diff mbox

[3/8] xen/x86: Remove %z modifier from inline assembly

Message ID 1455048108-5045-4-git-send-email-andrew.cooper3@citrix.com (mailing list archive)
State New, archived
Headers show

Commit Message

Andrew Cooper Feb. 9, 2016, 8:01 p.m. UTC 
Clang doesn't support the %z modifier.  Replace both uses with an explicit l
suffix, and cover the changes with BUILD_BUG_ON()s

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
---
 xen/arch/x86/xstate.c          | 3 ++-
 xen/include/asm-x86/spinlock.h | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

Comments

Jan Beulich Feb. 10, 2016, 1:10 p.m. UTC | #1 
>>> On 09.02.16 at 21:01, <andrew.cooper3@citrix.com> wrote:
> Clang doesn't support the %z modifier.  Replace both uses with an explicit l
> suffix, and cover the changes with BUILD_BUG_ON()s

Ugly. Really ugly. But well - what do you do.

> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Acked-by: Jan Beulich <jbeulich@suse.com>
diff mbox

Patch

diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
index c5d17ff..4f2fb8e 100644
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -353,11 +353,12 @@  void xrstor(struct vcpu *v, uint64_t mask)
     {
         switch ( __builtin_expect(ptr->fpu_sse.x[FPU_WORD_SIZE_OFFSET], 8) )
         {
+            BUILD_BUG_ON(sizeof(faults) != 4); /* Clang doesn't support %z in asm. */
 #define XRSTOR(pfx) \
         alternative_io("1: .byte " pfx "0x0f,0xae,0x2f\n" \
                        "3:\n" \
                        "   .section .fixup,\"ax\"\n" \
-                       "2: inc%z[faults] %[faults]\n" \
+                       "2: incl %[faults]\n" \
                        "   jmp 3b\n" \
                        "   .previous\n" \
                        _ASM_EXTABLE(1b, 2b), \
diff --git a/xen/include/asm-x86/spinlock.h b/xen/include/asm-x86/spinlock.h
index 70a85af..be72c0f 100644
--- a/xen/include/asm-x86/spinlock.h
+++ b/xen/include/asm-x86/spinlock.h
@@ -2,7 +2,8 @@ 
 #define __ASM_SPINLOCK_H
 
 #define _raw_read_unlock(l) \
-    asm volatile ( "lock; dec%z0 %0" : "+m" ((l)->lock) :: "memory" )
+    BUILD_BUG_ON(sizeof((l)->lock) != 4); /* Clang doesn't support %z in asm. */ \
+    asm volatile ( "lock; decl %0" : "+m" ((l)->lock) :: "memory" )
 
 /*
  * On x86 the only reordering is of reads with older writes.  In the