Hi Boris,
I'm a bit confused, I thought the plan was to separate the FW_PAGE_SIZE
from the rest of Panthor's PAGE_SIZE.
On Mon, Oct 14, 2024 at 11:31:34AM +0200, 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.
This ^
>
> 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.
> ---
> 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)) {
is falsified by this.
I think panthor_vm_page_size() is an useful helper to have, but in panthor_fw.c we should use
the 4K page mask for allocating firmware sections.
I've asked for confirmation from the firmware team regarding plans for the future wrt section's page size
and will get back to you if my assumption that is going to stay at 4K is wrong.
Best regards,
Liviu
> 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);
> + 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);
>
> --
> 2.46.2
>
--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯
