| Message ID | 20220422143643.727871-10-Frank.Li@nxp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Enable designware PCI EP EDMA locally | expand |
On Fri, Apr 22, 2022 at 09:36:43AM -0500, Frank Li wrote: > Designware provided eDMA support in controller. This enabled use > this eDMA controller to transfer data. > > The whole flow align with standard DMA usage module > > 1. Using dma_request_channel() and filter function to find correct > RX and TX Channel. > 2. dmaengine_slave_config() config remote side physcial address. > 3. using dmaengine_prep_slave_single() create transfer descriptor > 4. tx_submit(); > 5. dma_async_issue_pending(); > > Tested at i.MX8DXL platform. > > root@imx8qmmek:~# /usr/bin/pcitest -d -w > WRITE ( 102400 bytes): OKAY > root@imx8qmmek:~# /usr/bin/pcitest -d -r > READ ( 102400 bytes): OKAY > > WRITE => Size: 102400 bytes DMA: YES Time: 0.000180145 seconds Rate: 555108 KB/s > READ => Size: 102400 bytes DMA: YES Time: 0.000194397 seconds Rate: 514411 KB/s > > READ => Size: 102400 bytes DMA: NO Time: 0.013532597 seconds Rate: 7389 KB/s > WRITE => Size: 102400 bytes DMA: NO Time: 0.000857090 seconds Rate: 116673 KB/s > > Signed-off-by: Frank Li <Frank.Li@nxp.com> Patch looks good to me but I cannot test it on my platform. So, Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Thanks, Mani > --- > Change from v6 to v9: > - none > Change from v5 to v6: > - change subject > Change from v4 to v5: > - none > Change from v3 to v4: > - reverse Xmas tree order > - local -> dma_local > - change error message > - IS_ERR -> IS_ERR_OR_NULL > - check return value of dmaengine_slave_config() > Change from v1 to v2: > - none > > drivers/pci/endpoint/functions/pci-epf-test.c | 108 ++++++++++++++++-- > 1 file changed, 98 insertions(+), 10 deletions(-) > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > index 90d84d3bc868f..f26afd02f3a86 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -52,9 +52,11 @@ struct pci_epf_test { > enum pci_barno test_reg_bar; > size_t msix_table_offset; > struct delayed_work cmd_handler; > - struct dma_chan *dma_chan; > + struct dma_chan *dma_chan_tx; > + struct dma_chan *dma_chan_rx; > struct completion transfer_complete; > bool dma_supported; > + bool dma_private; > const struct pci_epc_features *epc_features; > }; > > @@ -105,12 +107,15 @@ static void pci_epf_test_dma_callback(void *param) > */ > 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) > + size_t len, dma_addr_t dma_remote, > + enum dma_transfer_direction dir) > { > + struct dma_chan *chan = (dir == DMA_DEV_TO_MEM) ? epf_test->dma_chan_tx : epf_test->dma_chan_rx; > + dma_addr_t dma_local = (dir == DMA_MEM_TO_DEV) ? dma_src : dma_dst; > 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_async_tx_descriptor *tx; > + struct dma_slave_config sconf = {}; > struct device *dev = &epf->dev; > dma_cookie_t cookie; > int ret; > @@ -120,7 +125,22 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, > return -EINVAL; > } > > - tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); > + if (epf_test->dma_private) { > + sconf.direction = dir; > + if (dir == DMA_MEM_TO_DEV) > + sconf.dst_addr = dma_remote; > + else > + sconf.src_addr = dma_remote; > + > + if (dmaengine_slave_config(chan, &sconf)) { > + dev_err(dev, "DMA slave config fail\n"); > + return -EIO; > + } > + tx = dmaengine_prep_slave_single(chan, dma_local, len, dir, flags); > + } else { > + tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); > + } > + > if (!tx) { > dev_err(dev, "Failed to prepare DMA memcpy\n"); > return -EIO; > @@ -148,6 +168,23 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, > return 0; > } > > +struct epf_dma_filter { > + struct device *dev; > + u32 dma_mask; > +}; > + > +static bool epf_dma_filter_fn(struct dma_chan *chan, void *node) > +{ > + struct epf_dma_filter *filter = node; > + struct dma_slave_caps caps; > + > + memset(&caps, 0, sizeof(caps)); > + dma_get_slave_caps(chan, &caps); > + > + return chan->device->dev == filter->dev > + && (filter->dma_mask & caps.directions); > +} > + > /** > * pci_epf_test_init_dma_chan() - Function to initialize EPF test DMA channel > * @epf_test: the EPF test device that performs data transfer operation > @@ -158,10 +195,44 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) > { > struct pci_epf *epf = epf_test->epf; > struct device *dev = &epf->dev; > + struct epf_dma_filter filter; > struct dma_chan *dma_chan; > dma_cap_mask_t mask; > int ret; > > + filter.dev = epf->epc->dev.parent; > + filter.dma_mask = BIT(DMA_DEV_TO_MEM); > + > + dma_cap_zero(mask); > + dma_cap_set(DMA_SLAVE, mask); > + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); > + if (IS_ERR_OR_NULL(dma_chan)) { > + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); > + goto