[PATCH 6.18 167/752] drm/amdkfd: Relax size checking during queue buffer get

Sasha Levin
2026-02-28T17:50:29Z

From: Donet Tom <donettom@linux.ibm.com>

[ Upstream commit 42ea9cf2f16b7131cb7302acb3dac510968f8bdc ]

HW-supported EOP buffer sizes are 4K and 32K. On systems that do not
use 4K pages, the minimum buffer object (BO) allocation size is
PAGE_SIZE (for example, 64K). During queue buffer acquisition, the driver
currently checks the allocated BO size against the supported EOP buffer
size. Since the allocated BO is larger than the expected size, this check
fails, preventing queue creation.

Relax the strict size validation and allow PAGE_SIZE-sized BOs to be used.
Only the required 4K region of the buffer will be used as the EOP buffer
and avoids queue creation failures on non-4K page systems.

Acked-by: Christian König <christian.koenig@amd.com>
Suggested-by: Philip Yang <yangp@amd.com>
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Signed-off-by: Felix Kuehling <felix.kuehling@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdkfd/kfd_queue.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_queue.c b/drivers/gpu/drm/amd/amdkfd/kfd_queue.c
index 80c4fa2b0975d..2822c90bd7be4 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_queue.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_queue.c
@@ -275,8 +275,8 @@ int kfd_queue_acquire_buffers(struct kfd_process_device *pdd, struct queue_prope

/* EOP buffer is not required for all ASICs */
if (properties->eop_ring_buffer_address) {
- if (properties->eop_ring_buffer_size != topo_dev->node_props.eop_buffer_size) {
- pr_debug("queue eop bo size 0x%x not equal to node eop buf size 0x%x\n",
+ if (properties->eop_ring_buffer_size < topo_dev->node_props.eop_buffer_size) {
+ pr_debug("queue eop bo size 0x%x is less than node eop buf size 0x%x\n",
properties->eop_ring_buffer_size,
topo_dev->node_props.eop_buffer_size);
err = -EINVAL;
@@ -284,7 +284,7 @@ int kfd_queue_acquire_buffers(struct kfd_process_device *pdd, struct queue_prope
}
err = kfd_queue_buffer_get(vm, (void *)properties->eop_ring_buffer_address,
&properties->eop_buf_bo,
- properties->eop_ring_buffer_size);
+ ALIGN(properties->eop_ring_buffer_size, PAGE_SIZE));
if (err)
goto out_err_unreserve;
}
--
2.51.0