From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Garry Subject: Re: [PATCH v13 1/9] LIB: Introduce a generic PIO mapping method Date: Wed, 14 Feb 2018 16:13:57 +0000 Message-ID: References: <1518543933-22456-1-git-send-email-john.garry@huawei.com> <1518543933-22456-2-git-send-email-john.garry@huawei.com> <20180213230551.GA24986@xps13.dannf> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180213230551.GA24986@xps13.dannf> Sender: linux-kernel-owner@vger.kernel.org To: dann frazier Cc: mika.westerberg@linux.intel.com, rafael@kernel.org, lorenzo.pieralisi@arm.com, rjw@rjwysocki.net, hanjun.guo@linaro.org, robh+dt@kernel.org, bhelgaas@google.com, arnd@arndb.de, mark.rutland@arm.com, olof@lixom.net, andy.shevchenko@gmail.com, robh@kernel.org, joe@perches.com, benh@kernel.crashing.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linuxarm@huawei.com, minyard@acm.org, devicetree@vger.kernel.org, linux-arch@vger.kernel.org, rdunlap@infradead.org List-Id: linux-acpi@vger.kernel.org On 13/02/2018 23:05, dann frazier wrote: >> bool >> > >> > +config INDIRECT_PIO >> > + bool "Access I/O in non-MMIO mode" >> > + depends on ARM64 >> > + help >> > + On some platforms where no separate I/O space exists, there are I/O >> > + hosts which can not be accessed in MMIO mode. Using the logical PIO >> > + mechanism, the host-local I/O resource can be mapped into system >> > + logic PIO space shared with MMIO hosts, such as PCI/PCIE, then the >> > + system can access the I/O devices with the mapped logic PIO through >> > + I/O accessors. >> > + This way has a relatively little I/O performance cost. Please make > grammar nit - s/a relatively/relatively/ > Fine, thanks John > -dann > >> > + sure your devices really need this configure item enabled. >> > +