBASE5} } },
+/*9*/ {0},
+/*10*/ {0},
+/*11*/ {0},
+/*12*/ { IDT_SW_NTP12_PCIECMDSTS, IDT_SW_NTP12_PCIELCTLSTS,
+ IDT_SW_NTP12_NTCTL,
+ IDT_SW_SWPORT12CTL, IDT_SW_SWPORT12STS,
+ { {IDT_SW_NTP12_BARSETUP0, IDT_SW_NTP12_BARLIMIT0,
+ IDT_SW_NTP12_BARLTBASE0, IDT_SW_NTP12_BARUTBASE0},
+ {IDT_SW_NTP12_BARSETUP1, IDT_SW_NTP12_BARLIMIT1,
+ IDT_SW_NTP12_BARLTBASE1, IDT_SW_NTP12_BARUTBASE1},
+ {IDT_SW_NTP12_BARSETUP2, IDT_SW_NTP12_BARLIMIT2,
+ IDT_SW_NTP12_BARLTBASE2, IDT_SW_NTP12_BARUTBASE2},
+ {IDT_SW_NTP12_BARSETUP3, IDT_SW_NTP12_BARLIMIT3,
+ IDT_SW_NTP12_BARLTBASE3, IDT_SW_NTP12_BARUTBASE3},
+ {IDT_SW_NTP12_BARSETUP4, IDT_SW_NTP12_BARLIMIT4,
+ IDT_SW_NTP12_BARLTBASE4, IDT_SW_NTP12_BARUTBASE4},
+ {IDT_SW_NTP12_BARSETUP5, IDT_SW_NTP12_BARLIMIT5,
+ IDT_SW_NTP12_BARLTBASE5, IDT_SW_NTP12_BARUTBASE5} } },
+/*13*/ {0},
+/*14*/ {0},
+/*15*/ {0},
+/*16*/ { IDT_SW_NTP16_PCIECMDSTS, IDT_SW_NTP16_PCIELCTLSTS,
+ IDT_SW_NTP16_NTCTL,
+ IDT_SW_SWPORT16CTL, IDT_SW_SWPORT16STS,
+ { {IDT_SW_NTP16_BARSETUP0, IDT_SW_NTP16_BARLIMIT0,
+ IDT_SW_NTP16_BARLTBASE0, IDT_SW_NTP16_BARUTBASE0},
+ {IDT_SW_NTP16_BARSETUP1, IDT_SW_NTP16_BARLIMIT1,
+ IDT_SW_NTP16_BARLTBASE1, IDT_SW_NTP16_BARUTBASE1},
+ {IDT_SW_NTP16_BARSETUP2, IDT_SW_NTP16_BARLIMIT2,
+ IDT_SW_NTP16_BARLTBASE2, IDT_SW_NTP16_BARUTBASE2},
+ {IDT_SW_NTP16_BARSETUP3, IDT_SW_NTP16_BARLIMIT3,
+ IDT_SW_NTP16_BARLTBASE3, IDT_SW_NTP16_BARUTBASE3},
+ {IDT_SW_NTP16_BARSETUP4, IDT_SW_NTP16_BARLIMIT4,
+ IDT_SW_NTP16_BARLTBASE4, IDT_SW_NTP16_BARUTBASE4},
+ {IDT_SW_NTP16_BARSETUP5, IDT_SW_NTP16_BARLIMIT5,
+ IDT_SW_NTP16_BARLTBASE5, IDT_SW_NTP16_BARUTBASE5} } },
+/*17*/ {0},
+/*18*/ {0},
+/*19*/ {0},
+/*20*/ { IDT_SW_NTP20_PCIECMDSTS, IDT_SW_NTP20_PCIELCTLSTS,
+ IDT_SW_NTP20_NTCTL,
+ IDT_SW_SWPORT20CTL, IDT_SW_SWPORT20STS,
+ { {IDT_SW_NTP20_BARSETUP0, IDT_SW_NTP20_BARLIMIT0,
+ IDT_SW_NTP20_BARLTBASE0, IDT_SW_NTP20_BARUTBASE0},
+ {IDT_SW_NTP20_BARSETUP1, IDT_SW_NTP20_BARLIMIT1,
+ IDT_SW_NTP20_BARLTBASE1, IDT_SW_NTP20_BARUTBASE1},
+ {IDT_SW_NTP20_BARSETUP2, IDT_SW_NTP20_BARLIMIT2,
+ IDT_SW_NTP20_BARLTBASE2, IDT_SW_NTP20_BARUTBASE2},
+ {IDT_SW_NTP20_BARSETUP3, IDT_SW_NTP20_BARLIMIT3,
+ IDT_SW_NTP20_BARLTBASE3, IDT_SW_NTP20_BARUTBASE3},
+ {IDT_SW_NTP20_BARSETUP4, IDT_SW_NTP20_BARLIMIT4,
+ IDT_SW_NTP20_BARLTBASE4, IDT_SW_NTP20_BARUTBASE4},
+ {IDT_SW_NTP20_BARSETUP5, IDT_SW_NTP20_BARLIMIT5,
+ IDT_SW_NTP20_BARLTBASE5, IDT_SW_NTP20_BARUTBASE5} } },
+/*21*/ {0},
+/*22*/ {0},
+/*23*/ {0}
+};
+
+/*
+ * IDT PCIe-switch partitions table with the corresponding control, status
+ * and messages control registers
+ */
+static const struct idt_ntb_part partdata_tbl[IDT_MAX_NR_PARTS] = {
+/*0*/ { IDT_SW_SWPART0CTL, IDT_SW_SWPART0STS,
+ {IDT_SW_SWP0MSGCTL0, IDT_SW_SWP0MSGCTL1,
+ IDT_SW_SWP0MSGCTL2, IDT_SW_SWP0MSGCTL3} },
+/*1*/ { IDT_SW_SWPART1CTL, IDT_SW_SWPART1STS,
+ {IDT_SW_SWP1MSGCTL0, IDT_SW_SWP1MSGCTL1,
+ IDT_SW_SWP1MSGCTL2, IDT_SW_SWP1MSGCTL3} },
+/*2*/ { IDT_SW_SWPART2CTL, IDT_SW_SWPART2STS,
+ {IDT_SW_SWP2MSGCTL0, IDT_SW_SWP2MSGCTL1,
+ IDT_SW_SWP2MSGCTL2, IDT_SW_SWP2MSGCTL3} },
+/*3*/ { IDT_SW_SWPART3CTL, IDT_SW_SWPART3STS,
+ {IDT_SW_SWP3MSGCTL0, IDT_SW_SWP3MSGCTL1,
+ IDT_SW_SWP3MSGCTL2, IDT_SW_SWP3MSGCTL3} },
+/*4*/ { IDT_SW_SWPART4CTL, IDT_SW_SWPART4STS,
+ {IDT_SW_SWP4MSGCTL0, IDT_SW_SWP4MSGCTL1,
+ IDT_SW_SWP4MSGCTL2, IDT_SW_SWP4MSGCTL3} },
+/*5*/ { IDT_SW_SWPART5CTL, IDT_SW_SWPART5STS,
+ {IDT_SW_SWP5MSGCTL0, IDT_SW_SWP5MSGCTL1,
+ IDT_SW_SWP5MSGCTL2, IDT_SW_SWP5MSGCTL3} },
+/*6*/ { IDT_SW_SWPART6CTL, IDT_SW_SWPART6STS,
+ {IDT_SW_SWP6MSGCTL0, IDT_SW_SWP6MSGCTL1,
+ IDT_SW_SWP6MSGCTL2, IDT_SW_SWP6MSGCTL3} },
+/*7*/ { IDT_SW_SWPART7CTL, IDT_SW_SWPART7STS,
+ {IDT_SW_SWP7MSGCTL0, IDT_SW_SWP7MSGCTL1,
+ IDT_SW_SWP7MSGCTL2, IDT_SW_SWP7MSGCTL3} }
+};
+
+/*
+ * DebugFS directory to place the driver debug file
+ */
+static struct dentry *dbgfs_topdir;
+
+/*=============================================================================
+ * 1. IDT PCIe-switch registers IO-functions
+ *
+ * Beside ordinary configuration space registers IDT PCIe-switch expose
+ * global configuration registers, which are used to determine state of other
+ * device ports as well as being notified of some switch-related events.
+ * Additionally all the configuration space registers of all the IDT
+ * PCIe-switch functions are mapped to the Global Address space, so each
+ * function can determine a configuration of any other PCI-function.
+ * Functions declared in this chapter are created to encapsulate access
+ * to configuration and global registers, so the driver code just need to
+ * provide IDT NTB hardware descriptor and a register address.
+ *=============================================================================
+ */
+
+/*
+ * idt_nt_write() - PCI configuration space registers write method
+ * @ndev: IDT NTB hardware driver descriptor
+ * @reg: Register to write data to
+ * @data: Value to write to the register
+ *
+ * IDT PCIe-switch registers are all Little endian.
+ */
+static void idt_nt_write(struct idt_ntb_dev *ndev,
+ const unsigned int reg, const u32 data)
+{
+ /*
+ * It's obvious bug to request a register exceeding the maximum possible
+ * value as well as to have it unaligned.
+ */
+ if (WARN_ON(reg > IDT_REG_PCI_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
+ return;
+
+ /* Just write the value to the specified register */
+ iowrite32(data, ndev->cfgspc + (ptrdiff_t)reg);
+}
+
+/*
+ * idt_nt_read() - PCI configuration space registers read method
+ * @ndev: IDT NTB hardware driver descriptor
+ * @reg: Register to write data to
+ *
+ * IDT PCIe-switch Global configuration registers are all Little endian.
+ *
+ * Return: register value
+ */
+static u32 idt_nt_read(struct idt_ntb_dev *ndev, const unsigned int reg)
+{
+ /*
+ * It's obvious bug to request a register exceeding the maximum possible
+ * value as well as to have it unaligned.
+ */
+ if (WARN_ON(reg > IDT_REG_PCI_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
+ return ~0;
+
+ /* Just read the value from the specified register */
+ return ioread32(ndev->cfgspc + (ptrdiff_t)reg);
+}
+
+/*
+ * idt_sw_write() - Global registers write method
+ * @ndev: IDT NTB hardware driver descriptor
+ * @reg: Register to write data to
+ * @data: Value to write to the register
+ *
+ * IDT PCIe-switch Global configuration registers are all Little endian.
+ */
+static void idt_sw_write(struct idt_ntb_dev *ndev,
+ const unsigned int reg, const u32 data)
+{
+ unsigned long irqflags;
+
+ /*
+ * It's obvious bug to request a register exceeding the maximum possible
+ * value as well as to have it unaligned.
+ */
+ if (WARN_ON(reg > IDT_REG_SW_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
+ return;
+
+ /* Lock GASA registers operations */
+ spin_lock_irqsave(&ndev->gasa_lock, irqflags);
+ /* Set the global register address */
+ iowrite32((u32)reg, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASAADDR);
+ /* Put the new value of the register */
+ iowrite32(data, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASADATA);
+ /* Make sure the PCIe transactions are executed */
+ mmiowb();
+ /* Unlock GASA registers operations */
+ spin_unlock_irqrestore(&ndev->gasa_lock, irqflags);
+}
+
+/*
+ * idt_sw_read() - Global registers read method
+ * @ndev: IDT NTB hardware driver descriptor
+ * @reg: Register to write data to
+ *
+ * IDT PCIe-switch Global configuration registers are all Little endian.
+ *
+ * Return: register value
+ */
+static u32 idt_sw_read(struct idt_ntb_dev *ndev, const unsigned int reg)
+{
+ unsigned long irqflags;
+ u32 data;
+
+ /*
+ * It's obvious bug to request a register exceeding the maximum possible
+ * value as well as to have it unaligned.
