On 16/09/2025 22:08, Chia-I Wu wrote:
> Rename lock_region to mmu_hw_cmd_lock.
>
> Signed-off-by: Chia-I Wu <olva...@gmail.com>
> ---
> drivers/gpu/drm/panthor/panthor_mmu.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c
> b/drivers/gpu/drm/panthor/panthor_mmu.c
> index d3af4f79012b4..8600d98842345 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -545,8 +545,17 @@ static int write_cmd(struct panthor_device *ptdev, u32
> as_nr, u32 cmd)
> return status;
> }
>
> -static void lock_region(struct panthor_device *ptdev, u32 as_nr,
> - u64 region_start, u64 size)
> +/**
> + * mmu_hw_cmd_lock() - Issue a LOCK command
> + * @ptdev: Device.
> + * @as_nr: AS to issue command to.
> + * @region_start: Start of the region.
> + * @size: Size of the region.
> + *
> + * Issue a LOCK command to invalidate MMU caches and block future
> transactions
> + * for a region.
The LOCK command doesn't invalidate the caches - that's the UNLOCK
command. LOCK just blocks any memory accesses that target the region.
[I guess the hardware implementation might flush TLBs to achieve the
block, but that's an implementation detail and shouldn't be relied upon].
I'm also not entirely clear what the benefit of this rename is? It's a
static function in a xxx_mmu.c file so it's fairly obvious this going to
MMU HW related. I also feel "_region" in the name makes it obvious that
there is a memory range that is affected by the lock.
Thanks,
Steve
> + */
> +static void mmu_hw_cmd_lock(struct panthor_device *ptdev, u32 as_nr, u64
> region_start, u64 size)
> {
> u8 region_width;
> u64 region;
> @@ -609,7 +618,7 @@ static int mmu_hw_do_operation_locked(struct
> panthor_device *ptdev, int as_nr,
> * power it up
> */
>
> - lock_region(ptdev, as_nr, iova, size);
> + mmu_hw_cmd_lock(ptdev, as_nr, iova, size);
>
> ret = mmu_hw_wait_ready(ptdev, as_nr);
> if (ret)
