Re: [PATCH v8 01/10] drm/xe/uc_fw: Allow re-initializing firmware

[Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>]

On 6/3/2026 3:17 AM, Raag Jadav wrote:
> In preparation of usecases which require re-initializing firmware without
> reloading the driver, introduce xe_uc_fw_reinit(). The uC firmware bo
> already exists but since it's contents are on VRAM, they are lost on PCIe
> FLR. Copy the firmware back to it's bo and mark it as loadable as part of
> re-initialization.
>
> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> Tested-by: Lukasz Laguna <lukasz.laguna@intel.com>

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>

> ---
> v2: Add kernel doc (Matthew Brost)
> v6: Skip uC firmware selection during re-initialization (Daniele)
> v8: Set fw state to XE_UC_FIRMWARE_INIT_FAIL on failure (Daniele)
> ---
>   drivers/gpu/drm/xe/xe_uc_fw.c | 67 +++++++++++++++++++++++++++++++++++
>   drivers/gpu/drm/xe/xe_uc_fw.h |  1 +
>   2 files changed, 68 insertions(+)
>
> diff --git a/drivers/gpu/drm/xe/xe_uc_fw.c b/drivers/gpu/drm/xe/xe_uc_fw.c
> index 3f08a3b54062..158ac15dde55 100644
> --- a/drivers/gpu/drm/xe/xe_uc_fw.c
> +++ b/drivers/gpu/drm/xe/xe_uc_fw.c
> @@ -833,6 +833,14 @@ static int uc_fw_copy(struct xe_uc_fw *uc_fw, const void *data, size_t size, u32
>   	return err;
>   }
>   
> +static void uc_fw_reinit(struct xe_uc_fw *uc_fw, const void *data)
> +{
> +	struct xe_device *xe = uc_fw_to_xe(uc_fw);
> +
> +	xe_map_memcpy_to(xe, &uc_fw->bo->vmap, 0, data, uc_fw->size);
> +	xe_uc_fw_change_status(uc_fw, XE_UC_FIRMWARE_LOADABLE);
> +}
> +
>   int xe_uc_fw_init(struct xe_uc_fw *uc_fw)
>   {
>   	const struct firmware *fw = NULL;
> @@ -856,6 +864,65 @@ int xe_uc_fw_init(struct xe_uc_fw *uc_fw)
>   }
>   ALLOW_ERROR_INJECTION(xe_uc_fw_init, ERRNO); /* See xe_pci_probe() */
>   
> +/**
> + * xe_uc_fw_reinit() - Re-initialize uC firmware into its bo
> + * @uc_fw: uC firmware
> + *
> + * Returns: 0 on success, negative error code otherwise.
> + */
> +int xe_uc_fw_reinit(struct xe_uc_fw *uc_fw)
> +{
> +	struct xe_device *xe = uc_fw_to_xe(uc_fw);
> +	struct xe_uc_fw_version old_fw, new_fw;
> +	const struct firmware *fw = NULL;
> +	int err;
> +
> +	/* Make sure the status was cleared the last time we reset the uc */
> +	xe_assert(xe, !xe_uc_fw_is_loaded(uc_fw));
> +
> +	/* We shouldn't be here for the firmware which wasn't available */
> +	if (!xe_uc_fw_is_available(uc_fw))
> +		return -ENOEXEC;
> +
> +	old_fw = uc_fw->versions.found[XE_UC_FW_VER_RELEASE];
> +
> +	err = firmware_request_nowarn(&fw, uc_fw->path, xe->drm.dev);
> +	if (err)
> +		goto init_fail;
> +
> +	err = parse_headers(uc_fw, fw);
> +	if (err)
> +		goto restore_old;
> +
> +	new_fw = uc_fw->versions.found[XE_UC_FW_VER_RELEASE];
> +	if (memcmp(&old_fw, &new_fw, sizeof(old_fw)) || uc_fw->size != fw->size) {
> +		drm_err(&xe->drm, "%s firmware mismatch on %s",
> +			xe_uc_fw_type_repr(uc_fw->type), uc_fw->path);
> +
> +		err = -ENOEXEC;
> +		goto restore_old;
> +	}
> +
> +	uc_fw_reinit(uc_fw, fw->data);
> +	uc_fw_release(fw);
> +	return 0;
> +
> +restore_old:
> +	/*
> +	 * parse_headers() updates version details, so restore original version
> +	 * before bailing.
> +	 *
> +	 * TODO: Create a struct of all the fields touched by parse_headers()
> +	 * and restore them all.
> +	 */
> +	uc_fw->versions.found[XE_UC_FW_VER_RELEASE] = old_fw;
> +init_fail:
> +	xe_uc_fw_change_status(uc_fw, XE_UC_FIRMWARE_INIT_FAIL);
> +	/* OK even if fw is NULL */
> +	uc_fw_release(fw);
> +	return err;
> +}
> +
>   static u32 uc_fw_ggtt_offset(struct xe_uc_fw *uc_fw)
>   {
>   	return xe_bo_ggtt_addr(uc_fw->bo);
> diff --git a/drivers/gpu/drm/xe/xe_uc_fw.h b/drivers/gpu/drm/xe/xe_uc_fw.h
> index f2d3a3e7208b..6debdb924310 100644
> --- a/drivers/gpu/drm/xe/xe_uc_fw.h
> +++ b/drivers/gpu/drm/xe/xe_uc_fw.h
> @@ -15,6 +15,7 @@
>   struct drm_printer;
>   
>   int xe_uc_fw_init(struct xe_uc_fw *uc_fw);
> +int xe_uc_fw_reinit(struct xe_uc_fw *uc_fw);
>   size_t xe_uc_fw_copy_rsa(struct xe_uc_fw *uc_fw, void *dst, u32 max_len);
>   int xe_uc_fw_upload(struct xe_uc_fw *uc_fw, u32 offset, u32 dma_flags);
>   int xe_uc_fw_check_version_requirements(struct xe_uc_fw *uc_fw);