From: Alan Mikhak <alan.mikhak@sifive.com> To: Kishon Vijay Abraham I <kishon@ti.com> Cc: Gustavo Pimentel <Gustavo.Pimentel@synopsys.com>, "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>, "arnd@arndb.de" <arnd@arndb.de>, "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>, "jingoohan1@gmail.com" <jingoohan1@gmail.com>, "bhelgaas@google.com" <bhelgaas@google.com>, "wen.yang99@zte.com.cn" <wen.yang99@zte.com.cn>, "kjlu@umn.edu" <kjlu@umn.edu>, "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>, "palmer@sifive.com" <palmer@sifive.com>, "paul.walmsley@sifive.com" <paul.walmsley@sifive.com>, Vinod Koul <vkoul@kernel.org> Subject: Re: [PATCH] PCI: endpoint: Add DMA to Linux PCI EP Framework Date: Mon, 3 Jun 2019 10:42:34 -0700 [thread overview] Message-ID: <CABEDWGx2N66L=27JY6Ywbfny78UaxENkxBTqxU37PfuQO-ZMZw@mail.gmail.com> (raw) In-Reply-To: <6e692ff6-e64f-e651-c8ae-34d0034ad7b9@ti.com> On Sun, Jun 2, 2019 at 9:43 PM Kishon Vijay Abraham I <kishon@ti.com> wrote: > Hi Alan, > On 31/05/19 11:46 PM, Alan Mikhak wrote: > > On Thu, May 30, 2019 at 10:08 PM Kishon Vijay Abraham I <kishon@ti.com> wrote: > >> Hi Alan, > >>> Hi Kishon, > >> > >> I still have to look closer into your DMA patch but linked-list mode or single > >> block mode shouldn't be an user select-able option but should be determined by > >> the size of transfer. > > > > Please consider the following when taking a closer look at this patch. > > After seeing comments from Vinod and Arnd, it looks like the better way of > adding DMA support would be to register DMA within PCI endpoint controller to > DMA subsystem (as dmaengine) and use only dmaengine APIs in pci_epf_test. Thanks Kishon. That makes it clear where these pieces should go. > > In my specific use case, I need to verify that any valid block size, > > including a one byte transfer, can be transferred across the PCIe bus > > by memcpy_toio/fromio() or by DMA either as a single block or as > > linked-list. That is why, instead of deciding based on transfer size, > > this patch introduces the '-L' flag for pcitest to communicate the > > user intent across the PCIe bus to pci-epf-test so the endpoint can > > initiate the DMA transfer using a single block or in linked-list mode. > The -L option seems to select an internal DMA configuration which might be > specific to one implementation. As Gustavo already pointed, we should have only > generic options in pcitest. This would no longer be applicable when we move to > dmaengine. Single-block DMA seemed as generic as linked-list DMA and memcpy_toio/fromio. It remains unclear how else to communicate that intent to pci_epf_test each time I invoke pcitest. Regards, Alan
WARNING: multiple messages have this Message-ID (diff)
From: Alan Mikhak <alan.mikhak@sifive.com> To: Kishon Vijay Abraham I <kishon@ti.com> Cc: "lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>, "arnd@arndb.de" <arnd@arndb.de>, "jingoohan1@gmail.com" <jingoohan1@gmail.com>, Gustavo Pimentel <Gustavo.Pimentel@synopsys.com>, "palmer@sifive.com" <palmer@sifive.com>, "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Vinod Koul <vkoul@kernel.org>, "kjlu@umn.edu" <kjlu@umn.edu>, "paul.walmsley@sifive.com" <paul.walmsley@sifive.com>, "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>, "bhelgaas@google.com" <bhelgaas@google.com>, "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>, "wen.yang99@zte.com.cn" <wen.yang99@zte.com.cn> Subject: Re: [PATCH] PCI: endpoint: Add DMA to Linux PCI EP Framework Date: Mon, 3 Jun 2019 10:42:34 -0700 [thread