printk: ringbuffer: relocate get_data()

Move the internal get_data() function as-is above prb_reserve() so
that a later change can make use of the static function.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200914123354.832-2-john.ogness@linutronix.de

diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c
index 11b860ad52643a66afc0fa3252b91ad6c3def80e..664552cb931c3d0a981ba4f6dfa5a420a710c18b 100644 (file)
--- a/kernel/printk/printk_ringbuffer.c
+++ b/kernel/printk/printk_ringbuffer.c
@@ -1055,6 +1055,64 @@ static unsigned int space_used(struct prb_data_ring *data_ring,
                DATA_SIZE(data_ring) - DATA_INDEX(data_ring, blk_lpos->begin));
 }
 
+/*
+ * Given @blk_lpos, return a pointer to the writer data from the data block
+ * and calculate the size of the data part. A NULL pointer is returned if
+ * @blk_lpos specifies values that could never be legal.
+ *
+ * This function (used by readers) performs strict validation on the lpos
+ * values to possibly detect bugs in the writer code. A WARN_ON_ONCE() is
+ * triggered if an internal error is detected.
+ */
+static const char *get_data(struct prb_data_ring *data_ring,
+                           struct prb_data_blk_lpos *blk_lpos,
+                           unsigned int *data_size)
+{
+       struct prb_data_block *db;
+
+       /* Data-less data block description. */
+       if (LPOS_DATALESS(blk_lpos->begin) && LPOS_DATALESS(blk_lpos->next)) {
+               if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {
+                       *data_size = 0;
+                       return "";
+               }
+               return NULL;
+       }
+
+       /* Regular data block: @begin less than @next and in same wrap. */
+       if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next) &&
+           blk_lpos->begin < blk_lpos->next) {
+               db = to_block(data_ring, blk_lpos->begin);
+               *data_size = blk_lpos->next - blk_lpos->begin;
+
+       /* Wrapping data block: @begin is one wrap behind @next. */
+       } else if (DATA_WRAPS(data_ring, blk_lpos->begin + DATA_SIZE(data_ring)) ==
+                  DATA_WRAPS(data_ring, blk_lpos->next)) {
+               db = to_block(data_ring, 0);
+               *data_size = DATA_INDEX(data_ring, blk_lpos->next);
+
+       /* Illegal block description. */
+       } else {
+               WARN_ON_ONCE(1);
+               return NULL;
+       }
+
+       /* A valid data block will always be aligned to the ID size. */
+       if (WARN_ON_ONCE(blk_lpos->begin != ALIGN(blk_lpos->begin, sizeof(db->id))) ||
+           WARN_ON_ONCE(blk_lpos->next != ALIGN(blk_lpos->next, sizeof(db->id)))) {
+               return NULL;
+       }
+
+       /* A valid data block will always have at least an ID. */
+       if (WARN_ON_ONCE(*data_size < sizeof(db->id)))
+               return NULL;
+
+       /* Subtract block ID space from size to reflect data size. */
+       *data_size -= sizeof(db->id);
+
+       return &db->data[0];
+}
+
 /**
  * prb_reserve() - Reserve space in the ringbuffer.
  *
@@ -1209,64 +1267,6 @@ void prb_commit(struct prb_reserved_entry *e)
        local_irq_restore(e->irqflags);
 }
 
-/*
- * Given @blk_lpos, return a pointer to the writer data from the data block
- * and calculate the size of the data part. A NULL pointer is returned if
- * @blk_lpos specifies values that could never be legal.
- *
- * This function (used by readers) performs strict validation on the lpos
- * values to possibly detect bugs in the writer code. A WARN_ON_ONCE() is
- * triggered if an internal error is detected.
- */
-static const char *get_data(struct prb_data_ring *data_ring,
-                           struct prb_data_blk_lpos *blk_lpos,
-                           unsigned int *data_size)
-{
-       struct prb_data_block *db;
-
-       /* Data-less data block description. */
-       if (LPOS_DATALESS(blk_lpos->begin) && LPOS_DATALESS(blk_lpos->next)) {
-               if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {
-                       *data_size = 0;
-                       return "";
-               }
-               return NULL;
-       }
-
-       /* Regular data block: @begin less than @next and in same wrap. */
-       if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next) &&
-           blk_lpos->begin < blk_lpos->next) {
-               db = to_block(data_ring, blk_lpos->begin);
-               *data_size = blk_lpos->next - blk_lpos->begin;
-
-       /* Wrapping data block: @begin is one wrap behind @next. */
-       } else if (DATA_WRAPS(data_ring, blk_lpos->begin + DATA_SIZE(data_ring)) ==
-                  DATA_WRAPS(data_ring, blk_lpos->next)) {
-               db = to_block(data_ring, 0);
-               *data_size = DATA_INDEX(data_ring, blk_lpos->next);
-
-       /* Illegal block description. */
-       } else {
-               WARN_ON_ONCE(1);
-               return NULL;
-       }
-
-       /* A valid data block will always be aligned to the ID size. */
-       if (WARN_ON_ONCE(blk_lpos->begin != ALIGN(blk_lpos->begin, sizeof(db->id))) ||
-           WARN_ON_ONCE(blk_lpos->next != ALIGN(blk_lpos->next, sizeof(db->id)))) {
-               return NULL;
-       }
-
-       /* A valid data block will always have at least an ID. */
-       if (WARN_ON_ONCE(*data_size < sizeof(db->id)))
-               return NULL;
-
-       /* Subtract block ID space from size to reflect data size. */
-       *data_size -= sizeof(db->id);
-
-       return &db->data[0];
-}
-
 /*
  * Count the number of lines in provided text. All text has at least 1 line
  * (even if @text_size is 0). Each '\n' processed is counted as an additional