+ */
+ if (WARN_ON(reg > IDT_REG_SW_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
+ return ~0;
+
+ /* Lock GASA registers operations */
+ spin_lock_irqsave(&ndev->gasa_lock, irqflags);
+ /* Set the global register address */
+ iowrite32((u32)reg, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASAADDR);
+ /* Get the data of the register (read ops acts as MMIO barrier) */
+ data = ioread32(ndev->cfgspc + (ptrdiff_t)IDT_NT_GASADATA);
+ /* Unlock GASA registers operations */
+ spin_unlock_irqrestore(&ndev->gasa_lock, irqflags);
+
+ return data;
+}
+
+/*
+ * idt_reg_set_bits() - set bits of a passed register
+ * @ndev: IDT NTB hardware driver descriptor
+ * @reg: Register to change bits of
+ * @reg_lock: Register access spin lock
+ * @valid_mask: Mask of valid bits
+ * @set_bits: Bitmask to set
+ *
+ * Helper method to check whether a passed bitfield is valid and set
+ * corresponding bits of a register.
+ *
+ * WARNING! Make sure the passed register isn't accessed over plane
+ * idt_nt_write() method (read method is ok to be used concurrently).
+ *
+ * Return: zero on success, negative error on invalid bitmask.
+ */
+static inline int idt_reg_set_bits(struct idt_ntb_dev *ndev, unsigned int reg,
+ spinlock_t *reg_lock,
+ u64 valid_mask, u64 set_bits)
+{
+ unsigned long irqflags;
+ u32 data;
+
+ if (set_bits & ~(u64)valid_mask)
+ return -EINVAL;
+
+ /* Lock access to the register unless the change is written back */
+ spin_lock_irqsave(reg_lock, irqflags);
+ data = idt_nt_read(ndev, reg) | (u32)set_bits;
+ idt_nt_write(ndev, reg, data);
+ /* Unlock the register */
+ spin_unlock_irqrestore(reg_lock, irqflags);
+
+ return 0;
+}
+
+/*
+ * idt_reg_clear_bits() - clear bits of a passed register
+ * @ndev: IDT NTB hardware driver descriptor
+ * @reg: Register to change bits of
+ * @reg_lock: Register access spin lock
+ * @set_bits: Bitmask to clear
+ *
+ * Helper method to check whether a passed bitfield is valid and clear
+ * corresponding bits of a register.
+ *
+ * NOTE! Invalid bits are always considered cleared so it's not an error
+ * to clear them over.
+ *
+ * WARNING! Make sure the passed register isn't accessed over plane
+ * idt_nt_write() method (read method is ok to use concurrently).
+ */
+static inline void idt_reg_clear_bits(struct idt_ntb_dev *ndev,
+ unsigned int reg, spinlock_t *reg_lock,
+ u64 clear_bits)
+{
+ unsigned long irqflags;
+ u32 data;
+
+ /* Lock access to the register unless the change is written back */
+ spin_lock_irqsave(reg_lock, irqflags);
+ data = idt_nt_read(ndev, reg) & ~(u32)clear_bits;
+ idt_nt_write(ndev, reg, data);
+ /* Unlock the register */
+ spin_unlock_irqrestore(reg_lock, irqflags);
+}
+
+/*===========================================================================
+ * 2. Ports operations
+ *
+ * IDT PCIe-switches can have from 3 up to 8 ports with possible
+ * NT-functions enabled. So all the possible ports need to be scanned looking
+ * for NTB activated. NTB API will have enumerated only the ports with NTB.
+ *===========================================================================
+ */
+
+/*
+ * idt_scan_ports() - scan IDT PCIe-switch ports collecting info in the tables
+ * @ndev: Pointer to the PCI device descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_scan_ports(struct idt_ntb_dev *ndev)
+{
+ unsigned char pidx, port, part;
+ u32 data, portsts, partsts;
+
+ /* Retrieve the local port number */
+ data = idt_nt_read(ndev, IDT_NT_PCIELCAP);
+ ndev->port = GET_FIELD(PCIELCAP_PORTNUM, data);
+
+ /* Retrieve the local partition number */
+ portsts = idt_sw_read(ndev, portdata_tbl[ndev->port].sts);
+ ndev->part = GET_FIELD(SWPORTxSTS_SWPART, portsts);
+
+ /* Initialize port/partition -> index tables with invalid values */
+ memset(ndev->port_idx_map, -EINVAL, sizeof(ndev->port_idx_map));
+ memset(ndev->part_idx_map, -EINVAL, sizeof(ndev->part_idx_map));
+
+ /*
+ * Walk over all the possible ports checking whether any of them has
+ * NT-function activated
+ */
+ ndev->peer_cnt = 0;
+ for (pidx = 0; pidx < ndev->swcfg->port_cnt; pidx++) {
+ port = ndev->swcfg->ports[pidx];
+ /* Skip local port */
+ if (port == ndev->port)
+ continue;
+
+ /* Read the port status register to get it partition */
+ portsts = idt_sw_read(ndev, portdata_tbl[port].sts);
+ part = GET_FIELD(SWPORTxSTS_SWPART, portsts);
+
+ /* Retrieve the partition status */
+ partsts = idt_sw_read(ndev, partdata_tbl[part].sts);
+ /* Check if partition state is active and port has NTB */
+ if (IS_FLD_SET(SWPARTxSTS_STATE, partsts, ACT) &&
+ (IS_FLD_SET(SWPORTxSTS_MODE, portsts, NT) ||
+ IS_FLD_SET(SWPORTxSTS_MODE, portsts, USNT) ||
+ IS_FLD_SET(SWPORTxSTS_MODE, portsts, USNTDMA) ||
+ IS_FLD_SET(SWPORTxSTS_MODE, portsts, NTDMA))) {
+ /* Save the port and partition numbers */
+ ndev->peers[ndev->peer_cnt].port = port;
+ ndev->peers[ndev->peer_cnt].part = part;
+ /* Fill in the port/partition -> index tables */
+ ndev->port_idx_map[port] = ndev->peer_cnt;
+ ndev->part_idx_map[part] = ndev->peer_cnt;
+ ndev->peer_cnt++;
+ }
+ }
+
+ dev_dbg(&ndev->ntb.pdev->dev, "Local port: %hhu, num of peers: %hhu\n",
+ ndev->port, ndev->peer_cnt);
+
+ /* It's useless to have this driver loaded if there is no any peer */
+ if (ndev->peer_cnt == 0) {
+ dev_warn(&ndev->ntb.pdev->dev, "No active peer found\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+/*
+ * idt_ntb_port_number() - get the local port number
+ * @ntb: NTB device context.
+ *
+ * Return: the local port number
+ */
+static int idt_ntb_port_number(struct ntb_dev *ntb)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ return ndev->port;
+}
+
+/*
+ * idt_ntb_peer_port_count() - get the number of peer ports
+ * @ntb: NTB device context.
+ *
+ * Return the count of detected peer NT-functions.
+ *
+ * Return: number of peer ports
+ */
+static int idt_ntb_peer_port_count(struct ntb_dev *ntb)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ return ndev->peer_cnt;
+}
+
+/*
+ * idt_ntb_peer_port_number() - get peer port by given index
+ * @ntb: NTB device context.
+ * @pidx: Peer port index.
+ *
+ * Return: peer port or negative error
+ */
+static int idt_ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ if (pidx < 0 || ndev->peer_cnt <= pidx)
+ return -EINVAL;
+
+ /* Return the detected NT-function port number */
+ return ndev->peers[pidx].port;
+}
+
+/*
+ * idt_ntb_peer_port_idx() - get peer port index by given port number
+ * @ntb: NTB device context.
+ * @port: Peer port number.
+ *
+ * Internal port -> index table is pre-initialized with -EINVAL values,
+ * so we just need to return it value
+ *
+ * Return: peer NT-function port index or negative error
+ */
+static int idt_ntb_peer_port_idx(struct ntb_dev *ntb, int port)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ if (port < 0 || IDT_MAX_NR_PORTS <= port)
+ return -EINVAL;
+
+ return ndev->port_idx_map[port];
+}
+
+/*===========================================================================
+ * 3. Link status operations
+ * There is no any ready-to-use method to have peer ports notified if NTB
+ * link is set up or got down. Instead global signal can be used instead.
+ * In case if any one of ports changes local NTB link state, it sends
+ * global signal and clears corresponding global state bit. Then all the ports
+ * receive a notification of that, so to make client driver being aware of
+ * possible NTB link change.
+ * Additionally each of active NT-functions is subscribed to PCIe-link
+ * state changes of peer ports.
+ *===========================================================================
+ */
+
+static void idt_ntb_local_link_disable(struct idt_ntb_dev *ndev);
+
+/*
+ * idt_init_link() - Initialize NTB link state notification subsystem
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Function performs the basic initialization of some global registers
+ * needed to enable IRQ-based notifications of PCIe Link Up/Down and
+ * Global Signal events.
+ * NOTE Since it's not possible to determine when all the NTB peer drivers are
+ * unloaded as well as have those registers accessed concurrently, we must
+ * preinitialize them with the same value and leave it uncleared on local
+ * driver unload.
+ */
+static void idt_init_link(struct idt_ntb_dev *ndev)
+{
+ u32 part_mask, port_mask, se_mask;
+ unsigned char pidx;
+
+ /* Initialize spin locker of Mapping Table access registers */
+ spin_lock_init(&ndev->mtbl_lock);
+
+ /* Walk over all detected peers collecting port and partition masks */
+ port_mask = ~BIT(ndev->port);
+ part_mask = ~BIT(ndev->part);
+ for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
+ port_mask &= ~BIT(ndev->peers[pidx].port);
+ part_mask &= ~BIT(ndev->peers[pidx].part);
+ }
+
+ /* Clean the Link Up/Down and GLobal Signal status registers */
+ idt_sw_write(ndev, IDT_SW_SELINKUPSTS, (u32)-1);
+ idt_sw_write(ndev, IDT_SW_SELINKDNSTS, (u32)-1);
+ idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)-1);
+
+ /* Unmask NT-activated partitions to receive Global Switch events */
+ idt_sw_write(ndev, IDT_SW_SEPMSK, part_mask);
+
+ /* Enable PCIe Link Up events of NT-activated ports */
+ idt_sw_write(ndev, IDT_SW_SELINKUPMSK, port_mask);
+
+ /* Enable PCIe Link Down events of NT-activated ports */
+ idt_sw_write(ndev, IDT_SW_SELINKDNMSK, port_mask);
+
+ /* Unmask NT-activated partitions to receive Global Signal events */
+ idt_sw_write(ndev, IDT_SW_SEGSIGMSK, part_mask);
+
+ /* Unmask Link Up/Down and Global Switch Events */
+ se_mask = ~(IDT_SEMSK_LINKUP | IDT_SEMSK_LINKDN | IDT_SEMSK_GSIGNAL);
+ idt_sw_write(ndev, IDT_SW_SEMSK, se_mask);
+
+ dev_dbg(&ndev->ntb.pdev->dev, "NTB link status events initialized");
+}
+
+/*
+ * idt_deinit_link() - deinitialize link subsystem
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Just disable the link back.
+ */
+static void idt_deinit_link(struct idt_ntb_dev *ndev)
+{
+ /* Disable the link */
+ idt_ntb_local_link_disable(ndev);
+
+ dev_dbg(&ndev->ntb.pdev->dev, "NTB link status events deinitialized");
+}
+
+/*
+ * idt_se_isr() - switch events ISR
+ * @ndev: IDT NTB hardware driver descriptor
+ * @ntint_sts: NT-function interrupt status
+ *
+ * This driver doesn't support IDT PCIe-switch dynamic reconfigurations,
+ * Failover capability, etc, so switch events are utilized to notify of
+ * PCIe and NTB link events.
+ * The method is called from PCIe ISR bottom-half routine.
