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

From: Gustavo Pimentel
Date: Fri Jul 06 2018 - 11:54:40 EST


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;
EPC_FEATURE_SET_BAR(epc->features, BAR_0);

ep->epc = epc;
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index eb9cd00..123f58c 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)
@@ -47,6 +48,7 @@ struct pci_epf_test {
struct pci_epf *epf;
enum pci_barno test_reg_bar;
bool linkup_notifier;
+ bool msix_available;
struct delayed_work cmd_handler;
};

@@ -266,6 +268,9 @@ 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 +297,7 @@ 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 +351,16 @@ 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));
@@ -459,6 +474,8 @@ static int pci_epf_test_bind(struct pci_epf *epf)
else
epf_test->linkup_notifier = true;

+ epf_test->msix_available = epc->features & EPC_FEATURE_MSIX_AVAILABLE;
+
epf_test->test_reg_bar = EPC_FEATURE_GET_BAR(epc->features);

ret = pci_epc_write_header(epc, epf->func_no, header);
@@ -481,6 +498,14 @@ static int pci_epf_test_bind(struct pci_epf *epf)
return ret;
}

+ if (epf_test->msix_available) {
+ ret = pci_epc_set_msix(epc, epf->func_no, epf->msix_interrupts);
+ if (ret) {
+ dev_err(dev, "MSI-X configuration failed\n");
+ return ret;
+ }
+ }
+
if (!epf_test->linkup_notifier)
queue_work(kpcitest_workqueue, &epf_test->cmd_handler.work);

diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index bb2395b..37dab81 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -102,6 +102,7 @@ struct pci_epc {

#define EPC_FEATURE_NO_LINKUP_NOTIFIER BIT(0)
#define EPC_FEATURE_BAR_MASK (BIT(1) | BIT(2) | BIT(3))
+#define EPC_FEATURE_MSIX_AVAILABLE BIT(4)
#define EPC_FEATURE_SET_BAR(features, bar) \
(features |= (EPC_FEATURE_BAR_MASK & (bar << 1)))
#define EPC_FEATURE_GET_BAR(features) \
diff --git a/include/uapi/linux/pcitest.h b/include/uapi/linux/pcitest.h
index 953cf03..d746fb1 100644
--- a/include/uapi/linux/pcitest.h
+++ b/include/uapi/linux/pcitest.h
@@ -16,5 +16,6 @@
#define PCITEST_WRITE _IOW('P', 0x4, unsigned long)
#define PCITEST_READ _IOW('P', 0x5, unsigned long)
#define PCITEST_COPY _IOW('P', 0x6, unsigned long)
+#define PCITEST_MSIX _IOW('P', 0x7, int)

#endif /* __UAPI_LINUX_PCITEST_H */
--
2.7.4