Re: [PATCH v1.3 2/18] arcmsr: Add code to support MSI-X, MSI interrupt

From: Alexander Gordeev
Date: Fri Aug 01 2014 - 04:46:33 EST

On Fri, Aug 01, 2014 at 04:33:09PM +0800, Ching Huang wrote:
>
> This patch adds code to support MSI, MSI-X interrupt.
>
> Signed-off-by: Ching<ching2048@xxxxxxxxxxxx>
> ---
>
> diff -uprN a/drivers/scsi/arcmsr/arcmsr.h b/drivers/scsi/arcmsr/arcmsr.h
> --- a/drivers/scsi/arcmsr/arcmsr.h 2014-04-28 16:02:46.000000000 +0800
> +++ b/drivers/scsi/arcmsr/arcmsr.h 2014-05-06 15:24:36.000000000 +0800
> @@ -64,6 +64,7 @@ struct device_attribute;
> #define ARCMSR_MAX_HBB_POSTQUEUE 264
> #define ARCMSR_MAX_XFER_LEN 0x26000 /* 152K */
> #define ARCMSR_CDB_SG_PAGE_LENGTH 256
> +#define ARCMST_NUM_MSIX_VECTORS 4
> #ifndef PCI_DEVICE_ID_ARECA_1880
> #define PCI_DEVICE_ID_ARECA_1880 0x1880
> #endif
> @@ -508,6 +509,7 @@ struct AdapterControlBlock
> struct pci_dev * pdev;
> struct Scsi_Host * host;
> unsigned long vir2phy_offset;
> + struct msix_entry entries[ARCMST_NUM_MSIX_VECTORS];
> /* Offset is used in making arc cdb physical to virtual calculations */
> uint32_t outbound_int_enable;
> uint32_t cdb_phyaddr_hi32;
> @@ -544,6 +546,8 @@ struct AdapterControlBlock
> /* iop init */
> #define ACB_F_ABORT 0x0200
> #define ACB_F_FIRMWARE_TRAP 0x0400
> + #define ACB_F_MSI_ENABLED 0x1000
> + #define ACB_F_MSIX_ENABLED 0x2000
> struct CommandControlBlock * pccb_pool[ARCMSR_MAX_FREECCB_NUM];
> /* used for memory free */
> struct list_head ccb_free_list;
> @@ -594,6 +598,7 @@ struct AdapterControlBlock
> #define FW_DEADLOCK 0x0010
> atomic_t rq_map_token;
> atomic_t ante_token_value;
> + int msix_vector_count;
> };/* HW_DEVICE_EXTENSION */
> /*
> *******************************************************************************
> diff -uprN a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
> --- a/drivers/scsi/arcmsr/arcmsr_hba.c 2014-08-01 11:02:44.000000000 +0800
> +++ b/drivers/scsi/arcmsr/arcmsr_hba.c 2014-08-01 11:03:00.000000000 +0800
> @@ -603,6 +603,60 @@ static void arcmsr_message_isr_bh_fn(str
> }
> }
>
> +static int
> +arcmsr_request_irq(struct pci_dev *pdev, struct AdapterControlBlock *acb)
> +{
> + int i, j, r;
> + struct msix_entry entries[ARCMST_NUM_MSIX_VECTORS];
> +
> + if (!pci_find_capability(pdev, PCI_CAP_ID_MSIX))
> + goto msi_int;

It is not on top of my head, but checking the capability is discouraged.
pci_enable_msix_range() will fail if MSI-X is not supported. Hence, it
is redundant.

> + for (i = 0; i < ARCMST_NUM_MSIX_VECTORS; i++)
> + entries[i].entry = i;
> + r = pci_enable_msix_range(pdev, entries, 1, ARCMST_NUM_MSIX_VECTORS);
> + if (r < 0)
> + goto msi_int;
> + acb->msix_vector_count = r;

Not sure how msix_vector_count is used throughout the rest of the code,
but placing this assignment after successful initialization of MSI-X
is generally safer and clearer.

> + for (i = 0; i < r; i++) {
> + if (request_irq(entries[i].vector,
> + arcmsr_do_interrupt, 0, "arcmsr", acb)) {
> + pr_warn("arcmsr%d: request_irq =%d failed!\n",
> + acb->host->host_no, pdev->irq);

Nah, pdev->irq is wrong here. Should be entries[i].vector.

> + for (j = 0 ; j < i ; j++)
> + free_irq(entries[j].vector, acb);
> + pci_disable_msix(pdev);
> + goto msi_int;
> + }
> + acb->entries[i] = entries[i];
> + }
> + acb->acb_flags |= ACB_F_MSIX_ENABLED;
> + pr_info("arcmsr%d: msi-x enabled\n", acb->host->host_no);
> + return ARC_SUCCESS;
> +msi_int:
> + if (!pci_find_capability(pdev, PCI_CAP_ID_MSI))
> + goto legacy_int;

The same as with MSI-X (above).

> + if (pci_enable_msi_range(pdev, 1, 1) < 0)
> + goto legacy_int;

pci_enable_msi_exact() or pci_enable_msi() is better choice here.

