On Wed, Apr 27, 2022 at 12:01 PM Zhi Li <lznuaa@xxxxxxxxx> wrote:
>
> On Wed, Apr 27, 2022 at 4:30 AM Lorenzo Pieralisi
> <lorenzo.pieralisi@xxxxxxx> 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@xxxxxxx>
> > > ---
> > > 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
> > >
