IB/core: IB/core: Allow legacy verbs through extended interfaces

When an extended verb is an extension to a legacy verb, the original
functionality is preserved. Hence we do not require each hardware driver
to set the extended capability. This will allow the use of the extended
verb in its simple form with drivers that do not support the extended
capability.

Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/uverbs_main.c

@@ -683,6 +683,21 @@ struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd)
 	return ev_file;
 }
 
+static int verify_command_mask(struct ib_device *ib_dev, __u32 command)
+{
+	u64 mask;
+
+	if (command <= IB_USER_VERBS_CMD_OPEN_QP)
+		mask = ib_dev->uverbs_cmd_mask;
+	else
+		mask = ib_dev->uverbs_ex_cmd_mask;
+
+	if (mask & ((u64)1 << command))
+		return 0;
+
+	return -1;
+}
+
 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 			     size_t count, loff_t *pos)
 {
@@ -715,6 +730,10 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 	}
 
 	command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
+	if (verify_command_mask(ib_dev, command)) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
 
 	flags = (hdr.command &
 		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
@@ -732,11 +751,6 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 			goto out;
 		}
 
-		if (!(ib_dev->uverbs_cmd_mask & (1ull << command))) {
-			ret = -ENOSYS;
-			goto out;
-		}
-
 		if (hdr.in_words * 4 != count) {
 			ret = -EINVAL;
 			goto out;
@@ -764,11 +778,6 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 			goto out;
 		}
 
-		if (!(ib_dev->uverbs_ex_cmd_mask & (1ull << command))) {
-			ret = -ENOSYS;
-			goto out;
-		}
-
 		if (count < (sizeof(hdr) + sizeof(ex_hdr))) {
 			ret = -EINVAL;
 			goto out;