[PATCH v21 7/9] misc: pci_endpoint_test: Add doorbell test case

[Frank Li via B4 Relay <devnull+Frank.Li.nxp.com@kernel.org>]

From: Frank Li <Frank.Li@nxp.com>

Add three registers: PCIE_ENDPOINT_TEST_DB_BAR, PCIE_ENDPOINT_TEST_DB_ADDR,
and PCIE_ENDPOINT_TEST_DB_DATA.

Trigger the doorbell by writing data from PCI_ENDPOINT_TEST_DB_DATA to the
address provided by PCI_ENDPOINT_TEST_DB_OFFSET and wait for endpoint
feedback.

Add two command to COMMAND_ENABLE_DOORBELL and COMMAND_DISABLE_DOORBELL
to enable EP side's doorbell support and avoid compatible problem, which
host side driver miss-match with endpoint side function driver. See below
table:

		Host side new driver	Host side old driver
EP: new driver		S			F
EP: old driver		F			F

S: If EP side support MSI, 'pci_endpoint_test -f pcie_ep_doorbell' return
success.
   If EP side doesn't support MSI, the same to 'F'.

F: 'pci_endpoint_test -f pcie_ep_doorbell' return failure, other case as
usual.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
changes in v20
- add return value check of wait_for_completion_timeout()
- fix some error message
- remove Tested-by: Niklas Cassel <cassel@kernel.org>

change from v14 to v16
- none

Change from v13 to v14
- update to use pci_endpoint_test -f pcie_ep_doorbell
- change ioctrl id to fix conflict

Change from v9 to v13
- none

Change from v8 to v9
- change PCITEST_DOORBELL to 0xa

Change form v6 to v8
- none

Change from v5 to v6
- %s/PCI_ENDPOINT_TEST_DB_ADDR/PCI_ENDPOINT_TEST_DB_OFFSET/g

Change from v4 to v5
- remove unused varible
- add irq_type at pci_endpoint_test_doorbell();

change from v3 to v4
- Add COMMAND_ENABLE_DOORBELL and COMMAND_DISABLE_DOORBELL.
- Remove new DID requirement.
---
 drivers/misc/pci_endpoint_test.c | 85 +++++++++++++++++++++++++++++++++++++++-
 include/uapi/linux/pcitest.h     |  1 +
 2 files changed, 85 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index c4e5e2c977be27adf1451b67ee10cc3ae6fb0cef..254b7f9cbe87b97b4d5d555ffbccc9055fc52330 100644
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -37,6 +37,8 @@
 #define COMMAND_READ				BIT(3)
 #define COMMAND_WRITE				BIT(4)
 #define COMMAND_COPY				BIT(5)
+#define COMMAND_ENABLE_DOORBELL			BIT(6)
+#define COMMAND_DISABLE_DOORBELL		BIT(7)
 
 #define PCI_ENDPOINT_TEST_STATUS		0x8
 #define STATUS_READ_SUCCESS			BIT(0)
@@ -48,6 +50,11 @@
 #define STATUS_IRQ_RAISED			BIT(6)
 #define STATUS_SRC_ADDR_INVALID			BIT(7)
 #define STATUS_DST_ADDR_INVALID			BIT(8)
+#define STATUS_DOORBELL_SUCCESS			BIT(9)
+#define STATUS_DOORBELL_ENABLE_SUCCESS		BIT(10)
+#define STATUS_DOORBELL_ENABLE_FAIL		BIT(11)
+#define STATUS_DOORBELL_DISABLE_SUCCESS		BIT(12)
+#define STATUS_DOORBELL_DISABLE_FAIL		BIT(13)
 
 #define PCI_ENDPOINT_TEST_LOWER_SRC_ADDR	0x0c
 #define PCI_ENDPOINT_TEST_UPPER_SRC_ADDR	0x10
@@ -62,6 +69,7 @@
 #define PCI_ENDPOINT_TEST_IRQ_NUMBER		0x28
 
 #define PCI_ENDPOINT_TEST_FLAGS			0x2c
+
 #define FLAG_USE_DMA				BIT(0)
 
 #define PCI_ENDPOINT_TEST_CAPS			0x30
@@ -70,6 +78,10 @@
 #define CAP_MSIX				BIT(2)
 #define CAP_INTX				BIT(3)
 
