[SCSI] csiostor: Chelsio FCoE offload driver

Signed-off-by: Naresh Kumar Inna <naresh@chelsio.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 624 insertions, 0 deletions

diff --git a/drivers/scsi/csiostor/csio_isr.c b/drivers/scsi/csiostor/csio_isr.c
new file mode 100644
index 000000000000..7ee9777ae2c5
--- /dev/null
+++ b/drivers/scsi/csiostor/csio_isr.c
@@ -0,0 +1,624 @@
+/*
+ * This file is part of the Chelsio FCoE driver for Linux.
+ *
+ * Copyright (c) 2008-2012 Chelsio Communications, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/cpumask.h>
+#include <linux/string.h>
+
+#include "csio_init.h"
+#include "csio_hw.h"
+
+static irqreturn_t
+csio_nondata_isr(int irq, void *dev_id)
+{
+	struct csio_hw *hw = (struct csio_hw *) dev_id;
+	int rv;
+	unsigned long flags;
+
+	if (unlikely(!hw))
+		return IRQ_NONE;
+
+	if (unlikely(pci_channel_offline(hw->pdev))) {
+		CSIO_INC_STATS(hw, n_pcich_offline);
+		return IRQ_NONE;
+	}
+
+	spin_lock_irqsave(&hw->lock, flags);
+	csio_hw_slow_intr_handler(hw);
+	rv = csio_mb_isr_handler(hw);
+
+	if (rv == 0 && !(hw->flags & CSIO_HWF_FWEVT_PENDING)) {
+		hw->flags |= CSIO_HWF_FWEVT_PENDING;
+		spin_unlock_irqrestore(&hw->lock, flags);
+		schedule_work(&hw->evtq_work);
+		return IRQ_HANDLED;
+	}
+	spin_unlock_irqrestore(&hw->lock, flags);
+	return IRQ_HANDLED;
+}
+
+/*
+ * csio_fwevt_handler - Common FW event handler routine.
+ * @hw: HW module.
+ *
+ * This is the ISR for FW events. It is shared b/w MSIX
+ * and INTx handlers.
+ */
+static void
+csio_fwevt_handler(struct csio_hw *hw)
+{
+	int rv;
+	unsigned long flags;
+
+	rv = csio_fwevtq_handler(hw);
+
+	spin_lock_irqsave(&hw->lock, flags);
+	if (rv == 0 && !(hw->flags & CSIO_HWF_FWEVT_PENDING)) {
+		hw->flags |= CSIO_HWF_FWEVT_PENDING;
+		spin_unlock_irqrestore(&hw->lock, flags);
+		schedule_work(&hw->evtq_work);
+		return;
+	}
+	spin_unlock_irqrestore(&hw->lock, flags);
+
+} /* csio_fwevt_handler */
+
+/*
+ * csio_fwevt_isr() - FW events MSIX ISR
+ * @irq:
+ * @dev_id:
+ *
+ * Process WRs on the FW event queue.
+ *
+ */
+static irqreturn_t
+csio_fwevt_isr(int irq, void *dev_id)
+{
+	struct csio_hw *hw = (struct csio_hw *) dev_id;
+
+	if (unlikely(!hw))
+		return IRQ_NONE;
+
+	if (unlikely(pci_channel_offline(hw->pdev))) {
+		CSIO_INC_STATS(hw, n_pcich_offline);
+		return IRQ_NONE;
+	}
+
+	csio_fwevt_handler(hw);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * csio_fwevt_isr() - INTx wrapper for handling FW events.
+ * @irq:
+ * @dev_id:
+ */
+void
+csio_fwevt_intx_handler(struct csio_hw *hw, void *wr, uint32_t len,
+			   struct csio_fl_dma_buf *flb, void *priv)
+{
+	csio_fwevt_handler(hw);
+} /* csio_fwevt_intx_handler */
+
+/*
+ * csio_process_scsi_cmpl - Process a SCSI WR completion.
+ * @hw: HW module.
+ * @wr: The completed WR from the ingress queue.
+ * @len: Length of the WR.
+ * @flb: Freelist buffer array.