+ */
+static void idt_se_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
+{
+ u32 sests;
+
+ /* Read Switch Events status */
+ sests = idt_sw_read(ndev, IDT_SW_SESTS);
+
+ /* Clean the Link Up/Down and Global Signal status registers */
+ idt_sw_write(ndev, IDT_SW_SELINKUPSTS, (u32)-1);
+ idt_sw_write(ndev, IDT_SW_SELINKDNSTS, (u32)-1);
+ idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)-1);
+
+ /* Clean the corresponding interrupt bit */
+ idt_nt_write(ndev, IDT_NT_NTINTSTS, IDT_NTINTSTS_SEVENT);
+
+ dev_dbg(&ndev->ntb.pdev->dev, "SE IRQ detected %#08x (SESTS %#08x)",
+ ntint_sts, sests);
+
+ /* Notify the client driver of possible link state change */
+ ntb_link_event(&ndev->ntb);
+}
+
+/*
+ * idt_ntb_local_link_enable() - enable the local NTB link.
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * In order to enable the NTB link we need:
+ * - enable Completion TLPs translation
+ * - initialize mapping table to enable the Request ID translation
+ * - notify peers of NTB link state change
+ */
+static void idt_ntb_local_link_enable(struct idt_ntb_dev *ndev)
+{
+ u32 reqid, mtbldata = 0;
+ unsigned long irqflags;
+
+ /* Enable the ID protection and Completion TLPs translation */
+ idt_nt_write(ndev, IDT_NT_NTCTL, IDT_NTCTL_CPEN);
+
+ /* Retrieve the current Requester ID (Bus:Device:Function) */
+ reqid = idt_nt_read(ndev, IDT_NT_REQIDCAP);
+
+ /*
+ * Set the corresponding NT Mapping table entry of port partition index
+ * with the data to perform the Request ID translation
+ */
+ mtbldata = SET_FIELD(NTMTBLDATA_REQID, 0, reqid) |
+ SET_FIELD(NTMTBLDATA_PART, 0, ndev->part) |
+ IDT_NTMTBLDATA_VALID;
+ spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+ idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
+ idt_nt_write(ndev, IDT_NT_NTMTBLDATA, mtbldata);
+ mmiowb();
+ spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+ /* Notify the peers by setting and clearing the global signal bit */
+ idt_nt_write(ndev, IDT_NT_NTGSIGNAL, IDT_NTGSIGNAL_SET);
+ idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)1 << ndev->part);
+}
+
+/*
+ * idt_ntb_local_link_disable() - disable the local NTB link.
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * In order to enable the NTB link we need:
+ * - disable Completion TLPs translation
+ * - clear corresponding mapping table entry
+ * - notify peers of NTB link state change
+ */
+static void idt_ntb_local_link_disable(struct idt_ntb_dev *ndev)
+{
+ unsigned long irqflags;
+
+ /* Disable Completion TLPs translation */
+ idt_nt_write(ndev, IDT_NT_NTCTL, 0);
+
+ /* Clear the corresponding NT Mapping table entry */
+ spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+ idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
+ idt_nt_write(ndev, IDT_NT_NTMTBLDATA, 0);
+ mmiowb();
+ spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+ /* Notify the peers by setting and clearing the global signal bit */
+ idt_nt_write(ndev, IDT_NT_NTGSIGNAL, IDT_NTGSIGNAL_SET);
+ idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)1 << ndev->part);
+}
+
+/*
+ * idt_ntb_local_link_is_up() - test wethter local NTB link is up
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Local link is up under the following conditions:
+ * - Bus mastering is enabled
+ * - NTCTL has Completion TLPs translation enabled
+ * - Mapping table permits Request TLPs translation
+ * NOTE: We don't need to check PCIe link state since it's obviously
+ * up while we are able to communicate with IDT PCIe-switch
+ *
+ * Return: true if link is up, otherwise false
+ */
+static bool idt_ntb_local_link_is_up(struct idt_ntb_dev *ndev)
+{
+ unsigned long irqflags;
+ u32 data;
+
+ /* Read the local Bus Master Enable status */
+ data = idt_nt_read(ndev, IDT_NT_PCICMDSTS);
+ if (!(data & IDT_PCICMDSTS_BME))
+ return false;
+
+ /* Read the local Completion TLPs translation enable status */
+ data = idt_nt_read(ndev, IDT_NT_NTCTL);
+ if (!(data & IDT_NTCTL_CPEN))
+ return false;
+
+ /* Read Mapping table entry corresponding to the local partition */
+ spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+ idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
+ data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
+ spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+ return !!(data & IDT_NTMTBLDATA_VALID);
+}
+
+/*
+ * idt_ntb_peer_link_is_up() - test whether peer NTB link is up
+ * @ndev: IDT NTB hardware driver descriptor
+ * @pidx: Peer port index
+ *
+ * Peer link is up under the following conditions:
+ * - PCIe link is up
+ * - Bus mastering is enabled
+ * - NTCTL has Completion TLPs translation enabled
+ * - Mapping table permits Request TLPs translation
+ *
+ * Return: true if link is up, otherwise false
+ */
+static bool idt_ntb_peer_link_is_up(struct idt_ntb_dev *ndev, int pidx)
+{
+ unsigned long irqflags;
+ unsigned char port;
+ u32 data;
+
+ /* Retrieve the device port number */
+ port = ndev->peers[pidx].port;
+
+ /* Check whether PCIe link is up */
+ data = idt_sw_read(ndev, portdata_tbl[port].sts);
+ if (!(data & IDT_SWPORTxSTS_LINKUP))
+ return false;
+
+ /* Check whether bus mastering is enabled on the peer port */
+ data = idt_sw_read(ndev, portdata_tbl[port].pcicmdsts);
+ if (!(data & IDT_PCICMDSTS_BME))
+ return false;
+
+ /* Check if Completion TLPs translation is enabled on the peer port */
+ data = idt_sw_read(ndev, portdata_tbl[port].ntctl);
+ if (!(data & IDT_NTCTL_CPEN))
+ return false;
+
+ /* Read Mapping table entry corresponding to the peer partition */
+ spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+ idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->peers[pidx].part);
+ data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
+ spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+ return !!(data & IDT_NTMTBLDATA_VALID);
+}
+
+/*
+ * idt_ntb_link_is_up() - get the current ntb link state (NTB API callback)
+ * @ntb: NTB device context.
+ * @speed: OUT - The link speed expressed as PCIe generation number.
+ * @width: OUT - The link width expressed as the number of PCIe lanes.
+ *
+ * Get the bitfield of NTB link states for all peer ports
+ *
+ * Return: bitfield of indexed ports link state: bit is set/cleared if the
+ * link is up/down respectively.
+ */
+static u64 idt_ntb_link_is_up(struct ntb_dev *ntb,
+ enum ntb_speed *speed, enum ntb_width *width)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+ unsigned char pidx;
+ u64 status;
+ u32 data;
+
+ /* Retrieve the local link speed and width */
+ if (speed != NULL || width != NULL) {
+ data = idt_nt_read(ndev, IDT_NT_PCIELCTLSTS);
+ if (speed != NULL)
+ *speed = GET_FIELD(PCIELCTLSTS_CLS, data);
+ if (width != NULL)
+ *width = GET_FIELD(PCIELCTLSTS_NLW, data);
+ }
+
+ /* If local NTB link isn't up then all the links are considered down */
+ if (!idt_ntb_local_link_is_up(ndev))
+ return 0;
+
+ /* Collect all the peer ports link states into the bitfield */
+ status = 0;
+ for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
+ if (idt_ntb_peer_link_is_up(ndev, pidx))
+ status |= ((u64)1 << pidx);
+ }
+
+ return status;
+}
+
+/*
+ * idt_ntb_link_enable() - enable local port ntb link (NTB API callback)
+ * @ntb: NTB device context.
+ * @max_speed: The maximum link speed expressed as PCIe generation number.
+ * @max_width: The maximum link width expressed as the number of PCIe lanes.
+ *
+ * Enable just local NTB link. PCIe link parameters are ignored.
+ *
+ * Return: always zero.
+ */
+static int idt_ntb_link_enable(struct ntb_dev *ntb, enum ntb_speed speed,
+ enum ntb_width width)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ /* Just enable the local NTB link */
+ idt_ntb_local_link_enable(ndev);
+
+ dev_dbg(&ndev->ntb.pdev->dev, "Local NTB link enabled");
+
+ return 0;
+}
+
+/*
+ * idt_ntb_link_disable() - disable local port ntb link (NTB API callback)
+ * @ntb: NTB device context.
+ *
+ * Disable just local NTB link.
+ *
+ * Return: always zero.
+ */
+static int idt_ntb_link_disable(struct ntb_dev *ntb)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ /* Just disable the local NTB link */
+ idt_ntb_local_link_disable(ndev);
+
+ dev_dbg(&ndev->ntb.pdev->dev, "Local NTB link disabled");
+
+ return 0;
+}
+
+/*=============================================================================
+ * 4. Memory Window operations
+ *
+ * IDT PCIe-switches have two types of memory windows: MWs with direct
+ * address translation and MWs with LUT based translation. The first type of
+ * MWs is simple map of corresponding BAR address space to a memory space
+ * of specified target port. So it implemets just ont-to-one mapping. Lookup
+ * table in its turn can map one BAR address space to up to 24 different
+ * memory spaces of different ports.
+ * NT-functions BARs can be turned on to implement either direct or lookup
+ * table based address translations, so:
+ * BAR0 - NT configuration registers space/direct address translation
+ * BAR1 - direct address translation/upper address of BAR0x64
+ * BAR2 - direct address translation/Lookup table with either 12 or 24 entries
+ * BAR3 - direct address translation/upper address of BAR2x64
+ * BAR4 - direct address translation/Lookup table with either 12 or 24 entries
+ * BAR5 - direct address translation/upper address of BAR4x64
+ * Additionally BAR2 and BAR4 can't have 24-entries LUT enabled at the same
+ * time. Since the BARs setup can be rather complicated this driver implements
+ * a scanning algorithm to have all the possible memory windows configuration
+ * covered.
+ *
+ * NOTE 1 BAR setup must be done before Linux kernel enumerated NT-function
+ * of any port, so this driver would have memory windows configurations fixed.
+ * In this way all initializations must be performed either by platform BIOS
+ * or using EEPROM connected to IDT PCIe-switch master SMBus.
+ *
+ * NOTE 2 This driver expects BAR0 mapping NT-function configuration space.
+ * Easy calculation can give us an upper boundary of 29 possible memory windows
+ * per each NT-function if all the BARs are of 32bit type.
+ *=============================================================================
+ */
+
+/*
+ * idt_get_mw_count() - get memory window count
+ * @mw_type: Memory window type
+ *
+ * Return: number of memory windows with respect to the BAR type
+ */
+static inline unsigned char idt_get_mw_count(enum idt_mw_type mw_type)
+{
+ switch (mw_type) {
+ case IDT_MW_DIR:
+ return 1;
+ case IDT_MW_LUT12:
+ return 12;
+ case IDT_MW_LUT24:
+ return 24;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+/*
+ * idt_get_mw_name() - get memory window name
+ * @mw_type: Memory window type
+ *
+ * Return: pointer to a string with name
+ */
+static inline char *idt_get_mw_name(enum idt_mw_type mw_type)
+{
+ switch (mw_type) {
+ case IDT_MW_DIR:
+ return "DIR ";
+ case IDT_MW_LUT12:
+ return "LUT12";
+ case IDT_MW_LUT24:
+ return "LUT24";
+ default:
+ break;
+ }
+
+ return "unknown";
+}
+
+/*
+ * idt_scan_mws() - scan memory windows of the port
+ * @ndev: IDT NTB hardware driver descriptor
+ * @port: Port to get number of memory windows for
+ * @mw_cnt: Out - number of memory windows
+ *
+ * It walks over BAR setup registers of the specified port and determines
+ * the memory windows parameters if any activated.
