[PATCH AUTOSEL 5.15 07/12] drm/amdkfd: clamp queue size to minimum

[Sasha Levin]

From: David Yat Sin <david.yat...@amd.com>

[ Upstream commit e90711946b53590371ecce32e8fcc381a99d6333 ]

If queue size is less than minimum, clamp it to minimum to prevent
underflow when writing queue mqd.

Signed-off-by: David Yat Sin <david.yat...@amd.com>
Reviewed-by: Jay Cornwall <jay.cornw...@amd.com>
Reviewed-by: Harish Kasiviswanathan <harish.kasiviswanat...@amd.com>
Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 10 ++++++++++
 include/uapi/linux/kfd_ioctl.h           |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 34c466e8eee98..7b2111be3019a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -191,6 +191,11 @@ static int set_queue_properties_from_user(struct 
queue_properties *q_properties,
                return -EINVAL;
        }
 
+       if (args->ring_size < KFD_MIN_QUEUE_RING_SIZE) {
+               args->ring_size = KFD_MIN_QUEUE_RING_SIZE;
+               pr_debug("Size lower. clamped to KFD_MIN_QUEUE_RING_SIZE");
+       }
+
        if (!access_ok((const void __user *) args->read_pointer_address,
                        sizeof(uint32_t))) {
                pr_err("Can't access read pointer\n");
@@ -395,6 +400,11 @@ static int kfd_ioctl_update_queue(struct file *filp, 
struct kfd_process *p,
                return -EINVAL;
        }
 
+       if (args->ring_size < KFD_MIN_QUEUE_RING_SIZE) {
+               args->ring_size = KFD_MIN_QUEUE_RING_SIZE;
+               pr_debug("Size lower. clamped to KFD_MIN_QUEUE_RING_SIZE");
+       }
+
        properties.queue_address = args->ring_base_address;
        properties.queue_size = args->ring_size;
        properties.queue_percent = args->queue_percentage;
diff --git a/include/uapi/linux/kfd_ioctl.h b/include/uapi/linux/kfd_ioctl.h
index af96af174dc47..48d747f3ee8db 100644
--- a/include/uapi/linux/kfd_ioctl.h
+++ b/include/uapi/linux/kfd_ioctl.h
@@ -50,6 +50,8 @@ struct kfd_ioctl_get_version_args {
 #define KFD_MAX_QUEUE_PERCENTAGE       100
 #define KFD_MAX_QUEUE_PRIORITY         15
 
+#define KFD_MIN_QUEUE_RING_SIZE                1024
+
 struct kfd_ioctl_create_queue_args {
        __u64 ring_base_address;        /* to KFD */
        __u64 write_pointer_address;    /* from KFD */
-- 
2.39.5