From: Jason Gunthorpe <jgg@nvidia.com> To: Clint Sbisa <csbisa@amazon.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, <linux-pci@vger.kernel.org>, Bjorn Helgaas <helgaas@kernel.org>, <linux-arm-kernel@lists.infradead.org>, <will@kernel.org>, <catalin.marinas@arm.com>, Leon Romanovsky <leon@kernel.org> Subject: Re: [PATCH] arm64: Enable PCI write-combine resources under sysfs Date: Mon, 14 Sep 2020 11:17:26 -0300 [thread overview] Message-ID: <20200914141726.GA904879@nvidia.com> (raw) In-Reply-To: <20200911214225.hml2wbbq2rofn4re@amazon.com> On Fri, Sep 11, 2020 at 09:42:25PM +0000, Clint Sbisa wrote: > There's no DMA involved with this BAR-- the driver writes a portion of the > packet contents in addition to the descriptors, which generally increases the > number of TLPs if write-combine isn't used. Furthermore, this BAR is only used > for writes and never for reads. You use DPDK without DMA? How does receive work? > As Jason noted in the other reply to this email, the Linux ENA driver makes use > of WC by using devm_ioremap_wc(). As Ben noted we don't have kernel accessors to make this portable or safe :( Jason
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@nvidia.com> To: Clint Sbisa <csbisa@amazon.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, catalin.marinas@arm.com, Leon Romanovsky <leon@kernel.org>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Bjorn Helgaas <helgaas@kernel.org>, linux-pci@vger.kernel.org, will@kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] arm64: Enable PCI write-combine resources under sysfs Date: Mon, 14 Sep 2020 11:17:26 -0300 [thread overview] Message-ID: <20200914141726.GA904879@nvidia.com> (raw) In-Reply-To: <20200911214225.hml2wbbq2rofn4re@amazon.com> On Fri, Sep 11, 2020 at 09:42:25PM +0000, Clint Sbisa wrote: > There's no DMA involved with this BAR-- the driver writes a portion of the > packet contents in addition to the descriptors, which generally increases the > number of TLPs if write-combine isn't used. Furthermore, this BAR is only used > for writes and never for reads. You use DPDK without DMA? How does receive work? > As Jason noted in the other reply to this email, the Linux ENA driver makes use > of WC by using devm_ioremap_wc(). As Ben noted we don't have kernel accessors to make this portable or safe :( Jason _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-09-14 14:18 UTC|newest] Thread overview: 117+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-08-31 15:18 [PATCH] arm64: Enable PCI write-combine resources under sysfs Clint Sbisa 2020-08-31 23:24 ` Benjamin Herrenschmidt 2020-09-01 18:37 ` Bjorn Helgaas 2020-09-01 23:22 ` Benjamin Herrenschmidt 2020-09-02 8:57 ` Will Deacon 2020-09-02 11:32 ` Lorenzo Pieralisi 2020-09-02 14:29 ` Clint Sbisa 2020-09-02 16:47 ` Lorenzo Pieralisi 2020-09-02 16:47 ` Lorenzo Pieralisi 2020-09-02 17:21 ` Catalin Marinas 2020-09-02 17:21 ` Catalin Marinas 2020-09-02 17:54 ` Lorenzo Pieralisi 2020-09-02 17:54 ` Lorenzo Pieralisi 2020-09-02 23:03 ` Benjamin Herrenschmidt 2020-09-02 23:03 ` Benjamin Herrenschmidt 2020-09-02 23:08 ` Benjamin Herrenschmidt 2020-09-02 23:08 ` Benjamin Herrenschmidt 2020-09-02 23:08 ` Benjamin Herrenschmidt 2020-09-02 23:08 ` Benjamin Herrenschmidt 2020-09-02 23:07 ` Benjamin Herrenschmidt 2020-09-02 23:07 ` Benjamin Herrenschmidt 2020-09-03 11:08 ` Lorenzo Pieralisi 2020-09-03 11:08 ` Lorenzo Pieralisi 2020-09-03 14:36 ` Clint Sbisa 2020-09-03 14:36 ` Clint Sbisa 