On 2016年06月15日 17:20, Will Deacon wrote:
On Wed, Jun 15, 2016 at 05:16:17PM +0800, Pan Xinhui wrote:
This patch aims to get rid of endianness in queued_write_unlock(). We
want to set __qrwlock->wmode to NULL, however the address is not
&lock->cnts in big endian machine. That causes queued_write_unlock()
write NULL to the wrong field of __qrwlock.
Actually qrwlock can have same layout, IOW we can remove the #if
__little_endian in struct __qrwlock. With such modification, we only
need define some _QW* and _QR* with corresponding values in different
endian systems.
Suggested-by: Will Deacon <will.dea...@arm.com>
Signed-off-by: Pan Xinhui <xinhui....@linux.vnet.ibm.com>
---
include/asm-generic/qrwlock.h | 15 +++++++++++----
kernel/locking/qrwlock.c | 10 ++++------
2 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index 54a8e65..b135c11 100644
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -27,11 +27,18 @@
/*
* Writer states & reader shift and bias
*/
-#define _QW_WAITING 1 /* A writer is waiting */
-#define _QW_LOCKED 0xff /* A writer holds the lock */
-#define _QW_WMASK 0xff /* Writer mask */
+#ifdef __LITTLE_ENDIAN
#define _QR_SHIFT 8 /* Reader count shift */
-#define _QR_BIAS (1U << _QR_SHIFT)
+#define _QW_SHIFF 0 /* Writer mode shift */
Well, there are other typos that could've been worse, but you probably
want to fix this...
oh... I am really in rush. sorry. will fix it and seed patch v2 soon.
thank you for pointing it out.
Will