fail_back_tx; > + } > + > + epf_test->dma_chan_rx = dma_chan; > + > + filter.dma_mask = BIT(DMA_MEM_TO_DEV); > + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); > + > + if (IS_ERR(dma_chan)) { > + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); > + goto fail_back_rx; > + } > + > + epf_test->dma_chan_tx = dma_chan; > + epf_test->dma_private = true; > + > + init_completion(&epf_test->transfer_complete); > + > + return 0; > + > +fail_back_rx: > + dma_release_channel(epf_test->dma_chan_rx); > + epf_test->dma_chan_tx = NULL; > + > +fail_back_tx: > dma_cap_zero(mask); > dma_cap_set(DMA_MEMCPY, mask); > > @@ -174,7 +245,7 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) > } > init_completion(&epf_test->transfer_complete); > > - epf_test->dma_chan = dma_chan; > + epf_test->dma_chan_tx = epf_test->dma_chan_rx = dma_chan; > > return 0; > } > @@ -190,8 +261,17 @@ static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test) > if (!epf_test->dma_supported) > return; > > - dma_release_channel(epf_test->dma_chan); > - epf_test->dma_chan = NULL; > + dma_release_channel(epf_test->dma_chan_tx); > + if (epf_test->dma_chan_tx == epf_test->dma_chan_rx) { > + epf_test->dma_chan_tx = NULL; > + epf_test->dma_chan_rx = NULL; > + return; > + } > + > + dma_release_channel(epf_test->dma_chan_rx); > + epf_test->dma_chan_rx = NULL; > + > + return; > } > > static void pci_epf_test_print_rate(const char *ops, u64 size, > @@ -280,8 +360,14 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test) > goto err_map_addr; > } > > + if (epf_test->dma_private) { > + dev_err(dev, "Cannot transfer data using DMA\n"); > + ret = -EINVAL; > + goto err_map_addr; > + } > + > ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr, > - src_phys_addr, reg->size); > + src_phys_addr, reg->size, 0, DMA_MEM_TO_MEM); > if (ret) > dev_err(dev, "Data transfer failed\n"); > } else { > @@ -363,7 +449,8 @@ 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); > + phys_addr, reg->size, > + reg->src_addr, DMA_DEV_TO_MEM); > if (ret) > dev_err(dev, "Data transfer failed\n"); > ktime_get_ts64(&end); > @@ -453,8 +540,9 @@ 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); > + src_phys_addr, reg->size, reg->dst_addr, DMA_MEM_TO_DEV); > if (ret) > dev_err(dev, "Data transfer failed\n"); > ktime_get_ts64(&end); > -- > 2.35.1 >
On Fri, Apr 22, 2022 at 09:36:43AM -0500, Frank Li wrote: > Designware provided eDMA support in controller. This enabled use > this eDMA controller to transfer data. > > The whole flow align with standard DMA usage module > > 1. Using dma_request_channel() and filter function to find correct > RX and TX Channel. > 2. dmaengine_slave_config() config remote side physcial address. > 3. using dmaengine_prep_slave_single() create transfer descriptor > 4. tx_submit(); > 5. dma_async_issue_pending(); > > Tested at i.MX8DXL platform. > > root@imx8qmmek:~# /usr/bin/pcitest -d -w > WRITE ( 102400 bytes): OKAY > root@imx8qmmek:~# /usr/bin/pcitest -d -r > READ ( 102400 bytes): OKAY > > WRITE => Size: 102400 bytes DMA: YES Time: 0.000180145 seconds Rate: 555108 KB/s > READ => Size: 102400 bytes DMA: YES Time: 0.000194397 seconds Rate: 514411 KB/s > > READ => Size: 102400 bytes DMA: NO Time: 0.013532597 seconds Rate: 7389 KB/s > WRITE => Size: 102400 bytes DMA: NO Time: 0.000857090 seconds Rate: 116673 KB/s > You should rewrite this commit log. 1) this is not Designware specific 2) On what platforms you tested is information for a cover letter but not very useful for a commit log 3) The commit log describes why you need the patch and what the patch does. It can be a one liner: "Enable DMA controller tests for endpoints with DMA capabilities". Or something along those lines. Lorenzo > Signed-off-by: Frank Li <Frank.Li@nxp.com> > --- > Change from v6 to v9: > - none > Change from v5 to v6: > - change subject > Change from v4 to v5: > - none > Change from v3 to v4: > - reverse Xmas tree order > - local -> dma_local > - change error message > - IS_ERR -> IS_ERR_OR_NULL > - check return value of dmaengine_slave_config() > Change from v1 to v2: > - none > > drivers/pci/endpoint/functions/pci-epf-test.c | 108 ++++++++++++++++-- > 1 file changed, 98 insertions(+), 10 deletions(-) > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > index 90d84d3bc868f..f26afd02f3a86 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -52,9 +52,11 @@ struct pci_epf_test { > enum pci_barno test_reg_bar; > size_t msix_table_offset; > struct delayed_work cmd_handler; > - struct dma_chan *dma_chan; > + struct dma_chan *dma_chan_tx; > + struct dma_chan *dma_chan_rx; > struct completion transfer_complete; > bool dma_supported; > + bool dma_private; > const struct pci_epc_features *epc_features; > }; > > @@ -105,12 +107,15 @@ static void