Re: [PATCH 04/14] platform/x86/intel/ifs: Remove image loading during init

Sohil Mehta
2022-10-25T00:59:42Z

On 10/21/2022 1:34 PM, Jithu Joseph wrote:
> Existing implementation loads IFS test image during the driver
> init flow.
>
> Dropping test image loading from the init path improves
> module load time.
>
> Prior to starting IFS tests, the user has to load one of
> the IFS test images by writing to the current_batch sysfs file.
>

The kernel is still unaware of the 'current_batch' sysfs file. It will
be introduced in patch 12. You can avoid the reference here.

> Removing IFS test image loading during init also allows us to
> make ifs_sem static as it is used only within sysfs.c.
>

Does something like this sound better?

IFS test image is unnecessarily loaded during driver initialization. The
user has to load one when starting the tests.

Drop image loading during ifs_init() and improve module load time. As a
consequence, make ifs_sem static as it is only used within sysfs.c

> diff --git a/drivers/platform/x86/intel/ifs/core.c b/drivers/platform/x86/intel/ifs/core.c
> index 27204e3d674d..5fb7f655c291 100644
> --- a/drivers/platform/x86/intel/ifs/core.c
> +++ b/drivers/platform/x86/intel/ifs/core.c
> @@ -51,12 +51,8 @@ static int __init ifs_init(void)
> ifs_device.misc.groups = ifs_get_groups();
>
> if ((msrval & BIT(ifs_device.data.integrity_cap_bit)) &&

Is there a reason to store the integrity cap constant in the device.data
global structure?

.data = {
.integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
},

IIUC, you are basically reading an MSR and testing a bit within? You
already have an BIT macro (unused) for that.

#define MSR_INTEGRITY_CAPS_PERIODIC_BIST
BIT(MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT)

> - !misc_register(&ifs_device.misc)) {
> - down(&ifs_sem);
> - ifs_load_firmware(ifs_device.misc.this_device);
> - up(&ifs_sem);
> + !misc_register(&ifs_device.misc))
> return 0;
> - }
>
> return -ENODEV;
> }

Sohil