[PATCH 3/3] nvmet: expose firmware revision to configfs

[Aleksandr Miloserdov]

Allow user to set currently active firmware revision

Reviewed-by: Konstantin Shelekhin <k.shelekhin at yadro.com>
Reviewed-by: Dmitriy Bogdanov <d.bogdanov at yadro.com>
Signed-off-by: Aleksandr Miloserdov <a.miloserdov at yadro.com>
---
 drivers/nvme/target/admin-cmd.c |  2 +-
 drivers/nvme/target/configfs.c  | 63 +++++++++++++++++++++++++++++++++
 drivers/nvme/target/core.c      | 15 ++++++--
 drivers/nvme/target/nvmet.h     |  2 ++
 4 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 0b415335bb5f..92098032c85d 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -370,7 +370,7 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 	memcpy_and_pad(id->mn, sizeof(id->mn), subsys->model_number,
 		       strlen(subsys->model_number), ' ');
 	memcpy_and_pad(id->fr, sizeof(id->fr),
-		       UTS_RELEASE, strlen(UTS_RELEASE), ' ');
+		       subsys->firmware_rev, strlen(subsys->firmware_rev), ' ');
 
 	id->ieee[0] = (subsys->ieee_oui) & 0xff;
 	id->ieee[1] = (subsys->ieee_oui >> 8) & 0xff;
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index ad62e36ec997..1862b9479347 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -1313,6 +1313,68 @@ static ssize_t nvmet_subsys_attr_ieee_oui_store(struct config_item *item,
 }
 CONFIGFS_ATTR(nvmet_subsys_, attr_ieee_oui);
 
+static ssize_t nvmet_subsys_attr_firmware_show(struct config_item *item,
+					    char *page)
+{
+	struct nvmet_subsys *subsys = to_subsys(item);
+
+	return sysfs_emit(page, "%s\n", subsys->firmware_rev);
+}
+
+static ssize_t nvmet_subsys_attr_firmware_store_locked(struct nvmet_subsys *subsys,
+		const char *page, size_t count)
+{
+	int pos = 0, len;
+	char *val;
+
+	if (subsys->subsys_discovered) {
+		pr_err("Can't set firmware revision. %s is already assigned\n",
+		       subsys->firmware_rev);
+		return -EINVAL;
+	}
+
+	len = strcspn(page, "\n");
+	if (!len)
+		return -EINVAL;
+
+	if (len > NVMET_FR_MAX_SIZE) {
+		pr_err("Firmware revision size can not exceed %d Bytes\n",
+		       NVMET_FR_MAX_SIZE);
+		return -EINVAL;
+	}
+
+	for (pos = 0; pos < len; pos++) {
+		if (!nvmet_is_ascii(page[pos]))
+			return -EINVAL;
+	}
+
+	val = kmemdup_nul(page, len, GFP_KERNEL);
+	if (!val)
+		return -ENOMEM;
+
+	kfree(subsys->firmware_rev);
+
+	subsys->firmware_rev = val;
+
+	return count;
+}
+
+static ssize_t nvmet_subsys_attr_firmware_store(struct config_item *item,
+					     const char *page, size_t count)
+{
+	struct nvmet_subsys *subsys = to_subsys(item);
+	ssize_t ret;
+
+	down_write(&nvmet_config_sem);
+	mutex_lock(&subsys->lock);
+	ret = nvmet_subsys_attr_firmware_store_locked(subsys, page, count);
+	mutex_unlock(&subsys->lock);
+	up_write(&nvmet_config_sem);
+
+	return ret;
+}
+CONFIGFS_ATTR(nvmet_subsys_, attr_firmware);
+
 #ifdef CONFIG_BLK_DEV_INTEGRITY
 static ssize_t nvmet_subsys_attr_pi_enable_show(struct config_item *item,
 						char *page)
@@ -1372,6 +1434,7 @@ static struct configfs_attribute *nvmet_subsys_attrs[] = {
 	&nvmet_subsys_attr_attr_model,
 	&nvmet_subsys_attr_attr_qid_max,
 	&nvmet_subsys_attr_attr_ieee_oui,
+	&nvmet_subsys_attr_attr_firmware,
 #ifdef CONFIG_BLK_DEV_INTEGRITY
 	&nvmet_subsys_attr_attr_pi_enable,
 #endif
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index ec697ceeac56..98d41bbd3f72 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -10,6 +10,8 @@
 #include <linux/pci-p2pdma.h>
 #include <linux/scatterlist.h>
 
+#include <generated/utsrelease.h>
+
 #define CREATE_TRACE_POINTS
 #include "trace.h"
 
@@ -1563,6 +1565,12 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
 
 	subsys->ieee_oui = 0;
 
+	subsys->firmware_rev = kstrndup(UTS_RELEASE, NVMET_FR_MAX_SIZE, GFP_KERNEL);
+	if (!subsys->firmware_rev) {
+		ret = -ENOMEM;
+		goto free_mn;
+	}
+
 	switch (type) {
 	case NVME_NQN_NVME:
 		subsys->max_qid = NVMET_NR_QUEUES;
@@ -1574,14 +1582,14 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
 	default:
 		pr_err("%s: Unknown Subsystem type - %d\n", __func__, type);
 		ret = -EINVAL;
-		goto free_mn;
+		goto free_fr;
 	}
 	subsys->type = type;
 	subsys->subsysnqn = kstrndup(subsysnqn, NVMF_NQN_SIZE,
 			GFP_KERNEL);
 	if (!subsys->subsysnqn) {
 		ret = -ENOMEM;
-		goto free_mn;
+		goto free_fr;
 	}
 	subsys->cntlid_min = NVME_CNTLID_MIN;
 	subsys->cntlid_max = NVME_CNTLID_MAX;
@@ -1594,6 +1602,8 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
 
 	return subsys;
 
+free_fr:
+	kfree(subsys->firmware_rev);
 free_mn:
 	kfree(subsys->model_number);
 free_subsys:
@@ -1613,6 +1623,7 @@ static void nvmet_subsys_free(struct kref *ref)
 
 	kfree(subsys->subsysnqn);
 	kfree(subsys->model_number);
+	kfree(subsys->firmware_rev);
 	kfree(subsys);
 }
 
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 1dc0ff8b2f3f..dd8985b54a84 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -29,6 +29,7 @@
 #define NVMET_DEFAULT_CTRL_MODEL	"Linux"
 #define NVMET_MN_MAX_SIZE		40
 #define NVMET_SN_MAX_SIZE		20
+#define NVMET_FR_MAX_SIZE		8
 
 /*
  * Supported optional AENs:
@@ -265,6 +266,7 @@ struct nvmet_subsys {
 
 	char			*model_number;
 	u32			ieee_oui;
+	char			*firmware_rev;
 
 #ifdef CONFIG_NVME_TARGET_PASSTHRU
 	struct nvme_ctrl	*passthru_ctrl;
-- 
2.37.0