From 5666a7e7da2f003a8fc327d3c0cce0b506193d86 Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@intel.com>
Date: Tue, 4 Feb 2025 15:03:02 -0700
Subject: [PATCH 1/7] cxl: Refactor user ioctl command path from mds to mailbox

With 'struct cxl_mailbox' context introduced, the helper functions
cxl_query_cmd() and cxl_send_cmd() can take a cxl_mailbox directly
rather than a cxl_memdev parameter. Refactor to use cxl_mailbox
directly.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20250204220430.4146187-2-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/core/core.h   |  6 ++-
 drivers/cxl/core/mbox.c   | 88 +++++++++++++++++++--------------------
 drivers/cxl/core/memdev.c | 22 ++++++----
 drivers/cxl/cxlmem.h      | 40 ------------------
 include/cxl/mailbox.h     | 41 +++++++++++++++++-
 5 files changed, 101 insertions(+), 96 deletions(-)

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 800466f96a685..f77fcf71ade51 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -4,6 +4,8 @@
 #ifndef __CXL_CORE_H__
 #define __CXL_CORE_H__
 
+#include <cxl/mailbox.h>
+
 extern const struct device_type cxl_nvdimm_bridge_type;
 extern const struct device_type cxl_nvdimm_type;
 extern const struct device_type cxl_pmu_type;
@@ -65,9 +67,9 @@ static inline void cxl_region_exit(void)
 
 struct cxl_send_command;
 struct cxl_mem_query_commands;
-int cxl_query_cmd(struct cxl_memdev *cxlmd,
+int cxl_query_cmd(struct cxl_mailbox *cxl_mbox,
 		  struct cxl_mem_query_commands __user *q);
-int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s);
+int cxl_send_cmd(struct cxl_mailbox *cxl_mbox, struct cxl_send_command __user *s);
 void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
 				   resource_size_t length);
 
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 548564c770c02..9c1b9e353e3e3 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -349,40 +349,39 @@ static bool cxl_payload_from_user_allowed(u16 opcode, void *payload_in)
 	return true;
 }
 
-static int cxl_mbox_cmd_ctor(struct cxl_mbox_cmd *mbox,
-			     struct cxl_memdev_state *mds, u16 opcode,
+static int cxl_mbox_cmd_ctor(struct cxl_mbox_cmd *mbox_cmd,
+			     struct cxl_mailbox *cxl_mbox, u16 opcode,
 			     size_t in_size, size_t out_size, u64 in_payload)
 {
-	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
-	*mbox = (struct cxl_mbox_cmd) {
+	*mbox_cmd = (struct cxl_mbox_cmd) {
 		.opcode = opcode,
 		.size_in = in_size,
 	};
 
 	if (in_size) {
-		mbox->payload_in = vmemdup_user(u64_to_user_ptr(in_payload),
-						in_size);
-		if (IS_ERR(mbox->payload_in))
-			return PTR_ERR(mbox->payload_in);
+		mbox_cmd->payload_in = vmemdup_user(u64_to_user_ptr(in_payload),
+						    in_size);
+		if (IS_ERR(mbox_cmd->payload_in))
+			return PTR_ERR(mbox_cmd->payload_in);
 
-		if (!cxl_payload_from_user_allowed(opcode, mbox->payload_in)) {
-			dev_dbg(mds->cxlds.dev, "%s: input payload not allowed\n",
+		if (!cxl_payload_from_user_allowed(opcode, mbox_cmd->payload_in)) {
+			dev_dbg(cxl_mbox->host, "%s: input payload not allowed\n",
 				cxl_mem_opcode_to_name(opcode));
-			kvfree(mbox->payload_in);
+			kvfree(mbox_cmd->payload_in);
 			return -EBUSY;
 		}
 	}
 
 	/* Prepare to handle a full payload for variable sized output */
 	if (out_size == CXL_VARIABLE_PAYLOAD)
-		mbox->size_out = cxl_mbox->payload_size;
+		mbox_cmd->size_out = cxl_mbox->payload_size;
 	else
-		mbox->size_out = out_size;
+		mbox_cmd->size_out = out_size;
 
-	if (mbox->size_out) {
-		mbox->payload_out = kvzalloc(mbox->size_out, GFP_KERNEL);
-		if (!mbox->payload_out) {
-			kvfree(mbox->payload_in);
+	if (mbox_cmd->size_out) {
+		mbox_cmd->payload_out = kvzalloc(mbox_cmd->size_out, GFP_KERNEL);
+		if (!mbox_cmd->payload_out) {
+			kvfree(mbox_cmd->payload_in);
 			return -ENOMEM;
 		}
 	}
@@ -397,10 +396,8 @@ static void cxl_mbox_cmd_dtor(struct cxl_mbox_cmd *mbox)
 
 static int cxl_to_mem_cmd_raw(struct cxl_mem_command *mem_cmd,
 			      const struct cxl_send_command *send_cmd,
-			      struct cxl_memdev_state *mds)
+			      struct cxl_mailbox *cxl_mbox)
 {
-	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
-
 	if (send_cmd->raw.rsvd)
 		return -EINVAL;
 
@@ -415,7 +412,7 @@ static int cxl_to_mem_cmd_raw(struct cxl_mem_command *mem_cmd,
 	if (!cxl_mem_raw_command_allowed(send_cmd->raw.opcode))
 		return -EPERM;
 
-	dev_WARN_ONCE(mds->cxlds.dev, true, "raw command path used\n");
+	dev_WARN_ONCE(cxl_mbox->host, true, "raw command path used\n");
 
 	*mem_cmd = (struct cxl_mem_command) {
 		.info = {
@@ -431,7 +428,7 @@ static int cxl_to_mem_cmd_raw(struct cxl_mem_command *mem_cmd,
 
 static int cxl_to_mem_cmd(struct cxl_mem_command *mem_cmd,
 			  const struct cxl_send_command *send_cmd,
-			  struct cxl_memdev_state *mds)
+			  struct cxl_mailbox *cxl_mbox)
 {
 	struct cxl_mem_command *c = &cxl_mem_commands[send_cmd->id];
 	const struct cxl_command_info *info = &c->info;
@@ -446,11 +443,11 @@ static int cxl_to_mem_cmd(struct cxl_mem_command *mem_cmd,
 		return -EINVAL;
 
 	/* Check that the command is enabled for hardware */
-	if (!test_bit(info->id, mds->enabled_cmds))
+	if (!test_bit(info->id, cxl_mbox->enabled_cmds))
 		return -ENOTTY;
 
 	/* Check that the command is not claimed for exclusive kernel use */
-	if (test_bit(info->id, mds->exclusive_cmds))
+	if (test_bit(info->id, cxl_mbox->exclusive_cmds))
 		return -EBUSY;
 
 	/* Check the input buffer is the expected size */
@@ -479,7 +476,7 @@ static int cxl_to_mem_cmd(struct cxl_mem_command *mem_cmd,
 /**
  * cxl_validate_cmd_from_user() - Check fields for CXL_MEM_SEND_COMMAND.
  * @mbox_cmd: Sanitized and populated &struct cxl_mbox_cmd.
- * @mds: The driver data for the operation
+ * @cxl_mbox: CXL mailbox context
  * @send_cmd: &struct cxl_send_command copied in from userspace.
  *
  * Return:
@@ -494,10 +491,9 @@ static int cxl_to_mem_cmd(struct cxl_mem_command *mem_cmd,
  * safe to send to the hardware.
  */
 static int cxl_validate_cmd_from_user(struct cxl_mbox_cmd *mbox_cmd,
-				      struct cxl_memdev_state *mds,
+				      struct cxl_mailbox *cxl_mbox,
 				      const struct cxl_send_command *send_cmd)
 {
-	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
 	struct cxl_mem_command mem_cmd;
 	int rc;
 
@@ -514,24 +510,23 @@ static int cxl_validate_cmd_from_user(struct cxl_mbox_cmd *mbox_cmd,
 
