Re: [PATCH v5 2/4] drivers/acpi: Introduce Platform Firmware Runtime Update device driver

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Sat, Oct 23, 2021 at 01:09:51AM +0800, Chen Yu wrote:
> Introduce the pfru_update driver which can be used for Platform Firmware
> Runtime code injection and driver update[1]. The user is expected to
> provide the update firmware in the form of capsule file, and pass it to
> the driver via ioctl. Then the driver would hand this capsule file to the
> Platform Firmware Runtime Update via the ACPI device _DSM method. At last
> the low level Management Mode would do the firmware update.
> 
> The corresponding userspace tool and man page will be introduced at
> tools/power/acpi/pfru.
> 
> [1] https://uefi.org/sites/default/files/resources/Intel_MM_OS_Interface_Spec_Rev100.pdf

Instead use Link: tag ?

...

> +enum cap_index {
> +	CAP_STATUS_IDX,
> +	CAP_UPDATE_IDX,
> +	CAP_CODE_TYPE_IDX,
> +	CAP_FW_VER_IDX,
> +	CAP_CODE_RT_VER_IDX,
> +	CAP_DRV_TYPE_IDX,
> +	CAP_DRV_RT_VER_IDX,
> +	CAP_DRV_SVN_IDX,
> +	CAP_PLAT_ID_IDX,
> +	CAP_OEM_ID_IDX,
> +	CAP_OEM_INFO_IDX,

> +	CAP_NR_IDX,

Is it terminator entry? Drop comma then. Same for all other similar cases.

> +};

...

> +static int get_image_type(efi_manage_capsule_image_header_t *img_hdr,
> +			  struct pfru_device *pfru_dev)
> +{
> +	guid_t *image_type_id = &img_hdr->image_type_id;
> +
> +	/* check whether this is a code injection or driver update */
> +	if (guid_equal(image_type_id, &pfru_dev->code_uuid))
> +		return CODE_INJECT_TYPE;

> +	else if (guid_equal(image_type_id, &pfru_dev->drv_uuid))
> +		return DRIVER_UPDATE_TYPE;
> +	else
> +		return -EINVAL;

In both cases redundant 'else'.

> +}

...

> +static int adjust_efi_size(efi_manage_capsule_image_header_t *img_hdr,
> +			   int size)
> +{
> +	/*
> +	 * The (u64 hw_ins) was introduced in UEFI spec version 2,
> +	 * and (u64 capsule_support) was introduced in version 3.
> +	 * The size needs to be adjusted accordingly. That is to
> +	 * say, version 1 should subtract the size of hw_ins+capsule_support,
> +	 * and version 2 should sbstract the size of capsule_support.
> +	 */
> +	size += sizeof(efi_manage_capsule_image_header_t);
> +	switch (img_hdr->ver) {
> +	case 1:
> +		size -= 2 * sizeof(u64);
> +		break;
> +	case 2:
> +		size -= sizeof(u64);
> +		break;
> +	default:
> +		/* only support version 1 and 2 */
> +		return -EINVAL;
> +	}

> +	return size;

Perhaps directly return this from the cases?

> +}

...

> +static long pfru_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +{
> +	struct pfru_update_cap_info cap;
> +	struct pfru_device *pfru_dev;
> +	void __user *p;

> +	int ret = 0, rev;

return 0;  (see below)?

> +	pfru_dev = to_pfru_dev(file);
> +	p = (void __user *)arg;
> +
> +	switch (cmd) {
> +	case PFRU_IOC_QUERY_CAP:
> +		ret = query_capability(&cap, pfru_dev);
> +		if (ret)
> +			return ret;
> +
> +		if (copy_to_user(p, &cap, sizeof(cap)))
> +			return -EFAULT;
> +
> +		break;
> +	case PFRU_IOC_SET_REV:
> +		if (copy_from_user(&rev, p, sizeof(unsigned int)))
> +			return -EFAULT;
> +
> +		if (!pfru_valid_revid(rev))
> +			return -EINVAL;
> +
> +		pfru_dev->rev_id = rev;
> +		break;
> +	case PFRU_IOC_STAGE:
> +		ret = start_acpi_update(START_STAGE, pfru_dev);
> +		break;
> +	case PFRU_IOC_ACTIVATE:
> +		ret = start_acpi_update(START_ACTIVATE, pfru_dev);
> +		break;
> +	case PFRU_IOC_STAGE_ACTIVATE:
> +		ret = start_acpi_update(START_STAGE_ACTIVATE, pfru_dev);
> +		break;
> +	default:
> +		ret = -ENOTTY;
> +		break;
> +	}

> +	return ret;

You may return 0 here and directly return from the cases above.

> +}

...

> +	/* map the communication buffer */

Comment style inconsistency. Compare to...

> +	/* Check if the capsule header has a valid version number. */

...this one. However, here, since it's one line, no period is needed.


...

> +out:
> +	devm_kfree(&pdev->dev, pfru_dev);

What is this? WHy?!

> +}

...


> +static int __init pfru_init(void)
> +{
> +	return platform_driver_register(&acpi_pfru_driver);
> +}
> +
> +static void __exit pfru_exit(void)
> +{
> +	platform_driver_unregister(&acpi_pfru_driver);
> +}
> +
> +module_init(pfru_init);
> +module_exit(pfru_exit);

NIH module_platform_driver().

...

> +#include <linux/uuid.h>

This is wrong. Please, use raw buffers.

...

Missed types.h.

...

> +struct pfru_payload_hdr {
> +	__u32	sig;
> +	__u32	hdr_version;
> +	__u32	hdr_size;
> +	__u32	hw_ver;
> +	__u32	rt_ver;

> +	uuid_t	platform_id;

No way. Use __u8[16].
uuid_t is internal type for kernel.

> +};

...

> +struct pfru_update_cap_info {
> +	enum pfru_dsm_status status;
> +	__u32 update_cap;
> +
> +	uuid_t code_type;

Ditto.

> +	__u32 fw_version;
> +	__u32 code_rt_version;

> +	uuid_t drv_type;

Ditto.

> +	__u32 drv_rt_version;
> +	__u32 drv_svn;

> +	uuid_t platform_id;
> +	uuid_t oem_id;

Ditto.

> +	char oem_info[];
> +};

...

> +struct pfru_updated_result {

> +	enum pfru_dsm_status status;
> +	enum pfru_dsm_status ext_status;

What?! Are you sure enum is the same size on all possible architectures?

> +	__u64 low_auth_time;
> +	__u64 high_auth_time;
> +	__u64 low_exec_time;
> +	__u64 high_exec_time;
> +};

-- 
With Best Regards,
Andy Shevchenko