[PATCH 10/26] drm/xe: Add sa/guc_buf_cache sync interface

Michał Winiarski
2025-10-11T19:41:04Z

In upcoming changes the cached buffers are going to be used to read data
produced by the GuC. Add a counterpart to flush, which synchronizes the
CPU-side of suballocation with the GPU data and propagate the interface
to GuC Buffer Cache.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
---
drivers/gpu/drm/xe/xe_guc_buf.c | 9 +++++++++
drivers/gpu/drm/xe/xe_guc_buf.h | 1 +
drivers/gpu/drm/xe/xe_sa.c | 21 +++++++++++++++++++++
drivers/gpu/drm/xe/xe_sa.h | 1 +
4 files changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_guc_buf.c b/drivers/gpu/drm/xe/xe_guc_buf.c
index 502ca3a4ee606..1be26145f0b98 100644
--- a/drivers/gpu/drm/xe/xe_guc_buf.c
+++ b/drivers/gpu/drm/xe/xe_guc_buf.c
@@ -127,6 +127,15 @@ u64 xe_guc_buf_flush(const struct xe_guc_buf buf)
return xe_sa_bo_gpu_addr(buf.sa);
}

+/**
+ * xe_guc_buf_sync() - Copy the data from the GPU memory to the sub-allocation.
+ * @buf: the &xe_guc_buf to sync
+ */
+void xe_guc_buf_sync(const struct xe_guc_buf buf)
+{
+ xe_sa_bo_sync(buf.sa);
+}
+
/**
* xe_guc_buf_cpu_ptr() - Obtain a CPU pointer to the sub-allocation.
* @buf: the &xe_guc_buf to query
diff --git a/drivers/gpu/drm/xe/xe_guc_buf.h b/drivers/gpu/drm/xe/xe_guc_buf.h
index 0d67604d96bdd..fe6b5ffe0d6eb 100644
--- a/drivers/gpu/drm/xe/xe_guc_buf.h
+++ b/drivers/gpu/drm/xe/xe_guc_buf.h
@@ -31,6 +31,7 @@ static inline bool xe_guc_buf_is_valid(const struct xe_guc_buf buf)

void *xe_guc_buf_cpu_ptr(const struct xe_guc_buf buf);
u64 xe_guc_buf_flush(const struct xe_guc_buf buf);
+void xe_guc_buf_sync(const struct xe_guc_buf buf);
u64 xe_guc_buf_gpu_addr(const struct xe_guc_buf buf);
u64 xe_guc_cache_gpu_addr_from_ptr(struct xe_guc_buf_cache *cache, const void *ptr, u32 size);

diff --git a/drivers/gpu/drm/xe/xe_sa.c b/drivers/gpu/drm/xe/xe_sa.c
index fedd017d6dd36..2115789c2bfb7 100644
--- a/drivers/gpu/drm/xe/xe_sa.c
+++ b/drivers/gpu/drm/xe/xe_sa.c
@@ -110,6 +110,10 @@ struct drm_suballoc *__xe_sa_bo_new(struct xe_sa_manager *sa_manager, u32 size,
return drm_suballoc_new(&sa_manager->base, size, gfp, true, 0);
}

+/**
+ * xe_sa_bo_flush_write() - Copy the data from the sub-allocation to the GPU memory.
+ * @sa_bo: the &drm_suballoc to flush
+ */
void xe_sa_bo_flush_write(struct drm_suballoc *sa_bo)
{
struct xe_sa_manager *sa_manager = to_xe_sa_manager(sa_bo->manager);
@@ -123,6 +127,23 @@ void xe_sa_bo_flush_write(struct drm_suballoc *sa_bo)
drm_suballoc_size(sa_bo));
}

+/**
+ * xe_sa_bo_sync() - Copy the data from GPU memory to the sub-allocation.
+ * @sa_bo: the &drm_suballoc to sync
+ */
+void xe_sa_bo_sync(struct drm_suballoc *sa_bo)
+{
+ struct xe_sa_manager *sa_manager = to_xe_sa_manager(sa_bo->manager);
+ struct xe_device *xe = tile_to_xe(sa_manager->bo->tile);
+
+ if (!sa_manager->bo->vmap.is_iomem)
+ return;
+
+ xe_map_memcpy_from(xe, xe_sa_bo_cpu_addr(sa_bo), &sa_manager->bo->vmap,
+ drm_suballoc_soffset(sa_bo),
+ drm_suballoc_size(sa_bo));
+}
+
void xe_sa_bo_free(struct drm_suballoc *sa_bo,
struct dma_fence *fence)
{
diff --git a/drivers/gpu/drm/xe/xe_sa.h b/drivers/gpu/drm/xe/xe_sa.h
index 99dbf0eea5402..28fd8bb6450c2 100644
--- a/drivers/gpu/drm/xe/xe_sa.h
+++ b/drivers/gpu/drm/xe/xe_sa.h
@@ -37,6 +37,7 @@ static inline struct drm_suballoc *xe_sa_bo_new(struct xe_sa_manager *sa_manager
}

void xe_sa_bo_flush_write(struct drm_suballoc *sa_bo);
+void xe_sa_bo_sync(struct drm_suballoc *sa_bo);
void xe_sa_bo_free(struct drm_suballoc *sa_bo, struct dma_fence *fence);

static inline struct xe_sa_manager *
--
2.50.1