[PATCH RESEND] block: sed-opal: Add ioctl to return device status

[Douglas Miller <dougmill@linux.vnet.ibm.com>]

Provide a mechanism to retrieve basic status information about
the device, including the "supported" flag indicating whether
SED-OPAL is supported. The information returned is from the various
feature descriptors received during the discovery0 step, and so
this ioctl does nothing more than perform the discovery0 step
and then save the information received. See "struct opal_status"
for the status information currently returned.

Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
---
  block/opal_proto.h            |  5 +++
  block/sed-opal.c              | 81 ++++++++++++++++++++++++++++++++++--
  include/linux/sed-opal.h      |  1 +
  include/uapi/linux/sed-opal.h | 11 +++++
  4 files changed, 94 insertions(+), 4 deletions(-)

diff --git a/block/opal_proto.h b/block/opal_proto.h
index b486b3e..7152aa1 100644
--- a/block/opal_proto.h
+++ b/block/opal_proto.h
@@ -39,7 +39,12 @@ enum opal_response_token {
  #define FIRST_TPER_SESSION_NUM	4096
  
  #define TPER_SYNC_SUPPORTED 0x01
+/* FC_LOCKING features */
+#define LOCKING_SUPPORTED_MASK 0x01
+#define LOCKING_ENABLED_MASK 0x02
+#define LOCKED_MASK 0x04
  #define MBR_ENABLED_MASK 0x10
+#define MBR_DONE_MASK 0x20
  
  #define TINY_ATOM_DATA_MASK 0x3F
  #define TINY_ATOM_SIGNED 0x40
diff --git a/block/sed-opal.c b/block/sed-opal.c
index daafadb..6a67b20 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -75,7 +75,11 @@ struct parsed_resp {
  
  struct opal_dev {
  	bool supported;
+	bool locking_supported;
+	bool locking_enabled;
+	bool locked;
  	bool mbr_enabled;
+	bool mbr_done;
  
  	void *data;
  	sec_send_recv *send_recv;
@@ -280,6 +284,30 @@ static bool check_tper(const void *data)
  	return true;
  }
  
+static bool check_lcksuppt(const void *data)
+{
+	const struct d0_locking_features *lfeat = data;
+	u8 sup_feat = lfeat->supported_features;
+
+	return !!(sup_feat & LOCKING_SUPPORTED_MASK);
+}
+
+static bool check_lckenabled(const void *data)
+{
+	const struct d0_locking_features *lfeat = data;
+	u8 sup_feat = lfeat->supported_features;
+
+	return !!(sup_feat & LOCKING_ENABLED_MASK);
+}
+
+static bool check_locked(const void *data)
+{
+	const struct d0_locking_features *lfeat = data;
+	u8 sup_feat = lfeat->supported_features;
+
+	return !!(sup_feat & LOCKED_MASK);
+}
+
  static bool check_mbrenabled(const void *data)
  {
  	const struct d0_locking_features *lfeat = data;
@@ -288,6 +316,14 @@ static bool check_mbrenabled(const void *data)
  	return !!(sup_feat & MBR_ENABLED_MASK);
  }
  
+static bool check_mbrdone(const void *data)
+{
+	const struct d0_locking_features *lfeat = data;
+	u8 sup_feat = lfeat->supported_features;
+
+	return !!(sup_feat & MBR_DONE_MASK);
+}
+
  static bool check_sum(const void *data)
  {
  	const struct d0_single_user_mode *sum = data;
@@ -435,7 +471,11 @@ static int opal_discovery0_end(struct opal_dev *dev)
  	u32 hlen = be32_to_cpu(hdr->length);
  
  	print_buffer(dev->resp, hlen);
+	dev->locking_supported = false;
+	dev->locking_enabled = false;
+	dev->locked = false;
  	dev->mbr_enabled = false;
+	dev->mbr_done = false;
  
  	if (hlen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
  		pr_debug("Discovery length overflows buffer (%zu+%u)/%u\n",
@@ -461,7 +501,11 @@ static int opal_discovery0_end(struct opal_dev *dev)
  			check_geometry(dev, body);
  			break;
  		case FC_LOCKING:
+			dev->locking_supported = check_lcksuppt(body->features);
+			dev->locking_enabled = check_lckenabled(body->features);
+			dev->locked = check_locked(body->features);
  			dev->mbr_enabled = check_mbrenabled(body->features);
+			dev->mbr_done = check_mbrdone(body->features);
  			break;
  		case FC_ENTERPRISE:
  		case FC_DATASTORE:
@@ -2620,6 +2664,29 @@ static int opal_generic_read_write_table(struct opal_dev *dev,
  	return ret;
  }
  