 	/* Sanitize and construct a cxl_mem_command */
 	if (send_cmd->id == CXL_MEM_COMMAND_ID_RAW)
-		rc = cxl_to_mem_cmd_raw(&mem_cmd, send_cmd, mds);
+		rc = cxl_to_mem_cmd_raw(&mem_cmd, send_cmd, cxl_mbox);
 	else
-		rc = cxl_to_mem_cmd(&mem_cmd, send_cmd, mds);
+		rc = cxl_to_mem_cmd(&mem_cmd, send_cmd, cxl_mbox);
 
 	if (rc)
 		return rc;
 
 	/* Sanitize and construct a cxl_mbox_cmd */
-	return cxl_mbox_cmd_ctor(mbox_cmd, mds, mem_cmd.opcode,
+	return cxl_mbox_cmd_ctor(mbox_cmd, cxl_mbox, mem_cmd.opcode,
 				 mem_cmd.info.size_in, mem_cmd.info.size_out,
 				 send_cmd->in.payload);
 }
 
-int cxl_query_cmd(struct cxl_memdev *cxlmd,
+int cxl_query_cmd(struct cxl_mailbox *cxl_mbox,
 		  struct cxl_mem_query_commands __user *q)
 {
-	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
-	struct device *dev = &cxlmd->dev;
+	struct device *dev = cxl_mbox->host;
 	struct cxl_mem_command *cmd;
 	u32 n_commands;
 	int j = 0;
@@ -552,9 +547,9 @@ int cxl_query_cmd(struct cxl_memdev *cxlmd,
 	cxl_for_each_cmd(cmd) {
 		struct cxl_command_info info = cmd->info;
 
-		if (test_bit(info.id, mds->enabled_cmds))
+		if (test_bit(info.id, cxl_mbox->enabled_cmds))
 			info.flags |= CXL_MEM_COMMAND_FLAG_ENABLED;
-		if (test_bit(info.id, mds->exclusive_cmds))
+		if (test_bit(info.id, cxl_mbox->exclusive_cmds))
 			info.flags |= CXL_MEM_COMMAND_FLAG_EXCLUSIVE;
 
 		if (copy_to_user(&q->commands[j++], &info, sizeof(info)))
@@ -569,7 +564,7 @@ int cxl_query_cmd(struct cxl_memdev *cxlmd,
 
 /**
  * handle_mailbox_cmd_from_user() - Dispatch a mailbox command for userspace.
- * @mds: The driver data for the operation
+ * @cxl_mbox: The mailbox context for the operation.
  * @mbox_cmd: The validated mailbox command.
  * @out_payload: Pointer to userspace's output payload.
  * @size_out: (Input) Max payload size to copy out.
@@ -590,13 +585,12 @@ int cxl_query_cmd(struct cxl_memdev *cxlmd,
  *
  * See cxl_send_cmd().
  */
-static int handle_mailbox_cmd_from_user(struct cxl_memdev_state *mds,
+static int handle_mailbox_cmd_from_user(struct cxl_mailbox *cxl_mbox,
 					struct cxl_mbox_cmd *mbox_cmd,
 					u64 out_payload, s32 *size_out,
 					u32 *retval)
 {
-	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
-	struct device *dev = mds->cxlds.dev;
+	struct device *dev = cxl_mbox->host;
 	int rc;
 
 	dev_dbg(dev,
@@ -633,10 +627,9 @@ static int handle_mailbox_cmd_from_user(struct cxl_memdev_state *mds,
 	return rc;
 }
 
-int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s)
+int cxl_send_cmd(struct cxl_mailbox *cxl_mbox, struct cxl_send_command __user *s)
 {
-	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
-	struct device *dev = &cxlmd->dev;
+	struct device *dev = cxl_mbox->host;
 	struct cxl_send_command send;
 	struct cxl_mbox_cmd mbox_cmd;
 	int rc;
@@ -646,11 +639,11 @@ int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s)
 	if (copy_from_user(&send, s, sizeof(send)))
 		return -EFAULT;
 
-	rc = cxl_validate_cmd_from_user(&mbox_cmd, mds, &send);
+	rc = cxl_validate_cmd_from_user(&mbox_cmd, cxl_mbox, &send);
 	if (rc)
 		return rc;
 
-	rc = handle_mailbox_cmd_from_user(mds, &mbox_cmd, send.out.payload,
+	rc = handle_mailbox_cmd_from_user(cxl_mbox, &mbox_cmd, send.out.payload,
 					  &send.out.size, &send.retval);
 	if (rc)
 		return rc;
@@ -724,6 +717,7 @@ static int cxl_xfer_log(struct cxl_memdev_state *mds, uuid_t *uuid,
  */
 static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
 {
+	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
 	struct cxl_cel_entry *cel_entry;
 	const int cel_entries = size / sizeof(*cel_entry);
 	struct device *dev = mds->cxlds.dev;
@@ -737,7 +731,7 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
 		int enabled = 0;
 
 		if (cmd) {
-			set_bit(cmd->info.id, mds->enabled_cmds);
+			set_bit(cmd->info.id, cxl_mbox->enabled_cmds);
 			enabled++;
 		}
 
@@ -807,6 +801,7 @@ static const uuid_t log_uuid[] = {
  */
 int cxl_enumerate_cmds(struct cxl_memdev_state *mds)
 {
+	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
 	struct cxl_mbox_get_supported_logs *gsl;
 	struct device *dev = mds->cxlds.dev;
 	struct cxl_mem_command *cmd;
@@ -845,7 +840,7 @@ int cxl_enumerate_cmds(struct cxl_memdev_state *mds)
 		/* In case CEL was bogus, enable some default commands. */
 		cxl_for_each_cmd(cmd)
 			if (cmd->flags & CXL_CMD_FLAG_FORCE_ENABLE)
-				set_bit(cmd->info.id, mds->enabled_cmds);
+				set_bit(cmd->info.id, cxl_mbox->enabled_cmds);
 
 		/* Found the required CEL */
 		rc = 0;
@@ -1448,6 +1443,7 @@ struct cxl_memdev_state *cxl_memdev_state_create(struct device *dev)
 	mutex_init(&mds->event.log_lock);
 	mds->cxlds.dev = dev;
 	mds->cxlds.reg_map.host = dev;
+	mds->cxlds.cxl_mbox.host = dev;
 	mds->cxlds.reg_map.resource = CXL_RESOURCE_NONE;
 	mds->cxlds.type = CXL_DEVTYPE_CLASSMEM;
 	mds->ram_perf.qos_class = CXL_QOS_CLASS_INVALID;
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index ae3dfcbe89389..2e2e035abdaae 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -564,9 +564,11 @@ EXPORT_SYMBOL_NS_GPL(is_cxl_memdev, "CXL");
 void set_exclusive_cxl_commands(struct cxl_memdev_state *mds,
 				unsigned long *cmds)
 {
+	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
+
 	down_write(&cxl_memdev_rwsem);
-	bitmap_or(mds->exclusive_cmds, mds->exclusive_cmds, cmds,
-		  CXL_MEM_COMMAND_ID_MAX);
+	bitmap_or(cxl_mbox->exclusive_cmds, cxl_mbox->exclusive_cmds,
+		  cmds, CXL_MEM_COMMAND_ID_MAX);
 	up_write(&cxl_memdev_rwsem);
 }
 EXPORT_SYMBOL_NS_GPL(set_exclusive_cxl_commands, "CXL");
@@ -579,9 +581,11 @@ EXPORT_SYMBOL_NS_GPL(set_exclusive_cxl_commands, "CXL");
 void clear_exclusive_cxl_commands(struct cxl_memdev_state *mds,
 				  unsigned long *cmds)
 {
+	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
+
 	down_write(&cxl_memdev_rwsem);
-	bitmap_andnot(mds->exclusive_cmds, mds->exclusive_cmds, cmds,
-		      CXL_MEM_COMMAND_ID_MAX);
+	bitmap_andnot(cxl_mbox->exclusive_cmds, cxl_mbox->exclusive_cmds,
+		      cmds, CXL_MEM_COMMAND_ID_MAX);
 	up_write(&cxl_memdev_rwsem);
 }
 EXPORT_SYMBOL_NS_GPL(clear_exclusive_cxl_commands, "CXL");
@@ -656,11 +660,14 @@ static struct cxl_memdev *cxl_memdev_alloc(struct cxl_dev_state *cxlds,
 static long __cxl_memdev_ioctl(struct cxl_memdev *cxlmd, unsigned int cmd,
 			       unsigned long arg)
 {
+	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
+	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
+
 	switch (cmd) {
 	case CXL_MEM_QUERY_COMMANDS:
-		return cxl_query_cmd(cxlmd, (void __user *)arg);
+		return cxl_query_cmd(cxl_mbox, (void __user *)arg);
 	case CXL_MEM_SEND_COMMAND:
-		return cxl_send_cmd(cxlmd, (void __user *)arg);
+		return cxl_send_cmd(cxl_mbox, (void __user *)arg);
 	default:
 		return -ENOTTY;
 	}
@@ -994,10 +1001,11 @@ static void cxl_remove_fw_upload(void *fwl)
 int devm_cxl_setup_fw_upload(struct device *host, struct cxl_memdev_state *mds)
 {
 	struct cxl_dev_state *cxlds = &mds->cxlds;
+	struct cxl_mailbox *cxl_mbox = &cxlds->cxl_mbox;
 	struct device *dev = &cxlds->cxlmd->dev;
 	struct fw_upload *fwl;
 
