Hi Ard, Any comments?
Anyway we can modify the code if you insist on using an intermediate CPU IO address space. Thanks, Heyi On Sat, Mar 31, 2018 at 09:37:47AM +0800, Guo Heyi wrote: > Hi Ard, > > Thanks for your time of reviewing the patches. > Please see my opinions below. > > On Fri, Mar 30, 2018 at 05:40:20PM +0200, Ard Biesheuvel wrote: > > On 29 March 2018 at 02:20, Guo Heyi <heyi....@linaro.org> wrote: > > > On Wed, Mar 28, 2018 at 10:43:41AM +0100, Ard Biesheuvel wrote: > > >> On 28 March 2018 at 02:05, Guo Heyi <heyi....@linaro.org> wrote: > > >> > Hi Leif, Ard, > > >> > > > >> > Any comments for this series of patches? > > >> > > > >> > > >> Hello Heyi, > > >> > > >> Thanks for sending these patches. Leif is at the plugfest, but I will > > >> look at these before the end of the week. > > > > > > Forgot the plugfest as I am not attending :) > > > > Hello Heyi, > > > > I think the series looks mostly fine in general, but there are two > > things that I'd like you to change (as noted in my replies): > > - please split the PCI to CPU I/O translation from the CPU I/O to CPU > > MMIO translation > > I heard that OS did the same as you indicated, but the reasons of why I > translated IO address into memory address in PCI host bridge are like below: > > 1. If we add an intermediate level of "CPU IO address space", it makes things > a > little more complicated but I don't see any real benefit. If we just make a > simple policy that on ARM/AARCH64 CPU IO address is equal to CPU memory > address, > we can even use a unified CPU IO driver for all ARM/AARCH64 platforms, while > the > translation is covered by PCI host bridge driver. > > 2. From hardware perspective, the translation is done by PCIe ATU; for IO bar > access, the address from CPU to ATU is a CPU memory address, not an > intermediate > CPU IO address; the intermediate CPU IO address is a totally logical concept, > and it also splits ATU function into separate drivers (CPU IO protocol driver > also sees part of ATU function). > > Please let me know if my understanding is not right. > > > - please fix the APPETURE spelling (in whichever way is most > > convenient for you: separate patch at the beginning, at the end, etc > > etc) > > Nice catch :) will fix that. > > Thanks, > > Heyi _______________________________________________ edk2-devel mailing list firstname.lastname@example.org https://lists.01.org/mailman/listinfo/edk2-devel