Re: [PATCH 11/26] drm/xe: Allow the caller to pass guc_buf_cache size

Michał Winiarski
2025-10-21T00:47:26Z

On Mon, Oct 13, 2025 at 01:08:39PM +0200, Michal Wajdeczko wrote:
>
>
> On 10/11/2025 9:38 PM, Michał Winiarski wrote:
> > An upcoming change will use GuC buffer cache as a place where GuC
> > migration data will be stored, and the memory requirement for that is
> > larger than indirect data.
> > Allow the caller to pass the size based on the intended usecase.
> >
> > Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
> > ---
> > drivers/gpu/drm/xe/tests/xe_guc_buf_kunit.c | 2 +-
> > drivers/gpu/drm/xe/xe_guc.c | 4 ++--
> > drivers/gpu/drm/xe/xe_guc_buf.c | 6 +++---
> > drivers/gpu/drm/xe/xe_guc_buf.h | 2 +-
> > 4 files changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xe/tests/xe_guc_buf_kunit.c b/drivers/gpu/drm/xe/tests/xe_guc_buf_kunit.c
> > index d266882adc0e0..c273ce8087f56 100644
> > --- a/drivers/gpu/drm/xe/tests/xe_guc_buf_kunit.c
> > +++ b/drivers/gpu/drm/xe/tests/xe_guc_buf_kunit.c
> > @@ -72,7 +72,7 @@ static int guc_buf_test_init(struct kunit *test)
> > kunit_activate_static_stub(test, xe_managed_bo_create_pin_map,
> > replacement_xe_managed_bo_create_pin_map);
> >
> > - KUNIT_ASSERT_EQ(test, 0, xe_guc_buf_cache_init(&guc->buf));
> > + KUNIT_ASSERT_EQ(test, 0, xe_guc_buf_cache_init(&guc->buf), SZ_8K);
>
> SZ_8K added to wrong place ;)

As buildbots & CI already noticed :)

> >
> > test->priv = &guc->buf;
> > return 0;
> > diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> > index d94490979adc0..ccc7c60ae9b77 100644
> > --- a/drivers/gpu/drm/xe/xe_guc.c
> > +++ b/drivers/gpu/drm/xe/xe_guc.c
> > @@ -809,7 +809,7 @@ static int vf_guc_init_post_hwconfig(struct xe_guc *guc)
> > if (err)
> > return err;
> >
> > - err = xe_guc_buf_cache_init(&guc->buf);
> > + err = xe_guc_buf_cache_init(&guc->buf, SZ_8K);
> > if (err)
> > return err;
> >
> > @@ -857,7 +857,7 @@ int xe_guc_init_post_hwconfig(struct xe_guc *guc)
> > if (ret)
> > return ret;
> >
> > - ret = xe_guc_buf_cache_init(&guc->buf);
> > + ret = xe_guc_buf_cache_init(&guc->buf, SZ_8K);
> > if (ret)
> > return ret;
> >
> > diff --git a/drivers/gpu/drm/xe/xe_guc_buf.c b/drivers/gpu/drm/xe/xe_guc_buf.c
> > index 1be26145f0b98..418ada00b99e3 100644
> > --- a/drivers/gpu/drm/xe/xe_guc_buf.c
> > +++ b/drivers/gpu/drm/xe/xe_guc_buf.c
> > @@ -28,16 +28,16 @@ static struct xe_gt *cache_to_gt(struct xe_guc_buf_cache *cache)
> > * @cache: the &xe_guc_buf_cache to initialize
> > *
> > * The Buffer Cache allows to obtain a reusable buffer that can be used to pass
> > - * indirect H2G data to GuC without a need to create a ad-hoc allocation.
> > + * data to GuC or read data from GuC without a need to create a ad-hoc allocation.
> > *
> > * Return: 0 on success or a negative error code on failure.
> > */
> > -int xe_guc_buf_cache_init(struct xe_guc_buf_cache *cache)
> > +int xe_guc_buf_cache_init(struct xe_guc_buf_cache *cache, u32 size)
> > {
> > struct xe_gt *gt = cache_to_gt(cache);
> > struct xe_sa_manager *sam;
> >
> > - sam = __xe_sa_bo_manager_init(gt_to_tile(gt), SZ_8K, 0, sizeof(u32));
>
> maybe we should promote this magic SZ_8K as
>
> #define XE_GUC_BUF_CACHE_DEFAULT_SIZE SZ_8K

Ok.

Thanks,
-Michał

>
> > + sam = __xe_sa_bo_manager_init(gt_to_tile(gt), size, 0, sizeof(u32));
> > if (IS_ERR(sam))
> > return PTR_ERR(sam);
> > cache->sam = sam;
> > diff --git a/drivers/gpu/drm/xe/xe_guc_buf.h b/drivers/gpu/drm/xe/xe_guc_buf.h
> > index fe6b5ffe0d6eb..fe5cf3b183497 100644
> > --- a/drivers/gpu/drm/xe/xe_guc_buf.h
> > +++ b/drivers/gpu/drm/xe/xe_guc_buf.h
> > @@ -11,7 +11,7 @@
> >
> > #include "xe_guc_buf_types.h"
> >
> > -int xe_guc_buf_cache_init(struct xe_guc_buf_cache *cache);
> > +int xe_guc_buf_cache_init(struct xe_guc_buf_cache *cache, u32 size);
> > u32 xe_guc_buf_cache_dwords(struct xe_guc_buf_cache *cache);
> > struct xe_guc_buf xe_guc_buf_reserve(struct xe_guc_buf_cache *cache, u32 dwords);
> > struct xe_guc_buf xe_guc_buf_from_data(struct xe_guc_buf_cache *cache,
>