drivers/scsi/snic/snic_isr.c

Source file repositories/reference/linux-study-clean/drivers/scsi/snic/snic_isr.c

File Facts

System
Linux kernel
Corpus path
drivers/scsi/snic/snic_isr.c
Extension
.c
Size
4490 bytes
Lines
181
Domain
Driver Families
Bucket
drivers/scsi
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (snic->msix[i].requested) {
			free_irq(pci_irq_vector(snic->pdev, i),
				 snic->msix[i].devid);
		}
	}
} /* end of snic_free_intr */

int
snic_request_intr(struct snic *snic)
{
	int ret = 0, i;
	enum vnic_dev_intr_mode intr_mode;

	intr_mode = svnic_dev_get_intr_mode(snic->vdev);
	SNIC_BUG_ON(intr_mode != VNIC_DEV_INTR_MODE_MSIX);

	/*
	 * Currently HW supports single WQ and CQ. So passing devid as snic.
	 * When hardware supports multiple WQs and CQs, one idea is
	 * to pass devid as corresponding WQ or CQ ptr and retrieve snic
	 * from queue ptr.
	 * Except for err_notify, which is always one.
	 */
	sprintf(snic->msix[SNIC_MSIX_WQ].devname,
		"%.11s-scsi-wq",
		snic->name);
	snic->msix[SNIC_MSIX_WQ].isr = snic_isr_msix_wq;
	snic->msix[SNIC_MSIX_WQ].devid = snic;

	sprintf(snic->msix[SNIC_MSIX_IO_CMPL].devname,
		"%.11s-io-cmpl",
		snic->name);
	snic->msix[SNIC_MSIX_IO_CMPL].isr = snic_isr_msix_io_cmpl;
	snic->msix[SNIC_MSIX_IO_CMPL].devid = snic;

	sprintf(snic->msix[SNIC_MSIX_ERR_NOTIFY].devname,
		"%.11s-err-notify",
		snic->name);
	snic->msix[SNIC_MSIX_ERR_NOTIFY].isr = snic_isr_msix_err_notify;
	snic->msix[SNIC_MSIX_ERR_NOTIFY].devid = snic;

	for (i = 0; i < ARRAY_SIZE(snic->msix); i++) {
		ret = request_irq(pci_irq_vector(snic->pdev, i),
				  snic->msix[i].isr,
				  0,
				  snic->msix[i].devname,
				  snic->msix[i].devid);
		if (ret) {
			SNIC_HOST_ERR(snic->shost,
				      "MSI-X: request_irq(%d) failed %d\n",
				      i,
				      ret);
			snic_free_intr(snic);
			break;
		}
		snic->msix[i].requested = 1;
	}

	return ret;
} /* end of snic_request_intr */

int
snic_set_intr_mode(struct snic *snic)
{
	unsigned int n = ARRAY_SIZE(snic->wq);
	unsigned int m = SNIC_CQ_IO_CMPL_MAX;
	unsigned int vecs = n + m + 1;

	/*
	 * We need n WQs, m CQs, and n+m+1 INTRs
	 * (last INTR is used for WQ/CQ errors and notification area
	 */
	BUILD_BUG_ON((ARRAY_SIZE(snic->wq) + SNIC_CQ_IO_CMPL_MAX) >
			ARRAY_SIZE(snic->intr));

	if (snic->wq_count < n || snic->cq_count < n + m)
		goto fail;

	if (pci_alloc_irq_vectors(snic->pdev, vecs, vecs, PCI_IRQ_MSIX) < 0)
		goto fail;

	snic->wq_count = n;
	snic->cq_count = n + m;
	snic->intr_count = vecs;
	snic->err_intr_offset = SNIC_MSIX_ERR_NOTIFY;

	SNIC_ISR_DBG(snic->shost, "Using MSI-X Interrupts\n");
	svnic_dev_set_intr_mode(snic->vdev, VNIC_DEV_INTR_MODE_MSIX);
	return 0;
fail:

Annotation

Implementation Notes