+ *
+ */
+static void
+csio_process_scsi_cmpl(struct csio_hw *hw, void *wr, uint32_t len,
+			struct csio_fl_dma_buf *flb, void *cbfn_q)
+{
+	struct csio_ioreq *ioreq;
+	uint8_t *scsiwr;
+	uint8_t subop;
+	void *cmnd;
+	unsigned long flags;
+
+	ioreq = csio_scsi_cmpl_handler(hw, wr, len, flb, NULL, &scsiwr);
+	if (likely(ioreq)) {
+		if (unlikely(*scsiwr == FW_SCSI_ABRT_CLS_WR)) {
+			subop = FW_SCSI_ABRT_CLS_WR_SUB_OPCODE_GET(
+					((struct fw_scsi_abrt_cls_wr *)
+					    scsiwr)->sub_opcode_to_chk_all_io);
+
+			csio_dbg(hw, "%s cmpl recvd ioreq:%p status:%d\n",
+				    subop ? "Close" : "Abort",
+				    ioreq, ioreq->wr_status);
+
+			spin_lock_irqsave(&hw->lock, flags);
+			if (subop)
+				csio_scsi_closed(ioreq,
+						 (struct list_head *)cbfn_q);
+			else
+				csio_scsi_aborted(ioreq,
+						  (struct list_head *)cbfn_q);
+			/*
+			 * We call scsi_done for I/Os that driver thinks aborts
+			 * have timed out. If there is a race caused by FW
+			 * completing abort at the exact same time that the
+			 * driver has deteced the abort timeout, the following
+			 * check prevents calling of scsi_done twice for the
+			 * same command: once from the eh_abort_handler, another
+			 * from csio_scsi_isr_handler(). This also avoids the
+			 * need to check if csio_scsi_cmnd(req) is NULL in the
+			 * fast path.
+			 */
+			cmnd = csio_scsi_cmnd(ioreq);
+			if (unlikely(cmnd == NULL))
+				list_del_init(&ioreq->sm.sm_list);
+
+			spin_unlock_irqrestore(&hw->lock, flags);
+
+			if (unlikely(cmnd == NULL))
+				csio_put_scsi_ioreq_lock(hw,
+						csio_hw_to_scsim(hw), ioreq);
+		} else {
+			spin_lock_irqsave(&hw->lock, flags);
+			csio_scsi_completed(ioreq, (struct list_head *)cbfn_q);
+			spin_unlock_irqrestore(&hw->lock, flags);
+		}
+	}
+}
+
+/*
+ * csio_scsi_isr_handler() - Common SCSI ISR handler.
+ * @iq: Ingress queue pointer.
+ *
+ * Processes SCSI completions on the SCSI IQ indicated by scm->iq_idx
+ * by calling csio_wr_process_iq_idx. If there are completions on the
+ * isr_cbfn_q, yank them out into a local queue and call their io_cbfns.
+ * Once done, add these completions onto the freelist.
+ * This routine is shared b/w MSIX and INTx.
+ */
+static inline irqreturn_t
+csio_scsi_isr_handler(struct csio_q *iq)
+{
+	struct csio_hw *hw = (struct csio_hw *)iq->owner;
+	LIST_HEAD(cbfn_q);
+	struct list_head *tmp;
+	struct csio_scsim *scm;
+	struct csio_ioreq *ioreq;
+	int isr_completions = 0;
+
+	scm = csio_hw_to_scsim(hw);
+
+	if (unlikely(csio_wr_process_iq(hw, iq, csio_process_scsi_cmpl,
+					&cbfn_q) != 0))
+		return IRQ_NONE;
+
+	/* Call back the completion routines */
+	list_for_each(tmp, &cbfn_q) {
+		ioreq = (struct csio_ioreq *)tmp;
+		isr_completions++;
+		ioreq->io_cbfn(hw, ioreq);
+		/* Release ddp buffer if used for this req */
+		if (unlikely(ioreq->dcopy))
+			csio_put_scsi_ddp_list_lock(hw, scm, &ioreq->gen_list,
+						    ioreq->nsge);
+	}
+
+	if (isr_completions) {
+		/* Return the ioreqs back to ioreq->freelist */
+		csio_put_scsi_ioreq_list_lock(hw, scm, &cbfn_q,
+					      isr_completions);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * csio_scsi_isr() - SCSI MSIX handler
+ * @irq:
+ * @dev_id:
+ *
+ * This is the top level SCSI MSIX handler. Calls csio_scsi_isr_handler()
+ * for handling SCSI completions.