-	if (!test_bit(CXL_MEM_COMMAND_ID_GET_FW_INFO, mds->enabled_cmds))
+	if (!test_bit(CXL_MEM_COMMAND_ID_GET_FW_INFO, cxl_mbox->enabled_cmds))
 		return 0;
 
 	fwl = firmware_upload_register(THIS_MODULE, dev, dev_name(dev),
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 2a25d1957ddb9..a0a49809cd76c 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -106,42 +106,6 @@ static inline struct cxl_ep *cxl_ep_load(struct cxl_port *port,
 	return xa_load(&port->endpoints, (unsigned long)&cxlmd->dev);
 }
 
-/**
- * struct cxl_mbox_cmd - A command to be submitted to hardware.
- * @opcode: (input) The command set and command submitted to hardware.
- * @payload_in: (input) Pointer to the input payload.
- * @payload_out: (output) Pointer to the output payload. Must be allocated by
- *		 the caller.
- * @size_in: (input) Number of bytes to load from @payload_in.
- * @size_out: (input) Max number of bytes loaded into @payload_out.
- *            (output) Number of bytes generated by the device. For fixed size
- *            outputs commands this is always expected to be deterministic. For
- *            variable sized output commands, it tells the exact number of bytes
- *            written.
- * @min_out: (input) internal command output payload size validation
- * @poll_count: (input) Number of timeouts to attempt.
- * @poll_interval_ms: (input) Time between mailbox background command polling
- *                    interval timeouts.
- * @return_code: (output) Error code returned from hardware.
- *
- * This is the primary mechanism used to send commands to the hardware.
- * All the fields except @payload_* correspond exactly to the fields described in
- * Command Register section of the CXL 2.0 8.2.8.4.5. @payload_in and
- * @payload_out are written to, and read from the Command Payload Registers
- * defined in CXL 2.0 8.2.8.4.8.
- */
-struct cxl_mbox_cmd {
-	u16 opcode;
-	void *payload_in;
-	void *payload_out;
-	size_t size_in;
-	size_t size_out;
-	size_t min_out;
-	int poll_count;
-	int poll_interval_ms;
-	u16 return_code;
-};
-
 /*
  * Per CXL 3.0 Section 8.2.8.4.5.1
  */
@@ -461,8 +425,6 @@ static inline struct cxl_dev_state *mbox_to_cxlds(struct cxl_mailbox *cxl_mbox)
  * @lsa_size: Size of Label Storage Area
  *                (CXL 2.0 8.2.9.5.1.1 Identify Memory Device)
  * @firmware_version: Firmware version for the memory device.
- * @enabled_cmds: Hardware commands found enabled in CEL.
- * @exclusive_cmds: Commands that are kernel-internal only
  * @total_bytes: sum of all possible capacities
  * @volatile_only_bytes: hard volatile capacity
  * @persistent_only_bytes: hard persistent capacity
@@ -485,8 +447,6 @@ struct cxl_memdev_state {
 	struct cxl_dev_state cxlds;
 	size_t lsa_size;
 	char firmware_version[0x10];
-	DECLARE_BITMAP(enabled_cmds, CXL_MEM_COMMAND_ID_MAX);
-	DECLARE_BITMAP(exclusive_cmds, CXL_MEM_COMMAND_ID_MAX);
 	u64 total_bytes;
 	u64 volatile_only_bytes;
 	u64 persistent_only_bytes;
diff --git a/include/cxl/mailbox.h b/include/cxl/mailbox.h
index bacd111e75f11..cc894f07a4351 100644
--- a/include/cxl/mailbox.h
+++ b/include/cxl/mailbox.h
@@ -3,12 +3,49 @@
 #ifndef __CXL_MBOX_H__
 #define __CXL_MBOX_H__
 #include <linux/rcuwait.h>
+#include <uapi/linux/cxl_mem.h>
 
-struct cxl_mbox_cmd;
+/**
+ * struct cxl_mbox_cmd - A command to be submitted to hardware.
+ * @opcode: (input) The command set and command submitted to hardware.
+ * @payload_in: (input) Pointer to the input payload.
+ * @payload_out: (output) Pointer to the output payload. Must be allocated by
+ *		 the caller.
+ * @size_in: (input) Number of bytes to load from @payload_in.
+ * @size_out: (input) Max number of bytes loaded into @payload_out.
+ *            (output) Number of bytes generated by the device. For fixed size
+ *            outputs commands this is always expected to be deterministic. For
+ *            variable sized output commands, it tells the exact number of bytes
+ *            written.
+ * @min_out: (input) internal command output payload size validation
+ * @poll_count: (input) Number of timeouts to attempt.
+ * @poll_interval_ms: (input) Time between mailbox background command polling
+ *                    interval timeouts.
+ * @return_code: (output) Error code returned from hardware.
+ *
+ * This is the primary mechanism used to send commands to the hardware.
+ * All the fields except @payload_* correspond exactly to the fields described in
+ * Command Register section of the CXL 2.0 8.2.8.4.5. @payload_in and
+ * @payload_out are written to, and read from the Command Payload Registers
+ * defined in CXL 2.0 8.2.8.4.8.
+ */
+struct cxl_mbox_cmd {
+	u16 opcode;
+	void *payload_in;
+	void *payload_out;
+	size_t size_in;
+	size_t size_out;
+	size_t min_out;
+	int poll_count;
+	int poll_interval_ms;
+	u16 return_code;
+};
 
 /**
  * struct cxl_mailbox - context for CXL mailbox operations
  * @host: device that hosts the mailbox
+ * @enabled_cmds: mailbox commands that are enabled by the driver
+ * @exclusive_cmds: mailbox commands that are exclusive to the kernel
  * @payload_size: Size of space for payload
  *                (CXL 3.1 8.2.8.4.3 Mailbox Capabilities Register)
  * @mbox_mutex: mutex protects device mailbox and firmware
@@ -17,6 +54,8 @@ struct cxl_mbox_cmd;
  */
 struct cxl_mailbox {
 	struct device *host;
+	DECLARE_BITMAP(enabled_cmds, CXL_MEM_COMMAND_ID_MAX);
+	DECLARE_BITMAP(exclusive_cmds, CXL_MEM_COMMAND_ID_MAX);
 	size_t payload_size;
 	struct mutex mbox_mutex; /* lock to protect mailbox context */
 	struct rcuwait mbox_wait;

From cbbca60a1efc1e8920be13d6bdaf3345ff49132f Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@intel.com>
Date: Thu, 20 Feb 2025 12:42:39 -0700
Subject: [PATCH 2/7] cxl: Enumerate feature commands

