[PATCH] PCI: endpoint: functions/pci-epf-test: Support slave DMA transfer

Alan Mikhak
2020-05-02T00:29:26Z

From: Alan Mikhak <alan.mikhak@sifive.com>

Modify pci_epf_test_data_transfer() to also support slave DMA transfers.
Adds a direction parameter so caller can specify one of the supported DMA
transfer directions: DMA_MEM_TO_MEM, DMA_MEM_TO_DEV, and DMA_DEV_TO_MEM.
For DMA_MEM_TO_MEM, the function calls dmaengine_prep_dma_memcpy() as it
did before. For DMA_MEM_TO_DEV or DMA_DEV_TO_MEM direction, the function
calls dmaengine_slave_config() to configure the slave channel before it
calls dmaengine_prep_slave_single().

Modify existing callers to specify DMA_MEM_TO_MEM since that is the only
possible option so far. Rename the phys_addr local variable in some of the
callers for more readability. Tighten some of the timing function calls to
avoid counting error print time in case of error.

Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
---
drivers/pci/endpoint/functions/pci-epf-test.c | 67 ++++++++++++++++++---------
1 file changed, 44 insertions(+), 23 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 60330f3e3751..1d026682febb 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -104,25 +104,41 @@ static void pci_epf_test_dma_callback(void *param)
* The function returns '0' on success and negative value on failure.
*/
static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test,
- dma_addr_t dma_dst, dma_addr_t dma_src,
- size_t len)
+ dma_addr_t dma_dst,
+ dma_addr_t dma_src,
+ size_t len,
+ enum dma_transfer_direction dir)
{
enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
struct dma_chan *chan = epf_test->dma_chan;
struct pci_epf *epf = epf_test->epf;
+ struct dma_slave_config sconf;
struct dma_async_tx_descriptor *tx;
struct device *dev = &epf->dev;
dma_cookie_t cookie;
+ dma_addr_t buf;
int ret;

if (IS_ERR_OR_NULL(chan)) {
- dev_err(dev, "Invalid DMA memcpy channel\n");
+ dev_err(dev, "Invalid DMA channel\n");
return -EINVAL;
}

- tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags);
+ if (dir == DMA_MEM_TO_MEM) {
+ tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src,
+ len, flags);
+ } else {
+ memset(&sconf, 0, sizeof(sconf));
+ sconf.direction = dir;
+ sconf.dst_addr = dma_dst;
+ sconf.src_addr = dma_src;
+ dmaengine_slave_config(chan, &sconf);
+
+ buf = (dir == DMA_MEM_TO_DEV) ? dma_dst : dma_src;
+ tx = dmaengine_prep_slave_single(chan, buf, len, dir, flags);
+ }
if (!tx) {
- dev_err(dev, "Failed to prepare DMA memcpy\n");
+ dev_err(dev, "Failed to prepare DMA transfer\n");
return -EIO;
}

@@ -268,7 +284,6 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
goto err_dst_addr;
}

- ktime_get_ts64(&start);
use_dma = !!(reg->flags & FLAG_USE_DMA);
if (use_dma) {
if (!epf_test->dma_supported) {
@@ -277,14 +292,18 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
goto err_map_addr;
}

+ ktime_get_ts64(&start);
ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr,
- src_phys_addr, reg->size);
+ src_phys_addr, reg->size,
+ DMA_MEM_TO_MEM);
+ ktime_get_ts64(&end);
if (ret)
dev_err(dev, "Data transfer failed\n");
} else {
+ ktime_get_ts64(&start);
memcpy(dst_addr, src_addr, reg->size);
+ ktime_get_ts64(&end);
}
- ktime_get_ts64(&end);
pci_epf_test_print_rate("COPY", reg->size, &start, &end, use_dma);

err_map_addr:
@@ -310,7 +329,7 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
void *buf;
u32 crc32;
bool use_dma;
- phys_addr_t phys_addr;
+ phys_addr_t src_phys_addr;
phys_addr_t dst_phys_addr;
struct timespec64 start, end;
struct pci_epf *epf = epf_test->epf;
@@ -319,8 +338,9 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
struct device *dma_dev = epf->epc->dev.parent;
enum pci_barno test_reg_bar = epf_test->test_reg_bar;
struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
+ enum dma_transfer_direction dir = DMA_MEM_TO_MEM;

- src_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, reg->size);
+ src_addr = pci_epc_mem_alloc_addr(epc, &src_phys_addr, reg->size);
if (!src_addr) {
dev_err(dev, "Failed to allocate address\n");
reg->status = STATUS_SRC_ADDR_INVALID;
@@ -328,7 +348,7 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
goto err;
}

- ret = pci_epc_map_addr(epc, epf->func_no, phys_addr, reg->src_addr,
+ ret = pci_epc_map_addr(epc, epf->func_no, src_phys_addr, reg->src_addr,
reg->size);
if (ret) {
dev_err(dev, "Failed to map address\n");
@@ -360,10 +380,10 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)

ktime_get_ts64(&start);
ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr,
- phys_addr, reg->size);
+ src_phys_addr, reg->size, dir);
+ ktime_get_ts64(&end);
if (ret)
dev_err(dev, "Data transfer failed\n");
- ktime_get_ts64(&end);

dma_unmap_single(dma_dev, dst_phys_addr, reg->size,
DMA_FROM_DEVICE);
@@ -383,10 +403,10 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
kfree(buf);

err_map_addr:
- pci_epc_unmap_addr(epc, epf->func_no, phys_addr);
+ pci_epc_unmap_addr(epc, epf->func_no, src_phys_addr);

err_addr:
- pci_epc_mem_free_addr(epc, phys_addr, src_addr, reg->size);
+ pci_epc_mem_free_addr(epc, src_phys_addr, src_addr, reg->size);

err:
return ret;
@@ -398,7 +418,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
void __iomem *dst_addr;
void *buf;
bool use_dma;
- phys_addr_t phys_addr;
+ phys_addr_t dst_phys_addr;
phys_addr_t src_phys_addr;
struct timespec64 start, end;
struct pci_epf *epf = epf_test->epf;
@@ -407,8 +427,9 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
struct device *dma_dev = epf->epc->dev.parent;
enum pci_barno test_reg_bar = epf_test->test_reg_bar;
struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
+ enum dma_transfer_direction dir = DMA_MEM_TO_MEM;

- dst_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, reg->size);
+ dst_addr = pci_epc_mem_alloc_addr(epc, &dst_phys_addr, reg->size);
if (!dst_addr) {
dev_err(dev, "Failed to allocate address\n");
reg->status = STATUS_DST_ADDR_INVALID;
@@ -416,7 +437,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
goto err;
}

- ret = pci_epc_map_addr(epc, epf->func_no, phys_addr, reg->dst_addr,
+ ret = pci_epc_map_addr(epc, epf->func_no, dst_phys_addr, reg->dst_addr,
reg->size);
if (ret) {
dev_err(dev, "Failed to map address\n");
@@ -450,11 +471,11 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
}

ktime_get_ts64(&start);
- ret = pci_epf_test_data_transfer(epf_test, phys_addr,
- src_phys_addr, reg->size);
+ ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr,
+ src_phys_addr, reg->size, dir);
+ ktime_get_ts64(&end);
if (ret)
dev_err(dev, "Data transfer failed\n");
- ktime_get_ts64(&end);

dma_unmap_single(dma_dev, src_phys_addr, reg->size,
DMA_TO_DEVICE);
@@ -476,10 +497,10 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
kfree(buf);

err_map_addr:
- pci_epc_unmap_addr(epc, epf->func_no, phys_addr);
+ pci_epc_unmap_addr(epc, epf->func_no, dst_phys_addr);

err_addr:
- pci_epc_mem_free_addr(epc, phys_addr, dst_addr, reg->size);
+ pci_epc_mem_free_addr(epc, dst_phys_addr, dst_addr, reg->size);

err:
return ret;
--
2.7.4