[PATCH v3 3/5] misc: pci_endpoint_test: Use streaming DMA APIs for buffer allocation

From: Kishon Vijay Abraham I
Date: Mon Mar 16 2020 - 07:20:34 EST


Use streaming DMA APIs (dma_map_single/dma_unmap_single) for buffers
transmitted/received by the endpoint device instead of allocating
a coherent memory. Also add default_data to set the alignment to
4KB since dma_map_single might not return a 4KB aligned address.

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
Tested-by: Alan Mikhak <alan.mikhak@xxxxxxxxxx>
---
drivers/misc/pci_endpoint_test.c | 100 ++++++++++++++++++++++++-------
1 file changed, 79 insertions(+), 21 deletions(-)

diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index a5e317073d95..5998df1c84e9 100644
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -341,14 +341,22 @@ static bool pci_endpoint_test_copy(struct pci_endpoint_test *test, size_t size)
goto err;
}

- orig_src_addr = dma_alloc_coherent(dev, size + alignment,
- &orig_src_phys_addr, GFP_KERNEL);
+ orig_src_addr = kzalloc(size + alignment, GFP_KERNEL);
if (!orig_src_addr) {
dev_err(dev, "Failed to allocate source buffer\n");
ret = false;
goto err;
}

+ get_random_bytes(orig_src_addr, size + alignment);
+ orig_src_phys_addr = dma_map_single(dev, orig_src_addr,
+ size + alignment, DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, orig_src_phys_addr)) {
+ dev_err(dev, "failed to map source buffer address\n");
+ ret = false;
+ goto err_src_phys_addr;
+ }
+
if (alignment && !IS_ALIGNED(orig_src_phys_addr, alignment)) {
src_phys_addr = PTR_ALIGN(orig_src_phys_addr, alignment);
offset = src_phys_addr - orig_src_phys_addr;
@@ -364,15 +372,21 @@ static bool pci_endpoint_test_copy(struct pci_endpoint_test *test, size_t size)
pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_UPPER_SRC_ADDR,
upper_32_bits(src_phys_addr));

- get_random_bytes(src_addr, size);
src_crc32 = crc32_le(~0, src_addr, size);

- orig_dst_addr = dma_alloc_coherent(dev, size + alignment,
- &orig_dst_phys_addr, GFP_KERNEL);
+ orig_dst_addr = kzalloc(size + alignment, GFP_KERNEL);
if (!orig_dst_addr) {
dev_err(dev, "Failed to allocate destination address\n");
ret = false;
- goto err_orig_src_addr;
+ goto err_dst_addr;
+ }
+
+ orig_dst_phys_addr = dma_map_single(dev, orig_dst_addr,
+ size + alignment, DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, orig_dst_phys_addr)) {
+ dev_err(dev, "failed to map destination buffer address\n");
+ ret = false;
+ goto err_dst_phys_addr;
}

if (alignment && !IS_ALIGNED(orig_dst_phys_addr, alignment)) {
@@ -399,16 +413,22 @@ static bool pci_endpoint_test_copy(struct pci_endpoint_test *test, size_t size)

wait_for_completion(&test->irq_raised);

+ dma_unmap_single(dev, orig_dst_phys_addr, size + alignment,
+ DMA_FROM_DEVICE);
+
dst_crc32 = crc32_le(~0, dst_addr, size);
if (dst_crc32 == src_crc32)
ret = true;

- dma_free_coherent(dev, size + alignment, orig_dst_addr,
- orig_dst_phys_addr);
+err_dst_phys_addr:
+ kfree(orig_dst_addr);

-err_orig_src_addr:
- dma_free_coherent(dev, size + alignment, orig_src_addr,
- orig_src_phys_addr);
+err_dst_addr:
+ dma_unmap_single(dev, orig_src_phys_addr, size + alignment,
+ DMA_TO_DEVICE);
+
+err_src_phys_addr:
+ kfree(orig_src_addr);

err:
return ret;
@@ -436,14 +456,23 @@ static bool pci_endpoint_test_write(struct pci_endpoint_test *test, size_t size)
goto err;
}

- orig_addr = dma_alloc_coherent(dev, size + alignment, &orig_phys_addr,
- GFP_KERNEL);
+ orig_addr = kzalloc(size + alignment, GFP_KERNEL);
if (!orig_addr) {
dev_err(dev, "Failed to allocate address\n");
ret = false;
goto err;
}

