[RFC PATCH V7 08/10] gpu/buddy: Add routine to dump allocated buddy blocks

[Tejas Upadhyay <tejas.upadhyay@intel.com>]

To implement the ability to see allocated blocks under a specific VRAM
instance in the drm driver, new api is introduced. While existing structs
often show the free block list, this addition provides a comprehensive view
of all currently resident VRAM allocations.

Dump will look like,

[  +0.000003] xe 0000:03:00.0: [drm] 0x00000002f8000000-0x00000002f8800000: 8388608
[  +0.000005] xe 0000:03:00.0: [drm] 0x00000002f8800000-0x00000002f8840000: 262144
[  +0.000004] xe 0000:03:00.0: [drm] 0x00000002f8840000-0x00000002f8860000: 131072
[  +0.000004] xe 0000:03:00.0: [drm] 0x00000002f8860000-0x00000002f8870000: 65536
[  +0.000005] xe 0000:03:00.0: [drm] 0x00000002f9000000-0x00000002f9800000: 8388608
[  +0.000004] xe 0000:03:00.0: [drm] 0x00000002f9800000-0x00000002f9880000: 524288
[  +0.000005] xe 0000:03:00.0: [drm] 0x00000002f9880000-0x00000002f9884000: 16384
[  +0.000004] xe 0000:03:00.0: [drm] 0x00000002f9900000-0x00000002f9980000: 524288
[  +0.000005] xe 0000:03:00.0: [drm] 0x00000002f9980000-0x00000002f9988000: 32768
[  +0.000004] xe 0000:03:00.0: [drm] 0x00000002f9988000-0x00000002f998c000: 16384

v2(MattB):
- Add lockdep assert

Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
---
 drivers/gpu/buddy.c       | 43 +++++++++++++++++++++++++++++++++++++++
 include/linux/gpu_buddy.h |  1 +
 2 files changed, 44 insertions(+)

diff --git a/drivers/gpu/buddy.c b/drivers/gpu/buddy.c
index 44bf926aca56..09aa4a33f928 100644
--- a/drivers/gpu/buddy.c
+++ b/drivers/gpu/buddy.c
@@ -10,6 +10,7 @@
 #include <linux/sizes.h>
 
 #include <linux/gpu_buddy.h>
+#include <drm/drm_print.h>
 
 /**
  * gpu_buddy_assert - assert a condition in the buddy allocator
@@ -1295,6 +1296,48 @@ int gpu_buddy_block_trim(struct gpu_buddy *mm,
 }
 EXPORT_SYMBOL(gpu_buddy_block_trim);
 
+/**
+ * gpu_buddy_dump_allocated_blocks - print all allocated blocks in drm buddy
+ *
+ * @mm: DRM buddy manager to look into
+ *
+ * Looks into buddy manager for each block and their status and if allocated
+ * print allocated block range and size
+ *
+ * Returns:
+ * void
+ */
+void gpu_buddy_dump_allocated_blocks(struct gpu_buddy *mm)
+{
+	struct gpu_buddy_block *block;
+	LIST_HEAD(dfs);
+	int i;
+
+	gpu_buddy_driver_lock_held(mm);
+
+	for (i = 0; i < mm->n_roots; ++i)
+		list_add_tail(&mm->roots[i]->tmp_link, &dfs);
+
+	do {
+		block = list_first_entry_or_null(&dfs,
+						 struct gpu_buddy_block,
+						 tmp_link);
+		if (!block)
+			break;
+
+		list_del(&block->tmp_link);
+
+		if (gpu_buddy_block_is_allocated(block))
+			gpu_buddy_block_print(mm, block);
+
+		if (gpu_buddy_block_is_split(block)) {
+			list_add(&block->right->tmp_link, &dfs);
+			list_add(&block->left->tmp_link, &dfs);
+		}
+	} while (1);
+}
+EXPORT_SYMBOL(gpu_buddy_dump_allocated_blocks);
+
 static struct gpu_buddy_block *
 __gpu_buddy_alloc_blocks(struct gpu_buddy *mm,
 			 u64 start, u64 end,
diff --git a/include/linux/gpu_buddy.h b/include/linux/gpu_buddy.h
index e42c38a2a9f5..2834ea06da56 100644
--- a/include/linux/gpu_buddy.h
+++ b/include/linux/gpu_buddy.h
@@ -267,6 +267,7 @@ int gpu_buddy_block_trim(struct gpu_buddy *mm,
 			 u64 *start,
 			 u64 new_size,
 			 struct list_head *blocks);
+void gpu_buddy_dump_allocated_blocks(struct gpu_buddy *mm);
 
 void gpu_buddy_reset_clear(struct gpu_buddy *mm, bool is_clear);
 
-- 
2.52.0