Add feature commands enumeration code in order to detect and enumerate
the 3 feature related commands "get supported features", "get feature",
and "set feature". The enumeration will help determine whether the driver
can issue any of the 3 commands to the device.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Shiju Jose <shiju.jose@huawei.com>
Link: https://patch.msgid.link/20250220194438.2281088-2-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/core/mbox.c | 36 +++++++++++++++++++++++++++++++++++-
 drivers/cxl/cxlmem.h    |  3 +++
 include/cxl/features.h  | 13 +++++++++++++
 include/cxl/mailbox.h   |  3 +++
 4 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 include/cxl/features.h

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 9c1b9e353e3e3..78c5346e3e891 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -706,6 +706,35 @@ static int cxl_xfer_log(struct cxl_memdev_state *mds, uuid_t *uuid,
 	return 0;
 }
 
+static int check_features_opcodes(u16 opcode, int *ro_cmds, int *wr_cmds)
+{
+	switch (opcode) {
+	case CXL_MBOX_OP_GET_SUPPORTED_FEATURES:
+	case CXL_MBOX_OP_GET_FEATURE:
+		(*ro_cmds)++;
+		return 1;
+	case CXL_MBOX_OP_SET_FEATURE:
+		(*wr_cmds)++;
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+/* 'Get Supported Features' and 'Get Feature' */
+#define MAX_FEATURES_READ_CMDS	2
+static void set_features_cap(struct cxl_mailbox *cxl_mbox,
+			     int ro_cmds, int wr_cmds)
+{
+	/* Setting up Features capability while walking the CEL */
+	if (ro_cmds == MAX_FEATURES_READ_CMDS) {
+		if (wr_cmds)
+			cxl_mbox->feat_cap = CXL_FEATURES_RW;
+		else
+			cxl_mbox->feat_cap = CXL_FEATURES_RO;
+	}
+}
+
 /**
  * cxl_walk_cel() - Walk through the Command Effects Log.
  * @mds: The driver data for the operation
@@ -721,7 +750,7 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
 	struct cxl_cel_entry *cel_entry;
 	const int cel_entries = size / sizeof(*cel_entry);
 	struct device *dev = mds->cxlds.dev;
-	int i;
+	int i, ro_cmds = 0, wr_cmds = 0;
 
 	cel_entry = (struct cxl_cel_entry *) cel;
 
@@ -735,6 +764,9 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
 			enabled++;
 		}
 
+		enabled += check_features_opcodes(opcode, &ro_cmds,
+						  &wr_cmds);
+
 		if (cxl_is_poison_command(opcode)) {
 			cxl_set_poison_cmd_enabled(&mds->poison, opcode);
 			enabled++;
@@ -748,6 +780,8 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
 		dev_dbg(dev, "Opcode 0x%04x %s\n", opcode,
 			enabled ? "enabled" : "unsupported by driver");
 	}
+
+	set_features_cap(cxl_mbox, ro_cmds, wr_cmds);
 }
 
 static struct cxl_mbox_get_supported_logs *cxl_get_gsl(struct cxl_memdev_state *mds)
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index a0a49809cd76c..55c55685cb39f 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -490,6 +490,9 @@ enum cxl_opcode {
 	CXL_MBOX_OP_GET_LOG_CAPS	= 0x0402,
 	CXL_MBOX_OP_CLEAR_LOG           = 0x0403,
 	CXL_MBOX_OP_GET_SUP_LOG_SUBLIST = 0x0405,
+	CXL_MBOX_OP_GET_SUPPORTED_FEATURES	= 0x0500,
+	CXL_MBOX_OP_GET_FEATURE		= 0x0501,
+	CXL_MBOX_OP_SET_FEATURE		= 0x0502,
 	CXL_MBOX_OP_IDENTIFY		= 0x4000,
 	CXL_MBOX_OP_GET_PARTITION_INFO	= 0x4100,
 	CXL_MBOX_OP_SET_PARTITION_INFO	= 0x4101,
diff --git a/include/cxl/features.h b/include/cxl/features.h
new file mode 100644
index 0000000000000..357d3acf8429d
--- /dev/null
+++ b/include/cxl/features.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2024-2025 Intel Corporation. */
+#ifndef __CXL_FEATURES_H__
+#define __CXL_FEATURES_H__
+
+/* Feature commands capability supported by a device */
+enum cxl_features_capability {
+	CXL_FEATURES_NONE = 0,
+	CXL_FEATURES_RO,
+	CXL_FEATURES_RW,
+};
+
+#endif
diff --git a/include/cxl/mailbox.h b/include/cxl/mailbox.h
index cc894f07a4351..c4e99e2e3a9d4 100644
--- a/include/cxl/mailbox.h
+++ b/include/cxl/mailbox.h
@@ -3,6 +3,7 @@
 #ifndef __CXL_MBOX_H__
 #define __CXL_MBOX_H__
 #include <linux/rcuwait.h>
+#include <cxl/features.h>
 #include <uapi/linux/cxl_mem.h>
 
 /**
@@ -51,6 +52,7 @@ struct cxl_mbox_cmd {
  * @mbox_mutex: mutex protects device mailbox and firmware
  * @mbox_wait: rcuwait for mailbox
  * @mbox_send: @dev specific transport for transmitting mailbox commands
+ * @feat_cap: Features capability
  */
 struct cxl_mailbox {
 	struct device *host;
@@ -60,6 +62,7 @@ struct cxl_mailbox {
 	struct mutex mbox_mutex; /* lock to protect mailbox context */
 	struct rcuwait mbox_wait;
 	int (*mbox_send)(struct cxl_mailbox *cxl_mbox, struct cxl_mbox_cmd *cmd);
+	enum cxl_features_capability feat_cap;
 };
 
 int cxl_mailbox_init(struct cxl_mailbox *cxl_mbox, struct device *host);

From f0e6a2329bf9d44138be2163370ae9537cbdaf74 Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@intel.com>
Date: Thu, 20 Feb 2025 12:42:40 -0700
Subject: [PATCH 3/7] cxl: Add Get Supported Features command for kernel usage

CXL spec r3.2 8.2.9.6.1 Get Supported Features (Opcode 0500h)
The command retrieve the list of supported device-specific features
(identified by UUID) and general information about each Feature.

The driver will retrieve the Feature entries in order to make checks and
provide information for the Get Feature and Set Feature command. One of
the main piece of information retrieved are the effects a Set Feature
command would have for a particular feature. The retrieved Feature
entries are stored in the cxl_mailbox context.

The setup of Features is initiated via devm_cxl_setup_features() during the
pci probe function before the cxl_memdev is enumerated.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Shiju Jose <shiju.jose@huawei.com>
Link: https://patch.msgid.link/20250220194438.2281088-3-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/Kconfig          |  11 +++
 drivers/cxl/core/Makefile    |   1 +
 drivers/cxl/core/features.c  | 175 +++++++++++++++++++++++++++++++++++
 drivers/cxl/cxlmem.h         |   4 +
 drivers/cxl/pci.c            |   4 +
 include/cxl/features.h       |  87 +++++++++++++++++
 tools/testing/cxl/Kbuild     |   1 +
 tools/testing/cxl/test/mem.c |   4 +
 8 files changed, 287 insertions(+)
 create mode 100644 drivers/cxl/core/features.c

diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
index 876469e23f7a7..ad2e796e4ac63 100644
--- a/drivers/cxl/Kconfig
+++ b/drivers/cxl/Kconfig
@@ -102,6 +102,17 @@ config CXL_MEM
 
 	  If unsure say 'm'.
 
