Re: [PATCH v2 1/9] platform/x86/intel/ifs: Store IFS generation number

[Ilpo Järvinen]

On Fri, 22 Sep 2023, Jithu Joseph wrote:

> IFS generation number is reported via MSR_INTEGRITY_CAPS.  As IFS
> support gets added to newer CPUs, some differences are expected during
> IFS image loading and test flows.
> 
> Define MSR bitmasks to extract and store the generation in driver data,
> so that driver can modify its MSR interaction appropriately.
> 
> Signed-off-by: Jithu Joseph <jithu.joseph@xxxxxxxxx>
> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
> Tested-by: Pengfei Xu <pengfei.xu@xxxxxxxxx>
> ---
>  arch/x86/include/asm/msr-index.h      | 1 +
>  drivers/platform/x86/intel/ifs/ifs.h  | 2 ++
>  drivers/platform/x86/intel/ifs/core.c | 3 +++
>  3 files changed, 6 insertions(+)
> 
> diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
> index 1d111350197f..838e5a013a07 100644
> --- a/arch/x86/include/asm/msr-index.h
> +++ b/arch/x86/include/asm/msr-index.h
> @@ -222,6 +222,7 @@
>  #define MSR_INTEGRITY_CAPS_ARRAY_BIST          BIT(MSR_INTEGRITY_CAPS_ARRAY_BIST_BIT)
>  #define MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT	4
>  #define MSR_INTEGRITY_CAPS_PERIODIC_BIST	BIT(MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT)
> +#define MSR_INTEGRITY_CAPS_SAF_GEN_MASK	GENMASK_ULL(10, 9)
>  
>  #define MSR_LBR_NHM_FROM		0x00000680
>  #define MSR_LBR_NHM_TO			0x000006c0
> diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
> index 93191855890f..d666aeed20fc 100644
> --- a/drivers/platform/x86/intel/ifs/ifs.h
> +++ b/drivers/platform/x86/intel/ifs/ifs.h
> @@ -229,6 +229,7 @@ struct ifs_test_caps {
>   * @status: it holds simple status pass/fail/untested
>   * @scan_details: opaque scan status code from h/w
>   * @cur_batch: number indicating the currently loaded test file
> + * @generation: IFS test generation enumerated by hardware
>   */
>  struct ifs_data {
>  	int	loaded_version;
> @@ -238,6 +239,7 @@ struct ifs_data {
>  	int	status;
>  	u64	scan_details;
>  	u32	cur_batch;
> +	u32	generation;
>  };
>  
>  struct ifs_work {
> diff --git a/drivers/platform/x86/intel/ifs/core.c b/drivers/platform/x86/intel/ifs/core.c
> index 306f886b52d2..4ff2aa4b484b 100644
> --- a/drivers/platform/x86/intel/ifs/core.c
> +++ b/drivers/platform/x86/intel/ifs/core.c
> @@ -1,6 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0-only
>  /* Copyright(c) 2022 Intel Corporation. */
>  
> +#include <linux/bitfield.h>
>  #include <linux/module.h>
>  #include <linux/kdev_t.h>
>  #include <linux/semaphore.h>
> @@ -94,6 +95,8 @@ static int __init ifs_init(void)
>  	for (i = 0; i < IFS_NUMTESTS; i++) {
>  		if (!(msrval & BIT(ifs_devices[i].test_caps->integrity_cap_bit)))
>  			continue;
> +		ifs_devices[i].rw_data.generation = FIELD_GET(MSR_INTEGRITY_CAPS_SAF_GEN_MASK,
> +							      msrval);
>  		ret = misc_register(&ifs_devices[i].misc);
>  		if (ret)
>  			goto err_exit;
> 

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>

-- 
 i.