[PATCH v3 1/7] drm/xe/sa: Avoid caching GGTT address within the manager

[Tomasz Lis]

Non-virtualized resources require fixups after SRIOV VF migration.
Caching GGTT references rather than re-computing them from the
underlying Buffer Object is something we want to avoid, as such
code would require additional fixup step and additional locking
around all the places where the address is accessed.

This change removes the cached GPU address from the Sub-Allocation
Manager, and introduces a function which recomputes and returns
the address instead.

v2: renamed xe_sa_manager_gpu_addr(), added kerneldoc

Signed-off-by: Tomasz Lis <tomasz.lis at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Matthew Brost <matthew.brost at intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
---
 drivers/gpu/drm/xe/xe_gt_debugfs.c |  3 ++-
 drivers/gpu/drm/xe/xe_guc_buf.c    |  2 +-
 drivers/gpu/drm/xe/xe_sa.c         |  1 -
 drivers/gpu/drm/xe/xe_sa.h         | 15 ++++++++++++++-
 drivers/gpu/drm/xe/xe_sa_types.h   |  1 -
 5 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_debugfs.c b/drivers/gpu/drm/xe/xe_gt_debugfs.c
index 119a55bb7580..68b2ae0ab945 100644
--- a/drivers/gpu/drm/xe/xe_gt_debugfs.c
+++ b/drivers/gpu/drm/xe/xe_gt_debugfs.c
@@ -29,6 +29,7 @@
 #include "xe_pm.h"
 #include "xe_reg_sr.h"
 #include "xe_reg_whitelist.h"
+#include "xe_sa.h"
 #include "xe_sriov.h"
 #include "xe_tuning.h"
 #include "xe_uc_debugfs.h"
@@ -146,7 +147,7 @@ static int sa_info(struct xe_gt *gt, struct drm_printer *p)
 
 	xe_pm_runtime_get(gt_to_xe(gt));
 	drm_suballoc_dump_debug_info(&tile->mem.kernel_bb_pool->base, p,
-				     tile->mem.kernel_bb_pool->gpu_addr);
+				     xe_sa_manager_gpu_addr(tile->mem.kernel_bb_pool));
 	xe_pm_runtime_put(gt_to_xe(gt));
 
 	return 0;
diff --git a/drivers/gpu/drm/xe/xe_guc_buf.c b/drivers/gpu/drm/xe/xe_guc_buf.c
index 14a07dca48e7..502ca3a4ee60 100644
--- a/drivers/gpu/drm/xe/xe_guc_buf.c
+++ b/drivers/gpu/drm/xe/xe_guc_buf.c
@@ -164,7 +164,7 @@ u64 xe_guc_cache_gpu_addr_from_ptr(struct xe_guc_buf_cache *cache, const void *p
 	if (offset < 0 || offset + size > cache->sam->base.size)
 		return 0;
 
-	return cache->sam->gpu_addr + offset;
+	return xe_sa_manager_gpu_addr(cache->sam) + offset;
 }
 
 #if IS_BUILTIN(CONFIG_DRM_XE_KUNIT_TEST)
diff --git a/drivers/gpu/drm/xe/xe_sa.c b/drivers/gpu/drm/xe/xe_sa.c
index 1d43e183ca21..fedd017d6dd3 100644
--- a/drivers/gpu/drm/xe/xe_sa.c
+++ b/drivers/gpu/drm/xe/xe_sa.c
@@ -69,7 +69,6 @@ struct xe_sa_manager *__xe_sa_bo_manager_init(struct xe_tile *tile, u32 size, u3
 	}
 	sa_manager->bo = bo;
 	sa_manager->is_iomem = bo->vmap.is_iomem;
-	sa_manager->gpu_addr = xe_bo_ggtt_addr(bo);
 
 	if (bo->vmap.is_iomem) {
 		sa_manager->cpu_ptr = kvzalloc(managed_size, GFP_KERNEL);
diff --git a/drivers/gpu/drm/xe/xe_sa.h b/drivers/gpu/drm/xe/xe_sa.h
index 1170ee5a81a8..74f6acaf97b1 100644
--- a/drivers/gpu/drm/xe/xe_sa.h
+++ b/drivers/gpu/drm/xe/xe_sa.h
@@ -7,6 +7,8 @@
 
 #include <linux/sizes.h>
 #include <linux/types.h>
+
+#include "xe_bo.h"
 #include "xe_sa_types.h"
 
 struct dma_fence;
@@ -43,9 +45,20 @@ to_xe_sa_manager(struct drm_suballoc_manager *mng)
 	return container_of(mng, struct xe_sa_manager, base);
 }
 
+/**
+ * xe_sa_manager_gpu_addr - Retrieve GPU address of a back storage BO
+ *   within suballocator.
+ * @sa_manager: the &xe_sa_manager struct instance
+ * Return: GGTT address of the back storage BO.
+ */
+static inline u64 xe_sa_manager_gpu_addr(struct xe_sa_manager *sa_manager)
+{
+	return xe_bo_ggtt_addr(sa_manager->bo);
+}
+
 static inline u64 xe_sa_bo_gpu_addr(struct drm_suballoc *sa)
 {
-	return to_xe_sa_manager(sa->manager)->gpu_addr +
+	return xe_sa_manager_gpu_addr(to_xe_sa_manager(sa->manager)) +
 		drm_suballoc_soffset(sa);
 }
 
diff --git a/drivers/gpu/drm/xe/xe_sa_types.h b/drivers/gpu/drm/xe/xe_sa_types.h
index 2b070ff1292e..cb7238799dcb 100644
--- a/drivers/gpu/drm/xe/xe_sa_types.h
+++ b/drivers/gpu/drm/xe/xe_sa_types.h
@@ -12,7 +12,6 @@ struct xe_bo;
 struct xe_sa_manager {
 	struct drm_suballoc_manager base;
 	struct xe_bo *bo;
-	u64 gpu_addr;
 	void *cpu_ptr;
 	bool is_iomem;
 };
-- 
2.25.1