+ */
+static irqreturn_t
+csio_scsi_isr(int irq, void *dev_id)
+{
+	struct csio_q *iq = (struct csio_q *) dev_id;
+	struct csio_hw *hw;
+
+	if (unlikely(!iq))
+		return IRQ_NONE;
+
+	hw = (struct csio_hw *)iq->owner;
+
+	if (unlikely(pci_channel_offline(hw->pdev))) {
+		CSIO_INC_STATS(hw, n_pcich_offline);
+		return IRQ_NONE;
+	}
+
+	csio_scsi_isr_handler(iq);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * csio_scsi_intx_handler() - SCSI INTx handler
+ * @irq:
+ * @dev_id:
+ *
+ * This is the top level SCSI INTx handler. Calls csio_scsi_isr_handler()
+ * for handling SCSI completions.
+ */
+void
+csio_scsi_intx_handler(struct csio_hw *hw, void *wr, uint32_t len,
+			struct csio_fl_dma_buf *flb, void *priv)
+{
+	struct csio_q *iq = priv;
+
+	csio_scsi_isr_handler(iq);
+
+} /* csio_scsi_intx_handler */
+
+/*
+ * csio_fcoe_isr() - INTx/MSI interrupt service routine for FCoE.
+ * @irq:
+ * @dev_id:
+ *
+ *
+ */
+static irqreturn_t
+csio_fcoe_isr(int irq, void *dev_id)
+{
+	struct csio_hw *hw = (struct csio_hw *) dev_id;
+	struct csio_q *intx_q = NULL;
+	int rv;
+	irqreturn_t ret = IRQ_NONE;
+	unsigned long flags;
+
+	if (unlikely(!hw))
+		return IRQ_NONE;
+
+	if (unlikely(pci_channel_offline(hw->pdev))) {
+		CSIO_INC_STATS(hw, n_pcich_offline);
+		return IRQ_NONE;
+	}
+
+	/* Disable the interrupt for this PCI function. */
+	if (hw->intr_mode == CSIO_IM_INTX)
+		csio_wr_reg32(hw, 0, MYPF_REG(PCIE_PF_CLI));
+
+	/*
+	 * The read in the following function will flush the
+	 * above write.
+	 */
+	if (csio_hw_slow_intr_handler(hw))
+		ret = IRQ_HANDLED;
+
+	/* Get the INTx Forward interrupt IQ. */
+	intx_q = csio_get_q(hw, hw->intr_iq_idx);
+
+	CSIO_DB_ASSERT(intx_q);
+
+	/* IQ handler is not possible for intx_q, hence pass in NULL */
+	if (likely(csio_wr_process_iq(hw, intx_q, NULL, NULL) == 0))
+		ret = IRQ_HANDLED;
+
+	spin_lock_irqsave(&hw->lock, flags);
+	rv = csio_mb_isr_handler(hw);
+	if (rv == 0 && !(hw->flags & CSIO_HWF_FWEVT_PENDING)) {
+		hw->flags |= CSIO_HWF_FWEVT_PENDING;
+		spin_unlock_irqrestore(&hw->lock, flags);
+		schedule_work(&hw->evtq_work);
+		return IRQ_HANDLED;
+	}
+	spin_unlock_irqrestore(&hw->lock, flags);
+
+	return ret;
+}
+
+static void
+csio_add_msix_desc(struct csio_hw *hw)
+{
+	int i;
+	struct csio_msix_entries *entryp = &hw->msix_entries[0];
+	int k = CSIO_EXTRA_VECS;
+	int len = sizeof(entryp->desc) - 1;
+	int cnt = hw->num_sqsets + k;
+
+	/* Non-data vector */
+	memset(entryp->desc, 0, len + 1);
+	snprintf(entryp->desc, len, "csio-%02x:%02x:%x-nondata",
+		 CSIO_PCI_BUS(hw), CSIO_PCI_DEV(hw), CSIO_PCI_FUNC(hw));
+
+	entryp++;
+	memset(entryp->desc, 0, len + 1);
+	snprintf(entryp->desc, len, "csio-%02x:%02x:%x-fwevt",
+		 CSIO_PCI_BUS(hw), CSIO_PCI_DEV(hw), CSIO_PCI_FUNC(hw));
+	entryp++;
+
+	/* Name SCSI vecs */
+	for (i = k; i < cnt; i++, entryp++) {
+		memset(entryp->desc, 0, len + 1);
+		snprintf(entryp->desc, len, "csio-%02x:%02x:%x-scsi%d",
+			 CSIO_PCI_BUS(hw), CSIO_PCI_DEV(hw),
+			 CSIO_PCI_FUNC(hw), i - CSIO_EXTRA_VECS);
+	}
+}
+
+int
+csio_request_irqs(struct csio_hw *hw)
+{
+	int rv, i, j, k = 0;
+	struct csio_msix_entries *entryp = &hw->msix_entries[0];
+	struct csio_scsi_cpu_info *info;
+
+	if (hw->intr_mode != CSIO_IM_MSIX) {
+		rv = request_irq(hw->pdev->irq, csio_fcoe_isr,
+					(hw->intr_mode == CSIO_IM_MSI) ?
