cxl/mbox: Convert poison list mutex to ACQUIRE()

Towards removing all explicit unlock calls in the CXL subsystem, convert
the conditional poison list mutex to use a conditional lock guard.

Rename the lock to have the compiler validate that all existing call sites
are converted.

Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Alison Schofield <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Ira Weiny <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Dave Jiang <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Reviewed-by: Alison Schofield <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Dave Jiang <[email protected]>

Author: djbw

drivers/cxl/core/mbox.c

@@ -1401,8 +1401,8 @@ int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
 	int nr_records = 0;
 	int rc;
 
-	rc = mutex_lock_interruptible(&mds->poison.lock);
-	if (rc)
+	ACQUIRE(mutex_intr, lock)(&mds->poison.mutex);
+	if ((rc = ACQUIRE_ERR(mutex_intr, &lock)))
 		return rc;
 
 	po = mds->poison.list_out;
@@ -1437,7 +1437,6 @@ int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
 		}
 	} while (po->flags & CXL_POISON_FLAG_MORE);
 
-	mutex_unlock(&mds->poison.lock);
 	return rc;
 }
 EXPORT_SYMBOL_NS_GPL(cxl_mem_get_poison, "CXL");
@@ -1473,7 +1472,7 @@ int cxl_poison_state_init(struct cxl_memdev_state *mds)
 		return rc;
 	}
 
-	mutex_init(&mds->poison.lock);
+	mutex_init(&mds->poison.mutex);
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(cxl_poison_state_init, "CXL");

drivers/cxl/cxlmem.h

@@ -254,7 +254,7 @@ enum security_cmd_enabled_bits {
  * @max_errors: Maximum media error records held in device cache
  * @enabled_cmds: All poison commands enabled in the CEL
  * @list_out: The poison list payload returned by device
- * @lock: Protect reads of the poison list
+ * @mutex: Protect reads of the poison list
  *
  * Reads of the poison list are synchronized to ensure that a reader
  * does not get an incomplete list because their request overlapped
@@ -265,7 +265,7 @@ struct cxl_poison_state {
 	u32 max_errors;
 	DECLARE_BITMAP(enabled_cmds, CXL_POISON_ENABLED_MAX);
 	struct cxl_mbox_poison_out *list_out;
-	struct mutex lock;  /* Protect reads of poison list */
+	struct mutex mutex;  /* Protect reads of poison list */
 };
 
 /*