On 5/19/2026 5:58 PM, Tejas Upadhyay wrote:
Add helper with primary purpose is to efficiently trace a specific
physical memory address back to its corresponding TTM buffer object.
v2:
- %s/gpu_buddy_addr_to_block/gpu_buddy_allocated_addr_to_block(MattA)
- remove clear->avail and split nodes check(MattA)
- Adapt lockdep(MattB)
Signed-off-by: Tejas Upadhyay <[email protected]>
Cc: Arunpravin Paneer Selvam <[email protected]>
Cc: [email protected]
---
drivers/gpu/buddy.c | 53 +++++++++++++++++++++++++++++++++++++++
include/linux/gpu_buddy.h | 2 ++
2 files changed, 55 insertions(+)
diff --git a/drivers/gpu/buddy.c b/drivers/gpu/buddy.c
index eb1457376307..9de9872294a6 100644
--- a/drivers/gpu/buddy.c
+++ b/drivers/gpu/buddy.c
@@ -594,6 +594,59 @@ void gpu_buddy_free_block(struct gpu_buddy *mm,
}
EXPORT_SYMBOL(gpu_buddy_free_block);
+/**
+ * gpu_buddy_allocated_addr_to_block - given relative address find the
allocated block
+ *
+ * @mm: GPU buddy manager
+ * @addr: Relative address
+ *
+ * Returns:
+ * gpu_buddy_block on success, NULL or error code on failure
+ */
+struct gpu_buddy_block *gpu_buddy_allocated_addr_to_block(struct gpu_buddy
*mm, u64 addr)
+{
+ struct gpu_buddy_block *block;
+ LIST_HEAD(dfs);
+ u64 end;
+ int i;
+
+ gpu_buddy_driver_lock_held(mm);
+
+ end = addr + SZ_4K - 1;
+ for (i = 0; i < mm->n_roots; ++i)
+ list_add_tail(&mm->roots[i]->tmp_link, &dfs);
+
+ do {
+ u64 block_start;
+ u64 block_end;
+
+ block = list_first_entry_or_null(&dfs,
+ struct gpu_buddy_block,
+ tmp_link);
+ if (!block)
+ break;
+
+ list_del(&block->tmp_link);
+
+ block_start = gpu_buddy_block_offset(block);
+ block_end = block_start + gpu_buddy_block_size(mm, block) - 1;
+
+ if (!overlaps(addr, end, block_start, block_end))
+ continue;
+
+ if (gpu_buddy_block_is_allocated(block))
+ return block;
+ else if (gpu_buddy_block_is_free(block))
+ return NULL;
+
+ list_add(&block->right->tmp_link, &dfs);
+ list_add(&block->left->tmp_link, &dfs);
+ } while (1);
+
+ return ERR_PTR(-ENXIO);
+}
+EXPORT_SYMBOL(gpu_buddy_allocated_addr_to_block);
+
static void __gpu_buddy_free_list(struct gpu_buddy *mm,
struct list_head *objects,
bool mark_clear,
diff --git a/include/linux/gpu_buddy.h b/include/linux/gpu_buddy.h
index 71941a039648..e7e22fa05ee2 100644
--- a/include/linux/gpu_buddy.h
+++ b/include/linux/gpu_buddy.h
@@ -272,6 +272,8 @@ void gpu_buddy_reset_clear(struct gpu_buddy *mm, bool
is_clear);
void gpu_buddy_free_block(struct gpu_buddy *mm, struct gpu_buddy_block *block);
+struct gpu_buddy_block *gpu_buddy_allocated_addr_to_block(struct gpu_buddy *mm, u64 addr);
Could you please clarify where we plan to use this helper function in
the code path? I do not see any callers added in the current patch series.
Regards,
Arun.
+
void gpu_buddy_free_list(struct gpu_buddy *mm,
struct list_head *objects,
unsigned int flags);