+ *
+ * Return: array of memory windows
+ */
+static struct idt_mw_cfg *idt_scan_mws(struct idt_ntb_dev *ndev, int port,
+ unsigned char *mw_cnt)
+{
+ struct idt_mw_cfg mws[IDT_MAX_NR_MWS], *ret_mws;
+ const struct idt_ntb_bar *bars;
+ enum idt_mw_type mw_type;
+ unsigned char widx, bidx, en_cnt;
+ bool bar_64bit = false;
+ int aprt_size;
+ u32 data;
+
+ /* Retrieve the array of the BARs registers */
+ bars = portdata_tbl[port].bars;
+
+ /* Scan all the BARs belonging to the port */
+ *mw_cnt = 0;
+ for (bidx = 0; bidx < IDT_BAR_CNT; bidx += 1 + bar_64bit) {
+ /* Read BARSETUP register value */
+ data = idt_sw_read(ndev, bars[bidx].setup);
+
+ /* Skip disabled BARs */
+ if (!(data & IDT_BARSETUP_EN)) {
+ bar_64bit = false;
+ continue;
+ }
+
+ /* Skip next BARSETUP if current one has 64bit addressing */
+ bar_64bit = IS_FLD_SET(BARSETUP_TYPE, data, 64);
+
+ /* Skip configuration space mapping BARs */
+ if (data & IDT_BARSETUP_MODE_CFG)
+ continue;
+
+ /* Retrieve MW type/entries count and aperture size */
+ mw_type = GET_FIELD(BARSETUP_ATRAN, data);
+ en_cnt = idt_get_mw_count(mw_type);
+ aprt_size = (u64)1 << GET_FIELD(BARSETUP_SIZE, data);
+
+ /* Save configurations of all available memory windows */
+ for (widx = 0; widx < en_cnt; widx++, (*mw_cnt)++) {
+ /*
+ * IDT can expose a limited number of MWs, so it's bug
+ * to have more than the driver expects
+ */
+ if (*mw_cnt >= IDT_MAX_NR_MWS)
+ return ERR_PTR(-EINVAL);
+
+ /* Save basic MW info */
+ mws[*mw_cnt].type = mw_type;
+ mws[*mw_cnt].bar = bidx;
+ mws[*mw_cnt].idx = widx;
+ /* It's always DWORD aligned */
+ mws[*mw_cnt].addr_align = IDT_TRANS_ALIGN;
+ /* DIR and LUT approachs differently configure MWs */
+ if (mw_type == IDT_MW_DIR)
+ mws[*mw_cnt].size_max = aprt_size;
+ else if (mw_type == IDT_MW_LUT12)
+ mws[*mw_cnt].size_max = aprt_size / 16;
+ else
+ mws[*mw_cnt].size_max = aprt_size / 32;
+ mws[*mw_cnt].size_align = (mw_type == IDT_MW_DIR) ?
+ IDT_DIR_SIZE_ALIGN : mws[*mw_cnt].size_max;
+ }
+ }
+
+ /* Allocate memory for memory window descriptors */
+ ret_mws = devm_kcalloc(&ndev->ntb.pdev->dev, *mw_cnt,
+ sizeof(*ret_mws), GFP_KERNEL);
+ if (IS_ERR_OR_NULL(ret_mws))
+ return ERR_PTR(-ENOMEM);
+
+ /* Copy the info of detected memory windows */
+ memcpy(ret_mws, mws, (*mw_cnt)*sizeof(*ret_mws));
+
+ return ret_mws;
+}
+
+/*
+ * idt_init_mws() - initialize memory windows subsystem
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Scan BAR setup registers of local and peer ports to determine the
+ * outbound and inbound memory windows parameters
+ *
+ * Return: zero on success, otherwise a negative error number
+ */
+static int idt_init_mws(struct idt_ntb_dev *ndev)
+{
+ struct idt_ntb_peer *peer;
+ unsigned char pidx;
+
+ /* Scan memory windows of the local port */
+ ndev->mws = idt_scan_mws(ndev, ndev->port, &ndev->mw_cnt);
+ if (IS_ERR(ndev->mws)) {
+ dev_err(&ndev->ntb.pdev->dev,
+ "Failed to scan mws of local port %hhu", ndev->port);
+ return PTR_ERR(ndev->mws);
+ }
+
+ /* Scan memory windows of the peer ports */
+ for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
+ peer = &ndev->peers[pidx];
+ peer->mws = idt_scan_mws(ndev, peer->port, &peer->mw_cnt);
+ if (IS_ERR(peer->mws)) {
+ dev_err(&ndev->ntb.pdev->dev,
+ "Failed to scan mws of port %hhu", peer->port);
+ return PTR_ERR(peer->mws);
+ }
+ }
+
+ /* Initialize spin locker of the LUT registers */
+ spin_lock_init(&ndev->lut_lock);
+
+ dev_dbg(&ndev->ntb.pdev->dev, "Outbound and inbound MWs initialized");
+
+ return 0;
+}
+
+/*
+ * idt_ntb_mw_count() - number of inbound memory windows (NTB API callback)
+ * @ntb: NTB device context.
+ * @pidx: Port index of peer device.
+ *
+ * The value is returned for the specified peer, so generally speaking it can
+ * be different for different port depending on the IDT PCIe-switch
+ * initialization.
+ *
+ * Return: the number of memory windows.
+ */
+static int idt_ntb_mw_count(struct ntb_dev *ntb, int pidx)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ if (pidx < 0 || ndev->peer_cnt <= pidx)
+ return -EINVAL;
+
+ return ndev->peers[pidx].mw_cnt;
+}
+
+/*
+ * idt_ntb_mw_get_align() - inbound memory window parameters (NTB API callback)
+ * @ntb: NTB device context.
+ * @pidx: Port index of peer device.
+ * @widx: Memory window index.
+ * @addr_align: OUT - the base alignment for translating the memory window
+ * @size_align: OUT - the size alignment for translating the memory window
+ * @size_max: OUT - the maximum size of the memory window
+ *
+ * The peer memory window parameters have already been determined, so just
+ * return the corresponding values, which mustn't change within session.
+ *
+ * Return: Zero on success, otherwise a negative error number.
+ */
+static int idt_ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx,
+ resource_size_t *addr_align,
+ resource_size_t *size_align,
+ resource_size_t *size_max)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+ struct idt_ntb_peer *peer;
+
+ if (pidx < 0 || ndev->peer_cnt <= pidx)
+ return -EINVAL;
+
+ peer = &ndev->peers[pidx];
+
+ if (widx < 0 || peer->mw_cnt <= widx)
+ return -EINVAL;
+
+ if (addr_align != NULL)
+ *addr_align = peer->mws[widx].addr_align;
+
+ if (size_align != NULL)
+ *size_align = peer->mws[widx].size_align;
+
+ if (size_max != NULL)
+ *size_max = peer->mws[widx].size_max;
+
+ return 0;
+}
+
+/*
+ * idt_ntb_peer_mw_count() - number of outbound memory windows
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ *
+ * Outbound memory windows parameters have been determined based on the
+ * BAR setup registers value, which are mostly constants within one session.
+ *
+ * Return: the number of memory windows.
+ */
+static int idt_ntb_peer_mw_count(struct ntb_dev *ntb)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ return ndev->mw_cnt;
+}
+
+/*
+ * idt_ntb_peer_mw_get_addr() - get map address of an outbound memory window
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @widx: Memory window index (within ntb_peer_mw_count() return value).
+ * @base: OUT - the base address of mapping region.
+ * @size: OUT - the size of mapping region.
+ *
+ * Return just parameters of BAR resources mapping. Size reflects just the size
+ * of the resource
+ *
+ * Return: Zero on success, otherwise a negative error number.
+ */
+static int idt_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int widx,
+ phys_addr_t *base, resource_size_t *size)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ if (widx < 0 || ndev->mw_cnt <= widx)
+ return -EINVAL;
+
+ /* Mapping address is just properly shifted BAR resource start */
+ if (base != NULL)
+ *base = pci_resource_start(ntb->pdev, ndev->mws[widx].bar) +
+ ndev->mws[widx].idx * ndev->mws[widx].size_max;
+
+ /* Mapping size has already been calculated at MWs scanning */
+ if (size != NULL)
+ *size = ndev->mws[widx].size_max;
+
+ return 0;
+}
+
+/*
+ * idt_ntb_peer_mw_set_trans() - set a translation address of a memory window
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @pidx: Port index of peer device the translation address received from.
+ * @widx: Memory window index.
+ * @addr: The dma address of the shared memory to access.
+ * @size: The size of the shared memory to access.
+ *
+ * The Direct address translation and LUT base translation is initialized a
+ * bit differenet. Although the parameters restriction are now determined by
+ * the same code.
+ *
+ * Return: Zero on success, otherwise an error number.
+ */
+static int idt_ntb_peer_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
+ u64 addr, resource_size_t size)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+ struct idt_mw_cfg *mw_cfg;
+ u32 data = 0, lutoff = 0;
+
+ if (pidx < 0 || ndev->peer_cnt <= pidx)
+ return -EINVAL;
+
+ if (widx < 0 || ndev->mw_cnt <= widx)
+ return -EINVAL;
+
+ /*
+ * Retrieve the memory window config to make sure the passed arguments
+ * fit it restrictions
+ */
+ mw_cfg = &ndev->mws[widx];
+ if (!IS_ALIGNED(addr, mw_cfg->addr_align))
+ return -EINVAL;
+ if (!IS_ALIGNED(size, mw_cfg->size_align) || size > mw_cfg->size_max)
+ return -EINVAL;
+
+ /* DIR and LUT based translations are initialized differently */
+ if (mw_cfg->type == IDT_MW_DIR) {
+ const struct idt_ntb_bar *bar = &ntdata_tbl.bars[mw_cfg->bar];
+ u64 limit;
+ /* Set destination partition of translation */
+ data = idt_nt_read(ndev, bar->setup);
+ data = SET_FIELD(BARSETUP_TPART, data, ndev->peers[pidx].part);
+ idt_nt_write(ndev, bar->setup, data);
+ /* Set translation base address */
+ idt_nt_write(ndev, bar->ltbase, (u32)addr);
+ idt_nt_write(ndev, bar->utbase, (u32)(addr >> 32));
+ /* Set the custom BAR aperture limit */
+ limit = pci_resource_start(ntb->pdev, mw_cfg->bar) + size;
+ idt_nt_write(ndev, bar->limit, (u32)limit);
+ if (IS_FLD_SET(BARSETUP_TYPE, data, 64))
+ idt_nt_write(ndev, (bar + 1)->limit, (limit >> 32));
+ } else {
+ unsigned long irqflags;
+ /* Initialize corresponding LUT entry */
+ lutoff = SET_FIELD(LUTOFFSET_INDEX, 0, mw_cfg->idx) |
+ SET_FIELD(LUTOFFSET_BAR, 0, mw_cfg->bar);
+ data = SET_FIELD(LUTUDATA_PART, 0, ndev->peers[pidx].part) |
+ IDT_LUTUDATA_VALID;
+ spin_lock_irqsave(&ndev->lut_lock, irqflags);
+ idt_nt_write(ndev, IDT_NT_LUTOFFSET, lutoff);
+ idt_nt_write(ndev, IDT_NT_LUTLDATA, (u32)addr);
+ idt_nt_write(ndev, IDT_NT_LUTMDATA, (u32)(addr >> 32));
+ idt_nt_write(ndev, IDT_NT_LUTUDATA, data);
+ mmiowb();
+ spin_unlock_irqrestore(&ndev->lut_lock, irqflags);
+ /* Limit address isn't specified since size is fixed for LUT */
+ }
+
+ return 0;
+}
+
+/*
+ * idt_ntb_peer_mw_clear_trans() - clear the outbound MW translation address
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @pidx: Port index of peer device.
+ * @widx: Memory window index.
+ *
+ * It effectively disables the translation over the specified outbound MW.
+ *
+ * Return: Zero on success, otherwise an error number.
