LGTM
Acked-by: Siva Mullati <siva.mullati@xxxxxxxxx>
On 06/04/22 14:48, Vivekanandan, Balasubramani wrote:
> When copying RSA use io memcpy functions if the destination address
> contains a GPU local memory address. Considering even the source
> address can be on local memory, a bounce buffer is used to copy from io
> to io.
> The intention of this patch is to make i915 portable outside x86 mainly
> on ARM64.
>
> Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 23 +++++++++++++++++++++--
> 1 file changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> index bb864655c495..06d30670e15c 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> @@ -589,7 +589,7 @@ static int uc_fw_rsa_data_create(struct intel_uc_fw *uc_fw)
> struct intel_gt *gt = __uc_fw_to_gt(uc_fw);
> struct i915_vma *vma;
> size_t copied;
> - void *vaddr;
> + void *vaddr, *bounce;
> int err;
>
> err = i915_inject_probe_error(gt->i915, -ENXIO);
> @@ -621,7 +621,26 @@ static int uc_fw_rsa_data_create(struct intel_uc_fw *uc_fw)
> goto unpin_out;
> }
>
> - copied = intel_uc_fw_copy_rsa(uc_fw, vaddr, vma->size);
> + if (i915_gem_object_is_lmem(vma->obj)) {
> + /* When vma is allocated from the GPU local memmory, it means
> + * the destination address contains an io memory and we need to
> + * use memcpy function for io memory for copying, to ensure
> + * i915 portability outside x86. It is most likely the RSA will
> + * also be on local memory and so the source of copy will also
> + * be an io address. Since we cannot directly copy from io to
> + * io, we use a bounce buffer to copy.
> + */
> + copied = 0;
> + bounce = kmalloc(vma->size, GFP_KERNEL);
> + if (likely(bounce)) {
> + copied = intel_uc_fw_copy_rsa(uc_fw, bounce, vma->size);
> + memcpy_toio((void __iomem *)vaddr, bounce, copied);
> + kfree(bounce);
> + }
> + } else {
> + copied = intel_uc_fw_copy_rsa(uc_fw, vaddr, vma->size);
> + }
> +
> i915_gem_object_unpin_map(vma->obj);
>
> if (copied < uc_fw->rsa_size) {