pci_epf_test_dma_callback(void *param) > */ > 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) > + size_t len, dma_addr_t dma_remote, > + enum dma_transfer_direction dir) > { > + struct dma_chan *chan = (dir == DMA_DEV_TO_MEM) ? epf_test->dma_chan_tx : epf_test->dma_chan_rx; > + dma_addr_t dma_local = (dir == DMA_MEM_TO_DEV) ? dma_src : dma_dst; > 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_async_tx_descriptor *tx; > + struct dma_slave_config sconf = {}; > struct device *dev = &epf->dev; > dma_cookie_t cookie; > int ret; > @@ -120,7 +125,22 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, > return -EINVAL; > } > > - tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); > + if (epf_test->dma_private) { > + sconf.direction = dir; > + if (dir == DMA_MEM_TO_DEV) > + sconf.dst_addr = dma_remote; > + else > + sconf.src_addr = dma_remote; > + > + if (dmaengine_slave_config(chan, &sconf)) { > + dev_err(dev, "DMA slave config fail\n"); > + return -EIO; > + } > + tx = dmaengine_prep_slave_single(chan, dma_local, len, dir, flags); > + } else { > + tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); > + } > + > if (!tx) { > dev_err(dev, "Failed to prepare DMA memcpy\n"); > return -EIO; > @@ -148,6 +168,23 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, > return 0; > } > > +struct epf_dma_filter { > + struct device *dev; > + u32 dma_mask; > +}; > + > +static bool epf_dma_filter_fn(struct dma_chan *chan, void *node) > +{ > + struct epf_dma_filter *filter = node; > + struct dma_slave_caps caps; > + > + memset(&caps, 0, sizeof(caps)); > + dma_get_slave_caps(chan, &caps); > + > + return chan->device->dev == filter->dev > + && (filter->dma_mask & caps.directions); > +} > + > /** > * pci_epf_test_init_dma_chan() - Function to initialize EPF test DMA channel > * @epf_test: the EPF test device that performs data transfer operation > @@ -158,10 +195,44 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) > { > struct pci_epf *epf = epf_test->epf; > struct device *dev = &epf->dev; > + struct epf_dma_filter filter; > struct dma_chan *dma_chan; > dma_cap_mask_t mask; > int ret; > > + filter.dev = epf->epc->dev.parent; > + filter.dma_mask = BIT(DMA_DEV_TO_MEM); > + > + dma_cap_zero(mask); > + dma_cap_set(DMA_SLAVE, mask); > + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); > + if (IS_ERR_OR_NULL(dma_chan)) { > + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); > + goto fail_back_tx; > + } > + > + epf_test->dma_chan_rx = dma_chan; > + > + filter.dma_mask = BIT(DMA_MEM_TO_DEV); > + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); > + > + if (IS_ERR(dma_chan)) { > + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); > + goto fail_back_rx; > + } > + > + epf_test->dma_chan_tx = dma_chan; > + epf_test->dma_private = true; > + > + init_completion(&epf_test->transfer_complete); > + > + return 0; > + > +fail_back_rx: > + dma_release_channel(epf_test->dma_chan_rx); > + epf_test->dma_chan_tx = NULL; > + > +fail_back_tx: > dma_cap_zero(mask); > dma_cap_set(DMA_MEMCPY, mask); > > @@ -174,7 +245,7 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) > } > init_completion(&epf_test->transfer_complete); > > - epf_test->dma_chan = dma_chan; > + epf_test->dma_chan_tx = epf_test->dma_chan_rx = dma_chan; > > return 0; > } > @@ -190,8 +261,17 @@ static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test) > if (!epf_test->dma_supported) > return; > > - dma_release_channel(epf_test->dma_chan); > - epf_test->dma_chan = NULL; > + dma_release_channel(epf_test->dma_chan_tx); > + if (epf_test->dma_chan_tx == epf_test->dma_chan_rx) { > + epf_test->dma_chan_tx = NULL; > + epf_test->dma_chan_rx = NULL; > + return; > + } > + > + dma_release_channel(epf_test->dma_chan_rx); > + epf_test->dma_chan_rx = NULL; > + > + return; > } > > static void pci_epf_test_print_rate(const char *ops, u64 size, > @@ -280,8 +360,14 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test) > goto err_map_addr; > } > > + if (epf_test->dma_private) { > + dev_err(dev, "Cannot transfer data using DMA\n"); > + ret = -EINVAL; > + goto err_map_addr; > + } > + > ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr, > - src_phys_addr, reg->size); > + src_phys_addr, reg->size, 0, DMA_MEM_TO_MEM); > if (ret) > dev_err(dev, "Data transfer failed\n"); > } else { > @@ -363,7 +449,8 @@ 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); > + phys_addr, reg->size, > + reg->src_addr, DMA_DEV_TO_MEM); > if (ret) > dev_err(dev, "Data transfer failed\n"); > ktime_get_ts64(&end); > @@ -453,8 +540,9 @@ 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); > + src_phys_addr, reg->size, reg->dst_addr, DMA_MEM_TO_DEV); > if (ret) > dev_err(dev, "Data transfer failed\n"); > ktime_get_ts64(&end); > -- > 2.35.1 >
