[PATCH 08/13] drm/xe/sa: Allow creating suballocator with custom guard size

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

Actual xe_sa_manager implementation uses hardcoded 4K to exclude
it from making suballocations but in upcoming patch we want to
reuse the xe_sa_manager where such 4K guard is not needed. Add
another variant of the xe_sa_bo_manager_init() function that
accepts arbitrary guard size.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/xe/xe_sa.c | 18 ++++++++++++++++--
 drivers/gpu/drm/xe/xe_sa.h |  9 +++++++--
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_sa.c b/drivers/gpu/drm/xe/xe_sa.c
index d92d9836fa91..94f05e704a43 100644
--- a/drivers/gpu/drm/xe/xe_sa.c
+++ b/drivers/gpu/drm/xe/xe_sa.c
@@ -32,14 +32,28 @@ static void sa_bo_manager_fini_bo(void *arg)
 	sa_manager->bo = NULL;
 }
 
-struct xe_sa_manager *xe_sa_bo_manager_init(struct xe_tile *tile, u32 size, u32 align)
+/**
+ * __xe_sa_bo_manager_init() - Create and initialize the suballocator
+ * @tile: the &xe_tile where allocate
+ * @size: number of bytes to allocate
+ * @guard: number of bytes to exclude from suballocations
+ * @align: alignment for each suballocated chunk
+ *
+ * Prepares the suballocation manager for suballocations.
+ *
+ * Return: a pointer to the &xe_sa_manager or an ERR_PTR on failure.
+ */
+struct xe_sa_manager *__xe_sa_bo_manager_init(struct xe_tile *tile, u32 size, u32 guard, u32 align)
 {
 	struct xe_device *xe = tile_to_xe(tile);
 	struct xe_sa_manager *sa_manager;
-	u32 managed_size = size - SZ_4K;
+	u32 managed_size;
 	struct xe_bo *bo;
 	int ret;
 
+	xe_tile_assert(tile, size > guard);
+	managed_size = size - guard;
+
 	sa_manager = drmm_kzalloc(&xe->drm, sizeof(*sa_manager), GFP_KERNEL);
 	if (!sa_manager)
 		return ERR_PTR(-ENOMEM);
diff --git a/drivers/gpu/drm/xe/xe_sa.h b/drivers/gpu/drm/xe/xe_sa.h
index bf55d8c3b5eb..9328b38eff6a 100644
--- a/drivers/gpu/drm/xe/xe_sa.h
+++ b/drivers/gpu/drm/xe/xe_sa.h
@@ -5,6 +5,7 @@
 #ifndef _XE_SA_H_
 #define _XE_SA_H_
 
+#include <linux/sizes.h>
 #include <linux/types.h>
 #include "xe_sa_types.h"
 
@@ -12,10 +13,14 @@ struct dma_fence;
 struct xe_bo;
 struct xe_tile;
 
-struct xe_sa_manager *xe_sa_bo_manager_init(struct xe_tile *tile, u32 size, u32 align);
-
+struct xe_sa_manager *__xe_sa_bo_manager_init(struct xe_tile *tile, u32 size, u32 guard, u32 align);
 struct drm_suballoc *__xe_sa_bo_new(struct xe_sa_manager *sa_manager, u32 size, gfp_t gfp);
 
+static inline struct xe_sa_manager *xe_sa_bo_manager_init(struct xe_tile *tile, u32 size, u32 align)
+{
+	return __xe_sa_bo_manager_init(tile, size, SZ_4K, align);
+}
+
 static inline struct drm_suballoc *xe_sa_bo_new(struct xe_sa_manager *sa_manager, u32 size)
 {
 	return __xe_sa_bo_new(sa_manager, size, GFP_KERNEL);
-- 
2.47.1