platform/x86/intel/ifs: Store IFS generation number

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@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Link: https://lore.kernel.org/r/20231005195137.3117166-2-jithu.joseph@intel.comSigned-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

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

drivers/platform/x86/intel/ifs/core.c

 // 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;

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 {