linux/drivers/scsi/fnic/fnic_isr.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2008 Cisco Systems, Inc.  All rights reserved.
 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
 */
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <scsi/libfc.h>
#include <scsi/fc_frame.h>
#include "vnic_dev.h"
#include "vnic_intr.h"
#include "vnic_stats.h"
#include "fnic_io.h"
#include "fnic.h"

static irqreturn_t fnic_isr_legacy(int irq, void *data)
{
	struct fnic *fnic = data;
	u32 pba;
	unsigned long work_done = 0;

	pba = vnic_intr_legacy_pba(fnic->legacy_pba);
	if (!pba)
		return IRQ_NONE;

	fnic->fnic_stats.misc_stats.last_isr_time = jiffies;
	atomic64_inc(&fnic->fnic_stats.misc_stats.isr_count);

	if (pba & (1 << FNIC_INTX_NOTIFY)) {
		vnic_intr_return_all_credits(&fnic->intr[FNIC_INTX_NOTIFY]);
		fnic_handle_link_event(fnic);
	}

	if (pba & (1 << FNIC_INTX_ERR)) {
		vnic_intr_return_all_credits(&fnic->intr[FNIC_INTX_ERR]);
		fnic_log_q_error(fnic);
	}

	if (pba & (1 << FNIC_INTX_DUMMY)) {
		atomic64_inc(&fnic->fnic_stats.misc_stats.intx_dummy);
		vnic_intr_return_all_credits(&fnic->intr[FNIC_INTX_DUMMY]);
	}

	if (pba & (1 << FNIC_INTX_WQ_RQ_COPYWQ)) {
		work_done += fnic_wq_copy_cmpl_handler(fnic, io_completions, FNIC_MQ_CQ_INDEX);
		work_done += fnic_wq_cmpl_handler(fnic, -1);
		work_done += fnic_rq_cmpl_handler(fnic, -1);

		vnic_intr_return_credits(&fnic->intr[FNIC_INTX_WQ_RQ_COPYWQ],
					 work_done,
					 1 /* unmask intr */,
					 1 /* reset intr timer */);
	}

	return IRQ_HANDLED;
}

static irqreturn_t fnic_isr_msi(int irq, void *data)
{
	struct fnic *fnic = data;
	unsigned long work_done = 0;

	fnic->fnic_stats.misc_stats.last_isr_time = jiffies;
	atomic64_inc(&fnic->fnic_stats.misc_stats.isr_count);

	work_done += fnic_wq_copy_cmpl_handler(fnic, io_completions, FNIC_MQ_CQ_INDEX);
	work_done += fnic_wq_cmpl_handler(fnic, -1);
	work_done += fnic_rq_cmpl_handler(fnic, -1);

	vnic_intr_return_credits(&fnic->intr[0],
				 work_done,
				 1 /* unmask intr */,
				 1 /* reset intr timer */);

	return IRQ_HANDLED;
}

static irqreturn_t fnic_isr_msix_rq(int irq, void *data)
{
	struct fnic *fnic = data;
	unsigned long rq_work_done = 0;

	fnic->fnic_stats.misc_stats.last_isr_time = jiffies;
	atomic64_inc(&fnic->fnic_stats.misc_stats.isr_count);

	rq_work_done = fnic_rq_cmpl_handler(fnic, -1);
	vnic_intr_return_credits(&fnic->intr[FNIC_MSIX_RQ],
				 rq_work_done,
				 1 /* unmask intr */,
				 1 /* reset intr timer */);

	return IRQ_HANDLED;
}

static irqreturn_t fnic_isr_msix_wq(int irq, void *data)
{
	struct fnic *fnic = data;
	unsigned long wq_work_done = 0;

	fnic->fnic_stats.misc_stats.last_isr_time = jiffies;
	atomic64_inc(&fnic->fnic_stats.misc_stats.isr_count);