+							0 : IRQF_SHARED,
+					KBUILD_MODNAME, hw);
+		if (rv) {
+			if (hw->intr_mode == CSIO_IM_MSI)
+				pci_disable_msi(hw->pdev);
+			csio_err(hw, "Failed to allocate interrupt line.\n");
+			return -EINVAL;
+		}
+
+		goto out;
+	}
+
+	/* Add the MSIX vector descriptions */
+	csio_add_msix_desc(hw);
+
+	rv = request_irq(entryp[k].vector, csio_nondata_isr, 0,
+			 entryp[k].desc, hw);
+	if (rv) {
+		csio_err(hw, "IRQ request failed for vec %d err:%d\n",
+			 entryp[k].vector, rv);
+		goto err;
+	}
+
+	entryp[k++].dev_id = (void *)hw;
+
+	rv = request_irq(entryp[k].vector, csio_fwevt_isr, 0,
+			 entryp[k].desc, hw);
+	if (rv) {
+		csio_err(hw, "IRQ request failed for vec %d err:%d\n",
+			 entryp[k].vector, rv);
+		goto err;
+	}
+
+	entryp[k++].dev_id = (void *)hw;
+
+	/* Allocate IRQs for SCSI */
+	for (i = 0; i < hw->num_pports; i++) {
+		info = &hw->scsi_cpu_info[i];
+		for (j = 0; j < info->max_cpus; j++, k++) {
+			struct csio_scsi_qset *sqset = &hw->sqset[i][j];
+			struct csio_q *q = hw->wrm.q_arr[sqset->iq_idx];
+
+			rv = request_irq(entryp[k].vector, csio_scsi_isr, 0,
+					 entryp[k].desc, q);
+			if (rv) {
+				csio_err(hw,
+				       "IRQ request failed for vec %d err:%d\n",
+				       entryp[k].vector, rv);
+				goto err;
+			}
+
+			entryp[k].dev_id = (void *)q;
+
+		} /* for all scsi cpus */
+	} /* for all ports */
+
+out:
+	hw->flags |= CSIO_HWF_HOST_INTR_ENABLED;
+
+	return 0;
+
+err:
+	for (i = 0; i < k; i++) {
+		entryp = &hw->msix_entries[i];
+		free_irq(entryp->vector, entryp->dev_id);
+	}
+	pci_disable_msix(hw->pdev);
+
+	return -EINVAL;
+}
+
+static void
+csio_disable_msix(struct csio_hw *hw, bool free)
+{
+	int i;
+	struct csio_msix_entries *entryp;
+	int cnt = hw->num_sqsets + CSIO_EXTRA_VECS;
+
+	if (free) {
+		for (i = 0; i < cnt; i++) {
+			entryp = &hw->msix_entries[i];
+			free_irq(entryp->vector, entryp->dev_id);
+		}
+	}
+	pci_disable_msix(hw->pdev);
+}
+
+/* Reduce per-port max possible CPUs */
+static void
+csio_reduce_sqsets(struct csio_hw *hw, int cnt)
+{
+	int i;
+	struct csio_scsi_cpu_info *info;
+
+	while (cnt < hw->num_sqsets) {
+		for (i = 0; i < hw->num_pports; i++) {
+			info = &hw->scsi_cpu_info[i];
+			if (info->max_cpus > 1) {
+				info->max_cpus--;
+				hw->num_sqsets--;
+				if (hw->num_sqsets <= cnt)
+					break;
+			}
+		}
+	}
+
+	csio_dbg(hw, "Reduced sqsets to %d\n", hw->num_sqsets);
+}
+
+static int
+csio_enable_msix(struct csio_hw *hw)
+{
+	int rv, i, j, k, n, min, cnt;
+	struct csio_msix_entries *entryp;
+	struct msix_entry *entries;
+	int extra = CSIO_EXTRA_VECS;
+	struct csio_scsi_cpu_info *info;
+
+	min = hw->num_pports + extra;
+	cnt = hw->num_sqsets + extra;
+
+	/* Max vectors required based on #niqs configured in fw */
