drm/xe: Introduce xe_ggtt_largest_hole

Introduce a new xe_ggtt_largest_hole helper that attends the SRIOV
demand and continue with the goal of limiting drm_mm access to xe_ggtt.

v2: Fix a typo (Michal)

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240821193842.352557-8-rodrigo.vivi@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c
index 7c8bbaa..2d055f4 100644 (file)
--- a/drivers/gpu/drm/xe/xe_ggtt.c
+++ b/drivers/gpu/drm/xe/xe_ggtt.c
@@ -584,6 +584,41 @@ void xe_ggtt_remove_bo(struct xe_ggtt *ggtt, struct xe_bo *bo)
                            bo->flags & XE_BO_FLAG_GGTT_INVALIDATE);
 }
 
+/**
+ * xe_ggtt_largest_hole - Largest GGTT hole
+ * @ggtt: the &xe_ggtt that will be inspected
+ * @alignment: minimum alignment
+ * @spare: If not NULL: in: desired memory size to be spared / out: Adjusted possible spare
+ *
+ * Return: size of the largest continuous GGTT region
+ */
+u64 xe_ggtt_largest_hole(struct xe_ggtt *ggtt, u64 alignment, u64 *spare)
+{
+       const struct drm_mm *mm = &ggtt->mm;
+       const struct drm_mm_node *entry;
+       u64 hole_min_start = xe_wopcm_size(tile_to_xe(ggtt->tile));
+       u64 hole_start, hole_end, hole_size;
+       u64 max_hole = 0;
+
+       mutex_lock(&ggtt->lock);
+
+       drm_mm_for_each_hole(entry, mm, hole_start, hole_end) {
+               hole_start = max(hole_start, hole_min_start);
+               hole_start = ALIGN(hole_start, alignment);
+               hole_end = ALIGN_DOWN(hole_end, alignment);
+               if (hole_start >= hole_end)
+                       continue;
+               hole_size = hole_end - hole_start;
+               if (spare)
+                       *spare -= min3(*spare, hole_size, max_hole);
+               max_hole = max(max_hole, hole_size);
+       }
+
+       mutex_unlock(&ggtt->lock);
+
+       return max_hole;
+}
+
 #ifdef CONFIG_PCI_IOV
 static u64 xe_encode_vfid_pte(u16 vfid)
 {

diff --git a/drivers/gpu/drm/xe/xe_ggtt.h b/drivers/gpu/drm/xe/xe_ggtt.h
index f816b3c..31060fe 100644 (file)
--- a/drivers/gpu/drm/xe/xe_ggtt.h
+++ b/drivers/gpu/drm/xe/xe_ggtt.h
@@ -29,6 +29,7 @@ int xe_ggtt_insert_bo(struct xe_ggtt *ggtt, struct xe_bo *bo);
 int xe_ggtt_insert_bo_at(struct xe_ggtt *ggtt, struct xe_bo *bo,
                         u64 start, u64 end);
 void xe_ggtt_remove_bo(struct xe_ggtt *ggtt, struct xe_bo *bo);
+u64 xe_ggtt_largest_hole(struct xe_ggtt *ggtt, u64 alignment, u64 *spare);
 
 int xe_ggtt_dump(struct xe_ggtt *ggtt, struct drm_printer *p);
 

diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
index 947750d..1852ff4 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
@@ -590,30 +590,11 @@ int xe_gt_sriov_pf_config_bulk_set_ggtt(struct xe_gt *gt, unsigned int vfid,
 static u64 pf_get_max_ggtt(struct xe_gt *gt)
 {
        struct xe_ggtt *ggtt = gt_to_tile(gt)->mem.ggtt;
-       const struct drm_mm *mm = &ggtt->mm;
-       const struct drm_mm_node *entry;
        u64 alignment = pf_get_ggtt_alignment(gt);
        u64 spare = pf_get_spare_ggtt(gt);
-       u64 hole_min_start = xe_wopcm_size(gt_to_xe(gt));
-       u64 hole_start, hole_end, hole_size;
-       u64 max_hole = 0;
-
-       mutex_lock(&ggtt->lock);
-
-       drm_mm_for_each_hole(entry, mm, hole_start, hole_end) {
-               hole_start = max(hole_start, hole_min_start);
-               hole_start = ALIGN(hole_start, alignment);
-               hole_end = ALIGN_DOWN(hole_end, alignment);
-               if (hole_start >= hole_end)
-                       continue;
-               hole_size = hole_end - hole_start;
-               xe_gt_sriov_dbg_verbose(gt, "HOLE start %llx size %lluK\n",
-                                       hole_start, hole_size / SZ_1K);
-               spare -= min3(spare, hole_size, max_hole);
-               max_hole = max(max_hole, hole_size);
-       }
+       u64 max_hole;
 
-       mutex_unlock(&ggtt->lock);
+       max_hole = xe_ggtt_largest_hole(ggtt, alignment, &spare);
 
        xe_gt_sriov_dbg_verbose(gt, "HOLE max %lluK reserved %lluK\n",
                                max_hole / SZ_1K, spare / SZ_1K);