Re: [PATCH v8 08/11] pci-epf-test/pci_endpoint_test: Add MSI-X support

From: Gustavo Pimentel
Date: Mon Jul 09 2018 - 06:10:27 EST


Hi,

On 09/07/2018 05:48, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Friday 06 July 2018 09:21 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.
>> Change v6->v7:
>> - Updated documentation.
>> - Added flag that enables or not the MSI-X on the EP features.
>> Change v7->v8:
>> - Re-sending the patch series.
>>
>> Documentation/PCI/endpoint/pci-test-function.txt | 2 +-
>> Documentation/ioctl/ioctl-number.txt | 1 +
>> Documentation/misc-devices/pci-endpoint-test.txt | 3 +++
>> drivers/misc/pci_endpoint_test.c | 29 +++++++++++++++++-------
>> drivers/pci/controller/dwc/pcie-designware-ep.c | 1 +
>> drivers/pci/endpoint/functions/pci-epf-test.c | 29 ++++++++++++++++++++++--
>> include/linux/pci-epc.h | 1 +
>> include/uapi/linux/pcitest.h | 1 +
>> 8 files changed, 56 insertions(+), 11 deletions(-)
>>
>> diff --git a/Documentation/PCI/endpoint/pci-test-function.txt b/Documentation/PCI/endpoint/pci-test-function.txt
>> index 7ee2361..b1cbff3 100644
>> --- a/Documentation/PCI/endpoint/pci-test-function.txt
>> +++ b/Documentation/PCI/endpoint/pci-test-function.txt
>> @@ -34,7 +34,7 @@ that the endpoint device must perform.
>> Bitfield Description:
>> Bit 0 : raise legacy IRQ
>> Bit 1 : raise MSI IRQ
>> - Bit 2 : raise MSI-X IRQ (reserved for future implementation)
>> + Bit 2 : raise MSI-X IRQ
>> Bit 3 : read command (read data from RC buffer)
>> Bit 4 : write command (write data to RC buffer)
>> Bit 5 : copy command (copy data from one RC buffer to another
>> 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 349794c..f4fef10 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);
>> @@ -542,6 +546,12 @@ 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");
>> }
>> @@ -558,8 +568,9 @@ 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++) {
>> @@ -625,6 +636,7 @@ 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:
>> @@ -656,6 +668,7 @@ 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/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
>> index 70d0688..36d83d1 100644
>> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
>> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
>> @@ -585,6 +585,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
>> ep->msix_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSIX);
>>
>> epc->features = EPC_FEATURE_NO_LINKUP_NOTIFIER;
>> + epc->features |= EPC_FEATURE_MSIX_AVAILABLE;
>
> This indicates all vendors of designware has MSIX enabled which is not true.
> We'll need more logic than that.

You mentioned and excellent point. Any particularity related to this features
should be implemented each specific driver (in this case on
pcie-designware-plat.c file).

And by looking at this code now that you mentioned, I think the line code
"epc->features = EPC_FEATURE_NO_LINKUP_NOTIFIER;" was added by mistake, if I
remember well by default the linkup notification is expected, right?

If I'm right, I may create an extra patch removing this 2 lines, do you agree?

epc->features = EPC_FEATURE_NO_LINKUP_NOTIFIER;
EPC_FEATURE_SET_BAR(epc->features, BAR_0);

Meanwhile can you please ack the other patch files (#3 and #4)? They have
remained unchanged for a long time.

>
> Thanks
> Kishon
>