	wq_work_done = fnic_wq_cmpl_handler(fnic, -1);
	vnic_intr_return_credits(&fnic->intr[FNIC_MSIX_WQ],
				 wq_work_done,
				 1 /* unmask intr */,
				 1 /* reset intr timer */);
	return IRQ_HANDLED;
}

static irqreturn_t fnic_isr_msix_wq_copy(int irq, void *data)
{
	struct fnic *fnic = data;
	unsigned long wq_copy_work_done = 0;
	int i;

	fnic->fnic_stats.misc_stats.last_isr_time = jiffies;
	atomic64_inc(&fnic->fnic_stats.misc_stats.isr_count);

	i = irq - fnic->msix[0].irq_num;
	if (i >= fnic->wq_copy_count + fnic->copy_wq_base ||
		i < 0 || fnic->msix[i].irq_num != irq) {
		for (i = fnic->copy_wq_base; i < fnic->wq_copy_count + fnic->copy_wq_base ; i++) {
			if (fnic->msix[i].irq_num == irq)
				break;
		}
	}

	wq_copy_work_done = fnic_wq_copy_cmpl_handler(fnic, io_completions, i);
	vnic_intr_return_credits(&fnic->intr[i],
				 wq_copy_work_done,
				 1 /* unmask intr */,
				 1 /* reset intr timer */);
	return IRQ_HANDLED;
}

static irqreturn_t fnic_isr_msix_err_notify(int irq, void *data)
{
	struct fnic *fnic = data;

	fnic->fnic_stats.misc_stats.last_isr_time = jiffies;
	atomic64_inc(&fnic->fnic_stats.misc_stats.isr_count);

	vnic_intr_return_all_credits(&fnic->intr[fnic->err_intr_offset]);
	fnic_log_q_error(fnic);
	fnic_handle_link_event(fnic);

	return IRQ_HANDLED;
}

void fnic_free_intr(struct fnic *fnic)
{
	int i;

	switch (vnic_dev_get_intr_mode(fnic->vdev)) {
	case VNIC_DEV_INTR_MODE_INTX:
	case VNIC_DEV_INTR_MODE_MSI:
		free_irq(pci_irq_vector(fnic->pdev, 0), fnic);
		break;

	case VNIC_DEV_INTR_MODE_MSIX:
		for (i = 0; i < ARRAY_SIZE(fnic->msix); i++)
			if (fnic->msix[i].requested)
				free_irq(pci_irq_vector(fnic->pdev, i),
					 fnic->msix[i].devid);
		break;

	default:
		break;
	}
}

int fnic_request_intr(struct fnic *fnic)
{
	int err = 0;
	int i;

	switch (vnic_dev_get_intr_mode(fnic->vdev)) {

	case VNIC_DEV_INTR_MODE_INTX:
		err = request_irq(pci_irq_vector(fnic->pdev, 0),
				&fnic_isr_legacy, IRQF_SHARED, DRV_NAME, fnic);
		break;

	case VNIC_DEV_INTR_MODE_MSI:
		err = request_irq(pci_irq_vector(fnic->pdev, 0), &fnic_isr_msi,
				  0, fnic->name, fnic);
		break;

	case VNIC_DEV_INTR_MODE_MSIX:

		sprintf(fnic->msix[FNIC_MSIX_RQ].devname,
			"%.11s-fcs-rq", fnic->name);
		fnic->msix[FNIC_MSIX_RQ].isr = fnic_isr_msix_rq;
		fnic->msix[FNIC_MSIX_RQ].devid = fnic;

		sprintf(fnic->msix[FNIC_MSIX_WQ].devname,
			"%.11s-fcs-wq", fnic->name);
		fnic->msix[FNIC_MSIX_WQ].isr = fnic_isr_msix_wq;
		fnic->msix[FNIC_MSIX_WQ].devid = fnic;