+ */
+static int idt_ntb_peer_mw_clear_trans(struct ntb_dev *ntb, int pidx,
+ int widx)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+ struct idt_mw_cfg *mw_cfg;
+
+ if (pidx < 0 || ndev->peer_cnt <= pidx)
+ return -EINVAL;
+
+ if (widx < 0 || ndev->mw_cnt <= widx)
+ return -EINVAL;
+
+ mw_cfg = &ndev->mws[widx];
+
+ /* DIR and LUT based translations are initialized differently */
+ if (mw_cfg->type == IDT_MW_DIR) {
+ const struct idt_ntb_bar *bar = &ntdata_tbl.bars[mw_cfg->bar];
+ u32 data;
+ /* Read BARSETUP to check BAR type */
+ data = idt_nt_read(ndev, bar->setup);
+ /* Disable translation by specifying zero BAR limit */
+ idt_nt_write(ndev, bar->limit, 0);
+ if (IS_FLD_SET(BARSETUP_TYPE, data, 64))
+ idt_nt_write(ndev, (bar + 1)->limit, 0);
+ } else {
+ unsigned long irqflags;
+ u32 lutoff;
+ /* Clear the corresponding LUT entry up */
+ lutoff = SET_FIELD(LUTOFFSET_INDEX, 0, mw_cfg->idx) |
+ SET_FIELD(LUTOFFSET_BAR, 0, mw_cfg->bar);
+ spin_lock_irqsave(&ndev->lut_lock, irqflags);
+ idt_nt_write(ndev, IDT_NT_LUTOFFSET, lutoff);
+ idt_nt_write(ndev, IDT_NT_LUTLDATA, 0);
+ idt_nt_write(ndev, IDT_NT_LUTMDATA, 0);
+ idt_nt_write(ndev, IDT_NT_LUTUDATA, 0);
+ mmiowb();
+ spin_unlock_irqrestore(&ndev->lut_lock, irqflags);
+ }
+
+ return 0;
+}
+
+/*=============================================================================
+ * 5. Doorbell operations
+ *
+ * Doorbell functionality of IDT PCIe-switches is pretty unusual. First of
+ * all there is global doorbell register which state can by changed by any
+ * NT-function of the IDT device in accordance with global permissions. These
+ * permissions configs are not supported by NTB API, so it must be done by
+ * either BIOS or EEPROM settings. In the same way the state of the global
+ * doorbell is reflected to the NT-functions local inbound doorbell registers.
+ * It can lead to situations when client driver sets some peer doorbell bits
+ * and get them bounced back to local inbound doorbell if permissions are
+ * granted.
+ * Secondly there is just one IRQ vector for Doorbell, Message, Temperature
+ * and Switch events, so if client driver left any of Doorbell bits set and
+ * some other event occurred, the driver will be notified of Doorbell event
+ * again.
+ *=============================================================================
+ */
+
+/*
+ * idt_db_isr() - doorbell event ISR
+ * @ndev: IDT NTB hardware driver descriptor
+ * @ntint_sts: NT-function interrupt status
+ *
+ * Doorbell event happans when DBELL bit of NTINTSTS switches from 0 to 1.
+ * It happens only when unmasked doorbell bits are set to ones on completely
+ * zeroed doorbell register.
+ * The method is called from PCIe ISR bottom-half routine.
+ */
+static void idt_db_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
+{
+ /*
+ * Doorbell IRQ status will be cleaned only when client
+ * driver unsets all the doorbell bits.
+ */
+ dev_dbg(&ndev->ntb.pdev->dev, "DB IRQ detected %#08x", ntint_sts);
+
+ /* Notify the client driver of possible doorbell state change */
+ ntb_db_event(&ndev->ntb, 0);
+}
+
+/*
+ * idt_ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ *
+ * IDT PCIe-switches expose just one Doorbell register of DWORD size.
+ *
+ * Return: A mask of doorbell bits supported by the ntb.
+ */
+static u64 idt_ntb_db_valid_mask(struct ntb_dev *ntb)
+{
+ return IDT_DBELL_MASK;
+}
+
+/*
+ * idt_ntb_db_read() - read the local doorbell register (NTB API callback)
+ * @ntb: NTB device context.
+ *
+ * There is just on inbound doorbell register of each NT-function, so
+ * this method return it value.
+ *
+ * Return: The bits currently set in the local doorbell register.
+ */
+static u64 idt_ntb_db_read(struct ntb_dev *ntb)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ return idt_nt_read(ndev, IDT_NT_INDBELLSTS);
+}
+
+/*
+ * idt_ntb_db_clear() - clear bits in the local doorbell register
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @db_bits: Doorbell bits to clear.
+ *
+ * Clear bits of inbound doorbell register by writing ones to it.
+ *
+ * NOTE! Invalid bits are always considered cleared so it's not an error
+ * to clear them over.
+ *
+ * Return: always zero as success.
+ */
+static int idt_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ idt_nt_write(ndev, IDT_NT_INDBELLSTS, (u32)db_bits);
+
+ return 0;
+}
+
+/*
+ * idt_ntb_db_read_mask() - read the local doorbell mask (NTB API callback)
+ * @ntb: NTB device context.
+ *
+ * Each inbound doorbell bit can be masked from generating IRQ by setting
+ * the corresponding bit in inbound doorbell mask. So this method returns
+ * the value of the register.
+ *
+ * Return: The bits currently set in the local doorbell mask register.
+ */
+static u64 idt_ntb_db_read_mask(struct ntb_dev *ntb)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ return idt_nt_read(ndev, IDT_NT_INDBELLMSK);
+}
+
+/*
+ * idt_ntb_db_set_mask() - set bits in the local doorbell mask
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @db_bits: Doorbell mask bits to set.
+ *
+ * The inbound doorbell register mask value must be read, then OR'ed with
+ * passed field and only then set back.
+ *
+ * Return: zero on success, negative error if invalid argument passed.
+ */
+static int idt_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ return idt_reg_set_bits(ndev, IDT_NT_INDBELLMSK, &ndev->db_mask_lock,
+ IDT_DBELL_MASK, db_bits);
+}
+
+/*
+ * idt_ntb_db_clear_mask() - clear bits in the local doorbell mask
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @db_bits: Doorbell bits to clear.
+ *
+ * The method just clears the set bits up in accordance with the passed
+ * bitfield. IDT PCIe-switch shall generate an interrupt if there hasn't
+ * been any unmasked bit set before current unmasking. Otherwise IRQ won't
+ * be generated since there is only one IRQ vector for all doorbells.
+ *
+ * Return: always zero as success
+ */
+static int idt_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ idt_reg_clear_bits(ndev, IDT_NT_INDBELLMSK, &ndev->db_mask_lock,
+ db_bits);
+
+ return 0;
+}
+
+/*
+ * idt_ntb_peer_db_set() - set bits in the peer doorbell register
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @db_bits: Doorbell bits to set.
+ *
+ * IDT PCIe-switches exposes local outbound doorbell register to change peer
+ * inbound doorbell register state.
+ *
+ * Return: zero on success, negative error if invalid argument passed.
+ */
+static int idt_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ if (db_bits & ~(u64)IDT_DBELL_MASK)
+ return -EINVAL;
+
+ idt_nt_write(ndev, IDT_NT_OUTDBELLSET, (u32)db_bits);
+ return 0;
+}
+
+/*=============================================================================
+ * 6. Messaging operations
+ *
+ * Each NT-function of IDT PCIe-switch has four inbound and four outbound
+ * message registers. Each outbound message register can be connected to one or
+ * even more than one peer inbound message registers by setting global
+ * configurations. Since NTB API permits one-on-one message registers mapping
+ * only, the driver acts in according with that restriction.
+ *=============================================================================
+ */
+
+/*
+ * idt_init_msg() - initialize messaging interface
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Just initialize the message registers routing tables locker.
+ */
+static void idt_init_msg(struct idt_ntb_dev *ndev)
+{
+ unsigned char midx;
+
+ /* Init the messages routing table lockers */
+ for (midx = 0; midx < IDT_MSG_CNT; midx++)
+ spin_lock_init(&ndev->msg_locks[midx]);
+
+ dev_dbg(&ndev->ntb.pdev->dev, "NTB Messaging initialized");
+}
+
+/*
+ * idt_msg_isr() - message event ISR
+ * @ndev: IDT NTB hardware driver descriptor
+ * @ntint_sts: NT-function interrupt status
+ *
+ * Message event happens when MSG bit of NTINTSTS switches from 0 to 1.
+ * It happens only when unmasked message status bits are set to ones on
+ * completely zeroed message status register.
+ * The method is called from PCIe ISR bottom-half routine.
+ */
+static void idt_msg_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
+{
+ /*
+ * Message IRQ status will be cleaned only when client
+ * driver unsets all the message status bits.
+ */
+ dev_dbg(&ndev->ntb.pdev->dev, "Message IRQ detected %#08x", ntint_sts);
+
+ /* Notify the client driver of possible message status change */
+ ntb_msg_event(&ndev->ntb);
+}
+
+/*
+ * idt_ntb_msg_count() - get the number of message registers (NTB API callback)
+ * @ntb: NTB device context.
+ *
+ * IDT PCIe-switches support four message registers.
+ *
+ * Return: the number of message registers.
+ */
+static int idt_ntb_msg_count(struct ntb_dev *ntb)
+{
+ return IDT_MSG_CNT;
+}
+
+/*
+ * idt_ntb_msg_inbits() - get a bitfield of inbound message registers status
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ *
+ * NT message status register is shared between inbound and outbound message
+ * registers status
+ *
+ * Return: bitfield of inbound message registers.
+ */
+static u64 idt_ntb_msg_inbits(struct ntb_dev *ntb)
+{
+ return (u64)IDT_INMSG_MASK;
+}
+
+/*
+ * idt_ntb_msg_outbits() - get a bitfield of outbound message registers status
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ *
+ * NT message status register is shared between inbound and outbound message
+ * registers status
+ *
+ * Return: bitfield of outbound message registers.
+ */
+static u64 idt_ntb_msg_outbits(struct ntb_dev *ntb)
+{
+ return (u64)IDT_OUTMSG_MASK;
+}
+
+/*
+ * idt_ntb_msg_read_sts() - read the message registers status (NTB API callback)
+ * @ntb: NTB device context.
+ *
+ * IDT PCIe-switches expose message status registers to notify drivers of
+ * incoming data and failures in case if peer message register isn't freed.
+ *
+ * Return: status bits of message registers
+ */
+static u64 idt_ntb_msg_read_sts(struct ntb_dev *ntb)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ return idt_nt_read(ndev, IDT_NT_MSGSTS);
+}
+
+/*
+ * idt_ntb_msg_clear_sts() - clear status bits of message registers
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @sts_bits: Status bits to clear.
+ *
+ * Clear bits in the status register by writing ones.
+ *
+ * NOTE! Invalid bits are always considered cleared so it's not an error
+ * to clear them over.
+ *
+ * Return: always zero as success.
+ */
+static int idt_ntb_msg_clear_sts(struct ntb_dev *ntb, u64 sts_bits)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ idt_nt_write(ndev, IDT_NT_MSGSTS, sts_bits);
+
+ return 0;
+}
+
+/*
+ * idt_ntb_msg_set_mask() - set mask of message register status bits
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @mask_bits: Mask bits.
+ *
+ * Mask the message status bits from raising an IRQ.
+ *
+ * Return: zero on success, negative error if invalid argument passed.
+ */
+static int idt_ntb_msg_set_mask(struct ntb_dev *ntb, u64 mask_bits)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ return idt_reg_set_bits(ndev, IDT_NT_MSGSTSMSK, &ndev->msg_mask_lock,
+ IDT_MSG_MASK, mask_bits);
+}
+
+/*
+ * idt_ntb_msg_clear_mask() - clear message registers mask
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @mask_bits: Mask bits.
+ *
+ * Clear mask of message status bits IRQs.
+ *
+ * Return: always zero as success.
+ */
+static int idt_ntb_msg_clear_mask(struct ntb_dev *ntb, u64 mask_bits)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ idt_reg_clear_bits(ndev, IDT_NT_MSGSTSMSK, &ndev->msg_mask_lock,
+ mask_bits);
+
+ return 0;
+}
+
+/*
+ * idt_ntb_msg_read() - read message register with specified index
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @midx: Message register index
+ * @pidx: OUT - Port index of peer device a message retrieved from
+ * @msg: OUT - Data
+ *
+ * Read data from the specified message register and source register.