+	if (hw->flags & CSIO_HWF_USING_SOFT_PARAMS || !csio_is_hw_master(hw))
+		cnt = min_t(uint8_t, hw->cfg_niq, cnt);
+
+	entries = kzalloc(sizeof(struct msix_entry) * cnt, GFP_KERNEL);
+	if (!entries)
+		return -ENOMEM;
+
+	for (i = 0; i < cnt; i++)
+		entries[i].entry = (uint16_t)i;
+
+	csio_dbg(hw, "FW supp #niq:%d, trying %d msix's\n", hw->cfg_niq, cnt);
+
+	while ((rv = pci_enable_msix(hw->pdev, entries, cnt)) >= min)
+		cnt = rv;
+	if (!rv) {
+		if (cnt < (hw->num_sqsets + extra)) {
+			csio_dbg(hw, "Reducing sqsets to %d\n", cnt - extra);
+			csio_reduce_sqsets(hw, cnt - extra);
+		}
+	} else {
+		if (rv > 0) {
+			pci_disable_msix(hw->pdev);
+			csio_info(hw, "Not using MSI-X, remainder:%d\n", rv);
+		}
+
+		kfree(entries);
+		return -ENOMEM;
+	}
+
+	/* Save off vectors */
+	for (i = 0; i < cnt; i++) {
+		entryp = &hw->msix_entries[i];
+		entryp->vector = entries[i].vector;
+	}
+
+	/* Distribute vectors */
+	k = 0;
+	csio_set_nondata_intr_idx(hw, entries[k].entry);
+	csio_set_mb_intr_idx(csio_hw_to_mbm(hw), entries[k++].entry);
+	csio_set_fwevt_intr_idx(hw, entries[k++].entry);
+
+	for (i = 0; i < hw->num_pports; i++) {
+		info = &hw->scsi_cpu_info[i];
+
+		for (j = 0; j < hw->num_scsi_msix_cpus; j++) {
+			n = (j % info->max_cpus) +  k;
+			hw->sqset[i][j].intr_idx = entries[n].entry;
+		}
+
+		k += info->max_cpus;
+	}
+
+	kfree(entries);
+	return 0;
+}
+
+void
+csio_intr_enable(struct csio_hw *hw)
+{
+	hw->intr_mode = CSIO_IM_NONE;
+	hw->flags &= ~CSIO_HWF_HOST_INTR_ENABLED;
+
+	/* Try MSIX, then MSI or fall back to INTx */
+	if ((csio_msi == 2) && !csio_enable_msix(hw))
+		hw->intr_mode = CSIO_IM_MSIX;
+	else {
+		/* Max iqs required based on #niqs configured in fw */
+		if (hw->flags & CSIO_HWF_USING_SOFT_PARAMS ||
+			!csio_is_hw_master(hw)) {
+			int extra = CSIO_EXTRA_MSI_IQS;
+
+			if (hw->cfg_niq < (hw->num_sqsets + extra)) {
+				csio_dbg(hw, "Reducing sqsets to %d\n",
+					 hw->cfg_niq - extra);
+				csio_reduce_sqsets(hw, hw->cfg_niq - extra);
+			}
+		}
+
+		if ((csio_msi == 1) && !pci_enable_msi(hw->pdev))
+			hw->intr_mode = CSIO_IM_MSI;
+		else
+			hw->intr_mode = CSIO_IM_INTX;
+	}
+
+	csio_dbg(hw, "Using %s interrupt mode.\n",
+		(hw->intr_mode == CSIO_IM_MSIX) ? "MSIX" :
+		((hw->intr_mode == CSIO_IM_MSI) ? "MSI" : "INTx"));
+}
+
+void
+csio_intr_disable(struct csio_hw *hw, bool free)
+{
+	csio_hw_intr_disable(hw);
+
+	switch (hw->intr_mode) {
+	case CSIO_IM_MSIX:
+		csio_disable_msix(hw, free);
+		break;
+	case CSIO_IM_MSI:
+		if (free)
+			free_irq(hw->pdev->irq, hw);
+		pci_disable_msi(hw->pdev);
+		break;
+	case CSIO_IM_INTX:
+		if (free)
+			free_irq(hw->pdev->irq, hw);
+		break;
+	default:
+		break;
+	}
+	hw->intr_mode = CSIO_IM_NONE;
+	hw->flags &= ~CSIO_HWF_HOST_INTR_ENABLED;
+}