Re: [PATCH 1/3] drm/msm: support firmware-name for zap fw

Bjorn Andersson
2020-01-08T05:01:01Z

On Tue 07 Jan 17:38 PST 2020, Rob Clark wrote:

> From: Rob Clark <robdclark@chromium.org>
>
> Since zap firmware can be device specific, allow for a firmware-name
> property in the zap node to specify which firmware to load, similarly to
> the scheme used for dsp/wifi/etc.
>
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
> drivers/gpu/drm/msm/adreno/adreno_gpu.c | 32 ++++++++++++++++++++++---
> 1 file changed, 29 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> index 112e8b8a261e..aa8737bd58db 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> @@ -26,6 +26,7 @@ static int zap_shader_load_mdt(struct msm_gpu *gpu, const char *fwname,
> {
> struct device *dev = &gpu->pdev->dev;
> const struct firmware *fw;
> + const char *signed_fwname = NULL;
> struct device_node *np, *mem_np;
> struct resource r;
> phys_addr_t mem_phys;
> @@ -58,8 +59,33 @@ static int zap_shader_load_mdt(struct msm_gpu *gpu, const char *fwname,
>
> mem_phys = r.start;
>
> - /* Request the MDT file for the firmware */
> - fw = adreno_request_fw(to_adreno_gpu(gpu), fwname);
> + /*
> + * Check for a firmware-name property. This is the new scheme
> + * to handle firmware that may be signed with device specific
> + * keys, allowing us to have a different zap fw path for different
> + * devices.
> + *
> + * If the firmware-name property is found, we bypass the
> + * adreno_request_fw() mechanism, because we don't need to handle
> + * the /lib/firmware/qcom/* vs /lib/firmware/* case.
> + *
> + * If the firmware-name property is not found, for backwards
> + * compatibility we fall back to the fwname from the gpulist
> + * table.
> + */
> + of_property_read_string_index(np, "firmware-name", 0, &signed_fwname);
> + if (signed_fwname) {
> + fwname = signed_fwname;
> + ret = request_firmware_direct(&fw, signed_fwname, gpu->dev->dev);
> + if (ret) {
> + DRM_DEV_ERROR(dev, "could not load signed zap firmware: %d\n", ret);
> + fw = ERR_PTR(ret);

Perhaps just return ret; here, or omit the error print here any rely
solely on the one below?

> + }
> + } else {
> + /* Request the MDT file for the firmware */

How about changing this to "Request the MDT file from the default
location" or something like that?

Rest looks good.

Regards,
Bjorn

> + fw = adreno_request_fw(to_adreno_gpu(gpu), fwname);
> + }
> +
> if (IS_ERR(fw)) {
> DRM_DEV_ERROR(dev, "Unable to load %s\n", fwname);
> return PTR_ERR(fw);
> @@ -95,7 +121,7 @@ static int zap_shader_load_mdt(struct msm_gpu *gpu, const char *fwname,
> * not. But since we've already gotten through adreno_request_fw()
> * we know which of the two cases it is:
> */
> - if (to_adreno_gpu(gpu)->fwloc == FW_LOCATION_LEGACY) {
> + if (signed_fwname || (to_adreno_gpu(gpu)->fwloc == FW_LOCATION_LEGACY)) {
> ret = qcom_mdt_load(dev, fw, fwname, pasid,
> mem_region, mem_phys, mem_size, NULL);
> } else {
> --
> 2.24.1
>