+config CXL_FEATURES
+	bool "CXL: Features"
+	depends on CXL_PCI
+	help
+	  Enable support for CXL Features. A CXL device that includes a mailbox
+	  supports commands that allows listing, getting, and setting of
+	  optionally defined features such as memory sparing or post package
+	  sparing. Vendors may define custom features for the device.
+
+	  If unsure say 'n'
+
 config CXL_PORT
 	default CXL_BUS
 	tristate
diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index 9259bcc6773c8..b0bfbd9eac9be 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -16,3 +16,4 @@ cxl_core-y += pmu.o
 cxl_core-y += cdat.o
 cxl_core-$(CONFIG_TRACING) += trace.o
 cxl_core-$(CONFIG_CXL_REGION) += region.o
+cxl_core-$(CONFIG_CXL_FEATURES) += features.o
diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
new file mode 100644
index 0000000000000..f2898a56bd634
--- /dev/null
+++ b/drivers/cxl/core/features.c
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2024-2025 Intel Corporation. All rights reserved. */
+#include <linux/device.h>
+#include <cxl/mailbox.h>
+#include <cxl/features.h>
+#include "cxl.h"
+#include "cxlmem.h"
+
+inline struct cxl_features_state *to_cxlfs(struct cxl_dev_state *cxlds)
+{
+	return cxlds->cxlfs;
+}
+EXPORT_SYMBOL_NS_GPL(to_cxlfs, "CXL");
+
+static int cxl_get_supported_features_count(struct cxl_mailbox *cxl_mbox)
+{
+	struct cxl_mbox_get_sup_feats_out mbox_out;
+	struct cxl_mbox_get_sup_feats_in mbox_in;
+	struct cxl_mbox_cmd mbox_cmd;
+	int rc;
+
+	memset(&mbox_in, 0, sizeof(mbox_in));
+	mbox_in.count = cpu_to_le32(sizeof(mbox_out));
+	memset(&mbox_out, 0, sizeof(mbox_out));
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_GET_SUPPORTED_FEATURES,
+		.size_in = sizeof(mbox_in),
+		.payload_in = &mbox_in,
+		.size_out = sizeof(mbox_out),
+		.payload_out = &mbox_out,
+		.min_out = sizeof(mbox_out),
+	};
+	rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+	if (rc < 0)
+		return rc;
+
+	return le16_to_cpu(mbox_out.supported_feats);
+}
+
+static struct cxl_feat_entries *
+get_supported_features(struct cxl_features_state *cxlfs)
+{
+	int remain_feats, max_size, max_feats, start, rc, hdr_size;
+	struct cxl_mailbox *cxl_mbox = &cxlfs->cxlds->cxl_mbox;
+	int feat_size = sizeof(struct cxl_feat_entry);
+	struct cxl_mbox_get_sup_feats_in mbox_in;
+	struct cxl_feat_entry *entry;
+	struct cxl_mbox_cmd mbox_cmd;
+	int count;
+
+	count = cxl_get_supported_features_count(cxl_mbox);
+	if (count <= 0)
+		return NULL;
+
+	struct cxl_feat_entries *entries __free(kvfree) =
+		kvmalloc(struct_size(entries, ent, count), GFP_KERNEL);
+	if (!entries)
+		return NULL;
+
+	struct cxl_mbox_get_sup_feats_out *mbox_out __free(kvfree) =
+		kvmalloc(cxl_mbox->payload_size, GFP_KERNEL);
+	if (!mbox_out)
+		return NULL;
+
+	hdr_size = struct_size(mbox_out, ents, 0);
+	max_size = cxl_mbox->payload_size - hdr_size;
+	/* max feat entries that can fit in mailbox max payload size */
+	max_feats = max_size / feat_size;
+	entry = entries->ent;
+
+	start = 0;
+	remain_feats = count;
+	do {
+		int retrieved, alloc_size, copy_feats;
+		int num_entries;
+
+		if (remain_feats > max_feats) {
+			alloc_size = struct_size(mbox_out, ents, max_feats);
+			remain_feats = remain_feats - max_feats;
+			copy_feats = max_feats;
+		} else {
+			alloc_size = struct_size(mbox_out, ents, remain_feats);
+			copy_feats = remain_feats;
+			remain_feats = 0;
+		}
+
+		memset(&mbox_in, 0, sizeof(mbox_in));
+		mbox_in.count = cpu_to_le32(alloc_size);
+		mbox_in.start_idx = cpu_to_le16(start);
+		memset(mbox_out, 0, alloc_size);
+		mbox_cmd = (struct cxl_mbox_cmd) {
+			.opcode = CXL_MBOX_OP_GET_SUPPORTED_FEATURES,
+			.size_in = sizeof(mbox_in),
+			.payload_in = &mbox_in,
+			.size_out = alloc_size,
+			.payload_out = mbox_out,
+			.min_out = hdr_size,
+		};
+		rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+		if (rc < 0)
+			return NULL;
+
+		if (mbox_cmd.size_out <= hdr_size)
+			return NULL;
+
+		/*
+		 * Make sure retrieved out buffer is multiple of feature
+		 * entries.
+		 */
+		retrieved = mbox_cmd.size_out - hdr_size;
+		if (retrieved % feat_size)
+			return NULL;
+
+		num_entries = le16_to_cpu(mbox_out->num_entries);
+		/*
+		 * If the reported output entries * defined entry size !=
+		 * retrieved output bytes, then the output package is incorrect.
+		 */
+		if (num_entries * feat_size != retrieved)
+			return NULL;
+
+		memcpy(entry, mbox_out->ents, retrieved);
+		entry += num_entries;
+		/*
+		 * If the number of output entries is less than expected, add the
+		 * remaining entries to the next batch.
+		 */
+		remain_feats += copy_feats - num_entries;
+		start += num_entries;
+	} while (remain_feats);
+
+	entries->num_features = count;
+
+	return no_free_ptr(entries);
+}
+
+static void free_cxlfs(void *_cxlfs)
+{
+	struct cxl_features_state *cxlfs = _cxlfs;
+	struct cxl_dev_state *cxlds = cxlfs->cxlds;
+
+	cxlds->cxlfs = NULL;
+	kvfree(cxlfs->entries);
+	kfree(cxlfs);
+}
+
+/**
+ * devm_cxl_setup_features() - Allocate and initialize features context
+ * @cxlds: CXL device context
+ *
+ * Return 0 on success or -errno on failure.
+ */
+int devm_cxl_setup_features(struct cxl_dev_state *cxlds)
+{
+	struct cxl_mailbox *cxl_mbox = &cxlds->cxl_mbox;
+
+	if (cxl_mbox->feat_cap < CXL_FEATURES_RO)
+		return -ENODEV;
+
+	struct cxl_features_state *cxlfs __free(kfree) =
+		kzalloc(sizeof(*cxlfs), GFP_KERNEL);
+	if (!cxlfs)
+		return -ENOMEM;
+
+	cxlfs->cxlds = cxlds;
+
+	cxlfs->entries = get_supported_features(cxlfs);
+	if (!cxlfs->entries)
+		return -ENOMEM;
+
+	cxlds->cxlfs = cxlfs;
+
+	return devm_add_action_or_reset(cxlds->dev, free_cxlfs, no_free_ptr(cxlfs));
+}
+EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_features, "CXL");
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 55c55685cb39f..dd2b7060d501c 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -392,6 +392,7 @@ struct cxl_dpa_perf {
  * @serial: PCIe Device Serial Number
  * @type: Generic Memory Class device or Vendor Specific Memory device
  * @cxl_mbox: CXL mailbox context
+ * @cxlfs: CXL features context
  */
 struct cxl_dev_state {
 	struct device *dev;
@@ -407,6 +408,9 @@ struct cxl_dev_state {
 	u64 serial;
 	enum cxl_devtype type;
 	struct cxl_mailbox cxl_mbox;
+#ifdef CONFIG_CXL_FEATURES
+	struct cxl_features_state *cxlfs;
+#endif
 };
 
 static inline struct cxl_dev_state *mbox_to_cxlds(struct cxl_mailbox *cxl_mbox)
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index a96e54c6259e1..3e666ec515808 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -997,6 +997,10 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (rc)
 		return rc;
 
+	rc = devm_cxl_setup_features(cxlds);
+	if (rc)
+		dev_dbg(&pdev->dev, "No CXL Features discovered\n");
+
 	cxlmd = devm_cxl_add_memdev(&pdev->dev, cxlds);
 	if (IS_ERR(cxlmd))
 		return PTR_ERR(cxlmd);
diff --git a/include/cxl/features.h b/include/cxl/features.h
index 357d3acf8429d..5b3485eb0f774 100644
--- a/include/cxl/features.h
+++ b/include/cxl/features.h
@@ -3,6 +3,8 @@
 #ifndef __CXL_FEATURES_H__
 #define __CXL_FEATURES_H__
 