		for (i = fnic->copy_wq_base; i < fnic->wq_copy_count + fnic->copy_wq_base; i++) {
			sprintf(fnic->msix[i].devname,
				"%.11s-scsi-wq-%d", fnic->name, i-FNIC_MSIX_WQ_COPY);
			fnic->msix[i].isr = fnic_isr_msix_wq_copy;
			fnic->msix[i].devid = fnic;
		}

		sprintf(fnic->msix[fnic->err_intr_offset].devname,
			"%.11s-err-notify", fnic->name);
		fnic->msix[fnic->err_intr_offset].isr =
			fnic_isr_msix_err_notify;
		fnic->msix[fnic->err_intr_offset].devid = fnic;

		for (i = 0; i < fnic->intr_count; i++) {
			fnic->msix[i].irq_num = pci_irq_vector(fnic->pdev, i);

			err = request_irq(fnic->msix[i].irq_num,
							fnic->msix[i].isr, 0,
							fnic->msix[i].devname,
							fnic->msix[i].devid);
			if (err) {
				FNIC_ISR_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
							"request_irq failed with error: %d\n",
							err);
				fnic_free_intr(fnic);
				break;
			}
			fnic->msix[i].requested = 1;
		}
		break;

	default:
		break;
	}

	return err;
}

int fnic_set_intr_mode_msix(struct fnic *fnic)
{
	unsigned int n = ARRAY_SIZE(fnic->rq);
	unsigned int m = ARRAY_SIZE(fnic->wq);
	unsigned int o = ARRAY_SIZE(fnic->hw_copy_wq);
	unsigned int min_irqs = n + m + 1 + 1; /*rq, raw wq, wq, err*/

	/*
	 * We need n RQs, m WQs, o Copy WQs, n+m+o CQs, and n+m+o+1 INTRs
	 * (last INTR is used for WQ/RQ errors and notification area)
	 */
	FNIC_ISR_DBG(KERN_INFO, fnic->lport->host, fnic->fnic_num,
		"rq-array size: %d wq-array size: %d copy-wq array size: %d\n",
		n, m, o);
	FNIC_ISR_DBG(KERN_INFO, fnic->lport->host, fnic->fnic_num,
		"rq_count: %d raw_wq_count: %d wq_copy_count: %d cq_count: %d\n",
		fnic->rq_count, fnic->raw_wq_count,
		fnic->wq_copy_count, fnic->cq_count);

	if (fnic->rq_count <= n && fnic->raw_wq_count <= m &&
		fnic->wq_copy_count <= o) {
		int vec_count = 0;
		int vecs = fnic->rq_count + fnic->raw_wq_count + fnic->wq_copy_count + 1;

		vec_count = pci_alloc_irq_vectors(fnic->pdev, min_irqs, vecs,
					PCI_IRQ_MSIX | PCI_IRQ_AFFINITY);
		FNIC_ISR_DBG(KERN_INFO, fnic->lport->host, fnic->fnic_num,
					"allocated %d MSI-X vectors\n",
					vec_count);

		if (vec_count > 0) {
			if (vec_count < vecs) {
				FNIC_ISR_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
				"interrupts number mismatch: vec_count: %d vecs: %d\n",
				vec_count, vecs);
				if (vec_count < min_irqs) {
					FNIC_ISR_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
								"no interrupts for copy wq\n");
					return 1;
				}
			}

			fnic->rq_count = n;
			fnic->raw_wq_count = m;
			fnic->copy_wq_base = fnic->rq_count + fnic->raw_wq_count;
			fnic->wq_copy_count = vec_count - n - m - 1;
			fnic->wq_count = fnic->raw_wq_count + fnic->wq_copy_count;
			if (fnic->cq_count != vec_count - 1) {
				FNIC_ISR_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
				"CQ count: %d does not match MSI-X vector count: %d\n",
				fnic->cq_count, vec_count);
				fnic->cq_count = vec_count - 1;
			}
			fnic->intr_count = vec_count;
			fnic->err_intr_offset = fnic->rq_count + fnic->wq_count;

