Commit 24f028b9 authored by Steven Price's avatar Steven Price
Browse files

drm/panthor: Simplify mmu_hw_do_operation_locked 



The only callers to mmu_hw_do_operation_locked() pass an 'op' of either
AS_COMAND_FLUSH_MEM or AS_COMMAND_FLUSH_PT. This means the code paths
after that are dead. Removing those paths means the
mmu_hw_do_flush_on_gpu_ctrl() function might has well be inlined.

Simplify everything by having a switch statement for the type of 'op'
(warning if we get an unexpected value) and removing the dead cases.

Suggested-by: default avatarDaniel Stone <daniel@fooishbar.org>
Signed-off-by: default avatarSteven Price <steven.price@arm.com>
Reviewed-by: default avatarKarunika Choo <karunika.choo@arm.com>
Link: https://lore.kernel.org/r/20250815134226.57703-1-steven.price@arm.com
parent 3c8d31b8

drivers/gpu/drm/panthor/panthor_mmu.c

+26 −31
Original line number Diff line number Diff line
@@ -569,15 +569,37 @@ static void lock_region(struct panthor_device *ptdev, u32 as_nr, 
	write_cmd(ptdev, as_nr, AS_COMMAND_LOCK);

}



static int mmu_hw_do_flush_on_gpu_ctrl(struct panthor_device *ptdev, int as_nr,

				       u32 op)

static int mmu_hw_do_operation_locked(struct panthor_device *ptdev, int as_nr,

				      u64 iova, u64 size, u32 op)

{

	const u32 l2_flush_op = CACHE_CLEAN | CACHE_INV;

	u32 lsc_flush_op = 0;

	u32 lsc_flush_op;

	int ret;



	if (op == AS_COMMAND_FLUSH_MEM)

	lockdep_assert_held(&ptdev->mmu->as.slots_lock);



	switch (op) {

	case AS_COMMAND_FLUSH_MEM:

		lsc_flush_op = CACHE_CLEAN | CACHE_INV;

		break;

	case AS_COMMAND_FLUSH_PT:

		lsc_flush_op = 0;

		break;

	default:

		drm_WARN(&ptdev->base, 1, "Unexpected AS_COMMAND: %d", op);

		return -EINVAL;

	}



	if (as_nr < 0)

		return 0;



	/*

	 * If the AS number is greater than zero, then we can be sure

	 * the device is up and running, so we don't need to explicitly

	 * power it up

	 */



	lock_region(ptdev, as_nr, iova, size);



	ret = wait_ready(ptdev, as_nr);

	if (ret)
@@ -598,33 +620,6 @@ static int mmu_hw_do_flush_on_gpu_ctrl(struct panthor_device *ptdev, int as_nr, 
	return wait_ready(ptdev, as_nr);

}



static int mmu_hw_do_operation_locked(struct panthor_device *ptdev, int as_nr,

				      u64 iova, u64 size, u32 op)

{

	lockdep_assert_held(&ptdev->mmu->as.slots_lock);



	if (as_nr < 0)

		return 0;



	/*

	 * If the AS number is greater than zero, then we can be sure

	 * the device is up and running, so we don't need to explicitly

	 * power it up

	 */



	if (op != AS_COMMAND_UNLOCK)

		lock_region(ptdev, as_nr, iova, size);



	if (op == AS_COMMAND_FLUSH_MEM || op == AS_COMMAND_FLUSH_PT)

		return mmu_hw_do_flush_on_gpu_ctrl(ptdev, as_nr, op);



	/* Run the MMU operation */

	write_cmd(ptdev, as_nr, op);



	/* Wait for the flush to complete */

	return wait_ready(ptdev, as_nr);

}



static int mmu_hw_do_operation(struct panthor_vm *vm,

			       u64 iova, u64 size, u32 op)

{