Hi Lucas,
On 2/3/2023 7:56 PM, Lucas De Marchi wrote:
On Thu, Feb 02, 2023 at 07:02:43PM +0100, Nirmoy Das wrote:
DSM granularity is 1MB so make sure we stick to that.
I think we need to be a bit more verbose here, because in future we may
need to refer to this commit if/when things change (e.g. the granularity
or the additional size needed on top of DSM).
The issue this is fixing is that the address set by firmware in
GEN12_DSMBASE
and read here doesn't mean "anything above it until the of lmem is
part of DSM".
There may be a few KB that is not part of DSM. How large is that space
is platform-dependent, but since it's always less than the DSM
granularity, it can be simplified by simply aligning the size like
is done here.
v2: replace "1 * SZ_1M" with SZ_1M (Andrzej).
Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Suggested-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Are you ok with me amending the commit message and applying?
Yes, I fine that, thanks for doing that. I agree this is very short
description that I have wrote.
After this patch I think you can follow the process to request committer
access.
Looking for to doing that :)
Nirmoy
Lucas De Marchi
---
drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
index 90a967374b1a..d8e06e783e30 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
@@ -909,7 +909,7 @@ i915_gem_stolen_lmem_setup(struct
drm_i915_private *i915, u16 type,
dsm_base = intel_uncore_read64(uncore, GEN12_DSMBASE) &
GEN12_BDSM_MASK;
if (WARN_ON(lmem_size < dsm_base))
return ERR_PTR(-ENODEV);
- dsm_size = lmem_size - dsm_base;
+ dsm_size = ALIGN_DOWN(lmem_size - dsm_base, SZ_1M);
}
io_size = dsm_size;
--
2.39.0
