linux-kernel - Re: [PATCH v5 05/45] drm/amd: Add a new helper for loading/validating microcode

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Message-ID: <CADnq5_M-JFEYtEOJyBAP1Z9zBkA-=ck8ZZMUC5eJ42zp-_9KjQ@mail.gmail.com>
Date:   Wed, 4 Jan 2023 12:09:32 -0500
From:   Alex Deucher <alexdeucher@...il.com>
To:     Mario Limonciello <mario.limonciello@....com>
Cc:     Alex Deucher <alexander.deucher@....com>,
        linux-kernel@...r.kernel.org, "Pan, Xinhui" <Xinhui.Pan@....com>,
        Lazar Lijo <Lijo.Lazar@....com>,
        Javier Martinez Canillas <javierm@...hat.com>,
        dri-devel@...ts.freedesktop.org, amd-gfx@...ts.freedesktop.org,
        Daniel Vetter <daniel@...ll.ch>,
        Carlos Soriano Sanchez <csoriano@...hat.com>,
        David Airlie <airlied@...il.com>, christian.koenig@....com
Subject: Re: [PATCH v5 05/45] drm/amd: Add a new helper for loading/validating microcode

On Wed, Jan 4, 2023 at 11:42 AM Mario Limonciello
<mario.limonciello@....com> 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>
> ---
> v4->v5:
>  * Rename symbols for amdgpu_ucode_request/amdgpu_ucode_release
>  * Make argument const
> ---
>  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..dc6af1fffdd9 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);
> +
> +       return err;
> +}
> +
> +/*
> + * amdgpu_ucode_release - Release firmware microcode
> + *
> + * @fw: pointer to firmware to release
> + */
> +void amdgpu_ucode_release(const struct firmware *fw)

This should be **fw if we want to set it to NULL.

Alex

> +{
> +       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..7fd2f04f7f98 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);
>
> --
> 2.34.1
>