From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52E76C433F5 for ; Wed, 11 May 2022 09:28:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229634AbiEKJ2f (ORCPT ); Wed, 11 May 2022 05:28:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233378AbiEKJ2e (ORCPT ); Wed, 11 May 2022 05:28:34 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4F4F41053C3; Wed, 11 May 2022 02:28:26 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2B3EB143D; Wed, 11 May 2022 02:28:26 -0700 (PDT) Received: from lpieralisi (unknown [10.57.1.148]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AE5FC3F73D; Wed, 11 May 2022 02:28:23 -0700 (PDT) Date: Wed, 11 May 2022 10:28:20 +0100 From: Lorenzo Pieralisi To: Frank Li Cc: gustavo.pimentel@synopsys.com, hongxing.zhu@nxp.com, l.stach@pengutronix.de, linux-imx@nxp.com, linux-pci@vger.kernel.org, dmaengine@vger.kernel.org, fancer.lancer@gmail.com, lznuaa@gmail.com, helgaas@kernel.org, vkoul@kernel.org, robh@kernel.org, kw@linux.com, bhelgaas@google.com, manivannan.sadhasivam@linaro.org, Sergey.Semin@baikalelectronics.ru, kishon@ti.com Subject: Re: [PATCH v10 9/9] PCI: endpoint: Enable DMA controller tests for endpoints with DMA capabilities Message-ID: References: <20220503005801.1714345-1-Frank.Li@nxp.com> <20220503005801.1714345-10-Frank.Li@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220503005801.1714345-10-Frank.Li@nxp.com> Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org [+Kishon] On Mon, May 02, 2022 at 07:58:01PM -0500, Frank Li wrote: > 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. I am sorry to be pedantic but which DMA controller ? Do you mean "DMA controllers embedded in Endpoint controllers" ? This is a bit vague and overall you are patching pci-epf-test.c, that's the change that has to be explained. If Kishon can have a look that would be greatly appreciated too. When we agree on a proper commit log I can ACK the patch, the whole series can then go via the DMA engine tree. Thanks, Lorenzo > > 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, fallback 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(); > > Signed-off-by: Frank Li > Acked-by: Manivannan Sadhasivam > --- > Change from v9 to v10: > - rewrite commit message > Change from v4 to v9: > - 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 >