On Wed, Apr 27, 2022 at 4:30 AM Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> wrote: > > On Fri, Apr 22, 2022 at 09:36:43AM -0500, Frank Li wrote: > > Designware provided eDMA support in controller. This enabled use > > this eDMA controller to transfer data. > > > > The whole flow align with standard DMA usage module > > > > 1. Using dma_request_channel() and filter function to find correct > > RX and TX Channel. > > 2. dmaengine_slave_config() config remote side physcial address. > > 3. using dmaengine_prep_slave_single() create transfer descriptor > > 4. tx_submit(); > > 5. dma_async_issue_pending(); > > > > Tested at i.MX8DXL platform. > > > > root@imx8qmmek:~# /usr/bin/pcitest -d -w > > WRITE ( 102400 bytes): OKAY > > root@imx8qmmek:~# /usr/bin/pcitest -d -r > > READ ( 102400 bytes): OKAY > > > > WRITE => Size: 102400 bytes DMA: YES Time: 0.000180145 seconds Rate: 555108 KB/s > > READ => Size: 102400 bytes DMA: YES Time: 0.000194397 seconds Rate: 514411 KB/s > > > > READ => Size: 102400 bytes DMA: NO Time: 0.013532597 seconds Rate: 7389 KB/s > > WRITE => Size: 102400 bytes DMA: NO Time: 0.000857090 seconds Rate: 116673 KB/s > > > > You should rewrite this commit log. > > 1) this is not Designware specific > 2) On what platforms you tested is information for a cover letter but > not very useful for a commit log > 3) The commit log describes why you need the patch and what the patch > does. > It can be a one liner: "Enable DMA controller tests for endpoints with > DMA capabilities". Or something along those lines. How about write as below PCI: endpoint: Enable DMA controller tests for endpoints with DMA capabilities Some Endpoints controllers have DMA capabilities. This DMA controller has more efficiency then a general external DMA controller. And this DMA controller can bypass outbound memory address translation unit. The whole flow use standard DMA usage module 1. Using dma_request_channel() and filter function to find correct RX and TX Channel. if not exist, failure back to try allocate general DMA controller channel. 2. dmaengine_slave_config() config remote side physcial address. 3. using dmaengine_prep_slave_single() create transfer descriptor 4. tx_submit(); 5. dma_async_issue_pending(); . best regards Frank Li > > Lorenzo > > > Signed-off-by: Frank Li <Frank.Li@nxp.com> > > --- > > Change from v6 to v9: > > - none > > Change from v5 to v6: > > - change subject > > Change from v4 to v5: > > - none > > Change from v3 to v4: > > - reverse Xmas tree order > > - local -> dma_local > > - change error message > > - IS_ERR -> IS_ERR_OR_NULL > > - check return value of dmaengine_slave_config() > > Change from v1 to v2: > > - none > > > > drivers/pci/endpoint/functions/pci-epf-test.c | 108 ++++++++++++++++-- > > 1 file changed, 98 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > > index 90d84d3bc868f..f26afd02f3a86 100644 > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > @@ -52,9 +52,11 @@ struct pci_epf_test { > > enum pci_barno test_reg_bar; > > size_t msix_table_offset; > > struct delayed_work cmd_handler; > > - struct dma_chan *dma_chan; > > + struct dma_chan *dma_chan_tx; > > + struct dma_chan *dma_chan_rx; > > struct completion transfer_complete; > > bool dma_supported; > > + bool dma_private; > > const struct pci_epc_features *epc_features; > > }; > > > > @@ -105,12 +107,15 @@ static void pci_epf_test_dma_callback(void *param) > > */ > > 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) > > + size_t len, dma_addr_t dma_remote, > > + enum dma_transfer_direction dir) > > { > > + struct dma_chan *chan = (dir == DMA_DEV_TO_MEM) ? epf_test->dma_chan_tx : epf_test->dma_chan_rx; > > + dma_addr_t dma_local = (dir == DMA_MEM_TO_DEV) ? dma_src : dma_dst; > > 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_async_tx_descriptor *tx; > > + struct dma_slave_config sconf = {}; > > struct device *dev = &epf->dev; > > dma_cookie_t cookie; > > int ret; > > @@ -120,7 +125,22 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, > > return -EINVAL; > > } > > > > - tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); > > + if (epf_test->dma_private) { > > + sconf.direction = dir; > > + if (dir == DMA_MEM_TO_DEV) > > + sconf.dst_addr = dma_remote; > > + else > > + sconf.src_addr = dma_remote; > > + > > + if (dmaengine_slave_config(chan, &sconf)) { > > + dev_err(dev, "DMA slave config fail\n"); > > + return -EIO; > > + } > > + tx = dmaengine_prep_slave_single(chan, dma_local, len, dir, flags); > > + } else { > > + tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); > > + } > > + > > if (!tx) { > > dev_err(dev, "Failed to prepare DMA memcpy\n"); > > return -EIO; > > @@ -148,6 +168,23 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, > > return 0; > > } > > > > +struct epf_dma_filter { > > + struct device *dev; > > + u32 dma_mask; > > +}; > > + > > +static bool epf_dma_filter_fn(struct dma_chan *chan, void *node) > > +{ > > + struct epf_dma_filter *filter = node; > > + struct dma_slave_caps caps; > > + > > + memset(&caps, 0, sizeof(caps)); > > + dma_get_slave_caps(chan, &caps); > > + > > + return chan->device->dev == filter->dev > > + && (filter->dma_mask & caps.directions); > > +} > > + > > /** > > * pci_epf_test_init_dma_chan() - Function to initialize EPF test DMA channel > > * @epf_test: the EPF test device that performs data transfer operation > > @@ -158,10 +195,44 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) > > { > > struct pci_epf *epf = epf_test->epf; > > struct device *dev = &epf->dev; > > + struct epf_dma_filter filter; > > struct dma_chan *dma_chan; > > dma_cap_mask_t mask; > > int ret; > > > > + filter.dev = epf->epc->dev.parent; > > + filter.dma_mask = BIT(DMA_DEV_TO_MEM); > > + > > + dma_cap_zero(mask); > > + dma_cap_set(DMA_SLAVE, mask); > > + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); > > + if (IS_ERR_OR_NULL(dma_chan)) { > > + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); > > + goto fail_back_tx; > > + } > > + > > + epf_test->dma_chan_rx = dma_chan; > > + > > + filter.dma_mask = BIT(DMA_MEM_TO_DEV); > > + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); > > + > > + if (IS_ERR(dma_chan)) { > > + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); > > + goto fail_back_rx; > > + } > > + > > + epf_test->dma_chan_tx = dma_chan; > > + epf_test->dma_private = true; > > + > > + init_completion(&epf_test->transfer_complete); > > + > > + return 0; > > + > > +fail_back_rx: > > + dma_release_channel(epf_test->dma_chan_rx); > > + epf_test->dma_chan_tx = NULL; > > + > > +fail_back_tx: > > dma_cap_zero(mask); > > dma_cap_set(DMA_MEMCPY, mask); > > > > @@ -174,7 +245,7 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) > > } > > init_completion(&epf_test->transfer_complete); > > > > - epf_test->dma_chan = dma_chan; > > + epf_test->dma_chan_tx = epf_test->dma_chan_rx = dma_chan; > > > > return 0; > > } > > @@ -190,8 +261,17 @@ static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test) > > if (!epf_test->dma_supported) > > return; > > > > - dma_release_channel(epf_test->dma_chan); > > - epf_test->dma_chan = NULL; > > + dma_release_channel(epf_test->dma_chan_tx); > > + if (epf_test->dma_chan_tx == epf_test->dma_chan_rx) { > > + epf_test->dma_chan_tx = NULL; > > + epf_test->dma_chan_rx = NULL; > > + return; > > + } > > + > > + dma_release_channel(epf_test->dma_chan_rx); > > + epf_test->dma_chan_rx = NULL; > > + > > + return; > > } > > > > static void pci_epf_test_print_rate(const char *ops, u64 size, > > @@ -280,8 +360,14 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test) > > goto err_map_addr; > > } > > > > + if (epf_test->dma_private) { > > + dev_err(dev, "Cannot transfer data using DMA\n"); > > + ret = -EINVAL; > > + goto err_map_addr; > > + } > > + > > ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr, > > - src_phys_addr, reg->size); > > + src_phys_addr, reg->size, 0, DMA_MEM_TO_MEM); > > if (ret) > > dev_err(dev, "Data transfer failed\n"); > > } else { > > @@ -363,7 +449,8 @@ 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); > > + phys_addr, reg->size, > > + reg->src_addr, DMA_DEV_TO_MEM); > > if (ret) > > dev_err(dev, "Data transfer failed\n"); > > ktime_get_ts64(&end); > > @@ -453,8 +540,9 @@ 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); > > + src_phys_addr, reg->size, reg->dst_addr, DMA_MEM_TO_DEV); > > if (ret) > > dev_err(dev, "Data transfer failed\n"); > > ktime_get_ts64(&end); > > -- > > 2.35.1 > >
On Wed, Apr 27, 2022 at 12:01 PM Zhi Li <lznuaa@gmail.com> wrote: > > On Wed, Apr 27, 2022 at 4:30 AM Lorenzo Pieralisi > <lorenzo.pieralisi@arm.com> wrote: > > > > On Fri, Apr 22, 2022 at 09:36:43AM -0500, Frank Li wrote: > > > Designware provided eDMA support in controller. This enabled use > > > this eDMA controller to transfer data. > > > > > > The whole flow align with standard DMA usage module > > > > > > 1. Using dma_request_channel() and filter function to find correct > > > RX and TX Channel. > > > 2. dmaengine_slave_config() config remote side physcial address. > > > 3. using dmaengine_prep_slave_single() create transfer descriptor > > > 4. tx_submit(); > > > 5. dma_async_issue_pending(); > > > > > > Tested at i.MX8DXL platform. > > > > > > root@imx8qmmek:~# /usr/bin/pcitest -d -w > > > WRITE ( 102400 bytes): OKAY > > > root@imx8qmmek:~# /usr/bin/pcitest -d -r > > > READ ( 102400 bytes): OKAY > > > > > > WRITE => Size: 102400 bytes DMA: YES Time: 0.000180145 seconds Rate: 555108 KB/s > > > READ => Size: 102400 bytes DMA: YES Time: 0.000194397 seconds Rate: 514411 KB/s > > > > > > READ => Size: 102400 bytes DMA: NO Time: 0.013532597 seconds Rate: 7389 KB/s > > > WRITE => Size: 102400 bytes DMA: NO Time: 0.000857090 seconds Rate: 116673 KB/s > > > > > > > You should rewrite this commit log. > > > > 1) this is not Designware specific > > 2) On what platforms you tested is information for a cover letter but > > not very useful for a commit log > > 3) The commit log describes why you need the patch and what the patch > > does. > > It can be a one liner: "Enable DMA controller tests for endpoints with > > DMA capabilities". Or something along those lines. > > How about write as below > > PCI: endpoint: Enable DMA controller tests for endpoints with DMA capabilities > > Some Endpoints controllers have DMA capabilities. This DMA controller has more > efficiency then a general external DMA controller. And this DMA > controller can bypass > outbound memory address translation unit. > > The whole flow use standard DMA usage module > > 1. Using dma_request_channel() and filter function to find correct > RX and TX Channel. if not exist, failure back to try allocate > general DMA controller > channel. > 2. dmaengine_slave_config() config remote side physcial address. > 3. using dmaengine_prep_slave_single() create transfer descriptor > 4. tx_submit(); > 5. dma_async_issue_pending(); > . > best regards > Frank Li @Lorenzo do you satisfy the above commit message? > > > > Lorenzo > > > > > Signed-off-by: Frank Li <Frank.Li@nxp.com> > > > --- > > > Change from v6 to v9: > > > - none > > > Change from v5 to v6: > > > - change subject > > > Change from v4 to v5: > > > - none > > > Change from v3 to v4: > > > - reverse Xmas tree order > > > - local -> dma_local > > > - change error message > > > - IS_ERR -> IS_ERR_OR_NULL > > > - check return value of dmaengine_slave_config() > > > Change from v1 to v2: > > > - none > > > > > > drivers/pci/endpoint/functions/pci-epf-test.c | 108 ++++++++++++++++-- > > > 1 file changed, 98 insertions(+), 10 deletions(-) > > > > > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > > > index 90d84d3bc868f..f26afd02f3a86 100644 > > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > > @@ -52,9 +52,11 @@ struct pci_epf_test { > > > enum pci_barno test_reg_bar; > > > size_t msix_table_offset; > > > struct delayed_work cmd_handler; > > > - struct dma_chan *dma_chan; > > > + struct dma_chan *dma_chan_tx; > > > + struct dma_chan *dma_chan_rx; > > > struct completion transfer_complete; > > > bool dma_supported; > > > + bool dma_private; > > > const struct pci_epc_features *epc_features; > > > }; > > > > > > @@ -105,12 +107,15 @@ static void pci_epf_test_dma_callback(void *param) > > > */ > > > 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) > > > + size_t len, dma_addr_t dma_remote, > > > + enum dma_transfer_direction dir) > > > { > > > + struct dma_chan *chan = (dir == DMA_DEV_TO_MEM) ? epf_test->dma_chan_tx : epf_test->dma_chan_rx; > > > + dma_addr_t dma_local = (dir == DMA_MEM_TO_DEV) ? dma_src : dma_dst; > > > 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_async_tx_descriptor *tx; > > > + struct dma_slave_config sconf = {}; > > > struct device *dev = &epf->dev; > > > dma_cookie_t cookie; > > > int ret; > > > @@ -120,7 +125,22 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, > > > return -EINVAL; > > > } > > > > > > - tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); > > > + if (epf_test->dma_private) { > > > + sconf.direction = dir; > > > + if (dir == DMA_MEM_TO_DEV) > > > + sconf.dst_addr = dma_remote; > > > + else > > > + sconf.src_addr = dma_remote; > > > + > > > + if (dmaengine_slave_config(chan, &sconf)) { > > > + dev_err(dev, "DMA slave config fail\n"); > > > + return -EIO; > > > + } > > > + tx = dmaengine_prep_slave_single(chan, dma_local, len, dir, flags); > > > + } else { > > > + tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); > > > + } > > > + > > > if (!tx) { > > > dev_err(dev, "Failed to prepare DMA memcpy\n"); > > > return -EIO; > > > @@ -148,6 +168,23 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, > > > return 0; > > > } > > > > > > +struct epf_dma_filter { > > > + struct device *dev; > > > + u32 dma_mask; > > > +}; > > > + > > > +static bool epf_dma_filter_fn(struct dma_chan *chan, void *node) > > > +{ > > > + struct epf_dma_filter *filter = node; > > > + struct dma_slave_caps caps; > > > + > > > + memset(&caps, 0, sizeof(caps)); > > > + dma_get_slave_caps(chan, &caps); > > > + > > > + return chan->device->dev == filter->dev > > > + && (filter->dma_mask & caps.directions); > > > +} > > > + > > > /** > > > * pci_epf_test_init_dma_chan() - Function to initialize EPF test DMA channel > > > * @epf_test: the EPF test device that performs data transfer operation > > > @@ -158,10 +195,44 