+ *
+ * Return: zero on success, negative error if invalid argument passed.
+ */
+static int idt_ntb_msg_read(struct ntb_dev *ntb, int midx, int *pidx, u32 *msg)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+ if (midx < 0 || IDT_MSG_CNT <= midx)
+ return -EINVAL;
+
+ /* Retrieve source port index of the message */
+ if (pidx != NULL) {
+ u32 srcpart;
+
+ srcpart = idt_nt_read(ndev, ntdata_tbl.msgs[midx].src);
+ *pidx = ndev->part_idx_map[srcpart];
+
+ /* Sanity check partition index (for initial case) */
+ if (*pidx == -EINVAL)
+ *pidx = 0;
+ }
+
+ /* Retrieve data of the corresponding message register */
+ if (msg != NULL)
+ *msg = idt_nt_read(ndev, ntdata_tbl.msgs[midx].in);
+
+ return 0;
+}
+
+/*
+ * idt_ntb_msg_write() - write data to the specified message register
+ * (NTB API callback)
+ * @ntb: NTB device context.
+ * @midx: Message register index
+ * @pidx: Port index of peer device a message being sent to
+ * @msg: Data to send
+ *
+ * Just try to send data to a peer. Message status register should be
+ * checked by client driver.
+ *
+ * Return: zero on success, negative error if invalid argument passed.
+ */
+static int idt_ntb_msg_write(struct ntb_dev *ntb, int midx, int pidx, u32 msg)
+{
+ struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+ unsigned long irqflags;
+ u32 swpmsgctl = 0;
+
+ if (midx < 0 || IDT_MSG_CNT <= midx)
+ return -EINVAL;
+
+ if (pidx < 0 || ndev->peer_cnt <= pidx)
+ return -EINVAL;
+
+ /* Collect the routing information */
+ swpmsgctl = SET_FIELD(SWPxMSGCTL_REG, 0, midx) |
+ SET_FIELD(SWPxMSGCTL_PART, 0, ndev->peers[pidx].part);
+
+ /* Lock the messages routing table of the specified register */
+ spin_lock_irqsave(&ndev->msg_locks[midx], irqflags);
+ /* Set the route and send the data */
+ idt_sw_write(ndev, partdata_tbl[ndev->part].msgctl[midx], swpmsgctl);
+ idt_nt_write(ndev, ntdata_tbl.msgs[midx].out, msg);
+ mmiowb();
+ /* Unlock the messages routing table */
+ spin_unlock_irqrestore(&ndev->msg_locks[midx], irqflags);
+
+ /* Client driver shall check the status register */
+ return 0;
+}
+
+/*=============================================================================
+ * 7. Temperature sensor operations
+ *
+ * IDT PCIe-switch has an embedded temperature sensor, which can be used to
+ * warn a user-space of possible chip overheating. Since workload temperature
+ * can be different on different platforms, temperature thresholds as well as
+ * general sensor settings must be setup in the framework of BIOS/EEPROM
+ * initializations. It includes the actual sensor enabling as well.
+ *=============================================================================
+ */
+
+/*
+ * idt_read_temp() - read temperature from chip sensor
+ * @ntb: NTB device context.
+ * @val: OUT - integer value of temperature
+ * @frac: OUT - fraction
+ */
+static void idt_read_temp(struct idt_ntb_dev *ndev, unsigned char *val,
+ unsigned char *frac)
+{
+ u32 data;
+
+ /* Read the data from TEMP field of the TMPSTS register */
+ data = idt_sw_read(ndev, IDT_SW_TMPSTS);
+ data = GET_FIELD(TMPSTS_TEMP, data);
+ /* TEMP field has one fractional bit and seven integer bits */
+ *val = data >> 1;
+ *frac = ((data & 0x1) ? 5 : 0);
+}
+
+/*
+ * idt_temp_isr() - temperature sensor alarm events ISR
+ * @ndev: IDT NTB hardware driver descriptor
+ * @ntint_sts: NT-function interrupt status
+ *
+ * It handles events of temperature crossing alarm thresholds. Since reading
+ * of TMPALARM register clears it up, the function doesn't analyze the
+ * read value, instead the current temperature value just warningly printed to
+ * log.
+ * The method is called from PCIe ISR bottom-half routine.
+ */
+static void idt_temp_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
+{
+ unsigned char val, frac;
+
+ /* Read the current temperature value */
+ idt_read_temp(ndev, &val, &frac);
+
+ /* Read the temperature alarm to clean the alarm status out */
+ /*(void)idt_sw_read(ndev, IDT_SW_TMPALARM);*/
+
+ /* Clean the corresponding interrupt bit */
+ idt_nt_write(ndev, IDT_NT_NTINTSTS, IDT_NTINTSTS_TMPSENSOR);
+
+ dev_dbg(&ndev->ntb.pdev->dev,
+ "Temp sensor IRQ detected %#08x", ntint_sts);
+
+ /* Print temperature value to log */
+ dev_warn(&ndev->ntb.pdev->dev, "Temperature %hhu.%hhu", val, frac);
+}
+
+/*=============================================================================
+ * 8. ISRs related operations
+ *
+ * IDT PCIe-switch has strangely developed IRQ system. There is just one
+ * interrupt vector for doorbell and message registers. So the hardware driver
+ * can't determine actual source of IRQ if, for example, message event happened
+ * while any of unmasked doorbell is still set. The similar situation may be if
+ * switch or temperature sensor events pop up. The difference is that SEVENT
+ * and TMPSENSOR bits of NT interrupt status register can be cleaned by
+ * IRQ handler so a next interrupt request won't have false handling of
+ * corresponding events.
+ * The hardware driver has only bottom-half handler of the IRQ, since if any
+ * of events happened the device won't raise it again before the last one is
+ * handled by clearing of corresponding NTINTSTS bit.
+ *=============================================================================
+ */
+
+static irqreturn_t idt_thread_isr(int irq, void *devid);
+
+/*
+ * idt_init_isr() - initialize PCIe interrupt handler
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_init_isr(struct idt_ntb_dev *ndev)
+{
+ struct pci_dev *pdev = ndev->ntb.pdev;
+ u32 ntint_mask;
+ int ret;
+
+ /* Allocate just one interrupt vector for the ISR */
+ ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI | PCI_IRQ_LEGACY);
+ if (ret != 1) {
+ dev_err(&pdev->dev, "Failed to allocate IRQ vector");
+ return ret;
+ }
+
+ /* Retrieve the IRQ vector */
+ ret = pci_irq_vector(pdev, 0);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to get IRQ vector");
+ goto err_free_vectors;
+ }
+
+ /* Set the IRQ handler */
+ ret = devm_request_threaded_irq(&pdev->dev, ret, NULL, idt_thread_isr,
+ IRQF_ONESHOT, NTB_IRQNAME, ndev);
+ if (ret != 0) {
+ dev_err(&pdev->dev, "Failed to set MSI IRQ handler, %d", ret);
+ goto err_free_vectors;
+ }
+
+ /* Unmask Message/Doorbell/SE/Temperature interrupts */
+ ntint_mask = idt_nt_read(ndev, IDT_NT_NTINTMSK) & ~IDT_NTINTMSK_ALL;
+ idt_nt_write(ndev, IDT_NT_NTINTMSK, ntint_mask);
+
+ /* From now on the interrupts are enabled */
+ dev_dbg(&pdev->dev, "NTB interrupts initialized");
+
+ return 0;
+
+err_free_vectors:
+ pci_free_irq_vectors(pdev);
+
+ return ret;
+}
+
+
+/*
+ * idt_deinit_ist() - deinitialize PCIe interrupt handler
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Disable corresponding interrupts and free allocated IRQ vectors.
+ */
+static void idt_deinit_isr(struct idt_ntb_dev *ndev)
+{
+ struct pci_dev *pdev = ndev->ntb.pdev;
+ u32 ntint_mask;
+
+ /* Mask interrupts back */
+ ntint_mask = idt_nt_read(ndev, IDT_NT_NTINTMSK) | IDT_NTINTMSK_ALL;
+ idt_nt_write(ndev, IDT_NT_NTINTMSK, ntint_mask);
+
+ /* Manually free IRQ otherwise PCI free irq vectors will fail */
+ devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 0), ndev);
+
+ /* Free allocated IRQ vectors */
+ pci_free_irq_vectors(pdev);
+
+ dev_dbg(&pdev->dev, "NTB interrupts deinitialized");
+}
+
+/*
+ * idt_thread_isr() - NT function interrupts handler
+ * @irq: IRQ number
+ * @devid: Custom buffer
+ *
+ * It reads current NT interrupts state register and handles all the event
+ * it declares.
+ * The method is bottom-half routine of actual default PCIe IRQ handler.
+ */
+static irqreturn_t idt_thread_isr(int irq, void *devid)
+{
+ struct idt_ntb_dev *ndev = devid;
+ bool handled = false;
+ u32 ntint_sts;
+
+ /* Read the NT interrupts status register */
+ ntint_sts = idt_nt_read(ndev, IDT_NT_NTINTSTS);
+
+ /* Handle messaging interrupts */
+ if (ntint_sts & IDT_NTINTSTS_MSG) {
+ idt_msg_isr(ndev, ntint_sts);
+ handled = true;
+ }
+
+ /* Handle doorbell interrupts */
+ if (ntint_sts & IDT_NTINTSTS_DBELL) {
+ idt_db_isr(ndev, ntint_sts);
+ handled = true;
+ }
+
+ /* Handle switch event interrupts */
+ if (ntint_sts & IDT_NTINTSTS_SEVENT) {
+ idt_se_isr(ndev, ntint_sts);
+ handled = true;
+ }
+
+ /* Handle temperature sensor interrupt */
+ if (ntint_sts & IDT_NTINTSTS_TMPSENSOR) {
+ idt_temp_isr(ndev, ntint_sts);
+ handled = true;
+ }
+
+ dev_dbg(&ndev->ntb.pdev->dev, "IDT IRQs 0x%08x handled", ntint_sts);
+
+ return handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+/*===========================================================================
+ * 9. NTB hardware driver initialization
+ *===========================================================================
+ */
+
+/*
+ * NTB API operations
+ */
+static const struct ntb_dev_ops idt_ntb_ops = {
+ .port_number = idt_ntb_port_number,
+ .peer_port_count = idt_ntb_peer_port_count,
+ .peer_port_number = idt_ntb_peer_port_number,
+ .peer_port_idx = idt_ntb_peer_port_idx,
+ .link_is_up = idt_ntb_link_is_up,
+ .link_enable = idt_ntb_link_enable,
+ .link_disable = idt_ntb_link_disable,
+ .mw_count = idt_ntb_mw_count,
+ .mw_get_align = idt_ntb_mw_get_align,
+ .peer_mw_count = idt_ntb_peer_mw_count,
+ .peer_mw_get_addr = idt_ntb_peer_mw_get_addr,
+ .peer_mw_set_trans = idt_ntb_peer_mw_set_trans,
+ .peer_mw_clear_trans = idt_ntb_peer_mw_clear_trans,
+ .db_valid_mask = idt_ntb_db_valid_mask,
+ .db_read = idt_ntb_db_read,
+ .db_clear = idt_ntb_db_clear,
+ .db_read_mask = idt_ntb_db_read_mask,
+ .db_set_mask = idt_ntb_db_set_mask,
+ .db_clear_mask = idt_ntb_db_clear_mask,
+ .peer_db_set = idt_ntb_peer_db_set,
+ .msg_count = idt_ntb_msg_count,
+ .msg_inbits = idt_ntb_msg_inbits,
+ .msg_outbits = idt_ntb_msg_outbits,
+ .msg_read_sts = idt_ntb_msg_read_sts,
+ .msg_clear_sts = idt_ntb_msg_clear_sts,
+ .msg_set_mask = idt_ntb_msg_set_mask,
+ .msg_clear_mask = idt_ntb_msg_clear_mask,
+ .msg_read = idt_ntb_msg_read,
+ .msg_write = idt_ntb_msg_write
+};
+
+/*
+ * idt_register_device() - register IDT NTB device
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_register_device(struct idt_ntb_dev *ndev)
+{
+ int ret;
+
+ /* Initialize the rest of NTB device structure and register it */
+ ndev->ntb.ops = &idt_ntb_ops;
+ ndev->ntb.topo = NTB_TOPO_PRI;
+
+ ret = ntb_register_device(&ndev->ntb);
+ if (ret != 0) {
+ dev_err(&ndev->ntb.pdev->dev, "Failed to register NTB device");
+ return ret;
+ }
+
+ dev_dbg(&ndev->ntb.pdev->dev, "NTB device successfully registered");
+
+ return 0;
+}
+
+/*
+ * idt_unregister_device() - unregister IDT NTB device
+ * @ndev: IDT NTB hardware driver descriptor
+ */
+static void idt_unregister_device(struct idt_ntb_dev *ndev)
+{
+ /* Just unregister the NTB device */
+ ntb_unregister_device(&ndev->ntb);
+
+ dev_dbg(&ndev->ntb.pdev->dev, "NTB device unregistered");
+}
+
+/*=============================================================================
+ * 10. DebugFS node initialization
+ *=============================================================================
+ */
+
+static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *offp);
+
+/*
+ * Driver DebugFS info file operations
+ */
+static const struct file_operations idt_dbgfs_info_ops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = idt_dbgfs_info_read
+};
+
+/*
+ * idt_dbgfs_info_read() - DebugFS read info node callback
+ * @file: File node descriptor.