+#include <linux/uuid.h>
+
 /* Feature commands capability supported by a device */
 enum cxl_features_capability {
 	CXL_FEATURES_NONE = 0,
@@ -10,4 +12,89 @@ enum cxl_features_capability {
 	CXL_FEATURES_RW,
 };
 
+/* Get Supported Features (0x500h) CXL r3.2 8.2.9.6.1 */
+struct cxl_mbox_get_sup_feats_in {
+	__le32 count;
+	__le16 start_idx;
+	u8 reserved[2];
+} __packed;
+
+/* CXL spec r3.2 Table 8-87 command effects */
+#define CXL_CMD_CONFIG_CHANGE_COLD_RESET	BIT(0)
+#define CXL_CMD_CONFIG_CHANGE_IMMEDIATE		BIT(1)
+#define CXL_CMD_DATA_CHANGE_IMMEDIATE		BIT(2)
+#define CXL_CMD_POLICY_CHANGE_IMMEDIATE		BIT(3)
+#define CXL_CMD_LOG_CHANGE_IMMEDIATE		BIT(4)
+#define CXL_CMD_SECURITY_STATE_CHANGE		BIT(5)
+#define CXL_CMD_BACKGROUND			BIT(6)
+#define CXL_CMD_BGCMD_ABORT_SUPPORTED		BIT(7)
+#define CXL_CMD_EFFECTS_VALID			BIT(9)
+#define CXL_CMD_CONFIG_CHANGE_CONV_RESET	BIT(10)
+#define CXL_CMD_CONFIG_CHANGE_CXL_RESET		BIT(11)
+
+/*
+ * CXL spec r3.2 Table 8-109
+ * Get Supported Features Supported Feature Entry
+ */
+struct cxl_feat_entry {
+	uuid_t uuid;
+	__le16 id;
+	__le16 get_feat_size;
+	__le16 set_feat_size;
+	__le32 flags;
+	u8 get_feat_ver;
+	u8 set_feat_ver;
+	__le16 effects;
+	u8 reserved[18];
+} __packed;
+
+/* @flags field for 'struct cxl_feat_entry' */
+#define CXL_FEATURE_F_CHANGEABLE		BIT(0)
+#define CXL_FEATURE_F_PERSIST_FW_UPDATE		BIT(4)
+#define CXL_FEATURE_F_DEFAULT_SEL		BIT(5)
+#define CXL_FEATURE_F_SAVED_SEL			BIT(6)
+
+/*
+ * CXL spec r3.2 Table 8-108
+ * Get supported Features Output Payload
+ */
+struct cxl_mbox_get_sup_feats_out {
+	__struct_group(cxl_mbox_get_sup_feats_out_hdr, hdr, /* no attrs */,
+		__le16 num_entries;
+		__le16 supported_feats;
+		__u8 reserved[4];
+	);
+	struct cxl_feat_entry ents[] __counted_by_le(num_entries);
+} __packed;
+
+/**
+ * struct cxl_features_state - The Features state for the device
+ * @cxlds: Pointer to CXL device state
+ * @entries: CXl feature entry context
+ *	@num_features: total Features supported by the device
+ *	@ent: Flex array of Feature detail entries from the device
+ */
+struct cxl_features_state {
+	struct cxl_dev_state *cxlds;
+	struct cxl_feat_entries {
+		int num_features;
+		struct cxl_feat_entry ent[] __counted_by(num_features);
+	} *entries;
+};
+
+#ifdef CONFIG_CXL_FEATURES
+inline struct cxl_features_state *to_cxlfs(struct cxl_dev_state *cxlds);
+int devm_cxl_setup_features(struct cxl_dev_state *cxlds);
+#else
+static inline struct cxl_features_state *to_cxlfs(struct cxl_dev_state *cxlds)
+{
+	return NULL;
+}
+
+static inline int devm_cxl_setup_features(struct cxl_dev_state *cxlds)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
 #endif
diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index b1256fee3567f..0a6572ab6f372 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -63,6 +63,7 @@ cxl_core-y += $(CXL_CORE_SRC)/pmu.o
 cxl_core-y += $(CXL_CORE_SRC)/cdat.o
 cxl_core-$(CONFIG_TRACING) += $(CXL_CORE_SRC)/trace.o
 cxl_core-$(CONFIG_CXL_REGION) += $(CXL_CORE_SRC)/region.o
+cxl_core-$(CONFIG_CXL_FEATURES) += $(CXL_CORE_SRC)/features.o
 cxl_core-y += config_check.o
 cxl_core-y += cxl_core_test.o
 cxl_core-y += cxl_core_exports.o
diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
index 8d731bd639882..e9494cd446ef5 100644
--- a/tools/testing/cxl/test/mem.c
+++ b/tools/testing/cxl/test/mem.c
@@ -1558,6 +1558,10 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
 	if (rc)
 		return rc;
 
+	rc = devm_cxl_setup_features(cxlds);
+	if (rc)
+		dev_dbg(dev, "No CXL Features discovered\n");
+
 	cxl_mock_add_event_logs(&mdata->mes);
 
 	cxlmd = devm_cxl_add_memdev(&pdev->dev, cxlds);

From 44818d387e55fa11476249783d14f925a269b196 Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@intel.com>
Date: Thu, 20 Feb 2025 12:42:41 -0700
Subject: [PATCH 4/7] cxl/test: Add Get Supported Features mailbox command
 support

Add cxl-test emulation of Get Supported Features mailbox command.
Currently only adding a test feature with feature identifier of
all f's for testing.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Link: https://patch.msgid.link/20250220194438.2281088-4-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 tools/testing/cxl/test/mem.c | 70 ++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
index e9494cd446ef5..4809a90ff9b66 100644
--- a/tools/testing/cxl/test/mem.c
+++ b/tools/testing/cxl/test/mem.c
@@ -44,6 +44,10 @@ static struct cxl_cel_entry mock_cel[] = {
 		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_SUPPORTED_LOGS),
 		.effect = CXL_CMD_EFFECT_NONE,
 	},
+	{
+		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_SUPPORTED_FEATURES),
+		.effect = CXL_CMD_EFFECT_NONE,
+	},
 	{
 		.opcode = cpu_to_le16(CXL_MBOX_OP_IDENTIFY),
 		.effect = CXL_CMD_EFFECT_NONE,
@@ -1354,6 +1358,69 @@ static int mock_activate_fw(struct cxl_mockmem_data *mdata,
 	return -EINVAL;
 }
 
