Commit 32e593d7 authored by Boris Brezillon's avatar Boris Brezillon Committed by Liviu Dudau
Browse files

drm/panthor: Make sure caches are flushed/invalidated when an AS is recycled 



When we re-assign a slot to a different VM, we need to make sure the
old VM caches are flushed before doing the switch. Specialize
panthor_mmu_as_disable() so we can skip the slot programmation while
still getting the cache flushing, and call this helper from
panthor_vm_active() when an idle slot is recycled.

v2:
- Collect R-bs

Fixes: 6e2d3b3e ("drm/panthor: Add support for atomic page table updates")
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: default avatarLiviu Dudau <liviu.dudau@arm.com>
Reviewed-by: default avatarChia-I Wu <olvaffe@gmail.com>
Signed-off-by: default avatarLiviu Dudau <liviu.dudau@arm.com>
Link: https://patch.msgid.link/20251203121750.404340-3-boris.brezillon@collabora.com
parent 657803cb

drivers/gpu/drm/panthor/panthor_mmu.c

+20 −6
Original line number Diff line number Diff line
@@ -585,7 +585,8 @@ static int panthor_mmu_as_enable(struct panthor_device *ptdev, u32 as_nr, 
	return as_send_cmd_and_wait(ptdev, as_nr, AS_COMMAND_UPDATE);

}



static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr)

static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr,

				  bool recycle_slot)

{

	int ret;
@@ -595,6 +596,12 @@ static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr) 
	if (ret)

		return ret;



	/* If the slot is going to be used immediately, don't bother changing

	 * the config.

	 */

	if (recycle_slot)

		return 0;



	gpu_write64(ptdev, AS_TRANSTAB(as_nr), 0);

	gpu_write64(ptdev, AS_MEMATTR(as_nr), 0);

	gpu_write64(ptdev, AS_TRANSCFG(as_nr), AS_TRANSCFG_ADRMODE_UNMAPPED);
@@ -714,6 +721,11 @@ int panthor_vm_active(struct panthor_vm *vm) 


		drm_WARN_ON(&ptdev->base, refcount_read(&lru_vm->as.active_cnt));

		as = lru_vm->as.id;



		ret = panthor_mmu_as_disable(ptdev, as, true);

		if (ret)

			goto out_unlock;



		panthor_vm_release_as_locked(lru_vm);

	}
@@ -853,7 +865,7 @@ static void panthor_vm_declare_unusable(struct panthor_vm *vm) 
	vm->unusable = true;

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

	if (vm->as.id >= 0 && drm_dev_enter(&ptdev->base, &cookie)) {

		panthor_mmu_as_disable(ptdev, vm->as.id);

		panthor_mmu_as_disable(ptdev, vm->as.id, false);

		drm_dev_exit(cookie);

	}

	mutex_unlock(&ptdev->mmu->as.slots_lock);
@@ -1780,7 +1792,7 @@ static void panthor_mmu_irq_handler(struct panthor_device *ptdev, u32 status) 
			ptdev->mmu->as.slots[as].vm->unhandled_fault = true;



		/* Disable the MMU to kill jobs on this AS. */

		panthor_mmu_as_disable(ptdev, as);

		panthor_mmu_as_disable(ptdev, as, false);

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



		status &= ~mask;
@@ -1809,7 +1821,8 @@ void panthor_mmu_suspend(struct panthor_device *ptdev) 
		struct panthor_vm *vm = ptdev->mmu->as.slots[i].vm;



		if (vm) {

			drm_WARN_ON(&ptdev->base, panthor_mmu_as_disable(ptdev, i));

			drm_WARN_ON(&ptdev->base,

				    panthor_mmu_as_disable(ptdev, i, false));

			panthor_vm_release_as_locked(vm);

		}

	}
@@ -1930,7 +1943,7 @@ static void panthor_vm_free(struct drm_gpuvm *gpuvm) 
		int cookie;



		if (drm_dev_enter(&ptdev->base, &cookie)) {

			panthor_mmu_as_disable(ptdev, vm->as.id);

			panthor_mmu_as_disable(ptdev, vm->as.id, false);

			drm_dev_exit(cookie);

		}
@@ -2790,7 +2803,8 @@ void panthor_mmu_unplug(struct panthor_device *ptdev) 
		struct panthor_vm *vm = ptdev->mmu->as.slots[i].vm;



		if (vm) {

			drm_WARN_ON(&ptdev->base, panthor_mmu_as_disable(ptdev, i));

			drm_WARN_ON(&ptdev->base,

				    panthor_mmu_as_disable(ptdev, i, false));

			panthor_vm_release_as_locked(vm);

		}

	}