+#define PCI_ENDPOINT_TEST_DB_BAR		0x34
+#define PCI_ENDPOINT_TEST_DB_OFFSET		0x38
+#define PCI_ENDPOINT_TEST_DB_DATA		0x3c
+
 #define PCI_DEVICE_ID_TI_AM654			0xb00c
 #define PCI_DEVICE_ID_TI_J7200			0xb00f
 #define PCI_DEVICE_ID_TI_AM64			0xb010
@@ -100,6 +112,7 @@ enum pci_barno {
 	BAR_3,
 	BAR_4,
 	BAR_5,
+	NO_BAR = -1,
 };
 
 struct pci_endpoint_test {
@@ -505,7 +518,7 @@ static int pci_endpoint_test_copy(struct pci_endpoint_test *test,
 
 	if (irq_type < PCITEST_IRQ_TYPE_INTX ||
 	    irq_type > PCITEST_IRQ_TYPE_MSIX) {
-		dev_err(dev, "Invalid IRQ type option\n");
+		dev_err(dev, "Invalid IRQ type\n");
 		return -EINVAL;
 	}
 
@@ -841,6 +854,73 @@ static int pci_endpoint_test_set_irq(struct pci_endpoint_test *test,
 	return 0;
 }
 
+static int pci_endpoint_test_doorbell(struct pci_endpoint_test *test)
+{
+	struct pci_dev *pdev = test->pdev;
+	struct device *dev = &pdev->dev;
+	int irq_type = test->irq_type;
+	enum pci_barno bar;
+	u32 data, status;
+	u32 addr;
+	int left;
+
+	if (irq_type < PCITEST_IRQ_TYPE_INTX ||
+	    irq_type > PCITEST_IRQ_TYPE_MSIX) {
+		dev_err(dev, "Invalid IRQ type option\n");
+		return -EINVAL;
+	}
+
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_IRQ_TYPE, irq_type);
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_IRQ_NUMBER, 1);
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_COMMAND,
+				 COMMAND_ENABLE_DOORBELL);
+
+	left = wait_for_completion_timeout(&test->irq_raised, msecs_to_jiffies(1000));
+
+	status = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_STATUS);
+	if (!left || (status & STATUS_DOORBELL_ENABLE_FAIL)) {
+		dev_err(dev, "Failed to enable doorbell\n");
+		return -EINVAL;
+	}
+
+	data = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_DB_DATA);
+	addr = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_DB_OFFSET);
+	bar = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_DB_BAR);
+
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_IRQ_TYPE, irq_type);
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_IRQ_NUMBER, 1);
+
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_STATUS, 0);
+
+	bar = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_DB_BAR);
+
+	writel(data, test->bar[bar] + addr);
+
+	left = wait_for_completion_timeout(&test->irq_raised, msecs_to_jiffies(1000));
+
+	status = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_STATUS);
+
+	if (!left || !(status & STATUS_DOORBELL_SUCCESS))
+		dev_err(dev, "Failed to trigger doorbell in endpoint\n");
+
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_COMMAND,
+				 COMMAND_DISABLE_DOORBELL);
+
+	wait_for_completion_timeout(&test->irq_raised, msecs_to_jiffies(1000));
+
+	status |= pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_STATUS);
+
+	if (status & STATUS_DOORBELL_DISABLE_FAIL) {
+		dev_err(dev, "Failed to disable doorbell\n");
+		return -EINVAL;
+	}
+
+	if (!(status & STATUS_DOORBELL_SUCCESS))
+		return -EINVAL;
+
+	return 0;
+}
+
 static long pci_endpoint_test_ioctl(struct file *file, unsigned int cmd,
 				    unsigned long arg)
 {
@@ -891,6 +971,9 @@ static long pci_endpoint_test_ioctl(struct file *file, unsigned int cmd,
 	case PCITEST_CLEAR_IRQ:
 		ret = pci_endpoint_test_clear_irq(test);
 		break;
+	case PCITEST_DOORBELL:
+		ret = pci_endpoint_test_doorbell(test);
+		break;
 	}
 
 ret:
diff --git a/include/uapi/linux/pcitest.h b/include/uapi/linux/pcitest.h
index d3aa8715a525ea47485db734a42d13d333399112..d6023a45a9d03416e220c98643c4e86d144898ae 100644
--- a/include/uapi/linux/pcitest.h
+++ b/include/uapi/linux/pcitest.h
@@ -21,6 +21,7 @@
 #define PCITEST_SET_IRQTYPE	_IOW('P', 0x8, int)
 #define PCITEST_GET_IRQTYPE	_IO('P', 0x9)
 #define PCITEST_BARS		_IO('P', 0xa)
+#define PCITEST_DOORBELL	_IO('P', 0xb)
 #define PCITEST_CLEAR_IRQ	_IO('P', 0x10)
 
 #define PCITEST_IRQ_TYPE_UNDEFINED	-1

-- 
2.34.1