+#define CXL_VENDOR_FEATURE_TEST							\
+	UUID_INIT(0xffffffff, 0xffff, 0xffff, 0xff, 0xff, 0xff, 0xff, 0xff,	\
+		  0xff, 0xff, 0xff)
+
+static void fill_feature_vendor_test(struct cxl_feat_entry *feat)
+{
+	feat->uuid = CXL_VENDOR_FEATURE_TEST;
+	feat->id = 0;
+	feat->get_feat_size = cpu_to_le16(0x4);
+	feat->set_feat_size = cpu_to_le16(0x4);
+	feat->flags = cpu_to_le32(CXL_FEATURE_F_CHANGEABLE |
+				  CXL_FEATURE_F_DEFAULT_SEL |
+				  CXL_FEATURE_F_SAVED_SEL);
+	feat->get_feat_ver = 1;
+	feat->set_feat_ver = 1;
+	feat->effects = cpu_to_le16(CXL_CMD_CONFIG_CHANGE_COLD_RESET |
+				    CXL_CMD_EFFECTS_VALID);
+}
+
+#define MAX_CXL_TEST_FEATS	1
+
+static int mock_get_supported_features(struct cxl_mockmem_data *mdata,
+				       struct cxl_mbox_cmd *cmd)
+{
+	struct cxl_mbox_get_sup_feats_in *in = cmd->payload_in;
+	struct cxl_mbox_get_sup_feats_out *out = cmd->payload_out;
+	struct cxl_feat_entry *feat;
+	u16 start_idx, count;
+
+	if (cmd->size_out < sizeof(*out)) {
+		cmd->return_code = CXL_MBOX_CMD_RC_PAYLOADLEN;
+		return -EINVAL;
+	}
+
+	/*
+	 * Current emulation only supports 1 feature
+	 */
+	start_idx = le16_to_cpu(in->start_idx);
+	if (start_idx != 0) {
+		cmd->return_code = CXL_MBOX_CMD_RC_INPUT;
+		return -EINVAL;
+	}
+
+	count = le16_to_cpu(in->count);
+	if (count < struct_size(out, ents, 0)) {
+		cmd->return_code = CXL_MBOX_CMD_RC_PAYLOADLEN;
+		return -EINVAL;
+	}
+
+	out->supported_feats = cpu_to_le16(MAX_CXL_TEST_FEATS);
+	cmd->return_code = 0;
+	if (count < struct_size(out, ents, MAX_CXL_TEST_FEATS)) {
+		out->num_entries = 0;
+		return 0;
+	}
+
+	out->num_entries = cpu_to_le16(MAX_CXL_TEST_FEATS);
+	feat = out->ents;
+	fill_feature_vendor_test(feat);
+
+	return 0;
+}
+
 static int cxl_mock_mbox_send(struct cxl_mailbox *cxl_mbox,
 			      struct cxl_mbox_cmd *cmd)
 {
@@ -1439,6 +1506,9 @@ static int cxl_mock_mbox_send(struct cxl_mailbox *cxl_mbox,
 	case CXL_MBOX_OP_ACTIVATE_FW:
 		rc = mock_activate_fw(mdata, cmd);
 		break;
+	case CXL_MBOX_OP_GET_SUPPORTED_FEATURES:
+		rc = mock_get_supported_features(mdata, cmd);
+		break;
 	default:
 		break;
 	}

From 5e5ac21f629de796ab5d598b59c5e468c6fe4f95 Mon Sep 17 00:00:00 2001
From: Shiju Jose <shiju.jose@huawei.com>
Date: Thu, 20 Feb 2025 12:42:42 -0700
Subject: [PATCH 5/7] cxl/mbox: Add GET_FEATURE mailbox command

Add support for GET_FEATURE mailbox command.

CXL spec r3.2 section 8.2.9.6 describes optional device specific features.
The settings of a feature can be retrieved using Get Feature command.
CXL spec r3.2 section 8.2.9.6.2 describes Get Feature command.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Link: https://patch.msgid.link/20250220194438.2281088-5-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/core/core.h     |  7 ++++++
 drivers/cxl/core/features.c | 50 +++++++++++++++++++++++++++++++++++++
 include/cxl/features.h      | 24 ++++++++++++++++++
 3 files changed, 81 insertions(+)

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index f77fcf71ade51..7cd3b98150e61 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -117,4 +117,11 @@ bool cxl_need_node_perf_attrs_update(int nid);
 int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port,
 					struct access_coordinate *c);
 
+#ifdef CONFIG_CXL_FEATURES
+size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
+		       enum cxl_get_feat_selection selection,
+		       void *feat_out, size_t feat_out_size, u16 offset,
+		       u16 *return_code);
+#endif
+
 #endif /* __CXL_CORE_H__ */
diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
index f2898a56bd634..3fc6f8415f191 100644
--- a/drivers/cxl/core/features.c
+++ b/drivers/cxl/core/features.c
@@ -4,6 +4,7 @@
 #include <cxl/mailbox.h>
 #include <cxl/features.h>
 #include "cxl.h"
+#include "core.h"
 #include "cxlmem.h"
 
 inline struct cxl_features_state *to_cxlfs(struct cxl_dev_state *cxlds)
@@ -173,3 +174,52 @@ int devm_cxl_setup_features(struct cxl_dev_state *cxlds)
 	return devm_add_action_or_reset(cxlds->dev, free_cxlfs, no_free_ptr(cxlfs));
 }
 EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_features, "CXL");
+
+size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
+		       enum cxl_get_feat_selection selection,
+		       void *feat_out, size_t feat_out_size, u16 offset,
+		       u16 *return_code)
+{
+	size_t data_to_rd_size, size_out;
+	struct cxl_mbox_get_feat_in pi;
+	struct cxl_mbox_cmd mbox_cmd;
+	size_t data_rcvd_size = 0;
+	int rc;
+
+	if (return_code)
+		*return_code = CXL_MBOX_CMD_RC_INPUT;
+
+	if (!feat_out || !feat_out_size)
+		return 0;
+
+	size_out = min(feat_out_size, cxl_mbox->payload_size);
+	uuid_copy(&pi.uuid, feat_uuid);
+	pi.selection = selection;
+	do {
+		data_to_rd_size = min(feat_out_size - data_rcvd_size,
+				      cxl_mbox->payload_size);
+		pi.offset = cpu_to_le16(offset + data_rcvd_size);
+		pi.count = cpu_to_le16(data_to_rd_size);
+
+		mbox_cmd = (struct cxl_mbox_cmd) {
+			.opcode = CXL_MBOX_OP_GET_FEATURE,
+			.size_in = sizeof(pi),
+			.payload_in = &pi,
+			.size_out = size_out,
+			.payload_out = feat_out + data_rcvd_size,
+			.min_out = data_to_rd_size,
+		};
+		rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+		if (rc < 0 || !mbox_cmd.size_out) {
+			if (return_code)
+				*return_code = mbox_cmd.return_code;
+			return 0;
+		}
+		data_rcvd_size += mbox_cmd.size_out;
+	} while (data_rcvd_size < feat_out_size);
+
+	if (return_code)
+		*return_code = CXL_MBOX_CMD_RC_SUCCESS;
+
+	return data_rcvd_size;
+}
diff --git a/include/cxl/features.h b/include/cxl/features.h
index 5b3485eb0f774..766c09978e5e1 100644
--- a/include/cxl/features.h
+++ b/include/cxl/features.h
@@ -67,6 +67,29 @@ struct cxl_mbox_get_sup_feats_out {
 	struct cxl_feat_entry ents[] __counted_by_le(num_entries);
 } __packed;
 
+/*
+ * Get Feature CXL spec r3.2 Spec 8.2.9.6.2
+ */
+
+/*
+ * Get Feature input payload
+ * CXL spec r3.2 section 8.2.9.6.2 Table 8-99
+ */
+struct cxl_mbox_get_feat_in {
+	uuid_t uuid;
+	__le16 offset;
+	__le16 count;
+	u8 selection;
+}  __packed;
+
+/* Selection field for 'struct cxl_mbox_get_feat_in' */
+enum cxl_get_feat_selection {
+	CXL_GET_FEAT_SEL_CURRENT_VALUE,
+	CXL_GET_FEAT_SEL_DEFAULT_VALUE,
+	CXL_GET_FEAT_SEL_SAVED_VALUE,
+	CXL_GET_FEAT_SEL_MAX
+};
+
 /**
  * struct cxl_features_state - The Features state for the device
  * @cxlds: Pointer to CXL device state
@@ -82,6 +105,7 @@ struct cxl_features_state {
 	} *entries;
 };
 
+struct cxl_mailbox;
 #ifdef CONFIG_CXL_FEATURES
 inline struct cxl_features_state *to_cxlfs(struct cxl_dev_state *cxlds);
 int devm_cxl_setup_features(struct cxl_dev_state *cxlds);

From 14d502cc2718e6af44b575c95670292689a3ad65 Mon Sep 17 00:00:00 2001
From: Shiju Jose <shiju.jose@huawei.com>
Date: Thu, 20 Feb 2025 12:42:43 -0700
Subject: [PATCH 6/7] cxl/mbox: Add SET_FEATURE mailbox command

Add support for SET_FEATURE mailbox command.

