Intel MIC Card Driver for X100 family.

This patch does the following:
a) Initializes the Intel MIC X100 platform device and driver.
b) Sets up support to handle shutdown requests from the host.
c) Maps the device page after obtaining the device page address
from the scratchpad registers updated by the host.
d) Informs the host upon a card crash by registering a panic notifier.
e) Informs the host upon a poweroff/halt event.

Co-author: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Caz Yokoyama <Caz.Yokoyama@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Harshavardhan R Kharche <harshavardhan.r.kharche@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Acked-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Reviewed-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 299 insertions, 0 deletions

diff --git a/drivers/misc/mic/card/mic_device.c b/drivers/misc/mic/card/mic_device.c
new file mode 100644
index 000000000000..3c5c302dba41
--- /dev/null
+++ b/drivers/misc/mic/card/mic_device.c
@@ -0,0 +1,299 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2013 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms 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.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Disclaimer: The codes contained in these modules may be specific to
+ * the Intel Software Development Platform codenamed: Knights Ferry, and
+ * the Intel product codenamed: Knights Corner, and are not backward
+ * compatible with other Intel products. Additionally, Intel will NOT
+ * support the codes or instruction set in future products.
+ *
+ * Intel MIC Card driver.
+ *
+ */
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/reboot.h>
+
+#include <linux/mic_common.h>
+#include "../common/mic_device.h"
+#include "mic_device.h"
+
+static struct mic_driver *g_drv;
+static struct mic_irq *shutdown_cookie;
+
+static void mic_notify_host(u8 state)
+{
+	struct mic_driver *mdrv = g_drv;
+	struct mic_bootparam __iomem *bootparam = mdrv->dp;
+
+	iowrite8(state, &bootparam->shutdown_status);
+	dev_dbg(mdrv->dev, "%s %d system_state %d\n",
+		__func__, __LINE__, state);
+	mic_send_intr(&mdrv->mdev, ioread8(&bootparam->c2h_shutdown_db));
+}
+
+static int mic_panic_event(struct notifier_block *this, unsigned long event,
+		void *ptr)
+{
+	struct mic_driver *mdrv = g_drv;
+	struct mic_bootparam __iomem *bootparam = mdrv->dp;
+
+	iowrite8(-1, &bootparam->h2c_config_db);
+	iowrite8(-1, &bootparam->h2c_shutdown_db);
+	mic_notify_host(MIC_CRASHED);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block mic_panic = {
+	.notifier_call  = mic_panic_event,
+};
+
+static irqreturn_t mic_shutdown_isr(int irq, void *data)
+{
+	struct mic_driver *mdrv = g_drv;
+	struct mic_bootparam __iomem *bootparam = mdrv->dp;
+
+	mic_ack_interrupt(&g_drv->mdev);
+	if (ioread8(&bootparam->shutdown_card))
+		orderly_poweroff(true);
+	return IRQ_HANDLED;
+}
+
+static int mic_shutdown_init(void)
+{
+	int rc = 0;
+	struct mic_driver *mdrv = g_drv;
+	struct mic_bootparam __iomem *bootparam = mdrv->dp;
+	int shutdown_db;
+
+	shutdown_db = mic_next_card_db();
+	shutdown_cookie = mic_request_card_irq(mic_shutdown_isr,
+			"Shutdown", mdrv, shutdown_db);
+	if (IS_ERR(shutdown_cookie))
+		rc = PTR_ERR(shutdown_cookie);
+	else
+		iowrite8(shutdown_db, &bootparam->h2c_shutdown_db);
+	return rc;
+}
+
+static void mic_shutdown_uninit(void)
+{
+	struct mic_driver *mdrv = g_drv;
+	struct mic_bootparam __iomem *bootparam = mdrv->dp;
+
+	iowrite8(-1, &bootparam->h2c_shutdown_db);
+	mic_free_card_irq(shutdown_cookie, mdrv);
+}
+
+static int __init mic_dp_init(void)
+{
+	struct mic_driver *mdrv = g_drv;
+	struct mic_device *mdev = &mdrv->mdev;
+	struct mic_bootparam __iomem *bootparam;
+	u64 lo, hi, dp_dma_addr;
+	u32 magic;
+
+	lo = mic_read_spad(&mdrv->mdev, MIC_DPLO_SPAD);
+	hi = mic_read_spad(&mdrv->mdev, MIC_DPHI_SPAD);
+
+	dp_dma_addr = lo | (hi << 32);
+	mdrv->dp = mic_card_map(mdev, dp_dma_addr, MIC_DP_SIZE);
+	if (!mdrv->dp) {
+		dev_err(mdrv->dev, "Cannot remap Aperture BAR\n");
+		return -ENOMEM;
+	}
+	bootparam = mdrv->dp;
+	magic = ioread32(&bootparam->magic);
+	if (MIC_MAGIC != magic) {
