misc: pci_endpoint_test: Add support to get DMA option from userspace

'pcitest' utility now uses '-d' option to allow the user to test DMA.
Add support to parse option to use DMA from userspace application.
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: NAlan Mikhak <alan.mikhak@sifive.com>

drivers/misc/pci_endpoint_test.c

@@ -17,6 +17,7 @@
 #include <linux/mutex.h>
 #include <linux/random.h>
 #include <linux/slab.h>
+#include <linux/uaccess.h>
 #include <linux/pci.h>
 #include <linux/pci_ids.h>
 
@@ -52,6 +53,7 @@
 #define STATUS_SRC_ADDR_INVALID			BIT(7)
 #define STATUS_DST_ADDR_INVALID			BIT(8)
 
+#define PCI_ENDPOINT_TEST_STATUS		0x8
 #define PCI_ENDPOINT_TEST_LOWER_SRC_ADDR	0x0c
 #define PCI_ENDPOINT_TEST_UPPER_SRC_ADDR	0x10
 
@@ -64,6 +66,9 @@
 #define PCI_ENDPOINT_TEST_IRQ_TYPE		0x24
 #define PCI_ENDPOINT_TEST_IRQ_NUMBER		0x28
 
+#define PCI_ENDPOINT_TEST_FLAGS			0x2c
+#define FLAG_USE_DMA				BIT(0)
+
 #define PCI_DEVICE_ID_TI_AM654			0xb00c
 
 #define is_am654_pci_dev(pdev)		\
@@ -315,11 +320,16 @@ static bool pci_endpoint_test_msi_irq(struct pci_endpoint_test *test,
 	return false;
 }
 
-static bool pci_endpoint_test_copy(struct pci_endpoint_test *test, size_t size)
+static bool pci_endpoint_test_copy(struct pci_endpoint_test *test,
+				   unsigned long arg)
 {
+	struct pci_endpoint_test_xfer_param param;
 	bool ret = false;
 	void *src_addr;
 	void *dst_addr;
+	u32 flags = 0;
+	bool use_dma;
+	size_t size;
 	dma_addr_t src_phys_addr;
 	dma_addr_t dst_phys_addr;
 	struct pci_dev *pdev = test->pdev;
@@ -332,10 +342,22 @@ static bool pci_endpoint_test_copy(struct pci_endpoint_test *test, size_t size)
 	size_t alignment = test->alignment;
 	u32 src_crc32;
 	u32 dst_crc32;
+	int err;
+
+	err = copy_from_user(&param, (void __user *)arg, sizeof(param));
+	if (err) {
+		dev_err(dev, "Failed to get transfer param\n");
+		return false;
+	}
 
+	size = param.size;
 	if (size > SIZE_MAX - alignment)
 		goto err;
 
+	use_dma = !!(param.flags & PCITEST_FLAGS_USE_DMA);
+	if (use_dma)
+		flags |= FLAG_USE_DMA;
+
 	if (irq_type < IRQ_TYPE_LEGACY || irq_type > IRQ_TYPE_MSIX) {
 		dev_err(dev, "Invalid IRQ type option\n");
 		goto err;
@@ -406,6 +428,7 @@ static bool pci_endpoint_test_copy(struct pci_endpoint_test *test, size_t size)
 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_SIZE,
 				 size);
 
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_FLAGS, flags);
 	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,
@@ -434,9 +457,13 @@ static bool pci_endpoint_test_copy(struct pci_endpoint_test *test, size_t size)
 	return ret;
 }
 
-static bool pci_endpoint_test_write(struct pci_endpoint_test *test, size_t size)
+static bool pci_endpoint_test_write(struct pci_endpoint_test *test,
+				    unsigned long arg)
 {
+	struct pci_endpoint_test_xfer_param param;
 	bool ret = false;
+	u32 flags = 0;
+	bool use_dma;
 	u32 reg;
 	void *addr;
 	dma_addr_t phys_addr;
@@ -446,11 +473,24 @@ static bool pci_endpoint_test_write(struct pci_endpoint_test *test, size_t size)
 	dma_addr_t orig_phys_addr;
 	size_t offset;
 	size_t alignment = test->alignment;
+	size_t size;
 	u32 crc32;
+	int err;
 
+	err = copy_from_user(&param, (void __user *)arg, sizeof(param));
+	if (err != 0) {
+		dev_err(dev, "Failed to get transfer param\n");
+		return false;
+	}
+
+	size = param.size;
 	if (size > SIZE_MAX - alignment)
 		goto err;
 
+	use_dma = !!(param.flags & PCITEST_FLAGS_USE_DMA);
+	if (use_dma)
+		flags |= FLAG_USE_DMA;
+
 	if (irq_type < IRQ_TYPE_LEGACY || irq_type > IRQ_TYPE_MSIX) {
 		dev_err(dev, "Invalid IRQ type option\n");
 		goto err;
@@ -493,6 +533,7 @@ static bool pci_endpoint_test_write(struct pci_endpoint_test *test, size_t size)
 
 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_SIZE, size);
 
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_FLAGS, flags);
 	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,
@@ -514,9 +555,14 @@ static bool pci_endpoint_test_write(struct pci_endpoint_test *test, size_t size)
 	return ret;
 }
 
-static bool pci_endpoint_test_read(struct pci_endpoint_test *test, size_t size)
+static bool pci_endpoint_test_read(struct pci_endpoint_test *test,
+				   unsigned long arg)
 {
+	struct pci_endpoint_test_xfer_param param;
 	bool ret = false;
+	u32 flags = 0;
+	bool use_dma;
+	size_t size;
 	void *addr;
 	dma_addr_t phys_addr;
 	struct pci_dev *pdev = test->pdev;
@@ -526,10 +572,22 @@ static bool pci_endpoint_test_read(struct pci_endpoint_test *test, size_t size)
 	size_t offset;
 	size_t alignment = test->alignment;
 	u32 crc32;
+	int err;
 
+	err = copy_from_user(&param, (void __user *)arg, sizeof(param));
+	if (err) {
+		dev_err(dev, "Failed to get transfer param\n");
+		return false;
+	}
+
+	size = param.size;
 	if (size > SIZE_MAX - alignment)
 		goto err;
 
+	use_dma = !!(param.flags & PCITEST_FLAGS_USE_DMA);
+	if (use_dma)
+		flags |= FLAG_USE_DMA;
+
 	if (irq_type < IRQ_TYPE_LEGACY || irq_type > IRQ_TYPE_MSIX) {
 		dev_err(dev, "Invalid IRQ type option\n");
 		goto err;
@@ -566,6 +624,7 @@ static bool pci_endpoint_test_read(struct pci_endpoint_test *test, size_t size)
 
 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_SIZE, size);
 
+	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_FLAGS, flags);
 	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,