1 // Copyright 2006-2009 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // CPU specific code for arm independent of OS goes here.
6 #ifdef __arm__
7 #ifdef __QNXNTO__
8 #include <sys/mman.h>  // for cache flushing.
9 #undef MAP_TYPE
10 #else
11 #include <sys/syscall.h>  // for cache flushing.
12 #endif
13 #endif
14 
15 #if V8_TARGET_ARCH_ARM
16 
17 #include "src/assembler.h"
18 #include "src/macro-assembler.h"
19 
20 namespace v8 {
21 namespace internal {
22 
FlushICache(void * start,size_t size)23 void CpuFeatures::FlushICache(void* start, size_t size) {
24 #if !defined(USE_SIMULATOR)
25 #if V8_OS_QNX
26   msync(start, size, MS_SYNC | MS_INVALIDATE_ICACHE);
27 #else
28   register uint32_t beg asm("r0") = reinterpret_cast<uint32_t>(start);
29   register uint32_t end asm("r1") = beg + size;
30   register uint32_t flg asm("r2") = 0;
31 
32 #ifdef __clang__
33   // This variant of the asm avoids a constant pool entry, which can be
34   // problematic when LTO'ing. It is also slightly shorter.
35   register uint32_t scno asm("r7") = __ARM_NR_cacheflush;
36 
37   asm volatile("svc 0\n"
38                :
39                : "r"(beg), "r"(end), "r"(flg), "r"(scno)
40                : "memory");
41 #else
42   // Use a different variant of the asm with GCC because some versions doesn't
43   // support r7 as an asm input.
44   asm volatile(
45     // This assembly works for both ARM and Thumb targets.
46 
47     // Preserve r7; it is callee-saved, and GCC uses it as a frame pointer for
48     // Thumb targets.
49     "  push {r7}\n"
50                                   // r0 = beg
51                                   // r1 = end
52                                   // r2 = flags (0)
53     "  ldr r7, =%c[scno]\n"       // r7 = syscall number
54     "  svc 0\n"
55 
56     "  pop {r7}\n"
57     :
58     : "r" (beg), "r" (end), "r" (flg), [scno] "i" (__ARM_NR_cacheflush)
59     : "memory");
60 #endif
61 #endif
62 #endif  // !USE_SIMULATOR
63 }
64 
65 }  // namespace internal
66 }  // namespace v8
67 
68 #endif  // V8_TARGET_ARCH_ARM
69