[PATCH v4 06/15] cxl: Setup exclusive CXL features that are reserved for the kernel

[Dave Jiang <dave.jiang@intel.com>]

Certain features will be exclusively used by components such as in
kernel RAS driver. Setup an exclusion list that can be later filtered
out before exposing to user space.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/core/features.c | 26 ++++++++++++++++++++++++++
 include/cxl/features.h      | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
index d337224158fa..82f21f64452a 100644
--- a/drivers/cxl/core/features.c
+++ b/drivers/cxl/core/features.c
@@ -6,6 +6,28 @@
 #include "cxl.h"
 #include "cxlmem.h"
 
+/* All the features below are exclusive to the kernel */
+static const uuid_t cxl_exclusive_feats[] = {
+	CXL_FEAT_PATROL_SCRUB_UUID,
+	CXL_FEAT_ECS_UUID,
+	CXL_FEAT_SPPR_UUID,
+	CXL_FEAT_HPPR_UUID,
+	CXL_FEAT_CACHELINE_SPARING_UUID,
+	CXL_FEAT_ROW_SPARING_UUID,
+	CXL_FEAT_BANK_SPARING_UUID,
+	CXL_FEAT_RANK_SPARING_UUID,
+};
+
+static bool is_cxl_feature_exclusive(struct cxl_feat_entry *entry)
+{
+	for (int i = 0; i < ARRAY_SIZE(cxl_exclusive_feats); i++) {
+		if (uuid_equal(&entry->uuid, &cxl_exclusive_feats[i]))
+			return true;
+	}
+
+	return false;
+}
+
 inline struct cxl_features_state *to_cxlfs(struct cxl_dev_state *cxlds)
 {
 	return cxlds->cxlfs;
@@ -46,6 +68,7 @@ get_supported_features(struct cxl_features_state *cxlfs)
 	struct cxl_mbox_get_sup_feats_in mbox_in;
 	struct cxl_feat_entry *entry;
 	struct cxl_mbox_cmd mbox_cmd;
+	int user_feats = 0;
 	int count;
 
 	count = cxl_get_supported_features_count(cxl_mbox);
@@ -120,6 +143,8 @@ get_supported_features(struct cxl_features_state *cxlfs)
 			return NULL;
 
 		memcpy(entry, mbox_out->ents, retrieved);
+		if (!is_cxl_feature_exclusive(entry))
+			user_feats++;
 		entry += num_entries;
 		/*
 		 * If the number of output entries is less than expected, add the
@@ -130,6 +155,7 @@ get_supported_features(struct cxl_features_state *cxlfs)
 	} while (remain_feats);
 
 	entries->num_features = count;
+	entries->num_user_features = user_feats;
 
 	return no_free_ptr(entries);
 }
diff --git a/include/cxl/features.h b/include/cxl/features.h
index 4e3527ba8a1d..1ab97e676c03 100644
--- a/include/cxl/features.h
+++ b/include/cxl/features.h
@@ -5,6 +5,39 @@
 
 #include <linux/uuid.h>
 
+/* Feature UUIDs used by the kernel */
+#define CXL_FEAT_PATROL_SCRUB_UUID						\
+	UUID_INIT(0x96dad7d6, 0xfde8, 0x482b, 0xa7, 0x33, 0x75, 0x77, 0x4e,	\
+		  0x06, 0xdb, 0x8a)
+
+#define CXL_FEAT_ECS_UUID							\
+	UUID_INIT(0xe5b13f22, 0x2328, 0x4a14, 0xb8, 0xba, 0xb9, 0x69, 0x1e,	\
+		  0x89, 0x33, 0x86)
+
+#define CXL_FEAT_SPPR_UUID							\
+	UUID_INIT(0x892ba475, 0xfad8, 0x474e, 0x9d, 0x3e, 0x69, 0x2c, 0x91,	\
+		  0x75, 0x68, 0xbb)
+
+#define CXL_FEAT_HPPR_UUID							\
+	UUID_INIT(0x80ea4521, 0x786f, 0x4127, 0xaf, 0xb1, 0xec, 0x74, 0x59,	\
+		  0xfb, 0x0e, 0x24)
+
+#define CXL_FEAT_CACHELINE_SPARING_UUID						\
+	UUID_INIT(0x96C33386, 0x91dd, 0x44c7, 0x9e, 0xcb, 0xfd, 0xaf, 0x65,	\
+		  0x03, 0xba, 0xc4)
+
+#define CXL_FEAT_ROW_SPARING_UUID						\
+	UUID_INIT(0x450ebf67, 0xb135, 0x4f97, 0xa4, 0x98, 0xc2, 0xd5, 0x7f,	\
+		  0x27, 0x9b, 0xed)
+
+#define CXL_FEAT_BANK_SPARING_UUID						\
+	UUID_INIT(0x78b79636, 0x90ac, 0x4b64, 0xa4, 0xef, 0xfa, 0xac, 0x5d,	\
+		  0x18, 0xa8, 0x63)
+
+#define CXL_FEAT_RANK_SPARING_UUID						\
+	UUID_INIT(0x34dbaff5, 0x0552, 0x4281, 0x8f, 0x76, 0xda, 0x0b, 0x5e,	\
+		  0x7a, 0x76, 0xa7)
+
 /* Feature commands capability supported by a device */
 enum cxl_features_capability {
 	CXL_FEATURES_NONE = 0,
@@ -130,6 +163,7 @@ struct cxl_features_state {
 	struct cxl_dev_state *cxlds;
 	struct cxl_feat_entries {
 		int num_features;
+		int num_user_features;
 		struct cxl_feat_entry ent[] __counted_by(num_features);
 	} *entries;
 };
-- 
2.48.1