			FNIC_ISR_DBG(KERN_INFO, fnic->lport->host, fnic->fnic_num,
				"rq_count: %d raw_wq_count: %d copy_wq_base: %d\n",
				fnic->rq_count,
				fnic->raw_wq_count, fnic->copy_wq_base);

			FNIC_ISR_DBG(KERN_INFO, fnic->lport->host, fnic->fnic_num,
				"wq_copy_count: %d wq_count: %d cq_count: %d\n",
				fnic->wq_copy_count,
				fnic->wq_count, fnic->cq_count);

			FNIC_ISR_DBG(KERN_INFO, fnic->lport->host, fnic->fnic_num,
				"intr_count: %d err_intr_offset: %u",
				fnic->intr_count,
				fnic->err_intr_offset);

			vnic_dev_set_intr_mode(fnic->vdev, VNIC_DEV_INTR_MODE_MSIX);
			FNIC_ISR_DBG(KERN_INFO, fnic->lport->host, fnic->fnic_num,
					"fnic using MSI-X\n");
			return 0;
		}
	}
	return 1;
}

int fnic_set_intr_mode(struct fnic *fnic)
{
	int ret_status = 0;

	/*
	 * Set interrupt mode (INTx, MSI, MSI-X) depending
	 * system capabilities.
	 *
	 * Try MSI-X first
	 */
	ret_status = fnic_set_intr_mode_msix(fnic);
	if (ret_status == 0)
		return ret_status;

	/*
	 * Next try MSI
	 * We need 1 RQ, 1 WQ, 1 WQ_COPY, 3 CQs, and 1 INTR
	 */
	if (fnic->rq_count >= 1 &&
	    fnic->raw_wq_count >= 1 &&
	    fnic->wq_copy_count >= 1 &&
	    fnic->cq_count >= 3 &&
	    fnic->intr_count >= 1 &&
	    pci_alloc_irq_vectors(fnic->pdev, 1, 1, PCI_IRQ_MSI) == 1) {
		fnic->rq_count = 1;
		fnic->raw_wq_count = 1;
		fnic->wq_copy_count = 1;
		fnic->wq_count = 2;
		fnic->cq_count = 3;
		fnic->intr_count = 1;
		fnic->err_intr_offset = 0;

		FNIC_ISR_DBG(KERN_DEBUG, fnic->lport->host, fnic->fnic_num,
			     "Using MSI Interrupts\n");
		vnic_dev_set_intr_mode(fnic->vdev, VNIC_DEV_INTR_MODE_MSI);

		return 0;
	}

	/*
	 * Next try INTx
	 * We need 1 RQ, 1 WQ, 1 WQ_COPY, 3 CQs, and 3 INTRs
	 * 1 INTR is used for all 3 queues, 1 INTR for queue errors
	 * 1 INTR for notification area
	 */

	if (fnic->rq_count >= 1 &&
	    fnic->raw_wq_count >= 1 &&
	    fnic->wq_copy_count >= 1 &&
	    fnic->cq_count >= 3 &&
	    fnic->intr_count >= 3) {

		fnic->rq_count = 1;
		fnic->raw_wq_count = 1;
		fnic->wq_copy_count = 1;
		fnic->cq_count = 3;
		fnic->intr_count = 3;

		FNIC_ISR_DBG(KERN_DEBUG, fnic->lport->host, fnic->fnic_num,
			     "Using Legacy Interrupts\n");
		vnic_dev_set_intr_mode(fnic->vdev, VNIC_DEV_INTR_MODE_INTX);

		return 0;
	}

	vnic_dev_set_intr_mode(fnic->vdev, VNIC_DEV_INTR_MODE_UNKNOWN);

	return -EINVAL;
}

void fnic_clear_intr_mode(struct fnic *fnic)
{
	pci_free_irq_vectors(fnic->pdev);
	vnic_dev_set_intr_mode(fnic->vdev, VNIC_DEV_INTR_MODE_INTX);
}