+ * @ubuf: User-space buffer to put data to
+ * @count: Size of the buffer
+ * @offp: Offset within the buffer
+ */
+static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *offp)
+{
+ struct idt_ntb_dev *ndev = filp->private_data;
+ unsigned char temp, frac, idx, pidx, cnt;
+ ssize_t ret = 0, off = 0;
+ unsigned long irqflags;
+ enum ntb_speed speed;
+ enum ntb_width width;
+ char *strbuf;
+ size_t size;
+ u32 data;
+
+ /* Lets limit the buffer size the way the Intel/AMD drivers do */
+ size = min_t(size_t, count, 0x1000U);
+
+ /* Allocate the memory for the buffer */
+ strbuf = kmalloc(size, GFP_KERNEL);
+ if (strbuf == NULL)
+ return -ENOMEM;
+
+ /* Put the data into the string buffer */
+ off += scnprintf(strbuf + off, size - off,
+ "\n\t\tIDT NTB device Information:\n\n");
+
+ /* General local device configurations */
+ off += scnprintf(strbuf + off, size - off,
+ "Local Port %hhu, Partition %hhu\n", ndev->port, ndev->part);
+
+ /* Peer ports information */
+ off += scnprintf(strbuf + off, size - off, "Peers:\n");
+ for (idx = 0; idx < ndev->peer_cnt; idx++) {
+ off += scnprintf(strbuf + off, size - off,
+ "\t%hhu. Port %hhu, Partition %hhu\n",
+ idx, ndev->peers[idx].port, ndev->peers[idx].part);
+ }
+
+ /* Links status */
+ data = idt_ntb_link_is_up(&ndev->ntb, &speed, &width);
+ off += scnprintf(strbuf + off, size - off,
+ "NTB link status\t- 0x%08x, ", data);
+ off += scnprintf(strbuf + off, size - off, "PCIe Gen %d x%d lanes\n",
+ speed, width);
+
+ /* Mapping table entries */
+ off += scnprintf(strbuf + off, size - off, "NTB Mapping Table:\n");
+ for (idx = 0; idx < IDT_MTBL_ENTRY_CNT; idx++) {
+ spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+ idt_nt_write(ndev, IDT_NT_NTMTBLADDR, idx);
+ data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
+ spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+ /* Print valid entries only */
+ if (data & IDT_NTMTBLDATA_VALID) {
+ off += scnprintf(strbuf + off, size - off,
+ "\t%hhu. Partition %d, Requester ID 0x%04x\n",
+ idx, GET_FIELD(NTMTBLDATA_PART, data),
+ GET_FIELD(NTMTBLDATA_REQID, data));
+ }
+ }
+ off += scnprintf(strbuf + off, size - off, "\n");
+
+ /* Outbound memory windows information */
+ off += scnprintf(strbuf + off, size - off,
+ "Outbound Memory Windows:\n");
+ for (idx = 0; idx < ndev->mw_cnt; idx += cnt) {
+ data = ndev->mws[idx].type;
+ cnt = idt_get_mw_count(data);
+
+ /* Print Memory Window information */
+ if (data == IDT_MW_DIR)
+ off += scnprintf(strbuf + off, size - off,
+ "\t%hhu.\t", idx);
+ else
+ off += scnprintf(strbuf + off, size - off,
+ "\t%hhu-%hhu.\t", idx, idx + cnt - 1);
+
+ off += scnprintf(strbuf + off, size - off, "%s BAR%hhu, ",
+ idt_get_mw_name(data), ndev->mws[idx].bar);
+
+ off += scnprintf(strbuf + off, size - off,
+ "Address align 0x%08llx, ", ndev->mws[idx].addr_align);
+
+ off += scnprintf(strbuf + off, size - off,
+ "Size align 0x%08llx, Size max %llu\n",
+ ndev->mws[idx].size_align, ndev->mws[idx].size_max);
+ }
+
+ /* Inbound memory windows information */
+ for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
+ off += scnprintf(strbuf + off, size - off,
+ "Inbound Memory Windows for peer %hhu (Port %hhu):\n",
+ pidx, ndev->peers[pidx].port);
+
+ /* Print Memory Windows information */
+ for (idx = 0; idx < ndev->peers[pidx].mw_cnt; idx += cnt) {
+ data = ndev->peers[pidx].mws[idx].type;
+ cnt = idt_get_mw_count(data);
+
+ if (data == IDT_MW_DIR)
+ off += scnprintf(strbuf + off, size - off,
+ "\t%hhu.\t", idx);
+ else
+ off += scnprintf(strbuf + off, size - off,
+ "\t%hhu-%hhu.\t", idx, idx + cnt - 1);
+
+ off += scnprintf(strbuf + off, size - off,
+ "%s BAR%hhu, ", idt_get_mw_name(data),
+ ndev->peers[pidx].mws[idx].bar);
+
+ off += scnprintf(strbuf + off, size - off,
+ "Address align 0x%08llx, ",
+ ndev->peers[pidx].mws[idx].addr_align);
+
+ off += scnprintf(strbuf + off, size - off,
+ "Size align 0x%08llx, Size max %llu\n",
+ ndev->peers[pidx].mws[idx].size_align,
+ ndev->peers[pidx].mws[idx].size_max);
+ }
+ }
+ off += scnprintf(strbuf + off, size - off, "\n");
+
+ /* Doorbell information */
+ data = idt_sw_read(ndev, IDT_SW_GDBELLSTS);
+ off += scnprintf(strbuf + off, size - off,
+ "Global Doorbell state\t- 0x%08x\n", data);
+ data = idt_ntb_db_read(&ndev->ntb);
+ off += scnprintf(strbuf + off, size - off,
+ "Local Doorbell state\t- 0x%08x\n", data);
+ data = idt_nt_read(ndev, IDT_NT_INDBELLMSK);
+ off += scnprintf(strbuf + off, size - off,
+ "Local Doorbell mask\t- 0x%08x\n", data);
+ off += scnprintf(strbuf + off, size - off, "\n");
+
+ /* Messaging information */
+ off += scnprintf(strbuf + off, size - off,
+ "Message event valid\t- 0x%08x\n", IDT_MSG_MASK);
+ data = idt_ntb_msg_read_sts(&ndev->ntb);
+ off += scnprintf(strbuf + off, size - off,
+ "Message event status\t- 0x%08x\n", data);
+ data = idt_nt_read(ndev, IDT_NT_MSGSTSMSK);
+ off += scnprintf(strbuf + off, size - off,
+ "Message event mask\t- 0x%08x\n", data);
+ off += scnprintf(strbuf + off, size - off,
+ "Message data:\n");
+ for (idx = 0; idx < IDT_MSG_CNT; idx++) {
+ int src;
+ (void)idt_ntb_msg_read(&ndev->ntb, idx, &src, &data);
+ off += scnprintf(strbuf + off, size - off,
+ "\t%hhu. 0x%08x from peer %hhu (Port %hhu)\n",
+ idx, data, src, ndev->peers[src].port);
+ }
+ off += scnprintf(strbuf + off, size - off, "\n");
+
+ /* Current temperature */
+ idt_read_temp(ndev, &temp, &frac);
+ off += scnprintf(strbuf + off, size - off,
+ "Switch temperature\t\t- %hhu.%hhuC\n", temp, frac);
+
+ /* Copy the buffer to the User Space */
+ ret = simple_read_from_buffer(ubuf, count, offp, strbuf, off);
+ kfree(strbuf);
+
+ return ret;
+}
+
+/*
+ * idt_init_dbgfs() - initialize DebugFS node
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_init_dbgfs(struct idt_ntb_dev *ndev)
+{
+ char devname[64];
+
+ /* If the top directory is not created then do nothing */
+ if (IS_ERR_OR_NULL(dbgfs_topdir)) {
+ dev_info(&ndev->ntb.pdev->dev, "Top DebugFS directory absent");
+ return PTR_ERR(dbgfs_topdir);
+ }
+
+ /* Create the info file node */
+ snprintf(devname, 64, "info:%s", pci_name(ndev->ntb.pdev));
+ ndev->dbgfs_info = debugfs_create_file(devname, 0400, dbgfs_topdir,
+ ndev, &idt_dbgfs_info_ops);
+ if (IS_ERR(ndev->dbgfs_info)) {
+ dev_dbg(&ndev->ntb.pdev->dev, "Failed to create DebugFS node");
+ return PTR_ERR(ndev->dbgfs_info);
+ }
+
+ dev_dbg(&ndev->ntb.pdev->dev, "NTB device DebugFS node created");
+
+ return 0;
+}
+
+/*
+ * idt_deinit_dbgfs() - deinitialize DebugFS node
+ * @ndev: IDT NTB hardware driver descriptor
+ *
+ * Just discard the info node from DebugFS
+ */
+static void idt_deinit_dbgfs(struct idt_ntb_dev *ndev)
+{
+ debugfs_remove(ndev->dbgfs_info);
+
+ dev_dbg(&ndev->ntb.pdev->dev, "NTB device DebugFS node discarded");
+}
+
+/*=============================================================================
+ * 11. Basic PCIe device initialization
+ *=============================================================================
+ */
+
+/*
+ * idt_check_setup() - Check whether the IDT PCIe-swtich is properly
+ * pre-initialized
+ * @pdev: Pointer to the PCI device descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_check_setup(struct pci_dev *pdev)
+{
+ u32 data;
+ int ret;
+
+ /* Read the BARSETUP0 */
+ ret = pci_read_config_dword(pdev, IDT_NT_BARSETUP0, &data);
+ if (ret != 0) {
+ dev_err(&pdev->dev,
+ "Failed to read BARSETUP0 config register");
+ return ret;
+ }
+
+ /* Check whether the BAR0 register is enabled to be of config space */
+ if (!(data & IDT_BARSETUP_EN) || !(data & IDT_BARSETUP_MODE_CFG)) {
+ dev_err(&pdev->dev, "BAR0 doesn't map config space");
+ return -EINVAL;
+ }
+
+ /* Configuration space BAR0 must have certain size */
+ if ((data & IDT_BARSETUP_SIZE_MASK) != IDT_BARSETUP_SIZE_CFG) {
+ dev_err(&pdev->dev, "Invalid size of config space");
+ return -EINVAL;
+ }
+
+ dev_dbg(&pdev->dev, "NTB device pre-initialized correctly");
+
+ return 0;
+}
+
+/*
+ * Create the IDT PCIe-switch driver descriptor
+ * @pdev: Pointer to the PCI device descriptor
+ * @id: IDT PCIe-device configuration
+ *
+ * It just allocates a memory for IDT PCIe-switch device structure and
+ * initializes some commonly used fields.
