Hey, Den 2024-08-27 kl. 05:11, skrev Matthew Brost: > On Mon, Aug 26, 2024 at 09:42:54PM +0200, Maarten Lankhorst wrote: >> Hey, >> >> Den 2024-08-26 kl. 21:30, skrev Matthew Brost: >>> On Mon, Aug 26, 2024 at 07:01:16PM +0200, Maarten Lankhorst wrote: >>>> For CCS formats on affected platforms, CCS can be used freely, but >>>> display engine requires a multiple of 64k physical pages. No other >>>> changes are needed. >>>> >>>> At the BO creation time we don't know if the BO will be used for CCS >>>> or not. If the scanout flag is set, and the BO is a multiple of 64k, >>>> we take the safe route and force the physical alignment of 64k pages. >>>> >>>> If the BO is not a multiple of 64k, or the scanout flag was not set >>>> at BO creation, we reject it for usage as CCS in display. The physical >>>> pages are likely not aligned correctly, and this will cause corruption >>>> when used as FB. >>>> >>>> The scanout flag and size being a multiple of 64k are used together >>>> to enforce 64k physical placement. >>>> >>>> VM_BIND is completely unaffected, mappings to a VM can still be aligned >>>> to 4k, just like for normal buffers. >>>> >>>> Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@xxxxxxxxx> >>>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> >>>> Cc: Matthew Auld <matthew.auld@xxxxxxxxx> >>>> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> >>>> Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx> >>>> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> >>>> Cc: Juha-Pekka Heikkilä <juha-pekka.heikkila@xxxxxxxxx> >>>> --- >>>> drivers/gpu/drm/xe/display/intel_fb_bo.c | 9 +++++++++ >>>> drivers/gpu/drm/xe/xe_bo.c | 7 +++++++ >>>> drivers/gpu/drm/xe/xe_vm.c | 11 ++++++++++- >>>> 3 files changed, 26 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/gpu/drm/xe/display/intel_fb_bo.c b/drivers/gpu/drm/xe/display/intel_fb_bo.c >>>> index f835492f73fb4..63ce97cc4cfef 100644 >>>> --- a/drivers/gpu/drm/xe/display/intel_fb_bo.c >>>> +++ b/drivers/gpu/drm/xe/display/intel_fb_bo.c >>>> @@ -7,6 +7,7 @@ >>>> #include <drm/ttm/ttm_bo.h> >>>> >>>> #include "intel_display_types.h" >>>> +#include "intel_fb.h" >>>> #include "intel_fb_bo.h" >>>> #include "xe_bo.h" >>>> >>>> @@ -28,6 +29,14 @@ int intel_fb_bo_framebuffer_init(struct intel_framebuffer *intel_fb, >>>> struct xe_device *xe = to_xe_device(bo->ttm.base.dev); >>>> int ret; >>>> >>>> + /* >>>> + * Some modifiers require physical alignment of 64KiB VRAM pages; >>>> + * require that the BO in those cases is created correctly. >>>> + */ >>>> + if (XE_IOCTL_DBG(xe, intel_fb_needs_64k_phys(mode_cmd->modifier[0]) && >>>> + !(bo->flags & XE_BO_FLAG_NEEDS_64K))) >>>> + return -EINVAL; >>> >>> I don't think this is correct use of this macro as XE_BO_FLAG_NEEDS_64K >>> is an internal flag we set and typically this macro is used to santize >>> user input. An assert here or WARN would make more sense. >> Ideally we'd use 'is bo created as scanout', but that flag can be set by fb_init too, so if the BO was used for normal 4-tiled before, then as CCS it would pass when it wouldn't be valid. >> >> I could change it to bo_created_with_scanout_flag_on_64k_platform inline, but I doubt that's more readable. :) >> > > Not trying to block the patch and really don't know anything about > display but still think XE_IOCTL_DBG should replaced by either an > assert or WARN (or Xe flavor of warn). Kinda pedantic but we really are > trying hard to uniformly use these types of macros and this just doesn't > look correct. mode_cmd->modifier[0] is passed from userspace without validation, and this function is called very early on in fb creation. Anything more than XE_IOCTL_DBG would be invalid here.
