<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">Hi Wentao, well the problem is you don't seem to understand how the hardware works. See the engines see an MC address space with a hole in the middle, similar to the how x86 64bit CPU address space works. But the page tables are programmed linearly. So the calculation in amdgpu_driver_open_kms() is correct because it takes the MC address and mages a linear page table index from it again. The only thing we might need to fix here is shifting max_pfn before the subtraction and I doubt that even that is necessary. Regards, Christian. Am 16.01.19 um 10:34 schrieb Lou, Wentao: </div> <blockquote type="cite" cite="mid:BYAPR12MB2742181357E4D7DF7C171EE983820@BYAPR12MB2742.namprd12.prod.outlook.com"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> <div class="WordSection1"> Hi Christian,<o:p></o:p> <o:p> </o:p> Now vm_size was set to 0x4 0000 GB by below commit:<o:p></o:p> 1bf621c42137926ac249af761c0190a9258aa0db drm/amdgpu: Remove unnecessary VM size calculations<o:p></o:p> <o:p> </o:p> So that max_pfn would be 0x10 0000 0000.<o:p></o:p> amdgpu_csa_vaddr would make max_pfn << 12 to get 0x1 0000 0000 0000, and then minus AMDGPU_VA_RESERVED_SIZE, to get 0xFFFF FFF0 0000<o:p></o:p> unfortunately this number was between AMDGPU_GMC_HOLE_START and AMDGPU_GMC_HOLE_END, so that amdgpu_gmc_sign_extend was called to make it 0xFFFF FFFF FFF0 0000<o:p></o:p> <o:p> </o:p> in amdgpu_driver_open_kms, extended csa_addr cannot be passed into amdgpu_map_static_csa directly, it would be above the limit of max_pfn.<o:p></o:p> So that csa_addr was restricted by AMDGPU_GMC_HOLE_MASK to make it possible for amdgpu_vm_alloc_pts.<o:p></o:p> But this restriction by AMDGPU_GMC_HOLE_MASK would make the address fall back into AMDGPU_GMC_HOLE again, which causing GPU reset.<o:p></o:p> We just put amdgpu_csa_vaddr back to AMDGPU_GMC_HOLE_START, to avoid the address touching AMDGPU_GMC_HOLE.<o:p></o:p> By the way, if max_pfn was shift much to the left, it would always get zero, with or without min(*,*).<o:p></o:p> <o:p> </o:p> <o:p> </o:p> BR,<o:p></o:p> Wentao<o:p></o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> -----Original Message----- From: Koenig, Christian <a class="moz-txt-link-rfc2396E" href="mailto:Christian.Koenig@amd.com"> <Christian.Koenig@amd.com></a> Sent: Tuesday, January 15, 2019 4:02 PM To: Liu, Monk <a class="moz-txt-link-rfc2396E" href="mailto:Monk.Liu@amd.com"><Monk.Liu@amd.com></a>; Lou, Wentao <a class="moz-txt-link-rfc2396E" href="mailto:Wentao.Lou@amd.com"><Wentao.Lou@amd.com></a>; <a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a>; Zhu, Rex <a class="moz-txt-link-rfc2396E" href="mailto:Rex.Zhu@amd.com"><Rex.Zhu@amd.com></a> Subject: Re: [PATCH] drm/amdgpu: csa_vaddr should not larger than AMDGPU_GMC_HOLE_START <o:p> </o:p> Am 15.01.19 um 07:19 schrieb Liu, Monk:<o:p></o:p> > The max_pfn is now 1'0000'0000'0000'0000 (bytes) which is above 48 bit now, and it with AMDGPU_GMC_HOLE_MASK make it to zero ....<o:p></o:p> ><o:p> </o:p> > And in code "amdgpu_driver_open_kms()" I saw @Zhu, Rex write the code as :<o:p></o:p> ><o:p> </o:p> > "csa_addr = amdgpu_csa_vadr(adev) & AMDGPU_GMC_HOLE_MASK", I think this is wrong since you intentionally place the csa above GMC hole, right ?