On 14/10/2024 10:31, Boris Brezillon wrote:
> 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>
> ---
> Steve, Liviu, Adrian, I intentionally dropped the R-b because of
> the panthor_vm_page_size() change. Feel free to add it back if
> you're happy with the new version.
Personally I think the panthor_vm_page_size() function is overkill, a
#define would seem plenty to me.
One other minor nit (see below), but either way:
Reviewed-by: Steven Price <steven.price@xxxxxxx>
> ---
> drivers/gpu/drm/panthor/panthor_fw.c | 4 ++--
> drivers/gpu/drm/panthor/panthor_gem.c | 11 ++++++++---
> drivers/gpu/drm/panthor/panthor_mmu.c | 16 +++++++++++++---
> drivers/gpu/drm/panthor/panthor_mmu.h | 1 +
> 4 files changed, 24 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
> index ef232c0c2049..4e2d3a02ea06 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw.c
> +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> @@ -487,6 +487,7 @@ static int panthor_fw_load_section_entry(struct panthor_device *ptdev,
> struct panthor_fw_binary_iter *iter,
> u32 ehdr)
> {
> + ssize_t vm_pgsz = panthor_vm_page_size(ptdev->fw->vm);
> struct panthor_fw_binary_section_entry_hdr hdr;
> struct panthor_fw_section *section;
> u32 section_size;
> @@ -515,8 +516,7 @@ 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, vm_pgsz) || !IS_ALIGNED(hdr.va.end, vm_pgsz)) {
> 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..8244a4e6c2a2 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, panthor_vm_page_size(vm));
> 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..f009501e4c68 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -826,6 +826,14 @@ void panthor_vm_idle(struct panthor_vm *vm)
> mutex_unlock(&ptdev->mmu->as.slots_lock);
> }
>
> +u32 panthor_vm_page_size(struct panthor_vm *vm)
> +{
> + const struct io_pgtable *pgt = container_of(vm->pgtbl_ops, struct io_pgtable, ops);
NIT: io_pgtable_ops_to_pgtable() does this container_of() for you.
Steve
> + u32 pg_shift = ffs(pgt->cfg.pgsize_bitmap) - 1;
> +
> + return 1u << pg_shift;
> +}
> +
> static void panthor_vm_stop(struct panthor_vm *vm)
> {
> drm_sched_stop(&vm->sched, NULL);
> @@ -1025,12 +1033,13 @@ int
> panthor_vm_alloc_va(struct panthor_vm *vm, u64 va, u64 size,
> struct drm_mm_node *va_node)
> {
> + ssize_t vm_pgsz = panthor_vm_page_size(vm);
> int ret;
>
> - if (!size || (size & ~PAGE_MASK))
> + if (!size || !IS_ALIGNED(size, vm_pgsz))
> return -EINVAL;
>
> - if (va != PANTHOR_VM_KERNEL_AUTO_VA && (va & ~PAGE_MASK))
> + if (va != PANTHOR_VM_KERNEL_AUTO_VA && !IS_ALIGNED(va, vm_pgsz))
> return -EINVAL;
>
> mutex_lock(&vm->mm_lock);
> @@ -2366,11 +2375,12 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
> const struct drm_panthor_vm_bind_op *op,
> struct panthor_vm_op_ctx *op_ctx)
> {
> + ssize_t vm_pgsz = panthor_vm_page_size(vm);
> struct drm_gem_object *gem;
> int ret;
>
> /* Aligned on page size. */
> - if ((op->va | op->size) & ~PAGE_MASK)
> + if (!IS_ALIGNED(op->va | op->size, vm_pgsz))
> return -EINVAL;
>
> switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.h b/drivers/gpu/drm/panthor/panthor_mmu.h
> index 6788771071e3..8d21e83d8aba 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.h
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.h
> @@ -30,6 +30,7 @@ panthor_vm_get_bo_for_va(struct panthor_vm *vm, u64 va, u64 *bo_offset);
>
> int panthor_vm_active(struct panthor_vm *vm);
> void panthor_vm_idle(struct panthor_vm *vm);
> +u32 panthor_vm_page_size(struct panthor_vm *vm);
> int panthor_vm_as(struct panthor_vm *vm);
> int panthor_vm_flush_all(struct panthor_vm *vm);
>
