cxl/pmem: Add "Freeze Security State" security command support

Create callback function to support the nvdimm_security_ops() ->freeze()
callback. Translate the operation to send "Freeze Security State" security
command for CXL memory device.

See CXL rev3.0 spec section 8.2.9.8.6.5 for reference.
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983613019.2734609.10645754779802492122.stgit@djiang5-desk3.ch.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/mbox.c

@@ -68,6 +68,7 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
 	CXL_CMD(GET_SECURITY_STATE, 0, 0x4, 0),
 	CXL_CMD(SET_PASSPHRASE, 0x60, 0, 0),
 	CXL_CMD(DISABLE_PASSPHRASE, 0x40, 0, 0),
+	CXL_CMD(FREEZE_SECURITY, 0, 0, 0),
 };
 
 /*

drivers/cxl/cxlmem.h

@@ -276,6 +276,7 @@ enum cxl_opcode {
 	CXL_MBOX_OP_GET_SECURITY_STATE	= 0x4500,
 	CXL_MBOX_OP_SET_PASSPHRASE	= 0x4501,
 	CXL_MBOX_OP_DISABLE_PASSPHRASE	= 0x4502,
+	CXL_MBOX_OP_FREEZE_SECURITY	= 0x4504,
 	CXL_MBOX_OP_MAX			= 0x10000
 };
 

drivers/cxl/security.c

@@ -87,10 +87,20 @@ static int cxl_pmem_security_disable(struct nvdimm *nvdimm,
 	return rc;
 }
 
+static int cxl_pmem_security_freeze(struct nvdimm *nvdimm)
+{
+	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
+	struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+
+	return cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_FREEZE_SECURITY, NULL, 0, NULL, 0);
+}
+
 static const struct nvdimm_security_ops __cxl_security_ops = {
 	.get_flags = cxl_pmem_get_security_flags,
 	.change_key = cxl_pmem_security_change_key,
 	.disable = cxl_pmem_security_disable,
+	.freeze = cxl_pmem_security_freeze,
 };
 
 const struct nvdimm_security_ops *cxl_security_ops = &__cxl_security_ops;

include/uapi/linux/cxl_mem.h

@@ -44,6 +44,7 @@
 	___C(GET_SECURITY_STATE, "Get Security State"),			  \
 	___C(SET_PASSPHRASE, "Set Passphrase"),				  \
 	___C(DISABLE_PASSPHRASE, "Disable Passphrase"),			  \
+	___C(FREEZE_SECURITY, "Freeze Security"),			  \
 	___C(MAX, "invalid / last command")
 
 #define ___C(a, b) CXL_MEM_COMMAND_ID_##a