2020-09-03 22:26 ` Benjamin Herrenschmidt 2020-09-03 22:26 ` Benjamin Herrenschmidt 2020-09-07 23:33 ` Benjamin Herrenschmidt 2020-09-07 23:33 ` Benjamin Herrenschmidt 2020-09-10 9:46 ` Lorenzo Pieralisi 2020-09-10 9:46 ` Lorenzo Pieralisi 2020-09-10 10:54 ` Leon Romanovsky 2020-09-10 10:54 ` Leon Romanovsky 2020-09-10 12:37 ` Jason Gunthorpe 2020-09-10 12:37 ` Jason Gunthorpe 2020-09-10 15:17 ` Lorenzo Pieralisi 2020-09-10 15:17 ` Lorenzo Pieralisi 2020-09-10 17:10 ` Jason Gunthorpe 2020-09-10 17:10 ` Jason Gunthorpe 2020-09-10 21:46 ` Benjamin Herrenschmidt 2020-09-10 21:46 ` Benjamin Herrenschmidt 2020-09-10 23:29 ` Jason Gunthorpe 2020-09-10 23:29 ` Jason Gunthorpe 2020-09-11 0:39 ` Benjamin Herrenschmidt 2020-09-11 0:39 ` Benjamin Herrenschmidt 2020-09-11 14:21 ` Jason Gunthorpe 2020-09-11 14:21 ` Jason Gunthorpe 2020-09-11 21:42 ` Clint Sbisa 2020-09-11 21:42 ` Clint Sbisa 2020-09-14 14:17 ` Jason Gunthorpe [this message] 2020-09-14 14:17 ` Jason Gunthorpe 2020-09-14 14:24 ` Clint Sbisa 2020-09-14 14:24 ` Clint Sbisa 2020-09-14 14:38 ` Jason Gunthorpe 2020-09-14 14:38 ` Jason Gunthorpe 2020-09-14 21:42 ` Benjamin Herrenschmidt 2020-09-14 21:42 ` Benjamin Herrenschmidt 2020-09-14 22:00 ` Benjamin Herrenschmidt 2020-09-14 22:00 ` Benjamin Herrenschmidt 2020-09-14 22:32 ` Clint Sbisa 2020-09-14 22:32 ` Clint Sbisa 2020-09-14 22:57 ` Jason Gunthorpe 2020-09-14 22:57 ` Jason Gunthorpe 2020-09-14 23:25 ` Benjamin Herrenschmidt 2020-09-14 23:25 ` Benjamin Herrenschmidt 2020-09-15 10:18 ` Lorenzo Pieralisi 2020-09-15 10:18 ` Lorenzo Pieralisi 2020-09-15 11:05 ` Jason Gunthorpe 2020-09-15 11:05 ` Jason Gunthorpe 2020-09-15 23:17 ` Benjamin Herrenschmidt 2020-09-15 23:17 ` Benjamin Herrenschmidt 2020-09-15 23:40 ` Jason Gunthorpe 2020-09-15 23:40 ` Jason Gunthorpe 2020-09-16 7:59 ` Benjamin Herrenschmidt 2020-09-16 7:59 ` Benjamin Herrenschmidt 2020-09-16 12:12 ` Jason Gunthorpe 2020-09-16 12:12 ` Jason Gunthorpe 2020-09-16 14:09 ` Lorenzo Pieralisi 2020-09-16 14:09 ` Lorenzo Pieralisi 2020-09-16 14:14 ` Jason Gunthorpe 2020-09-16 14:14 ` Jason Gunthorpe 2020-09-16 23:59 ` Benjamin Herrenschmidt 2020-09-16 23:59 ` Benjamin Herrenschmidt 2020-09-17 10:28 ` Lorenzo Pieralisi 2020-09-17 10:28 ` Lorenzo Pieralisi 2020-09-17 11:32 ` Jason Gunthorpe 2020-09-17 11:32 ` Jason Gunthorpe 2020-09-17 14:01 ` Lorenzo Pieralisi 2020-09-17 14:01 ` Lorenzo Pieralisi 2020-09-17 16:08 ` Will Deacon 2020-09-17 16:08 ` Will Deacon 2020-09-16 12:48 ` Leon Romanovsky 2020-09-16 12:48 ` Leon Romanovsky 2020-09-16 8:33 ` Will Deacon 2020-09-16 8:33 ` Will Deacon 2020-09-16 8:48 ` Catalin Marinas 2020-09-16 8:48 ` Catalin Marinas 2020-09-16 14:15 ` Lorenzo Pieralisi 2020-09-16 14:15 ` Lorenzo Pieralisi 2020-09-16 17:00 ` Catalin Marinas 2020-09-16 17:00 ` Catalin Marinas 2020-09-16 21:29 ` Benjamin Herrenschmidt 2020-09-16 21:29 ` Benjamin Herrenschmidt 2020-09-16 12:08 ` Jason Gunthorpe 2020-09-16 12:08 ` Jason Gunthorpe 2020-09-15 23:00 ` Benjamin Herrenschmidt 2020-09-15 23:00 ` Benjamin Herrenschmidt 2020-09-15 23:12 ` Clint Sbisa 2020-09-15 23:12 ` Clint Sbisa 2020-09-14 21:41 ` Benjamin Herrenschmidt 2020-09-14 21:41 ` Benjamin Herrenschmidt -- strict thread matches above, loose matches on Subject: below -- 2020-08-21 15:51 Clint Sbisa 2020-08-21 15:51 ` Clint Sbisa 2020-08-27 14:41 ` Clint Sbisa 2020-08-27 14:41 ` Clint Sbisa 2020-08-31 15:22 ` Clint Sbisa 2020-08-31 15:22 ` Clint Sbisa
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