<o:p></o:p> <o:p> </o:p> The fix is just completely incorrect since min(adev->vm_manager.max_pfn << AMDGPU_GPU_PAGE_SHIFT, AMDGPU_GMC_HOLE_START) still gives you 0 when we shift max_pfn to much to the left.<o:p></o:p> <o:p> </o:p> The correct solution is to substract the reserved size first and then shift. E.g.:<o:p></o:p> <o:p> </o:p> addr = (max_pfn - (AMDGPU_VA_RESERVED_SIZE >> AMDGPU_PAGE_SHIFT)) << AMDGPU_PAGE_SHIFT;<o:p></o:p> <o:p> </o:p> Regards,<o:p></o:p> Christian.<o:p></o:p> <o:p> </o:p> ><o:p> </o:p> > Looks like we should modify this place<o:p></o:p> ><o:p> </o:p> > /Monk<o:p></o:p> ><o:p> </o:p> > -----Original Message-----<o:p></o:p> > From: amd-gfx <<a href="mailto:amd-gfx-bounces@lists.freedesktop.org" moz-do-not-send="true">amd-gfx-bounces@lists.freedesktop.org</a>> On Behalf Of <o:p></o:p> > Christian K?nig<o:p></o:p> > Sent: Monday, January 14, 2019 9:05 PM<o:p></o:p> > To: Lou, Wentao <<a href="mailto:Wentao.Lou@amd.com" moz-do-not-send="true">Wentao.Lou@amd.com</a>>; <a href="mailto:amd-gfx@lists.freedesktop.org" moz-do-not-send="true">amd-gfx@lists.freedesktop.org</a><o:p></o:p> > Subject: Re: [PATCH] drm/amdgpu: csa_vaddr should not larger than <o:p></o:p> > AMDGPU_GMC_HOLE_START<o:p></o:p> ><o:p> </o:p> > Am 14.01.19 um 09:40 schrieb wentalou:<o:p></o:p> >> After removing unnecessary VM size calculations, vm_manager.max_pfn <o:p></o:p> >> would reach 0x10,0000,0000 max_pfn << AMDGPU_GPU_PAGE_SHIFT exceeding <o:p></o:p> >> AMDGPU_GMC_HOLE_START would caused GPU reset.<o:p></o:p> >><o:p> </o:p> >> Change-Id: I47ad0be2b0bd9fb7490c4e1d7bb7bdacf71132cb<o:p></o:p> >> Signed-off-by: wentalou <<a href="mailto:Wentao.Lou@amd.com" moz-do-not-send="true">Wentao.Lou@amd.com</a>><o:p></o:p> > NAK, that is incorrect. We intentionally place the csa above the GMC hole.<o:p></o:p> ><o:p> </o:p> > Regards,<o:p></o:p> > Christian.<o:p></o:p> ><o:p> </o:p> >> ---<o:p></o:p> >> drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c | 3 ++-<o:p></o:p> >> 1 file changed, 2 insertions(+), 1 deletion(-)<o:p></o:p> >><o:p> </o:p> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c<o:p></o:p> >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c<o:p></o:p> >> index 7e22be7..dd3bd01 100644<o:p></o:p> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c<o:p></o:p> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c<o:p></o:p> >> @@ -26,7 +26,8 @@<o:p></o:p> >> <o:p></o:p> >> uint64_t amdgpu_csa_vaddr(struct amdgpu_device *adev)<o:p></o:p> >> {<o:p></o:p> >> - uint64_t addr = adev->vm_manager.max_pfn << AMDGPU_GPU_PAGE_SHIFT;<o:p></o:p> >> + uint64_t addr = min(adev->vm_manager.max_pfn << AMDGPU_GPU_PAGE_SHIFT,<o:p></o:p> >> + AMDGPU_GMC_HOLE_START);<o:p></o:p> >> <o:p></o:p> >> addr -= AMDGPU_VA_RESERVED_SIZE;<o:p></o:p> >> addr = amdgpu_gmc_sign_extend(addr);<o:p></o:p> > _______________________________________________<o:p></o:p> > amd-gfx mailing list<o:p></o:p> > <a href="mailto:amd-gfx@lists.freedesktop.org" moz-do-not-send="true"> amd-gfx@lists.freedesktop.org</a><o:p></o:p> > <a href="https://lists.freedesktop.org/mailman/listinfo/amd-gfx" moz-do-not-send="true"> https://lists.freedesktop.org/mailman/listinfo/amd-gfx</a><o:p></o:p> <o:p> </o:p> </div> </blockquote> </body> </html>