Use libgcc __clear_cache to clean icache, when available.

Calling the clear cache syscall directly generates an illegal instruction 
on some (armv4) kernels.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5843 c046a42c-6fe2-441c-8c8c-71466251a162

2 files changed, 13 insertions, 0 deletions

diff --git a/exec-all.h b/exec-all.h
index ca97f57..7f963b0 100644
--- a/exec-all.h
+++ b/exec-all.h
@@ -205,18 +205,26 @@ static inline void tb_set_jmp_target1(unsigned long jmp_addr, unsigned long addr
 #elif defined(__arm__)
 static inline void tb_set_jmp_target1(unsigned long jmp_addr, unsigned long addr)
 {
+#if QEMU_GNUC_PREREQ(4, 1)
+    void __clear_cache(char *beg, char *end);
+#else
     register unsigned long _beg __asm ("a1");
     register unsigned long _end __asm ("a2");
     register unsigned long _flg __asm ("a3");
+#endif
 
     /* we could use a ldr pc, [pc, #-4] kind of branch and avoid the flush */
     *(uint32_t *)jmp_addr |= ((addr - (jmp_addr + 8)) >> 2) & 0xffffff;
 
+#if QEMU_GNUC_PREREQ(4, 1)
+    __clear_cache((char *) jmp_addr, (char *) jmp_addr + 4);
+#else
     /* flush icache */
     _beg = jmp_addr;
     _end = jmp_addr + 4;
     _flg = 0;
     __asm __volatile__ ("swi 0x9f0002" : : "r" (_beg), "r" (_end), "r" (_flg));
+#endif
 }
 #endif
 
diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
index 6c180af..d0b11e8 100644
--- a/tcg/arm/tcg-target.h
+++ b/tcg/arm/tcg-target.h
@@ -69,8 +69,13 @@ enum {
 
 static inline void flush_icache_range(unsigned long start, unsigned long stop)
 {
+#if QEMU_GNUC_PREREQ(4, 1)
+    void __clear_cache(char *beg, char *end);
+    __clear_cache((char *) start, (char *) stop);
+#else
     register unsigned long _beg __asm ("a1") = start;
     register unsigned long _end __asm ("a2") = stop;
     register unsigned long _flg __asm ("a3") = 0;
     __asm __volatile__ ("swi 0x9f0002" : : "r" (_beg), "r" (_end), "r" (_flg));
+#endif
 }