drm/xe/bo: add GPU memory trace points

Add TRACE_GPU_MEM tracepoints for tracking global GPU memory usage.

These are required by VSR on Android 12+ for reporting GPU driver memory
allocations.

v5:
 - Drop process_mem tracking
 - Set the gpu_id field to dev->primary->index (Lucas, Tvrtko)
 - Formatting cleanup under 80 columns

v3:
 - Use now configurable CONFIG_TRACE_GPU_MEM instead of adding a
   per-driver Kconfig (Lucas)

v2:
 - Use u64 as preferred by checkpatch (Tvrtko)
 - Fix errors in comments/Kconfig description (Tvrtko)
 - drop redundant "CONFIG" in Kconfig

Signed-off-by: Juston Li <justonli@chromium.org>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250709192313.479336-2-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

Author: Juston Li

drivers/gpu/drm/xe/xe_bo.c

@@ -19,6 +19,8 @@
 
 #include <kunit/static_stub.h>
 
+#include <trace/events/gpu_mem.h>
+
 #include "xe_device.h"
 #include "xe_dma_buf.h"
 #include "xe_drm_client.h"
@@ -418,6 +420,19 @@ static void xe_ttm_tt_account_subtract(struct xe_device *xe, struct ttm_tt *tt)
 		xe_shrinker_mod_pages(xe->mem.shrinker, -(long)tt->num_pages, 0);
 }
 
+static void update_global_total_pages(struct ttm_device *ttm_dev,
+				      long num_pages)
+{
+#if IS_ENABLED(CONFIG_TRACE_GPU_MEM)
+	struct xe_device *xe = ttm_to_xe_device(ttm_dev);
+	u64 global_total_pages =
+		atomic64_add_return(num_pages, &xe->global_total_pages);
+
+	trace_gpu_mem_total(xe->drm.primary->index, 0,
+			    global_total_pages << PAGE_SHIFT);
+#endif
+}
+
 static struct ttm_tt *xe_ttm_tt_create(struct ttm_buffer_object *ttm_bo,
 				       u32 page_flags)
 {
@@ -525,6 +540,7 @@ static int xe_ttm_tt_populate(struct ttm_device *ttm_dev, struct ttm_tt *tt,
 
 	xe_tt->purgeable = false;
 	xe_ttm_tt_account_add(ttm_to_xe_device(ttm_dev), tt);
+	update_global_total_pages(ttm_dev, tt->num_pages);
 
 	return 0;
 }
@@ -541,6 +557,7 @@ static void xe_ttm_tt_unpopulate(struct ttm_device *ttm_dev, struct ttm_tt *tt)
 
 	ttm_pool_free(&ttm_dev->pool, tt);
 	xe_ttm_tt_account_subtract(xe, tt);
+	update_global_total_pages(ttm_dev, -(long)tt->num_pages);
 }
 
 static void xe_ttm_tt_destroy(struct ttm_device *ttm_dev, struct ttm_tt *tt)

drivers/gpu/drm/xe/xe_device_types.h

@@ -600,6 +600,14 @@ struct xe_device {
 	u8 vm_inject_error_position;
 #endif
 
+#if IS_ENABLED(CONFIG_TRACE_GPU_MEM)
+	/**
+	 * @global_total_pages: global GPU page usage tracked for gpu_mem
+	 * tracepoints
+	 */
+	atomic64_t global_total_pages;
+#endif
+
 	/* private: */
 
 #if IS_ENABLED(CONFIG_DRM_XE_DISPLAY)