Re: [PATCH v6 08/11] pci-epf-test/pci_endpoint_test: Add MSI-X support

From: Kishon Vijay Abraham I
Date: Fri Jul 06 2018 - 05:22:23 EST


Hi,

On Thursday 21 June 2018 09:31 PM, Gustavo Pimentel wrote:
> Add MSI-X support and update driver documentation accordingly.
>
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
> ---
> Change v2->v3:
> - New patch file created base on the previous patch
> "misc: pci_endpoint_test: Add MSI-X support" patch file following
> Kishon's suggestion.
> Change v3->v4:
> - Rebased to Lorenzo's master branch v4.18-rc1.
> Change v4->v5:
> - Nothing changed, just to follow the patch set version.
> Change v5->v6:
> - Moved PCITEST_MSIX ioctl entry from patch #10 to here.
> - Documented ioctl parameter type associated to
> drivers/misc/pci_endpoint_test.c driver.
>
> Documentation/ioctl/ioctl-number.txt | 1 +
> Documentation/misc-devices/pci-endpoint-test.txt | 3 +++
> drivers/misc/pci_endpoint_test.c | 29 +++++++++++++++++-------
> drivers/pci/endpoint/functions/pci-epf-test.c | 24 ++++++++++++++++++--
> include/uapi/linux/pcitest.h | 1 +
> 5 files changed, 48 insertions(+), 10 deletions(-)
>
> diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
> index 480c860..65259d4 100644
> --- a/Documentation/ioctl/ioctl-number.txt
> +++ b/Documentation/ioctl/ioctl-number.txt
> @@ -166,6 +166,7 @@ Code Seq#(hex) Include File Comments
> 'P' all linux/soundcard.h conflict!
> 'P' 60-6F sound/sscape_ioctl.h conflict!
> 'P' 00-0F drivers/usb/class/usblp.c conflict!
> +'P' 01-07 drivers/misc/pci_endpoint_test.c conflict!
> 'Q' all linux/soundcard.h
> 'R' 00-1F linux/random.h conflict!
> 'R' 01 linux/rfkill.h conflict!
> diff --git a/Documentation/misc-devices/pci-endpoint-test.txt b/Documentation/misc-devices/pci-endpoint-test.txt
> index 4ebc359..fdfa0f6 100644
> --- a/Documentation/misc-devices/pci-endpoint-test.txt
> +++ b/Documentation/misc-devices/pci-endpoint-test.txt
> @@ -10,6 +10,7 @@ The PCI driver for the test device performs the following tests
> *) verifying addresses programmed in BAR
> *) raise legacy IRQ
> *) raise MSI IRQ
> + *) raise MSI-X IRQ
> *) read data
> *) write data
> *) copy data
> @@ -25,6 +26,8 @@ ioctl
> PCITEST_LEGACY_IRQ: Tests legacy IRQ
> PCITEST_MSI: Tests message signalled interrupts. The MSI number
> to be tested should be passed as argument.
> + PCITEST_MSIX: Tests message signalled interrupts. The MSI-X number
> + to be tested should be passed as argument.
> PCITEST_WRITE: Perform write tests. The size of the buffer should be passed
> as argument.
> PCITEST_READ: Perform read tests. The size of the buffer should be passed
> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> index 4d2c9cb..2b58887 100644
> --- a/drivers/misc/pci_endpoint_test.c
> +++ b/drivers/misc/pci_endpoint_test.c
> @@ -39,13 +39,14 @@
>
> #define IRQ_TYPE_LEGACY 0
> #define IRQ_TYPE_MSI 1
> +#define IRQ_TYPE_MSIX 2
>
> #define PCI_ENDPOINT_TEST_MAGIC 0x0
>
> #define PCI_ENDPOINT_TEST_COMMAND 0x4
> #define COMMAND_RAISE_LEGACY_IRQ BIT(0)
> #define COMMAND_RAISE_MSI_IRQ BIT(1)
> -/* BIT(2) is reserved for raising MSI-X IRQ command */
> +#define COMMAND_RAISE_MSIX_IRQ BIT(2)
> #define COMMAND_READ BIT(3)
> #define COMMAND_WRITE BIT(4)
> #define COMMAND_COPY BIT(5)
> @@ -84,7 +85,7 @@ MODULE_PARM_DESC(no_msi, "Disable MSI interrupt in pci_endpoint_test");
>
> static int irq_type = IRQ_TYPE_MSI;
> module_param(irq_type, int, 0444);
> -MODULE_PARM_DESC(irq_type, "IRQ mode selection in pci_endpoint_test (0 - Legacy, 1 - MSI)");
> +MODULE_PARM_DESC(irq_type, "IRQ mode selection in pci_endpoint_test (0 - Legacy, 1 - MSI, 2 - MSI-X)");
>
> enum pci_barno {
> BAR_0,
> @@ -202,16 +203,18 @@ static bool pci_endpoint_test_legacy_irq(struct pci_endpoint_test *test)
> }
>
> static bool pci_endpoint_test_msi_irq(struct pci_endpoint_test *test,
> - u8 msi_num)
> + u16 msi_num, bool msix)
> {
> u32 val;
> struct pci_dev *pdev = test->pdev;
>
> pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_IRQ_TYPE,
> - IRQ_TYPE_MSI);
> + msix == false ? IRQ_TYPE_MSI :
> + IRQ_TYPE_MSIX);
> pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_IRQ_NUMBER, msi_num);
> pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_COMMAND,
> - COMMAND_RAISE_MSI_IRQ);
> + msix == false ? COMMAND_RAISE_MSI_IRQ :
> + COMMAND_RAISE_MSIX_IRQ);
> val = wait_for_completion_timeout(&test->irq_raised,
> msecs_to_jiffies(1000));
> if (!val)
> @@ -456,7 +459,8 @@ static long pci_endpoint_test_ioctl(struct file *file, unsigned int cmd,
> ret = pci_endpoint_test_legacy_irq(test);
> break;
> case PCITEST_MSI:
> - ret = pci_endpoint_test_msi_irq(test, arg);
> + case PCITEST_MSIX:
> + ret = pci_endpoint_test_msi_irq(test, arg, cmd == PCITEST_MSIX);
> break;
> case PCITEST_WRITE:
> ret = pci_endpoint_test_write(test, arg);
> @@ -543,6 +547,12 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
> dev_err(dev, "Failed to get MSI interrupts\n");
> test->num_irqs = irq;
> break;
> + case IRQ_TYPE_MSIX:
> + irq = pci_alloc_irq_vectors(pdev, 1, 2048, PCI_IRQ_MSIX);
> + if (irq < 0)
> + dev_err(dev, "Failed to get MSI-X interrupts\n");
> + test->num_irqs = irq;
> + break;
> default:
> dev_err(dev, "Invalid IRQ type selected\n");
> }
> @@ -560,8 +570,9 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
> pci_endpoint_test_irqhandler,
> IRQF_SHARED, DRV_MODULE_NAME, test);
> if (err)
> - dev_err(dev, "failed to request IRQ %d for MSI %d\n",
> - pci_irq_vector(pdev, i), i + 1);
> + dev_err(dev, "Failed to request IRQ %d for MSI%s %d\n",
> + pci_irq_vector(pdev, i),
> + irq_type == IRQ_TYPE_MSIX ? "-X" : "", i + 1);
> }
>
> for (bar = BAR_0; bar <= BAR_5; bar++) {
> @@ -627,6 +638,7 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
>
> err_disable_msi:
> pci_disable_msi(pdev);
> + pci_disable_msix(pdev);
> pci_release_regions(pdev);
>
> err_disable_pdev:
> @@ -658,6 +670,7 @@ static void pci_endpoint_test_remove(struct pci_dev *pdev)
> for (i = 0; i < test->num_irqs; i++)
> devm_free_irq(&pdev->dev, pci_irq_vector(pdev, i), test);
> pci_disable_msi(pdev);
> + pci_disable_msix(pdev);
> pci_release_regions(pdev);
> pci_disable_device(pdev);
> }
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index eb9cd00..bfef6d1 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -20,10 +20,11 @@
>
> #define IRQ_TYPE_LEGACY 0
> #define IRQ_TYPE_MSI 1
> +#define IRQ_TYPE_MSIX 2
>
> #define COMMAND_RAISE_LEGACY_IRQ BIT(0)
> #define COMMAND_RAISE_MSI_IRQ BIT(1)
> -/* BIT(2) is reserved for raising MSI-X IRQ command */
> +#define COMMAND_RAISE_MSIX_IRQ BIT(2)
> #define COMMAND_READ BIT(3)
> #define COMMAND_WRITE BIT(4)
> #define COMMAND_COPY BIT(5)
> @@ -266,6 +267,9 @@ static void pci_epf_test_raise_irq(struct pci_epf_test *epf_test, u8 irq_type,
> case IRQ_TYPE_MSI:
> pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_MSI, irq);
> break;
> + case IRQ_TYPE_MSIX:
> + pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_MSIX, irq);
> + break;
> default:
> dev_err(dev, "Failed to raise IRQ, unknown type\n");
> break;
> @@ -292,7 +296,7 @@ static void pci_epf_test_cmd_handler(struct work_struct *work)
> reg->command = 0;
> reg->status = 0;
>
> - if (reg->irq_type > IRQ_TYPE_MSI) {
> + if (reg->irq_type > IRQ_TYPE_MSIX) {
> dev_err(dev, "Failed to detect IRQ type\n");
> goto reset_handler;
> }
> @@ -346,6 +350,16 @@ static void pci_epf_test_cmd_handler(struct work_struct *work)
> goto reset_handler;
> }
>
> + if (command & COMMAND_RAISE_MSIX_IRQ) {
> + count = pci_epc_get_msix(epc, epf->func_no);
> + if (reg->irq_number > count || count <= 0)
> + goto reset_handler;
> + reg->status = STATUS_IRQ_RAISED;
> + pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_MSIX,
> + reg->irq_number);
> + goto reset_handler;
> + }
> +
> reset_handler:
> queue_delayed_work(kpcitest_workqueue, &epf_test->cmd_handler,
> msecs_to_jiffies(1));
> @@ -481,6 +495,12 @@ static int pci_epf_test_bind(struct pci_epf *epf)
> return ret;
> }
>
> + ret = pci_epc_set_msix(epc, epf->func_no, epf->msix_interrupts);
> + if (ret) {
> + dev_err(dev, "MSI-X configuration failed\n");
> + return ret;
> + }

This will break existing platforms using designware IP but doesn't support
MSIX. Either we should use epc->features or return 0 in set_msix callback if
msix capability is not present.

Thanks
Kishon