CXL spec r3.2 section 8.2.9.6 describes optional device specific features.
CXL devices supports features with changeable attributes.
The settings of a feature can be optionally modified using Set Feature
command.
CXL spec r3.2 section 8.2.9.6.3 describes Set Feature command.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Link: https://patch.msgid.link/20250220194438.2281088-6-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/core/core.h     |  4 ++
 drivers/cxl/core/features.c | 80 +++++++++++++++++++++++++++++++++++++
 include/cxl/features.h      | 33 +++++++++++++++
 3 files changed, 117 insertions(+)

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 7cd3b98150e61..17e99a25c29a5 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -122,6 +122,10 @@ size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
 		       enum cxl_get_feat_selection selection,
 		       void *feat_out, size_t feat_out_size, u16 offset,
 		       u16 *return_code);
+int cxl_set_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
+		    u8 feat_version, const void *feat_data,
+		    size_t feat_data_size, u32 feat_flag, u16 offset,
+		    u16 *return_code);
 #endif
 
 #endif /* __CXL_CORE_H__ */
diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
index 3fc6f8415f191..17a82734a3406 100644
--- a/drivers/cxl/core/features.c
+++ b/drivers/cxl/core/features.c
@@ -223,3 +223,83 @@ size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
 
 	return data_rcvd_size;
 }
+
+/*
+ * FEAT_DATA_MIN_PAYLOAD_SIZE - min extra number of bytes should be
+ * available in the mailbox for storing the actual feature data so that
+ * the feature data transfer would work as expected.
+ */
+#define FEAT_DATA_MIN_PAYLOAD_SIZE 10
+int cxl_set_feature(struct cxl_mailbox *cxl_mbox,
+		    const uuid_t *feat_uuid, u8 feat_version,
+		    const void *feat_data, size_t feat_data_size,
+		    u32 feat_flag, u16 offset, u16 *return_code)
+{
+	size_t data_in_size, data_sent_size = 0;
+	struct cxl_mbox_cmd mbox_cmd;
+	size_t hdr_size;
+
+	if (return_code)
+		*return_code = CXL_MBOX_CMD_RC_INPUT;
+
+	struct cxl_mbox_set_feat_in *pi __free(kfree) =
+			kzalloc(cxl_mbox->payload_size, GFP_KERNEL);
+	if (!pi)
+		return -ENOMEM;
+
+	uuid_copy(&pi->uuid, feat_uuid);
+	pi->version = feat_version;
+	feat_flag &= ~CXL_SET_FEAT_FLAG_DATA_TRANSFER_MASK;
+	feat_flag |= CXL_SET_FEAT_FLAG_DATA_SAVED_ACROSS_RESET;
+	hdr_size = sizeof(pi->hdr);
+	/*
+	 * Check minimum mbox payload size is available for
+	 * the feature data transfer.
+	 */
+	if (hdr_size + FEAT_DATA_MIN_PAYLOAD_SIZE > cxl_mbox->payload_size)
+		return -ENOMEM;
+
+	if (hdr_size + feat_data_size <= cxl_mbox->payload_size) {
+		pi->flags = cpu_to_le32(feat_flag |
+					CXL_SET_FEAT_FLAG_FULL_DATA_TRANSFER);
+		data_in_size = feat_data_size;
+	} else {
+		pi->flags = cpu_to_le32(feat_flag |
+					CXL_SET_FEAT_FLAG_INITIATE_DATA_TRANSFER);
+		data_in_size = cxl_mbox->payload_size - hdr_size;
+	}
+
+	do {
+		int rc;
+
+		pi->offset = cpu_to_le16(offset + data_sent_size);
+		memcpy(pi->feat_data, feat_data + data_sent_size, data_in_size);
+		mbox_cmd = (struct cxl_mbox_cmd) {
+			.opcode = CXL_MBOX_OP_SET_FEATURE,
+			.size_in = hdr_size + data_in_size,
+			.payload_in = pi,
+		};
+		rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+		if (rc < 0) {
+			if (return_code)
+				*return_code = mbox_cmd.return_code;
+			return rc;
+		}
+
+		data_sent_size += data_in_size;
+		if (data_sent_size >= feat_data_size) {
+			if (return_code)
+				*return_code = CXL_MBOX_CMD_RC_SUCCESS;
+			return 0;
+		}
+
+		if ((feat_data_size - data_sent_size) <= (cxl_mbox->payload_size - hdr_size)) {
+			data_in_size = feat_data_size - data_sent_size;
+			pi->flags = cpu_to_le32(feat_flag |
+						CXL_SET_FEAT_FLAG_FINISH_DATA_TRANSFER);
+		} else {
+			pi->flags = cpu_to_le32(feat_flag |
+						CXL_SET_FEAT_FLAG_CONTINUE_DATA_TRANSFER);
+		}
+	} while (true);
+}
diff --git a/include/cxl/features.h b/include/cxl/features.h
index 766c09978e5e1..ae56ef7ec9aba 100644
--- a/include/cxl/features.h
+++ b/include/cxl/features.h
@@ -90,6 +90,39 @@ enum cxl_get_feat_selection {
 	CXL_GET_FEAT_SEL_MAX
 };
 
+/*
+ * Set Feature CXL spec r3.2  8.2.9.6.3
+ */
+
+/*
+ * Set Feature input payload
+ * CXL spec r3.2 section 8.2.9.6.3 Table 8-101
+ */
+struct cxl_mbox_set_feat_in {
+	__struct_group(cxl_mbox_set_feat_hdr, hdr, /* no attrs */,
+		uuid_t uuid;
+		__le32 flags;
+		__le16 offset;
+		u8 version;
+		u8 rsvd[9];
+	);
+	__u8 feat_data[];
+}  __packed;
+
+/* Set Feature flags field */
+enum cxl_set_feat_flag_data_transfer {
+	CXL_SET_FEAT_FLAG_FULL_DATA_TRANSFER = 0,
+	CXL_SET_FEAT_FLAG_INITIATE_DATA_TRANSFER,
+	CXL_SET_FEAT_FLAG_CONTINUE_DATA_TRANSFER,
+	CXL_SET_FEAT_FLAG_FINISH_DATA_TRANSFER,
+	CXL_SET_FEAT_FLAG_ABORT_DATA_TRANSFER,
+	CXL_SET_FEAT_FLAG_DATA_TRANSFER_MAX
+};
+
+#define CXL_SET_FEAT_FLAG_DATA_TRANSFER_MASK	GENMASK(2, 0)
+
+#define CXL_SET_FEAT_FLAG_DATA_SAVED_ACROSS_RESET	BIT(3)
+
 /**
  * struct cxl_features_state - The Features state for the device
  * @cxlds: Pointer to CXL device state

From a8b773f24203ef41162fc035944a82909a35f567 Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@intel.com>
Date: Thu, 20 Feb 2025 12:42:44 -0700
Subject: [PATCH 7/7] cxl: Setup exclusive CXL features that are reserved for
 the kernel

Certain features will be exclusively used by components such as in
kernel RAS driver. Setup an exclusion list that can be used to detect
if a feature is exclusive to the kernel.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Tested-by: Shiju Jose <shiju.jose@huawei.com>
Link: https://patch.msgid.link/20250220194438.2281088-7-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/core/features.c | 28 ++++++++++++++++++++++++++++
 include/cxl/features.h      | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
index 17a82734a3406..048ba4fc3538e 100644
--- a/drivers/cxl/core/features.c
+++ b/drivers/cxl/core/features.c
@@ -7,6 +7,28 @@
 #include "core.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;
@@ -47,6 +69,7 @@ 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);
@@ -121,6 +144,10 @@ get_supported_features(struct cxl_features_state *cxlfs)
 			return NULL;
 
 		memcpy(entry, mbox_out->ents, retrieved);
+		for (int i = 0; i < num_entries; i++) {
+			if (!is_cxl_feature_exclusive(entry + i))
+				user_feats++;
+		}
 		entry += num_entries;
 		/*
 		 * If the number of output entries is less than expected, add the
@@ -131,6 +158,7 @@ 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 ae56ef7ec9aba..d2cde46b0fec8 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,
@@ -134,6 +167,7 @@ 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;
 };