[PATCH v4 5/8] cxl/edac: Add support for PERFORM_MAINTENANCE command

[<shiju.jose@huawei.com>]

From: Shiju Jose <shiju.jose@huawei.com>

Add support for PERFORM_MAINTENANCE command.

CXL spec 3.2 section 8.2.10.7.1 describes the Perform Maintenance command.
This command requests the device to execute the maintenance operation
specified by the maintenance operation class and the maintenance operation
subclass.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
---
 drivers/cxl/Kconfig     | 17 ++++++++++++++
 drivers/cxl/core/edac.c | 51 +++++++++++++++++++++++++++++++++++++++++
 drivers/cxl/cxlmem.h    |  1 +
 3 files changed, 69 insertions(+)

diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
index 51987f2a2548..2333f7c0b6db 100644
--- a/drivers/cxl/Kconfig
+++ b/drivers/cxl/Kconfig
@@ -164,6 +164,23 @@ config CXL_EDAC_ECS
 	  of a memory ECS feature established by the platform/device.
 	  Otherwise say 'n'.
 
+config CXL_EDAC_MEM_REPAIR
+	bool "Enable CXL Memory Repair"
+	depends on CXL_EDAC_MEM_FEATURES
+	depends on EDAC_MEM_REPAIR
+	help
+	  The CXL EDAC memory repair control is optional and allows host
+	  to control the memory repair features (e.g. sparing, PPR)
+	  configurations of CXL memory expander devices.
+
+	  When enabled 'cxl_mem' EDAC devices are published with memory
+	  repair control attributes as described by
+	  Documentation/ABI/testing/sysfs-edac-memory-repair.
+
+	  Say 'y' if you have an expert need to change default settings
+	  of a memory repair feature established by the platform/device.
+	  Otherwise say 'n'.
+
 config CXL_PORT
 	default CXL_BUS
 	tristate
diff --git a/drivers/cxl/core/edac.c b/drivers/cxl/core/edac.c
index a624fc90caf9..246a02785f1d 100644
--- a/drivers/cxl/core/edac.c
+++ b/drivers/cxl/core/edac.c
@@ -791,6 +791,57 @@ static int cxl_memdev_ecs_init(struct cxl_memdev *cxlmd,
 }
 #endif /* CONFIG_CXL_EDAC_ECS */
 
+#ifdef CONFIG_CXL_EDAC_MEM_REPAIR
+/*
+ * Perform Maintenance CXL 3.2 Spec 8.2.10.7.1
+ */
+
+/*
+ * Perform Maintenance input payload
+ * CXL rev 3.2 section 8.2.10.7.1 Table 8-117
+ */
+struct cxl_mbox_maintenance_hdr {
+	u8 op_class;
+	u8 op_subclass;
+} __packed;
+
+static int cxl_perform_maintenance(struct cxl_mailbox *cxl_mbox, u8 class,
+				   u8 subclass, void *data_in,
+				   size_t data_in_size)
+{
+	struct cxl_memdev_maintenance_pi {
+		struct cxl_mbox_maintenance_hdr hdr;
+		u8 data[];
+	} __packed;
+	struct cxl_mbox_cmd mbox_cmd;
+	size_t hdr_size;
+
+	struct cxl_memdev_maintenance_pi *pi __free(kvfree) =
+		kvzalloc(cxl_mbox->payload_size, GFP_KERNEL);
+	if (!pi)
+		return -ENOMEM;
+
+	pi->hdr.op_class = class;
+	pi->hdr.op_subclass = subclass;
+	hdr_size = sizeof(pi->hdr);
+	/*
+	 * Check minimum mbox payload size is available for
+	 * the maintenance data transfer.
+	 */
+	if (hdr_size + data_in_size > cxl_mbox->payload_size)
+		return -ENOMEM;
+
+	memcpy(pi->data, data_in, data_in_size);
+	mbox_cmd = (struct cxl_mbox_cmd){
+		.opcode = CXL_MBOX_OP_DO_MAINTENANCE,
+		.size_in = hdr_size + data_in_size,
+		.payload_in = pi,
+	};
+
+	return cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+}
+#endif /* CONFIG_CXL_EDAC_MEM_REPAIR */
+
 int devm_cxl_memdev_edac_register(struct cxl_memdev *cxlmd)
 {
 	struct edac_dev_feature ras_features[CXL_NR_EDAC_DEV_FEATURES];
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 685957b312ea..1b9bf6b42521 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -533,6 +533,7 @@ enum cxl_opcode {
 	CXL_MBOX_OP_GET_SUPPORTED_FEATURES	= 0x0500,
 	CXL_MBOX_OP_GET_FEATURE		= 0x0501,
 	CXL_MBOX_OP_SET_FEATURE		= 0x0502,
+	CXL_MBOX_OP_DO_MAINTENANCE	= 0x0600,
 	CXL_MBOX_OP_IDENTIFY		= 0x4000,
 	CXL_MBOX_OP_GET_PARTITION_INFO	= 0x4100,
 	CXL_MBOX_OP_SET_PARTITION_INFO	= 0x4101,
-- 
2.43.0