overview] Message-ID: <CABEDWGx2N66L=27JY6Ywbfny78UaxENkxBTqxU37PfuQO-ZMZw@mail.gmail.com> (raw) In-Reply-To: <6e692ff6-e64f-e651-c8ae-34d0034ad7b9@ti.com> On Sun, Jun 2, 2019 at 9:43 PM Kishon Vijay Abraham I <kishon@ti.com> wrote: > Hi Alan, > On 31/05/19 11:46 PM, Alan Mikhak wrote: > > On Thu, May 30, 2019 at 10:08 PM Kishon Vijay Abraham I <kishon@ti.com> wrote: > >> Hi Alan, > >>> Hi Kishon, > >> > >> I still have to look closer into your DMA patch but linked-list mode or single > >> block mode shouldn't be an user select-able option but should be determined by > >> the size of transfer. > > > > Please consider the following when taking a closer look at this patch. > > After seeing comments from Vinod and Arnd, it looks like the better way of > adding DMA support would be to register DMA within PCI endpoint controller to > DMA subsystem (as dmaengine) and use only dmaengine APIs in pci_epf_test. Thanks Kishon. That makes it clear where these pieces should go. > > In my specific use case, I need to verify that any valid block size, > > including a one byte transfer, can be transferred across the PCIe bus > > by memcpy_toio/fromio() or by DMA either as a single block or as > > linked-list. That is why, instead of deciding based on transfer size, > > this patch introduces the '-L' flag for pcitest to communicate the > > user intent across the PCIe bus to pci-epf-test so the endpoint can > > initiate the DMA transfer using a single block or in linked-list mode. > The -L option seems to select an internal DMA configuration which might be > specific to one implementation. As Gustavo already pointed, we should have only > generic options in pcitest. This would no longer be applicable when we move to > dmaengine. Single-block DMA seemed as generic as linked-list DMA and memcpy_toio/fromio. It remains unclear how else to communicate that intent to pci_epf_test each time I invoke pcitest. Regards, Alan _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2019-06-03 17:42 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-05-23 22:24 [PATCH] PCI: endpoint: Add DMA to Linux PCI EP Framework Alan Mikhak 2019-05-23 22:24 ` Alan Mikhak 2019-05-24 8:59 ` Gustavo Pimentel 2019-05-24 8:59 ` Gustavo Pimentel 2019-05-24 19:42 ` Alan Mikhak 2019-05-24 19:42 ` Alan Mikhak 2019-05-27 9:09 ` Gustavo Pimentel 2019-05-27 9:09 ` Gustavo Pimentel 2019-05-29 22:37 ` Alan Mikhak 2019-05-29 22:37 ` Alan Mikhak 2019-05-30 5:46 ` Kishon Vijay Abraham I 2019-05-30 5:46 ` Kishon Vijay Abraham I 2019-05-30 17:56 ` Alan Mikhak 2019-05-30 17:56 ` Alan Mikhak 2019-05-31 5:06 ` Kishon Vijay Abraham I 2019-05-31 5:06 ` Kishon Vijay Abraham I 2019-05-31 18:16 ` Alan Mikhak 2019-05-31 18:16 ` Alan Mikhak 2019-06-03 4:41 ` Kishon Vijay Abraham I 2019-06-03 4:41 ` Kishon Vijay Abraham I 2019-06-03 17:42 ` Alan Mikhak [this message] 2019-06-03 17:42 ` Alan Mikhak 2019-09-13 12:11 ` Kishon Vijay Abraham I 2019-09-13 12:11 ` Kishon Vijay Abraham I 2019-09-13 17:39 ` Alan Mikhak 2019-09-13 17:39 ` Alan Mikhak 2019-05-31 5:07 ` Vinod Koul 2019-05-31 5:07 ` Vinod Koul 2019-05-31 5:20 ` Kishon Vijay Abraham I 2019-05-31 5:20 ` Kishon Vijay Abraham I 2019-05-31 6:32 ` Vinod Koul 2019-05-31 6:32 ` Vinod Koul 2019-05-31 7:49 ` Arnd Bergmann 2019-05-31 7:49 ` Arnd Bergmann 2019-06-03 4:29 ` Kishon Vijay Abraham I 2019-06-03 4:29 ` Kishon Vijay Abraham I 2019-06-03 4:24 ` Kishon Vijay Abraham I 2019-06-03 4:24 ` Kishon Vijay Abraham I 2019-06-03 4:42 ` Vinod Koul 2019-06-03 4:42 ` Vinod Koul
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