> + if (request_irq(pdev->irq, arcmsr_do_interrupt,
> + IRQF_SHARED, "arcmsr", acb)) {
> + pr_warn("arcmsr%d: request_irq =%d failed!\n",
> + acb->host->host_no, pdev->irq);
> + pci_disable_msi(pdev);
> + goto legacy_int;
> + }
> + acb->acb_flags |= ACB_F_MSI_ENABLED;
> + pr_info("arcmsr%d: msi enabled\n", acb->host->host_no);
> + return ARC_SUCCESS;
> +legacy_int:
> + if (request_irq(pdev->irq, arcmsr_do_interrupt,
> + IRQF_SHARED, "arcmsr", acb)) {
> + pr_warn("arcmsr%d: request_irq = %d failed!\n",
> + acb->host->host_no, pdev->irq);
> + return ARC_FAILURE;
> + }
> + return ARC_SUCCESS;
> +}
> +
> static int arcmsr_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> {
> struct Scsi_Host *host;
> @@ -667,16 +721,13 @@ static int arcmsr_probe(struct pci_dev *
> if(error){
> goto free_hbb_mu;
> }
> - arcmsr_iop_init(acb);
> error = scsi_add_host(host, &pdev->dev);
> if(error){
> goto RAID_controller_stop;
> }
> - error = request_irq(pdev->irq, arcmsr_do_interrupt, IRQF_SHARED, "arcmsr", acb);
> - if(error){
> + if (arcmsr_request_irq(pdev, acb) == ARC_FAILURE)
> goto scsi_host_remove;
> - }
> - host->irq = pdev->irq;
> + arcmsr_iop_init(acb);
> scsi_scan_host(host);
> INIT_WORK(&acb->arcmsr_do_message_isr_bh, arcmsr_message_isr_bh_fn);
> atomic_set(&acb->rq_map_token, 16);
> @@ -710,6 +761,21 @@ pci_disable_dev:
> return -ENODEV;
> }
>
> +static void arcmsr_free_irq(struct pci_dev *pdev, struct AdapterControlBlock *acb)
> +{
> + int i;
> +
> + if (acb->acb_flags & ACB_F_MSI_ENABLED) {
> + free_irq(pdev->irq, acb);
> + pci_disable_msi(pdev);
> + } else if (acb->acb_flags & ACB_F_MSIX_ENABLED) {
> + for (i = 0; i < acb->msix_vector_count; i++)
> + free_irq(acb->entries[i].vector, acb);
> + pci_disable_msix(pdev);
> + } else
> + free_irq(pdev->irq, acb);
> +}
> +
> static uint8_t arcmsr_abort_hba_allcmd(struct AdapterControlBlock *acb)
> {
> struct MessageUnit_A __iomem *reg = acb->pmuA;
> @@ -992,6 +1058,7 @@ static void arcmsr_done4abort_postqueue(
> }
> }
> }
> +
> static void arcmsr_remove(struct pci_dev *pdev)
> {
> struct Scsi_Host *host = pci_get_drvdata(pdev);
> @@ -1029,7 +1096,7 @@ static void arcmsr_remove(struct pci_dev
> }
> }
> }
> - free_irq(pdev->irq, acb);
> + arcmsr_free_irq(pdev, acb);
> arcmsr_free_ccb_pool(acb);
> arcmsr_free_hbb_mu(acb);
> arcmsr_unmap_pciregion(acb);
> @@ -1045,6 +1112,7 @@ static void arcmsr_shutdown(struct pci_d
> (struct AdapterControlBlock *)host->hostdata;
> del_timer_sync(&acb->eternal_timer);
> arcmsr_disable_outbound_ints(acb);
> + arcmsr_free_irq(pdev, acb);
> flush_work(&acb->arcmsr_do_message_isr_bh);
> arcmsr_stop_adapter_bgrb(acb);
> arcmsr_flush_adapter_cache(acb);
> @@ -2516,8 +2584,6 @@ static int arcmsr_iop_confirm(struct Ada
> case ACB_ADAPTER_TYPE_A: {
> if (cdb_phyaddr_hi32 != 0) {
> struct MessageUnit_A __iomem *reg = acb->pmuA;
> - uint32_t intmask_org;
> - intmask_org = arcmsr_disable_outbound_ints(acb);
> writel(ARCMSR_SIGNATURE_SET_CONFIG, \
> &reg->message_rwbuffer[0]);
> writel(cdb_phyaddr_hi32, &reg->message_rwbuffer[1]);
> @@ -2529,7 +2595,6 @@ static int arcmsr_iop_confirm(struct Ada
> acb->host->host_no);
> return 1;
> }
> - arcmsr_enable_outbound_ints(acb, intmask_org);
> }
> }
> break;
> @@ -2539,8 +2604,6 @@ static int arcmsr_iop_confirm(struct Ada
> uint32_t __iomem *rwbuffer;
>
> struct MessageUnit_B *reg = acb->pmuB;
> - uint32_t intmask_org;
> - intmask_org = arcmsr_disable_outbound_ints(acb);
> reg->postq_index = 0;
> reg->doneq_index = 0;
> writel(ARCMSR_MESSAGE_SET_POST_WINDOW, reg->drv2iop_doorbell);
> @@ -2569,7 +2632,6 @@ static int arcmsr_iop_confirm(struct Ada
> return 1;
> }
> arcmsr_hbb_enable_driver_mode(acb);
> - arcmsr_enable_outbound_ints(acb, intmask_org);
> }
> break;
> case ACB_ADAPTER_TYPE_C: {
>
>

One general question. What is justification for replacing standard error
codes with ARC_xxxx ones?

Thanks!

--
Regards,
Alexander Gordeev
agordeev@xxxxxxxxxx
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