On Tue, Aug 27, 2024 at 08:43:36AM +0200, Maarten Lankhorst wrote: > 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. Ok, that makes this usage more clear then. Fine with it as is then. Sorry for the noise. Matt