+ *
+ * No need of release method, since managed device resource is used for
+ * memory allocation.
+ *
+ * Return: pointer to the descriptor, otherwise a negative error number.
+ */
+static struct idt_ntb_dev *idt_create_dev(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ struct idt_ntb_dev *ndev;
+
+ /* Allocate memory for the IDT PCIe-device descriptor */
+ ndev = devm_kzalloc(&pdev->dev, sizeof(*ndev), GFP_KERNEL);
+ if (IS_ERR_OR_NULL(ndev)) {
+ dev_err(&pdev->dev, "Memory allocation failed for descriptor");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /* Save the IDT PCIe-switch ports configuration */
+ ndev->swcfg = (struct idt_89hpes_cfg *)id->driver_data;
+ /* Save the PCI-device pointer inside the NTB device structure */
+ ndev->ntb.pdev = pdev;
+
+ /* Initialize spin locker of Doorbell, Message and GASA registers */
+ spin_lock_init(&ndev->db_mask_lock);
+ spin_lock_init(&ndev->msg_mask_lock);
+ spin_lock_init(&ndev->gasa_lock);
+
+ dev_info(&pdev->dev, "IDT %s discovered", ndev->swcfg->name);
+
+ dev_dbg(&pdev->dev, "NTB device descriptor created");
+
+ return ndev;
+}
+
+/*
+ * idt_init_pci() - initialize the basic PCI-related subsystem
+ * @ndev: Pointer to the IDT PCIe-switch driver descriptor
+ *
+ * Managed device resources will be freed automatically in case of failure or
+ * driver detachment.
+ *
+ * Return: zero on success, otherwise negative error number.
+ */
+static int idt_init_pci(struct idt_ntb_dev *ndev)
+{
+ struct pci_dev *pdev = ndev->ntb.pdev;
+ int ret;
+
+ /* Initialize the bit mask of DMA */
+ ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
+ if (ret != 0) {
+ ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+ if (ret != 0) {
+ dev_err(&pdev->dev, "Failed to set DMA bit mask\n");
+ return ret;
+ }
+ dev_warn(&pdev->dev, "Cannot set DMA highmem bit mask\n");
+ }
+ ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
+ if (ret != 0) {
+ ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
+ if (ret != 0) {
+ dev_err(&pdev->dev,
+ "Failed to set consistent DMA bit mask\n");
+ return ret;
+ }
+ dev_warn(&pdev->dev,
+ "Cannot set consistent DMA highmem bit mask\n");
+ }
+
+ /*
+ * Enable the device advanced error reporting. It's not critical to
+ * have AER disabled in the kernel.
+ */
+ ret = pci_enable_pcie_error_reporting(pdev);
+ if (ret != 0)
+ dev_warn(&pdev->dev, "PCIe AER capability disabled\n");
+ else /* Cleanup uncorrectable error status before getting to init */
+ pci_cleanup_aer_uncorrect_error_status(pdev);
+
+ /* First enable the PCI device */
+ ret = pcim_enable_device(pdev);
+ if (ret != 0) {
+ dev_err(&pdev->dev, "Failed to enable PCIe device\n");
+ goto err_disable_aer;
+ }
+
+ /*
+ * Enable the bus mastering, which effectively enables MSI IRQs and
+ * Request TLPs translation
+ */
+ pci_set_master(pdev);
+
+ /* Request all BARs resources and map BAR0 only */
+ ret = pcim_iomap_regions_request_all(pdev, 1, NTB_NAME);
+ if (ret != 0) {
+ dev_err(&pdev->dev, "Failed to request resources\n");
+ goto err_clear_master;
+ }
+
+ /* Retrieve virtual address of BAR0 - PCI configuration space */
+ ndev->cfgspc = pcim_iomap_table(pdev)[0];
+
+ /* Put the IDT driver data pointer to the PCI-device private pointer */
+ pci_set_drvdata(pdev, ndev);
+
+ dev_dbg(&pdev->dev, "NT-function PCIe interface initialized");
+
+ return 0;
+
+err_clear_master:
+ pci_clear_master(pdev);
+err_disable_aer:
+ (void)pci_disable_pcie_error_reporting(pdev);
+
+ return ret;
+}
+
+/*
+ * idt_deinit_pci() - deinitialize the basic PCI-related subsystem
+ * @ndev: Pointer to the IDT PCIe-switch driver descriptor
+ *
+ * Managed resources will be freed on the driver detachment
+ */
+static void idt_deinit_pci(struct idt_ntb_dev *ndev)
+{
+ struct pci_dev *pdev = ndev->ntb.pdev;
+
+ /* Clean up the PCI-device private data pointer */
+ pci_set_drvdata(pdev, NULL);
+
+ /* Clear the bus master disabling the Request TLPs translation */
+ pci_clear_master(pdev);
+
+ /* Disable the AER capability */
+ (void)pci_disable_pcie_error_reporting(pdev);
+
+ dev_dbg(&pdev->dev, "NT-function PCIe interface cleared");
+}
+
+/*===========================================================================
+ * 12. PCI bus callback functions
+ *===========================================================================
+ */
+
+/*
+ * idt_pci_probe() - PCI device probe callback
+ * @pdev: Pointer to PCI device structure
+ * @id: PCIe device custom descriptor
+ *
+ * Return: zero on success, otherwise negative error number
+ */
+static int idt_pci_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ struct idt_ntb_dev *ndev;
+ int ret;
+
+ /* Check whether IDT PCIe-switch is properly pre-initialized */
+ ret = idt_check_setup(pdev);
+ if (ret != 0)
+ return ret;
+
+ /* Allocate the memory for IDT NTB device data */
+ ndev = idt_create_dev(pdev, id);
+ if (IS_ERR_OR_NULL(ndev))
+ return PTR_ERR(ndev);
+
+ /* Initialize the basic PCI subsystem of the device */
+ ret = idt_init_pci(ndev);
+ if (ret != 0)
+ return ret;
+
+ /* Scan ports of the IDT PCIe-switch */
+ (void)idt_scan_ports(ndev);
+
+ /* Initialize NTB link events subsystem */
+ idt_init_link(ndev);
+
+ /* Initialize MWs subsystem */
+ ret = idt_init_mws(ndev);
+ if (ret != 0)
+ goto err_deinit_link;
+
+ /* Initialize Messaging subsystem */
+ idt_init_msg(ndev);
+
+ /* Initialize IDT interrupts handler */
+ ret = idt_init_isr(ndev);
+ if (ret != 0)
+ goto err_deinit_link;
+
+ /* Register IDT NTB devices on the NTB bus */
+ ret = idt_register_device(ndev);
+ if (ret != 0)
+ goto err_deinit_isr;
+
+ /* Initialize DebugFS info node */
+ (void)idt_init_dbgfs(ndev);
+
+ /* IDT PCIe-switch NTB driver is finally initialized */
+ dev_info(&pdev->dev, "IDT NTB device is ready");
+
+ /* May the force be with us... */
+ return 0;
+
+err_deinit_isr:
+ idt_deinit_isr(ndev);
+err_deinit_link:
+ idt_deinit_link(ndev);
+ idt_deinit_pci(ndev);
+
+ return ret;
+}
+
+/*
+ * idt_pci_probe() - PCI device remove callback
+ * @pdev: Pointer to PCI device structure
+ */
+static void idt_pci_remove(struct pci_dev *pdev)
+{
+ struct idt_ntb_dev *ndev = pci_get_drvdata(pdev);
+
+ /* Deinit the DebugFS node */
+ idt_deinit_dbgfs(ndev);
+
+ /* Unregister NTB device */
+ idt_unregister_device(ndev);
+
+ /* Stop the interrupts handling */
+ idt_deinit_isr(ndev);
+
+ /* Deinitialize link event subsystem */
+ idt_deinit_link(ndev);
+
+ /* Deinit basic PCI subsystem */
+ idt_deinit_pci(ndev);
+
+ /* IDT PCIe-switch NTB driver is finally initialized */
+ dev_info(&pdev->dev, "IDT NTB device is removed");
+
+ /* Sayonara... */
+}
+
+/*
+ * IDT PCIe-switch models ports configuration structures
+ */
+static struct idt_89hpes_cfg idt_89hpes24nt6ag2_config = {
+ .name = "89HPES24NT6AG2",
+ .port_cnt = 6, .ports = {0, 2, 4, 6, 8, 12}
+};
+static struct idt_89hpes_cfg idt_89hpes32nt8ag2_config = {
+ .name = "89HPES32NT8AG2",
+ .port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+static struct idt_89hpes_cfg idt_89hpes32nt8bg2_config = {
+ .name = "89HPES32NT8BG2",
+ .port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+static struct idt_89hpes_cfg idt_89hpes12nt12g2_config = {
+ .name = "89HPES12NT12G2",
+ .port_cnt = 3, .ports = {0, 8, 16}
+};
+static struct idt_89hpes_cfg idt_89hpes16nt16g2_config = {
+ .name = "89HPES16NT16G2",
+ .port_cnt = 4, .ports = {0, 8, 12, 16}
+};
+static struct idt_89hpes_cfg idt_89hpes24nt24g2_config = {
+ .name = "89HPES24NT24G2",
+ .port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+static struct idt_89hpes_cfg idt_89hpes32nt24ag2_config = {
+ .name = "89HPES32NT24AG2",
+ .port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+static struct idt_89hpes_cfg idt_89hpes32nt24bg2_config = {
+ .name = "89HPES32NT24BG2",
+ .port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+
+/*
+ * PCI-ids table of the supported IDT PCIe-switch devices
+ */
+static const struct pci_device_id idt_pci_tbl[] = {
+ {IDT_PCI_DEVICE_IDS(89HPES24NT6AG2, idt_89hpes24nt6ag2_config)},
+ {IDT_PCI_DEVICE_IDS(89HPES32NT8AG2, idt_89hpes32nt8ag2_config)},
+ {IDT_PCI_DEVICE_IDS(89HPES32NT8BG2, idt_89hpes32nt8bg2_config)},
+ {IDT_PCI_DEVICE_IDS(89HPES12NT12G2, idt_89hpes12nt12g2_config)},
+ {IDT_PCI_DEVICE_IDS(89HPES16NT16G2, idt_89hpes16nt16g2_config)},
+ {IDT_PCI_DEVICE_IDS(89HPES24NT24G2, idt_89hpes24nt24g2_config)},
+ {IDT_PCI_DEVICE_IDS(89HPES32NT24AG2, idt_89hpes32nt24ag2_config)},
+ {IDT_PCI_DEVICE_IDS(89HPES32NT24BG2, idt_89hpes32nt24bg2_config)},
+ {0}
+};
+MODULE_DEVICE_TABLE(pci, idt_pci_tbl);
+
+/*
+ * IDT PCIe-switch NT-function device driver structure definition
+ */
+static struct pci_driver idt_pci_driver = {
+ .name = KBUILD_MODNAME,
+ .probe = idt_pci_probe,
+ .remove = idt_pci_remove,
+ .id_table = idt_pci_tbl,
+};
+
+static int __init idt_pci_driver_init(void)
+{
+ pr_info("%s %s\n", NTB_DESC, NTB_VER);
+
+ /* Create the top DebugFS directory if the FS is initialized */
+ if (debugfs_initialized())
+ dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+ /* Register the NTB hardware driver to handle the PCI device */
+ return pci_register_driver(&idt_pci_driver);
+}
+module_init(idt_pci_driver_init);
+
+static void __exit idt_pci_driver_exit(void)
+{
+ /* Unregister the NTB hardware driver */
+ pci_unregister_driver(&idt_pci_driver);
+
+ /* Discard the top DebugFS directory */
+ debugfs_remove_recursive(dbgfs_topdir);
+}
+module_exit(idt_pci_driver_exit);
+