From: Frederik Deweerdt Date: Wed, 16 Jan 2008 16:19:08 +0000 (+0100) Subject: [SCSI] ultrastor: clean up inline asm warnings X-Git-Tag: v2.6.25-rc1~1230^2~2 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1292500b;p=karo-tx-linux.git [SCSI] ultrastor: clean up inline asm warnings To: linux-kernel@vger.kernel.org Cc: bunk@kernel.org Subject: [trivial patch] scsi/ultrastor: clean up inline asm warnings Hi, Compiling latest mainline with gcc 4.2.1 spews the following warnings: drivers/scsi/ultrastor.c: In function 'find_and_clear_bit_16': drivers/scsi/ultrastor.c:303: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:302: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c: At top level: drivers/scsi/ultrastor.c:1202: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:1202: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c: In function 'ultrastor_queuecommand': drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:302: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:302: warning: matching constraint does not allow a register The following patch fixes it by using the '+' operator on the (*field) operand, marking it as read-write to gcc. I diffed the two resulting .s, and gcc produced the same code. This was tested with gcc 4.2.1 and gcc 3.4.3 Signed-off-by: Frederik Deweerdt Cc: Adrian Bunk Signed-off-by: James Bottomley --- diff --git a/drivers/scsi/ultrastor.c b/drivers/scsi/ultrastor.c index 1d3b02976d74..75eca6b22db5 100644 --- a/drivers/scsi/ultrastor.c +++ b/drivers/scsi/ultrastor.c @@ -298,9 +298,16 @@ static inline int find_and_clear_bit_16(unsigned long *field) { int rv; - if (*field == 0) panic("No free mscp"); - asm("xorl %0,%0\n0:\tbsfw %1,%w0\n\tbtr %0,%1\n\tjnc 0b" - : "=&r" (rv), "=m" (*field) : "1" (*field)); + if (*field == 0) + panic("No free mscp"); + + asm volatile ( + "xorl %0,%0\n\t" + "0: bsfw %1,%w0\n\t" + "btr %0,%1\n\t" + "jnc 0b" + : "=&r" (rv), "=m" (*field) :); + return rv; }