From: Boris Brezillon <boris.brezillon@collabora.com>
To: "Boris Brezillon" <boris.brezillon@collabora.com>,
"Steven Price" <steven.price@arm.com>,
"Liviu Dudau" <liviu.dudau@arm.com>,
"Adrián Larumbe" <adrian.larumbe@collabora.com>
Cc: dri-devel@lists.freedesktop.org, kernel@collabora.com
Subject: [PATCH v2 3/4] drm/panthor: Relax the constraints on the tiler chunk size
Date: Tue, 30 Apr 2024 13:28:51 +0200 [thread overview]
Message-ID: <20240430112852.486424-4-boris.brezillon@collabora.com> (raw)
In-Reply-To: <20240430112852.486424-1-boris.brezillon@collabora.com>
The field used to store the chunk size if 12 bits wide, and the encoding
is chunk_size = chunk_header.chunk_size << 12, which gives us a
theoretical [4k:8M] range. This range is further limited by
implementation constraints, and all known implementations seem to
impose a [128k:8M] range, so do the same here.
We also relax the power-of-two constraint, which doesn't seem to
exist on v10. This will allow userspace to fine-tune initial/max
tiler memory on memory-constrained devices.
v2:
- Turn the power-of-two constraint into a page-aligned constraint to allow
fine-tune of the initial/max heap memory size
- Fix the panthor_heap_create() kerneldoc
Fixes: 9cca48fa4f89 ("drm/panthor: Add the heap logical block")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
---
drivers/gpu/drm/panthor/panthor_heap.c | 8 ++++----
include/uapi/drm/panthor_drm.h | 6 +++++-
2 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/panthor/panthor_heap.c b/drivers/gpu/drm/panthor/panthor_heap.c
index 3be86ec383d6..683bb94761bc 100644
--- a/drivers/gpu/drm/panthor/panthor_heap.c
+++ b/drivers/gpu/drm/panthor/panthor_heap.c
@@ -253,8 +253,8 @@ int panthor_heap_destroy(struct panthor_heap_pool *pool, u32 handle)
* @pool: Pool to instantiate the heap context from.
* @initial_chunk_count: Number of chunk allocated at initialization time.
* Must be at least 1.
- * @chunk_size: The size of each chunk. Must be a power of two between 256k
- * and 2M.
+ * @chunk_size: The size of each chunk. Must be page-aligned and lie in the
+ * [128k:2M] range.
* @max_chunks: Maximum number of chunks that can be allocated.
* @target_in_flight: Maximum number of in-flight render passes.
* @heap_ctx_gpu_va: Pointer holding the GPU address of the allocated heap
@@ -284,8 +284,8 @@ int panthor_heap_create(struct panthor_heap_pool *pool,
if (initial_chunk_count > max_chunks)
return -EINVAL;
- if (hweight32(chunk_size) != 1 ||
- chunk_size < SZ_256K || chunk_size > SZ_2M)
+ if (!IS_ALIGNED(chunk_size, PAGE_SIZE) ||
+ chunk_size < SZ_128K || chunk_size > SZ_8M)
return -EINVAL;
down_read(&pool->lock);
diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
index 5db80a0682d5..b8220d2e698f 100644
--- a/include/uapi/drm/panthor_drm.h
+++ b/include/uapi/drm/panthor_drm.h
@@ -898,7 +898,11 @@ struct drm_panthor_tiler_heap_create {
/** @initial_chunk_count: Initial number of chunks to allocate. Must be at least one. */
__u32 initial_chunk_count;
- /** @chunk_size: Chunk size. Must be a power of two at least 256KB large. */
+ /**
+ * @chunk_size: Chunk size.
+ *
+ * Must be page-aligned and lie in the [128k:8M] range.
+ */
__u32 chunk_size;
/**
--
2.44.0
next prev parent reply other threads:[~2024-04-30 11:29 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-30 11:28 [PATCH v2 0/4] drm/panthor: Collection of tiler heap related fixes Boris Brezillon
2024-04-30 11:28 ` [PATCH v2 1/4] drm/panthor: Fix tiler OOM handling to allow incremental rendering Boris Brezillon
2024-04-30 15:27 ` Liviu Dudau
2024-05-02 14:03 ` Steven Price
2024-04-30 11:28 ` [PATCH v2 2/4] drm/panthor: Make sure the tiler initial/max chunks are consistent Boris Brezillon
2024-04-30 15:31 ` Liviu Dudau
2024-05-02 14:03 ` Steven Price
2024-04-30 11:28 ` Boris Brezillon [this message]
2024-04-30 13:08 ` [PATCH v2 3/4] drm/panthor: Relax the constraints on the tiler chunk size Adrián Larumbe
2024-05-02 14:03 ` Steven Price
2024-04-30 16:10 ` Liviu Dudau
2024-04-30 11:28 ` [PATCH v2 4/4] drm/panthor: Fix an off-by-one in the heap context retrieval logic Boris Brezillon
2024-04-30 16:40 ` Liviu Dudau
2024-04-30 17:07 ` Boris Brezillon
2024-05-02 14:03 ` Steven Price
2024-05-02 14:15 ` Boris Brezillon
2024-05-02 14:26 ` Steven Price
2024-05-02 14:36 ` Boris Brezillon
2024-05-02 14:47 ` Boris Brezillon
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