linux-kernel - Re: [PATCH v6 05/45] drm/amd: Add a new helper for loading/validating microcode

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Message-ID: <804491f0-6e83-dae5-f108-f80950838a52@amd.com>
Date:   Thu, 5 Jan 2023 10:37:39 +0530
From:   "Lazar, Lijo" <lijo.lazar@....com>
To:     Mario Limonciello <mario.limonciello@....com>,
        Alex Deucher <alexander.deucher@....com>,
        linux-kernel@...r.kernel.org
Cc:     Javier Martinez Canillas <javierm@...hat.com>,
        Carlos Soriano Sanchez <csoriano@...hat.com>,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>, christian.koenig@....com,
        "Pan, Xinhui" <Xinhui.Pan@....com>
Subject: Re: [PATCH v6 05/45] drm/amd: Add a new helper for loading/validating
 microcode



On 1/5/2023 9:12 AM, Mario Limonciello wrote:
> All microcode runs a basic validation after it's been loaded. Each
> IP block as part of init will run both.
> 
> Introduce a wrapper for request_firmware and amdgpu_ucode_validate.
> This wrapper will also remap any error codes from request_firmware
> to -ENODEV.  This is so that early_init will fail if firmware couldn't
> be loaded instead of the IP block being disabled.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@....com>
> ---
> v5->v6:
>   * Fix argument to be ** not *
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c | 36 +++++++++++++++++++++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.h |  3 ++
>   2 files changed, 39 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c
> index eafcddce58d3..8ebfec12da87 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.c
> @@ -1312,3 +1312,39 @@ void amdgpu_ucode_ip_version_decode(struct amdgpu_device *adev, int block_type,
>   
>   	snprintf(ucode_prefix, len, "%s_%d_%d_%d", ip_name, maj, min, rev);
>   }
> +
> +/*
> + * amdgpu_ucode_request - Fetch and validate amdgpu microcode
> + *
> + * @adev: amdgpu device
> + * @fw: pointer to load firmware to
> + * @fw_name: firmware to load
> + *
> + * This is a helper that will use request_firmware and amdgpu_ucode_validate
> + * to load and run basic validation on firmware. If the load fails, remap
> + * the error code to -ENODEV, so that early_init functions will fail to load.
> + */
> +int amdgpu_ucode_request(struct amdgpu_device *adev, const struct firmware **fw,
> +			 const char *fw_name)
> +{
> +	int err = request_firmware(fw, fw_name, adev->dev);
> +
> +	if (err)
> +		return -ENODEV;
> +	err = amdgpu_ucode_validate(*fw);
> +	if (err)
> +		dev_dbg(adev->dev, "\"%s\" failed to validate\n", fw_name);
> +

Missed this earlier. If validate fails, shouldn't this undo the request 
operation by calling release?

Thanks,
Lijo

> +	return err;
> +}
> +
> +/*
> + * amdgpu_ucode_release - Release firmware microcode
> + *
> + * @fw: pointer to firmware to release
> + */
> +void amdgpu_ucode_release(const struct firmware **fw)
> +{
> +	release_firmware(*fw);
> +	*fw = NULL;
> +}
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.h
> index 552e06929229..848579d4988b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.h
> @@ -544,6 +544,9 @@ void amdgpu_ucode_print_sdma_hdr(const struct common_firmware_header *hdr);
>   void amdgpu_ucode_print_psp_hdr(const struct common_firmware_header *hdr);
>   void amdgpu_ucode_print_gpu_info_hdr(const struct common_firmware_header *hdr);
>   int amdgpu_ucode_validate(const struct firmware *fw);
> +int amdgpu_ucode_request(struct amdgpu_device *adev, const struct firmware **fw,
> +			 const char *fw_name);
> +void amdgpu_ucode_release(const struct firmware **fw);
>   bool amdgpu_ucode_hdr_version(union amdgpu_firmware_header *hdr,
>   				uint16_t hdr_major, uint16_t hdr_minor);
>