+ get_random_bytes(orig_addr, size + alignment);
+
+ orig_phys_addr = dma_map_single(dev, orig_addr, size + alignment,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, orig_phys_addr)) {
+ dev_err(dev, "failed to map source buffer address\n");
+ ret = false;
+ goto err_phys_addr;
+ }
+
if (alignment && !IS_ALIGNED(orig_phys_addr, alignment)) {
phys_addr = PTR_ALIGN(orig_phys_addr, alignment);
offset = phys_addr - orig_phys_addr;
@@ -453,8 +482,6 @@ static bool pci_endpoint_test_write(struct pci_endpoint_test *test, size_t size)
addr = orig_addr;
}

- get_random_bytes(addr, size);
-
crc32 = crc32_le(~0, addr, size);
pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_CHECKSUM,
crc32);
@@ -477,7 +504,11 @@ static bool pci_endpoint_test_write(struct pci_endpoint_test *test, size_t size)
if (reg & STATUS_READ_SUCCESS)
ret = true;

- dma_free_coherent(dev, size + alignment, orig_addr, orig_phys_addr);
+ dma_unmap_single(dev, orig_phys_addr, size + alignment,
+ DMA_TO_DEVICE);
+
+err_phys_addr:
+ kfree(orig_addr);

err:
return ret;
@@ -504,14 +535,21 @@ static bool pci_endpoint_test_read(struct pci_endpoint_test *test, size_t size)
goto err;
}

- orig_addr = dma_alloc_coherent(dev, size + alignment, &orig_phys_addr,
- GFP_KERNEL);
+ orig_addr = kzalloc(size + alignment, GFP_KERNEL);
if (!orig_addr) {
dev_err(dev, "Failed to allocate destination address\n");
ret = false;
goto err;
}

+ orig_phys_addr = dma_map_single(dev, orig_addr, size + alignment,
+ DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, orig_phys_addr)) {
+ dev_err(dev, "failed to map source buffer address\n");
+ ret = false;
+ goto err_phys_addr;
+ }
+
if (alignment && !IS_ALIGNED(orig_phys_addr, alignment)) {
phys_addr = PTR_ALIGN(orig_phys_addr, alignment);
offset = phys_addr - orig_phys_addr;
@@ -535,11 +573,15 @@ static bool pci_endpoint_test_read(struct pci_endpoint_test *test, size_t size)

wait_for_completion(&test->irq_raised);

+ dma_unmap_single(dev, orig_phys_addr, size + alignment,
+ DMA_FROM_DEVICE);
+
crc32 = crc32_le(~0, addr, size);
if (crc32 == pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_CHECKSUM))
ret = true;

- dma_free_coherent(dev, size + alignment, orig_addr, orig_phys_addr);
+err_phys_addr:
+ kfree(orig_addr);
err:
return ret;
}
@@ -667,6 +709,12 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
init_completion(&test->irq_raised);
mutex_init(&test->mutex);

+ if ((dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(48)) != 0) &&
+ dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)) != 0) {
+ dev_err(dev, "Cannot set DMA mask\n");
+ return -EINVAL;
+ }
+
err = pci_enable_device(pdev);
if (err) {
dev_err(dev, "Cannot enable PCI device\n");
@@ -783,6 +831,12 @@ static void pci_endpoint_test_remove(struct pci_dev *pdev)
pci_disable_device(pdev);
}

+static const struct pci_endpoint_test_data default_data = {
+ .test_reg_bar = BAR_0,
+ .alignment = SZ_4K,
+ .irq_type = IRQ_TYPE_MSI,
+};
+
static const struct pci_endpoint_test_data am654_data = {
.test_reg_bar = BAR_2,
.alignment = SZ_64K,
@@ -790,8 +844,12 @@ static const struct pci_endpoint_test_data am654_data = {
};

static const struct pci_device_id pci_endpoint_test_tbl[] = {
- { PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_DRA74x) },
- { PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_DRA72x) },
+ { PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_DRA74x),
+ .driver_data = (kernel_ulong_t)&default_data,
+ },
+ { PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_DRA72x),
+ .driver_data = (kernel_ulong_t)&default_data,
+ },
{ PCI_DEVICE(PCI_VENDOR_ID_FREESCALE, 0x81c0) },
{ PCI_DEVICE_DATA(SYNOPSYS, EDDA, NULL) },
{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_AM654),
--
2.17.1