+static int opal_get_status(struct opal_dev *dev, void __user *data)
+{
+	struct opal_status sts = {0};
+
+	/*
+	 * check_opal_support() error is not fatal,
+	 * !dev->supported is a valid condition
+	 */
+	if (!check_opal_support(dev)) {
+		sts.opal_supported = dev->supported;
+		sts.locking_supported = dev->locking_supported;
+		sts.locking_enabled = dev->locking_enabled;
+		sts.locked = dev->locked;
+		sts.mbr_enabled = dev->mbr_enabled;
+		sts.mbr_done = dev->mbr_done;
+	}
+	if (copy_to_user(data, &sts, sizeof(sts))) {
+		pr_debug("Error copying status to userspace\n");
+		return -EFAULT;
+	}
+	return 0;
+}
+
  int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
  {
  	void *p;
@@ -2632,9 +2699,11 @@ int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
  	if (!dev->supported)
  		return -ENOTSUPP;
  
-	p = memdup_user(arg, _IOC_SIZE(cmd));
-	if (IS_ERR(p))
-		return PTR_ERR(p);
+	if (cmd & IOC_IN) {
+		p = memdup_user(arg, _IOC_SIZE(cmd));
+		if (IS_ERR(p))
+			return PTR_ERR(p);
+	}
  
  	switch (cmd) {
  	case IOC_OPAL_SAVE:
@@ -2685,11 +2754,15 @@ int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
  	case IOC_OPAL_GENERIC_TABLE_RW:
  		ret = opal_generic_read_write_table(dev, p);
  		break;
+	case IOC_OPAL_GET_STATUS:
+		ret = opal_get_status(dev, arg);
+		break;
  	default:
  		break;
  	}
  
-	kfree(p);
+	if (cmd & IOC_IN)
+		kfree(p);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(sed_ioctl);
diff --git a/include/linux/sed-opal.h b/include/linux/sed-opal.h
index 1ac0d71..6f837bb 100644
--- a/include/linux/sed-opal.h
+++ b/include/linux/sed-opal.h
@@ -43,6 +43,7 @@ static inline bool is_sed_ioctl(unsigned int cmd)
  	case IOC_OPAL_MBR_DONE:
  	case IOC_OPAL_WRITE_SHADOW_MBR:
  	case IOC_OPAL_GENERIC_TABLE_RW:
+	case IOC_OPAL_GET_STATUS:
  		return true;
  	}
  	return false;
diff --git a/include/uapi/linux/sed-opal.h b/include/uapi/linux/sed-opal.h
index 6f5af1a..535ffc5 100644
--- a/include/uapi/linux/sed-opal.h
+++ b/include/uapi/linux/sed-opal.h
@@ -132,6 +132,16 @@ struct opal_read_write_table {
  	__u64 priv;
  };
  
+struct opal_status {
+	__u8 opal_supported;
+	__u8 locking_supported;
+	__u8 locking_enabled;
+	__u8 locked;
+	__u8 mbr_enabled;
+	__u8 mbr_done;
+	__u8 __align[2];
+};
+
  #define IOC_OPAL_SAVE		    _IOW('p', 220, struct opal_lock_unlock)
  #define IOC_OPAL_LOCK_UNLOCK	    _IOW('p', 221, struct opal_lock_unlock)
  #define IOC_OPAL_TAKE_OWNERSHIP	    _IOW('p', 222, struct opal_key)
@@ -148,5 +158,6 @@ struct opal_read_write_table {
  #define IOC_OPAL_MBR_DONE           _IOW('p', 233, struct opal_mbr_done)
  #define IOC_OPAL_WRITE_SHADOW_MBR   _IOW('p', 234, struct opal_shadow_mbr)
  #define IOC_OPAL_GENERIC_TABLE_RW   _IOW('p', 235, struct opal_read_write_table)
+#define IOC_OPAL_GET_STATUS         _IOR('p', 236, struct opal_status)
  
  #endif /* _UAPI_SED_OPAL_H */
-- 
1.8.3.1