linux-kernel - [PATCH 10/10] drm/panthor: simplify mmu_hw_flush

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Message-ID: <20250916210823.4033529-11-olvaffe@gmail.com>
Date: Tue, 16 Sep 2025 14:08:23 -0700
From: Chia-I Wu <olvaffe@...il.com>
To: Boris Brezillon <boris.brezillon@...labora.com>,
	Steven Price <steven.price@....com>,
	Liviu Dudau <liviu.dudau@....com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	Grant Likely <grant.likely@...aro.org>,
	Heiko Stuebner <heiko@...ech.de>,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 10/10] drm/panthor: simplify mmu_hw_flush_caches

Simplify flush op to a bool to control whether LSC is
flushed/invalidated. Remove mmu_hw_do_operation helper.

Signed-off-by: Chia-I Wu <olvaffe@...il.com>
---
 drivers/gpu/drm/panthor/panthor_mmu.c | 42 ++++++---------------------
 1 file changed, 9 insertions(+), 33 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index 743e9342eece7..5418f079444ce 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -613,33 +613,20 @@ static void mmu_hw_cmd_unlock(struct panthor_device *ptdev, u32 as_nr)
  * @as_nr: AS to issue command to.
  * @iova: Start of the region.
  * @size: Size of the region.
- * @op: AS_COMMAND_FLUSH_*
+ * @flush_lsc: True if LSC should be flushed/invalidated.
  *
  * Issue LOCK/GPU_FLUSH_CACHES/UNLOCK commands in order to flush and
  * invalidate L2/MMU/LSC caches for a region.
  *
  * Return: 0 on success, a negative error code otherwise.
  */
-static int mmu_hw_flush_caches(struct panthor_device *ptdev, int as_nr, u64 iova, u64 size, u32 op)
+static int mmu_hw_flush_caches(struct panthor_device *ptdev, int as_nr, u64 iova, u64 size,
+			       bool flush_lsc)
 {
 	const u32 l2_flush_op = CACHE_CLEAN | CACHE_INV;
-	u32 lsc_flush_op;
+	const u32 lsc_flush_op = flush_lsc ? l2_flush_op : 0;
 	int ret;
 
-	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 || !size)
 		return 0;
 
@@ -671,25 +658,12 @@ static int mmu_hw_flush_caches(struct panthor_device *ptdev, int as_nr, u64 iova
 	return ret;
 }
 
-static int mmu_hw_do_operation(struct panthor_vm *vm,
-			       u64 iova, u64 size, u32 op)
-{
-	struct panthor_device *ptdev = vm->ptdev;
-	int ret;
-
-	mutex_lock(&ptdev->mmu->as.slots_lock);
-	ret = mmu_hw_flush_caches(ptdev, vm->as.id, iova, size, op);
-	mutex_unlock(&ptdev->mmu->as.slots_lock);
-
-	return ret;
-}
-
 static int panthor_mmu_as_enable(struct panthor_device *ptdev, u32 as_nr,
 				 u64 transtab, u64 transcfg, u64 memattr)
 {
 	int ret;
 
-	ret = mmu_hw_flush_caches(ptdev, as_nr, 0, ~0ULL, AS_COMMAND_FLUSH_MEM);
+	ret = mmu_hw_flush_caches(ptdev, as_nr, 0, ~0ULL, true);
 	if (ret)
 		return ret;
 
@@ -706,7 +680,7 @@ static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr)
 {
 	int ret;
 
-	ret = mmu_hw_flush_caches(ptdev, as_nr, 0, ~0ULL, AS_COMMAND_FLUSH_MEM);
+	ret = mmu_hw_flush_caches(ptdev, as_nr, 0, ~0ULL, true);
 	if (ret)
 		return ret;
 
@@ -962,7 +936,9 @@ static int panthor_vm_flush_range(struct panthor_vm *vm, u64 iova, u64 size)
 	if (!drm_dev_enter(&ptdev->base, &cookie))
 		return 0;
 
-	ret = mmu_hw_do_operation(vm, iova, size, AS_COMMAND_FLUSH_PT);
+	mutex_lock(&ptdev->mmu->as.slots_lock);
+	ret = mmu_hw_flush_caches(ptdev, vm->as.id, iova, size, false);
+	mutex_unlock(&ptdev->mmu->as.slots_lock);
 
 	drm_dev_exit(cookie);
 	return ret;
-- 
2.51.0.384.g4c02a37b29-goog