[PATCH v3 2/2] cxl/mbox: Add Clear Log mailbox command

[<sthanneeru.opensrc@micron.com>]

From: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com>

Adding UAPI support for CXL r3.1 8.2.9.5.4
Clear Log command.

This proposed patch will be useful for clearing and populating
the Vendor debug log in certain scenarios, allowing for the
aggregation of results over time.

Signed-off-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com>
---
 drivers/cxl/core/mbox.c      | 10 ++++++++++
 drivers/cxl/cxlmem.h         |  1 +
 include/uapi/linux/cxl_mem.h |  1 +
 3 files changed, 12 insertions(+)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 30bd8264292f..58437ae56140 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -57,6 +57,7 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
 	CXL_CMD(GET_HEALTH_INFO, 0, 0x12, 0),
 	CXL_CMD(GET_LOG, 0x18, CXL_VARIABLE_PAYLOAD, CXL_CMD_FLAG_FORCE_ENABLE),
 	CXL_CMD(GET_LOG_CAPS, 0x10, 0x4, 0),
+	CXL_CMD(CLEAR_LOG, 0x10, 0, 0),
 	CXL_CMD(GET_SUP_LOG_SUBLIST, 0x2, CXL_VARIABLE_PAYLOAD, 0),
 	CXL_CMD(SET_PARTITION_INFO, 0x0a, 0, 0),
 	CXL_CMD(SET_LSA, CXL_VARIABLE_PAYLOAD, 0, 0),
@@ -333,6 +334,15 @@ static bool cxl_payload_from_user_allowed(u16 opcode, void *payload_in)
 			return false;
 		break;
 	}
+	case CXL_MBOX_OP_CLEAR_LOG: {
+		const uuid_t *uuid = (uuid_t *)payload_in;
+
+		/*
+		 * Restrict the ‘Clear log’ action to only apply to
+		 * Vendor debug logs.
+		 */
+		return uuid_equal(uuid, &DEFINE_CXL_VENDOR_DEBUG_UUID);
+	}
 	default:
 		break;
 	}
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 671e46538baa..11a5cd4f3ae1 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -530,6 +530,7 @@ enum cxl_opcode {
 	CXL_MBOX_OP_GET_SUPPORTED_LOGS	= 0x0400,
 	CXL_MBOX_OP_GET_LOG		= 0x0401,
 	CXL_MBOX_OP_GET_LOG_CAPS	= 0x0402,
+	CXL_MBOX_OP_CLEAR_LOG           = 0x0403,
 	CXL_MBOX_OP_GET_SUP_LOG_SUBLIST = 0x0405,
 	CXL_MBOX_OP_IDENTIFY		= 0x4000,
 	CXL_MBOX_OP_GET_PARTITION_INFO	= 0x4100,
diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
index 49c25056c222..c6c0fe27495d 100644
--- a/include/uapi/linux/cxl_mem.h
+++ b/include/uapi/linux/cxl_mem.h
@@ -48,6 +48,7 @@
 	___DEPRECATED(GET_SCAN_MEDIA, "Get Scan Media Results"),          \
 	___C(GET_TIMESTAMP, "Get Timestamp"),                             \
 	___C(GET_LOG_CAPS, "Get Log Capabilities"),			  \
+	___C(CLEAR_LOG, "Clear Log"),					  \
 	___C(GET_SUP_LOG_SUBLIST, "Get Supported Logs Sub-List"),	  \
 	___C(MAX, "invalid / last command")
 
-- 
2.25.1