[PATCH v2 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
1. Clearing and populating the Vendor debug log and Component
state dump log in certain scenarios, allowing for the aggregation
of results over time.
2. Clear the log when the device is shipped from manufacturing.
3. In some device failure cases, customer may want to clear
the log before shipping it back to the vendor.

Signed-off-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com>
---
 drivers/cxl/core/mbox.c      | 11 +++++++++++
 drivers/cxl/cxlmem.h         |  4 ++++
 include/uapi/linux/cxl_mem.h |  1 +
 3 files changed, 16 insertions(+)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 30bd8264292f..5fb01194f16f 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 +334,16 @@ 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 and Component state dump logs.
+		 */
+		return (uuid_equal(uuid, &DEFINE_CXL_VENDOR_DEBUG_UUID) ||
+			uuid_equal(uuid, &DEFINE_CXL_COMPONENT_STATE_DUMP_UUID));
+	}
 	default:
 		break;
 	}
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 671e46538baa..af7f8a4b84b2 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,
@@ -565,6 +566,9 @@ enum cxl_opcode {
 #define DEFINE_CXL_VENDOR_DEBUG_UUID                                           \
 	UUID_INIT(0xe1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 0x07, 0x19,     \
 		  0x40, 0x3d, 0x86)
+#define DEFINE_CXL_COMPONENT_STATE_DUMP_UUID                                   \
+	UUID_INIT(0xb3fab4cf, 0x01b6, 0x4332, 0x94, 0x3e, 0x5e, 0x99, 0x62,    \
+		0xf2, 0x35, 0x67)
 
 struct cxl_mbox_get_supported_logs {
 	__le16 entries;
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