+		dev_err(mdrv->dev, "bootparam magic mismatch 0x%x\n", magic);
+		return -EIO;
+	}
+	return 0;
+}
+
+/* Uninitialize the device page */
+static void mic_dp_uninit(void)
+{
+	mic_card_unmap(&g_drv->mdev, g_drv->dp);
+}
+
+/**
+ * mic_request_card_irq - request an irq.
+ *
+ * @func: The callback function that handles the interrupt.
+ * @name: The ASCII name of the callee requesting the irq.
+ * @data: private data that is returned back when calling the
+ * function handler.
+ * @index: The doorbell index of the requester.
+ *
+ * returns: The cookie that is transparent to the caller. Passed
+ * back when calling mic_free_irq. An appropriate error code
+ * is returned on failure. Caller needs to use IS_ERR(return_val)
+ * to check for failure and PTR_ERR(return_val) to obtained the
+ * error code.
+ *
+ */
+struct mic_irq *mic_request_card_irq(irqreturn_t (*func)(int irq, void *data),
+	const char *name, void *data, int index)
+{
+	int rc = 0;
+	unsigned long cookie;
+	struct mic_driver *mdrv = g_drv;
+
+	rc  = request_irq(mic_db_to_irq(mdrv, index), func,
+		0, name, data);
+	if (rc) {
+		dev_err(mdrv->dev, "request_irq failed rc = %d\n", rc);
+		goto err;
+	}
+	mdrv->irq_info.irq_usage_count[index]++;
+	cookie = index;
+	return (struct mic_irq *)cookie;
+err:
+	return ERR_PTR(rc);
+
+}
+
+/**
+ * mic_free_card_irq - free irq.
+ *
+ * @cookie: cookie obtained during a successful call to mic_request_irq
+ * @data: private data specified by the calling function during the
+ * mic_request_irq
+ *
+ * returns: none.
+ */
+void mic_free_card_irq(struct mic_irq *cookie, void *data)
+{
+	int index;
+	struct mic_driver *mdrv = g_drv;
+
+	index = (unsigned long)cookie & 0xFFFFU;
+	free_irq(mic_db_to_irq(mdrv, index), data);
+	mdrv->irq_info.irq_usage_count[index]--;
+}
+
+/**
+ * mic_next_card_db - Get the doorbell with minimum usage count.
+ *
+ * Returns the irq index.
+ */
+int mic_next_card_db(void)
+{
+	int i;
+	int index = 0;
+	struct mic_driver *mdrv = g_drv;
+
+	for (i = 0; i < mdrv->intr_info.num_intr; i++) {
+		if (mdrv->irq_info.irq_usage_count[i] <
+			mdrv->irq_info.irq_usage_count[index])
+			index = i;
+	}
+
+	return index;
+}
+
+/**
+ * mic_init_irq - Initialize irq information.
+ *
+ * Returns 0 in success. Appropriate error code on failure.
+ */
+static int mic_init_irq(void)
+{
+	struct mic_driver *mdrv = g_drv;
+
+	mdrv->irq_info.irq_usage_count = kzalloc((sizeof(u32) *
+			mdrv->intr_info.num_intr),
+			GFP_KERNEL);
+	if (!mdrv->irq_info.irq_usage_count)
+		return -ENOMEM;
+	return 0;
+}
+
+/**
+ * mic_uninit_irq - Uninitialize irq information.
+ *
+ * None.
+ */
+static void mic_uninit_irq(void)
+{
+	struct mic_driver *mdrv = g_drv;
+
+	kfree(mdrv->irq_info.irq_usage_count);
+}
+
+/*
+ * mic_driver_init - MIC driver initialization tasks.
+ *
+ * Returns 0 in success. Appropriate error code on failure.
+ */
+int __init mic_driver_init(struct mic_driver *mdrv)
+{
+	int rc;
+
+	g_drv = mdrv;
+	/*
+	 * Unloading the card module is not supported. The MIC card module
+	 * handles fundamental operations like host/card initiated shutdowns
+	 * and informing the host about card crashes and cannot be unloaded.
+	 */
+	if (!try_module_get(mdrv->dev->driver->owner)) {
+		rc = -ENODEV;
+		goto done;
+	}
+	rc = mic_dp_init();
+	if (rc)
+		goto put;
+	rc = mic_init_irq();
+	if (rc)
+		goto dp_uninit;
+	rc = mic_shutdown_init();
+	if (rc)
+		goto irq_uninit;
+	mic_create_card_debug_dir(mdrv);
+	atomic_notifier_chain_register(&panic_notifier_list, &mic_panic);
+done:
+	return rc;
+irq_uninit:
+	mic_uninit_irq();
+dp_uninit:
+	mic_dp_uninit();
+put:
+	module_put(mdrv->dev->driver->owner);
+	return rc;
+}
+
+/*
+ * mic_driver_uninit - MIC driver uninitialization tasks.
+ *
+ * Returns None
+ */
+void mic_driver_uninit(struct mic_driver *mdrv)
+{
+	mic_delete_card_debug_dir(mdrv);
+	/*
+	 * Inform the host about the shutdown status i.e. poweroff/restart etc.
+	 * The module cannot be unloaded so the only code path to call
+	 * mic_devices_uninit(..) is the shutdown callback.
+	 */
+	mic_notify_host(system_state);
+	mic_shutdown_uninit();
+	mic_uninit_irq();
+	mic_dp_uninit();
+	module_put(mdrv->dev->driver->owner);
+}