[PATCH] drm/panthor: Fix firmware initialization on systems with a page size > 4k

[Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>]

The system and GPU MMU page size might differ, which becomes a
problem for FW sections that need to be mapped at explicit address
since our PAGE_SIZE alignment might cover a VA range that's
expected to be used for another section.

Make sure we never map more than we need.

Fixes: 2718d91816ee ("drm/panthor: Add the FW logical block")
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/panthor/panthor_fw.c  |  3 +--
 drivers/gpu/drm/panthor/panthor_gem.c | 11 ++++++++---
 drivers/gpu/drm/panthor/panthor_mmu.c |  6 +++---
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index ef232c0c2049..293846400296 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -515,8 +515,7 @@ static int panthor_fw_load_section_entry(struct panthor_device *ptdev,
 		return -EINVAL;
 	}
 
-	if ((hdr.va.start & ~PAGE_MASK) != 0 ||
-	    (hdr.va.end & ~PAGE_MASK) != 0) {
+	if (!IS_ALIGNED(hdr.va.start, SZ_4K) || !IS_ALIGNED(hdr.va.end, SZ_4K)) {
 		drm_err(&ptdev->base, "Firmware corrupted, virtual addresses not page aligned: 0x%x-0x%x\n",
 			hdr.va.start, hdr.va.end);
 		return -EINVAL;
diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/panthor/panthor_gem.c
index c60b599665d8..2c8d6e2c7232 100644
--- a/drivers/gpu/drm/panthor/panthor_gem.c
+++ b/drivers/gpu/drm/panthor/panthor_gem.c
@@ -44,8 +44,7 @@ void panthor_kernel_bo_destroy(struct panthor_kernel_bo *bo)
 			to_panthor_bo(bo->obj)->exclusive_vm_root_gem != panthor_vm_root_gem(vm)))
 		goto out_free_bo;
 
-	ret = panthor_vm_unmap_range(vm, bo->va_node.start,
-				     panthor_kernel_bo_size(bo));
+	ret = panthor_vm_unmap_range(vm, bo->va_node.start, bo->va_node.size);
 	if (ret)
 		goto out_free_bo;
 
@@ -95,10 +94,16 @@ panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm,
 	}
 
 	bo = to_panthor_bo(&obj->base);
-	size = obj->base.size;
 	kbo->obj = &obj->base;
 	bo->flags = bo_flags;
 
+	/* The system and GPU MMU page size might differ, which becomes a
+	 * problem for FW sections that need to be mapped at explicit address
+	 * since our PAGE_SIZE alignment might cover a VA range that's
+	 * expected to be used for another section.
+	 * Make sure we never map more than we need.
+	 */
+	size = ALIGN(size, SZ_4K);
 	ret = panthor_vm_alloc_va(vm, gpu_va, size, &kbo->va_node);
 	if (ret)
 		goto err_put_obj;
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index 3cd2bce59edc..e53d131c53cc 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -1027,10 +1027,10 @@ panthor_vm_alloc_va(struct panthor_vm *vm, u64 va, u64 size,
 {
 	int ret;
 
-	if (!size || (size & ~PAGE_MASK))
+	if (!size || !IS_ALIGNED(size, SZ_4K))
 		return -EINVAL;
 
-	if (va != PANTHOR_VM_KERNEL_AUTO_VA && (va & ~PAGE_MASK))
+	if (va != PANTHOR_VM_KERNEL_AUTO_VA && !IS_ALIGNED(va, SZ_4K))
 		return -EINVAL;
 
 	mutex_lock(&vm->mm_lock);
@@ -2370,7 +2370,7 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
 	int ret;
 
 	/* Aligned on page size. */
-	if ((op->va | op->size) & ~PAGE_MASK)
+	if (!IS_ALIGNED(op->va | op->size, SZ_4K))
 		return -EINVAL;
 
 	switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {
-- 
2.46.2