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Subject[PATCH printk v5 2/6] printk: ringbuffer: add BLK_DATALESS() macro
Date
Rather than continually needing to explicitly check @begin and @next
to identify a dataless block, introduce and use a BLK_DATALESS()
macro.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
---
kernel/printk/printk_ringbuffer.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c
index aa6e31a27601..6ee5ebce1450 100644
--- a/kernel/printk/printk_ringbuffer.c
+++ b/kernel/printk/printk_ringbuffer.c
@@ -266,6 +266,8 @@

/* Determine if a logical position refers to a data-less block. */
#define LPOS_DATALESS(lpos) ((lpos) & 1UL)
+#define BLK_DATALESS(blk) (LPOS_DATALESS((blk)->begin) && \
+ LPOS_DATALESS((blk)->next))

/* Get the logical position at index 0 of the current wrap. */
#define DATA_THIS_WRAP_START_LPOS(data_ring, lpos) \
@@ -1021,7 +1023,7 @@ static unsigned int space_used(struct prb_data_ring *data_ring,
struct prb_data_blk_lpos *blk_lpos)
{
/* Data-less blocks take no space. */
- if (LPOS_DATALESS(blk_lpos->begin))
+ if (BLK_DATALESS(blk_lpos))
return 0;

if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next)) {
@@ -1054,7 +1056,7 @@ static const char *get_data(struct prb_data_ring *data_ring,
struct prb_data_block *db;

/* Data-less data block description. */
- if (LPOS_DATALESS(blk_lpos->begin) && LPOS_DATALESS(blk_lpos->next)) {
+ if (BLK_DATALESS(blk_lpos)) {
if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {
*data_size = 0;
return "";
--
2.20.1
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