On Mon, 29 Sep 2025 22:03:15 +0200
Loïc Molinari <loic.molinari@collabora.com> wrote:
> Log the number of pages and their sizes actually mapped/unmapped by
> the IOMMU page table driver. Since a map/unmap op is often split in
> several ops depending on the underlying scatter/gather table, add the
> start address and the total size to the debugging logs in order to
> help understand which batch an op is part of.
>
> Signed-off-by: Loïc Molinari <loic.molinari@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
> ---
> drivers/gpu/drm/panthor/panthor_mmu.c | 19 ++++++++++++++-----
> 1 file changed, 14 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> index 6dec4354e378..aefbd83d1a75 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -917,10 +917,9 @@ static int panthor_vm_unmap_pages(struct panthor_vm *vm, u64 iova, u64 size)
> {
> struct panthor_device *ptdev = vm->ptdev;
> struct io_pgtable_ops *ops = vm->pgtbl_ops;
> + u64 start_iova = iova;
> u64 offset = 0;
>
> - drm_dbg(&ptdev->base, "unmap: as=%d, iova=%llx, len=%llx", vm->as.id, iova, size);
> -
> while (offset < size) {
> size_t unmapped_sz = 0, pgcount;
> size_t pgsize = get_pgsize(iova + offset, size - offset, &pgcount);
> @@ -935,6 +934,12 @@ static int panthor_vm_unmap_pages(struct panthor_vm *vm, u64 iova, u64 size)
> panthor_vm_flush_range(vm, iova, offset + unmapped_sz);
> return -EINVAL;
> }
> +
> + drm_dbg(&ptdev->base,
> + "unmap: as=%d, iova=0x%llx, sz=%llu, va=0x%llx, pgcnt=%zu, pgsz=%zu",
> + vm->as.id, start_iova, size, iova + offset,
> + unmapped_sz / pgsize, pgsize);
> +
> offset += unmapped_sz;
> }
>
> @@ -950,6 +955,7 @@ panthor_vm_map_pages(struct panthor_vm *vm, u64 iova, int prot,
> struct scatterlist *sgl;
> struct io_pgtable_ops *ops = vm->pgtbl_ops;
> u64 start_iova = iova;
> + u64 start_size = size;
> int ret;
>
> if (!size)
> @@ -969,15 +975,18 @@ panthor_vm_map_pages(struct panthor_vm *vm, u64 iova, int prot,
> len = min_t(size_t, len, size);
> size -= len;
>
> - drm_dbg(&ptdev->base, "map: as=%d, iova=%llx, paddr=%pad, len=%zx",
> - vm->as.id, iova, &paddr, len);
> -
> while (len) {
> size_t pgcount, mapped = 0;
> size_t pgsize = get_pgsize(iova | paddr, len, &pgcount);
>
> ret = ops->map_pages(ops, iova, paddr, pgsize, pgcount, prot,
> GFP_KERNEL, &mapped);
> +
> + drm_dbg(&ptdev->base,
> + "map: as=%d, iova=0x%llx, sz=%llu, va=0x%llx, pa=%pad, pgcnt=%zu, pgsz=%zu",
> + vm->as.id, start_iova, start_size, iova, &paddr,
> + mapped / pgsize, pgsize);
> +
> iova += mapped;
> paddr += mapped;
> len -= mapped;