platform/x86/intel/ifs: Introduce Array Scan test to IFS

Array BIST is a new type of core test introduced under the Intel Infield
Scan (IFS) suite of tests.

Emerald Rapids (EMR) is the first CPU to support Array BIST.
Array BIST performs tests on some portions of the core logic such as
caches and register files. These are different portions of the silicon
compared to the parts tested by the first test type
i.e Scan at Field (SAF).

Make changes in the device driver init flow to register this new test
type with the device driver framework. Each test will have its own
sysfs directory (intel_ifs_0 , intel_ifs_1) under misc hierarchy to
accommodate for the differences in test type and how they are initiated.

Upcoming patches will add actual support.
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20230322003359.213046-6-jithu.joseph@intel.comReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

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

@@ -16,6 +16,7 @@
 
 static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
 	X86_MATCH(SAPPHIRERAPIDS_X),
+	X86_MATCH(EMERALDRAPIDS_X),
 	{}
 };
 MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
@@ -26,23 +27,50 @@ bool *ifs_pkg_auth;
 
 static const struct ifs_test_caps scan_test = {
 	.integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
-	.test_num = 0,
+	.test_num = IFS_TYPE_SAF,
 };
 
-static struct ifs_device ifs_device = {
-	.test_caps = &scan_test,
-	.misc = {
-		.name = "intel_ifs_0",
-		.minor = MISC_DYNAMIC_MINOR,
-		.groups = plat_ifs_groups,
+static const struct ifs_test_caps array_test = {
+	.integrity_cap_bit = MSR_INTEGRITY_CAPS_ARRAY_BIST_BIT,
+	.test_num = IFS_TYPE_ARRAY_BIST,
+};
+
+static struct ifs_device ifs_devices[] = {
+	[IFS_TYPE_SAF] = {
+		.test_caps = &scan_test,
+		.misc = {
+			.name = "intel_ifs_0",
+			.minor = MISC_DYNAMIC_MINOR,
+			.groups = plat_ifs_groups,
+		},
+	},
+	[IFS_TYPE_ARRAY_BIST] = {
+		.test_caps = &array_test,
+		.misc = {
+			.name = "intel_ifs_1",
+			.minor = MISC_DYNAMIC_MINOR,
+		},
 	},
 };
 
+#define IFS_NUMTESTS ARRAY_SIZE(ifs_devices)
+
+static void ifs_cleanup(void)
+{
+	int i;
+
+	for (i = 0; i < IFS_NUMTESTS; i++) {
+		if (ifs_devices[i].misc.this_device)
+			misc_deregister(&ifs_devices[i].misc);
+	}
+	kfree(ifs_pkg_auth);
+}
+
 static int __init ifs_init(void)
 {
 	const struct x86_cpu_id *m;
 	u64 msrval;
-	int ret;
+	int i, ret;
 
 	m = x86_match_cpu(ifs_cpu_ids);
 	if (!m)
@@ -57,26 +85,27 @@ static int __init ifs_init(void)
 	if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))
 		return -ENODEV;
 
-	if (!(msrval & BIT(ifs_device.test_caps->integrity_cap_bit)))
-		return -ENODEV;
-
 	ifs_pkg_auth = kmalloc_array(topology_max_packages(), sizeof(bool), GFP_KERNEL);
 	if (!ifs_pkg_auth)
 		return -ENOMEM;
 
-	ret = misc_register(&ifs_device.misc);
-	if (ret) {
-		kfree(ifs_pkg_auth);
-		return ret;
+	for (i = 0; i < IFS_NUMTESTS; i++) {
+		if (!(msrval & BIT(ifs_devices[i].test_caps->integrity_cap_bit)))
+			continue;
+		ret = misc_register(&ifs_devices[i].misc);
+		if (ret)
+			goto err_exit;
 	}
-
 	return 0;
+
+err_exit:
+	ifs_cleanup();
+	return ret;
 }
 
 static void __exit ifs_exit(void)
 {
-	misc_deregister(&ifs_device.misc);
-	kfree(ifs_pkg_auth);
+	ifs_cleanup();
 }
 
 module_init(ifs_init);

drivers/platform/x86/intel/ifs/ifs.h

@@ -137,6 +137,9 @@
 #define SCAN_TEST_PASS				1
 #define SCAN_TEST_FAIL				2
 
+#define IFS_TYPE_SAF			0
+#define IFS_TYPE_ARRAY_BIST		1
+
 /* MSR_SCAN_HASHES_STATUS bit fields */
 union ifs_scan_hashes_status {
 	u64	data;