tools/testing/cxl: add mechanism to lock mem device for testing

The mock cxl mem devs needs a way to go into "locked" status to simulate
when the platform is rebooted. Add a sysfs mechanism so the device security
state is set to "locked" and the frozen state bits are cleared.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983617602.2734609.7042497620931694717.stgit@djiang5-desk3.ch.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

tools/testing/cxl/test/mem.c

@@ -245,7 +245,7 @@ static int mock_set_passphrase(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd
 
 static int mock_disable_passphrase(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 {
-	struct cxl_mock_mem_pdata *mdata = dev_get_platdata(cxlds->dev);
+	struct cxl_mockmem_data *mdata = dev_get_drvdata(cxlds->dev);
 	struct cxl_disable_pass *dis_pass;
 
 	if (cmd->size_in != sizeof(*dis_pass))
@@ -316,7 +316,7 @@ static int mock_disable_passphrase(struct cxl_dev_state *cxlds, struct cxl_mbox_
 
 static int mock_freeze_security(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 {
-	struct cxl_mock_mem_pdata *mdata = dev_get_platdata(cxlds->dev);
+	struct cxl_mockmem_data *mdata = dev_get_drvdata(cxlds->dev);
 
 	if (cmd->size_in != 0)
 		return -EINVAL;
@@ -333,7 +333,7 @@ static int mock_freeze_security(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd
 
 static int mock_unlock_security(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 {
-	struct cxl_mock_mem_pdata *mdata = dev_get_platdata(cxlds->dev);
+	struct cxl_mockmem_data *mdata = dev_get_drvdata(cxlds->dev);
 
 	if (cmd->size_in != NVDIMM_PASSPHRASE_LEN)
 		return -EINVAL;
@@ -376,7 +376,7 @@ static int mock_unlock_security(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd
 static int mock_passphrase_secure_erase(struct cxl_dev_state *cxlds,
 					struct cxl_mbox_cmd *cmd)
 {
-	struct cxl_mock_mem_pdata *mdata = dev_get_platdata(cxlds->dev);
+	struct cxl_mockmem_data *mdata = dev_get_drvdata(cxlds->dev);
 	struct cxl_pass_erase *erase;
 
 	if (cmd->size_in != sizeof(*erase))
@@ -650,6 +650,45 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static ssize_t security_lock_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct cxl_mockmem_data *mdata = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%u\n",
+			  !!(mdata->security_state & CXL_PMEM_SEC_STATE_LOCKED));
+}
+
+static ssize_t security_lock_store(struct device *dev, struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct cxl_mockmem_data *mdata = dev_get_drvdata(dev);
+	u32 mask = CXL_PMEM_SEC_STATE_FROZEN | CXL_PMEM_SEC_STATE_USER_PLIMIT |
+		   CXL_PMEM_SEC_STATE_MASTER_PLIMIT;
+	int val;
+
+	if (kstrtoint(buf, 0, &val) < 0)
+		return -EINVAL;
+
+	if (val == 1) {
+		if (!(mdata->security_state & CXL_PMEM_SEC_STATE_USER_PASS_SET))
+			return -ENXIO;
+		mdata->security_state |= CXL_PMEM_SEC_STATE_LOCKED;
+		mdata->security_state &= ~mask;
+	} else {
+		return -EINVAL;
+	}
+	return count;
+}
+
+static DEVICE_ATTR_RW(security_lock);
+
+static struct attribute *cxl_mock_mem_attrs[] = {
+	&dev_attr_security_lock.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(cxl_mock_mem);
+
 static const struct platform_device_id cxl_mock_mem_ids[] = {
 	{ .name = "cxl_mem", },
 	{ },
@@ -661,6 +700,7 @@ static struct platform_driver cxl_mock_mem_driver = {
 	.id_table = cxl_mock_mem_ids,
 	.driver = {
 		.name = KBUILD_MODNAME,
+		.dev_groups = cxl_mock_mem_groups,
 	},
 };