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) > > > { > > > struct pci_epf *epf = epf_test->epf; > > > struct device *dev = &epf->dev; > > > + struct epf_dma_filter filter; > > > struct dma_chan *dma_chan; > > > dma_cap_mask_t mask; > > > int ret; > > > > > > + filter.dev = epf->epc->dev.parent; > > > + filter.dma_mask = BIT(DMA_DEV_TO_MEM); > > > + > > > + dma_cap_zero(mask); > > > + dma_cap_set(DMA_SLAVE, mask); > > > + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); > > > + if (IS_ERR_OR_NULL(dma_chan)) { > > > + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); > > > + goto fail_back_tx; > > > + } > > > + > > > + epf_test->dma_chan_rx = dma_chan; > > > + > > > + filter.dma_mask = BIT(DMA_MEM_TO_DEV); > > > + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); > > > + > > > + if (IS_ERR(dma_chan)) { > > > + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); > > > + goto fail_back_rx; > > > + } > > > + > > > + epf_test->dma_chan_tx = dma_chan; > > > + epf_test->dma_private = true; > > > + > > > + init_completion(&epf_test->transfer_complete); > > > + > > > + return 0; > > > + > > > +fail_back_rx: > > > + dma_release_channel(epf_test->dma_chan_rx); > > > + epf_test->dma_chan_tx = NULL; > > > + > > > +fail_back_tx: > > > dma_cap_zero(mask); > > > dma_cap_set(DMA_MEMCPY, mask); > > > > > > @@ -174,7 +245,7 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) > > > } > > > init_completion(&epf_test->transfer_complete); > > > > > > - epf_test->dma_chan = dma_chan; > > > + epf_test->dma_chan_tx = epf_test->dma_chan_rx = dma_chan; > > > > > > return 0; > > > } > > > @@ -190,8 +261,17 @@ static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test) > > > if (!epf_test->dma_supported) > > > return; > > > > > > - dma_release_channel(epf_test->dma_chan); > > > - epf_test->dma_chan = NULL; > > > + dma_release_channel(epf_test->dma_chan_tx); > > > + if (epf_test->dma_chan_tx == epf_test->dma_chan_rx) { > > > + epf_test->dma_chan_tx = NULL; > > > + epf_test->dma_chan_rx = NULL; > > > + return; > > > + } > > > + > > > + dma_release_channel(epf_test->dma_chan_rx); > > > + epf_test->dma_chan_rx = NULL; > > > + > > > + return; > > > } > > > > > > static void pci_epf_test_print_rate(const char *ops, u64 size, > > > @@ -280,8 +360,14 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test) > > > goto err_map_addr; > > > } > > > > > > + if (epf_test->dma_private) { > > > + dev_err(dev, "Cannot transfer data using DMA\n"); > > > + ret = -EINVAL; > > > + goto err_map_addr; > > > + } > > > + > > > ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr, > > > - src_phys_addr, reg->size); > > > + src_phys_addr, reg->size, 0, DMA_MEM_TO_MEM); > > > if (ret) > > > dev_err(dev, "Data transfer failed\n"); > > > } else { > > > @@ -363,7 +449,8 @@ 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); > > > + phys_addr, reg->size, > > > + reg->src_addr, DMA_DEV_TO_MEM); > > > if (ret) > > > dev_err(dev, "Data transfer failed\n"); > > > ktime_get_ts64(&end); > > > @@ -453,8 +540,9 @@ 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); > > > + src_phys_addr, reg->size, reg->dst_addr, DMA_MEM_TO_DEV); > > > if (ret) > > > dev_err(dev, "Data transfer failed\n"); > > > ktime_get_ts64(&end); > > > -- > > > 2.35.1 > > >
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 90d84d3bc868f..f26afd02f3a86 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -52,9 +52,11 @@ struct pci_epf_test { enum pci_barno test_reg_bar; size_t msix_table_offset; struct delayed_work cmd_handler; - struct dma_chan *dma_chan; + struct dma_chan *dma_chan_tx; + struct dma_chan *dma_chan_rx; struct completion transfer_complete; bool dma_supported; + bool dma_private; const struct pci_epc_features *epc_features; }; @@ -105,12 +107,15 @@ static void pci_epf_test_dma_callback(void *param) */ 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) + size_t len, dma_addr_t dma_remote, + enum dma_transfer_direction dir) { + struct dma_chan *chan = (dir == DMA_DEV_TO_MEM) ? epf_test->dma_chan_tx : epf_test->dma_chan_rx; + dma_addr_t dma_local = (dir == DMA_MEM_TO_DEV) ? dma_src : dma_dst; 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_async_tx_descriptor *tx; + struct dma_slave_config sconf = {}; struct device *dev = &epf->dev; dma_cookie_t cookie; int ret; @@ -120,7 +125,22 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, return -EINVAL; } - tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); + if (epf_test->dma_private) { + sconf.direction = dir; + if (dir == DMA_MEM_TO_DEV) + sconf.dst_addr = dma_remote; + else + sconf.src_addr = dma_remote; + + if (dmaengine_slave_config(chan, &sconf)) { + dev_err(dev, "DMA slave config fail\n"); + return -EIO; + } + tx = dmaengine_prep_slave_single(chan, dma_local, len, dir, flags); + } else { + tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); + } + if (!tx) { dev_err(dev, "Failed to prepare DMA memcpy\n"); return -EIO; @@ -148,6 +168,23 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, return 0; } +struct epf_dma_filter { + struct device *dev; + u32 dma_mask; +}; + +static bool epf_dma_filter_fn(struct dma_chan *chan, void *node) +{ + struct epf_dma_filter *filter = node; + struct dma_slave_caps caps; + + memset(&caps, 0, sizeof(caps)); + dma_get_slave_caps(chan, &caps); + + return chan->device->dev == filter->dev + && (filter->dma_mask & caps.directions); +} + /** * pci_epf_test_init_dma_chan() - Function to initialize EPF test DMA channel * @epf_test: the EPF test device that performs data transfer operation @@ -158,10 +195,44 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) { struct pci_epf *epf = epf_test->epf; struct device *dev = &epf->dev; + struct epf_dma_filter filter; struct dma_chan *dma_chan; dma_cap_mask_t mask; int ret; + filter.dev = epf->epc->dev.parent; + filter.dma_mask = BIT(DMA_DEV_TO_MEM); + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); + if (IS_ERR_OR_NULL(dma_chan)) { + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); + goto fail_back_tx; + } + + epf_test->dma_chan_rx = dma_chan; + + filter.dma_mask = BIT(DMA_MEM_TO_DEV); + dma_chan = dma_request_channel(mask, epf_dma_filter_fn, &filter); + + if (IS_ERR(dma_chan)) { + dev_info(dev, "Failed to get private DMA channel. Falling back to generic one\n"); + goto fail_back_rx; + } + + epf_test->dma_chan_tx = dma_chan; + epf_test->dma_private = true; + + init_completion(&epf_test->transfer_complete); + + return 0; + +fail_back_rx: + dma_release_channel(epf_test->dma_chan_rx); + epf_test->dma_chan_tx = NULL; + +fail_back_tx: dma_cap_zero(mask); dma_cap_set(DMA_MEMCPY, mask); @@ -174,7 +245,7 @@ static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) } init_completion(&epf_test->transfer_complete); - epf_test->dma_chan = dma_chan; + epf_test->dma_chan_tx = epf_test->dma_chan_rx = dma_chan; return 0; } @@ -190,8 +261,17 @@ static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test) if (!epf_test->dma_supported) return; - dma_release_channel(epf_test->dma_chan); - epf_test->dma_chan = NULL; + dma_release_channel(epf_test->dma_chan_tx); + if (epf_test->dma_chan_tx == epf_test->dma_chan_rx) { + epf_test->dma_chan_tx = NULL; + epf_test->dma_chan_rx = NULL; + return; + } + + dma_release_channel(epf_test->dma_chan_rx); + epf_test->dma_chan_rx = NULL; + + return; } static void pci_epf_test_print_rate(const char *ops, u64 size, @@ -280,8 +360,14 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test) goto err_map_addr; } + if (epf_test->dma_private) { + dev_err(dev, "Cannot transfer data using DMA\n"); + ret = -EINVAL; + goto err_map_addr; + } + ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr, - src_phys_addr, reg->size); + src_phys_addr, reg->size, 0, DMA_MEM_TO_MEM); if (ret) dev_err(dev, "Data transfer failed\n"); } else { @@ -363,7 +449,8 @@ 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); + phys_addr, reg->size, + reg->src_addr, DMA_DEV_TO_MEM); if (ret) dev_err(dev, "Data transfer failed\n"); ktime_get_ts64(&end); @@ -453,8 +540,9 @@ 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); + src_phys_addr, reg->size, reg->dst_addr, DMA_MEM_TO_DEV); if (ret) dev_err(dev, "Data transfer failed\n"); ktime_get_ts64(&end);
Designware provided eDMA support in controller. This enabled use this eDMA controller to transfer data. The whole flow align with standard DMA usage module 1. Using dma_request_channel() and filter function to find correct RX and TX Channel. 2. dmaengine_slave_config() config remote side physcial address. 3. using dmaengine_prep_slave_single() create transfer descriptor 4. tx_submit(); 5. dma_async_issue_pending(); Tested at i.MX8DXL platform. root@imx8qmmek:~# /usr/bin/pcitest -d -w WRITE ( 102400 bytes): OKAY root@imx8qmmek:~# /usr/bin/pcitest -d -r READ ( 102400 bytes): OKAY WRITE => Size: 102400 bytes DMA: YES Time: 0.000180145 seconds Rate: 555108 KB/s READ => Size: 102400 bytes DMA: YES Time: 0.000194397 seconds Rate: 514411 KB/s READ => Size: 102400 bytes DMA: NO Time: 0.013532597 seconds Rate: 7389 KB/s WRITE => Size: 102400 bytes DMA: NO Time: 0.000857090 seconds Rate: 116673 KB/s Signed-off-by: Frank Li <Frank.Li@nxp.com> --- Change from v6 to v9: - none Change from v5 to v6: - change subject Change from v4 to v5: - none Change from v3 to v4: - reverse Xmas tree order - local -> dma_local - change error message - IS_ERR -> IS_ERR_OR_NULL - check return value of dmaengine_slave_config() Change from v1 to v2: - none drivers/pci/endpoint/functions/pci-epf-test.c | 108 ++++++++++++++++-- 1 file changed, 98 insertions(+), 10 deletions(-)