1 /* ===-- clear_cache.c - Implement __clear_cache ---------------------------=== 2 * 3 * The LLVM Compiler Infrastructure 4 * 5 * This file is dual licensed under the MIT and the University of Illinois Open 6 * Source Licenses. See LICENSE.TXT for details. 7 * 8 * ===----------------------------------------------------------------------=== 9 */ 10 11 #include "int_lib.h" 12 #include <stddef.h> 13 14 #if __APPLE__ 15 #include <libkern/OSCacheControl.h> 16 #endif 17 18 #if defined(_WIN32) 19 /* Forward declare Win32 APIs since the GCC mode driver does not handle the 20 newer SDKs as well as needed. */ 21 uint32_t FlushInstructionCache(uintptr_t hProcess, void *lpBaseAddress, 22 uintptr_t dwSize); 23 uintptr_t GetCurrentProcess(void); 24 #endif 25 26 #if (defined(__FreeBSD__) || defined(__Bitrig__)) && defined(__arm__) 27 #include <sys/types.h> 28 #include <machine/sysarch.h> 29 #endif 30 31 #if defined(__NetBSD__) && defined(__arm__) 32 #include <machine/sysarch.h> 33 #endif 34 35 #if defined(__mips__) 36 #include <sys/cachectl.h> 37 #include <sys/syscall.h> 38 #include <unistd.h> 39 #if defined(__ANDROID__) && defined(__LP64__) 40 /* 41 * clear_mips_cache - Invalidates instruction cache for Mips. 42 */ 43 static void clear_mips_cache(const void* Addr, size_t Size) { 44 asm volatile ( 45 ".set push\n" 46 ".set noreorder\n" 47 ".set noat\n" 48 "beq %[Size], $zero, 20f\n" /* If size == 0, branch around. */ 49 "nop\n" 50 "daddu %[Size], %[Addr], %[Size]\n" /* Calculate end address + 1 */ 51 "rdhwr $v0, $1\n" /* Get step size for SYNCI. 52 $1 is $HW_SYNCI_Step */ 53 "beq $v0, $zero, 20f\n" /* If no caches require 54 synchronization, branch 55 around. */ 56 "nop\n" 57 "10:\n" 58 "synci 0(%[Addr])\n" /* Synchronize all caches around 59 address. */ 60 "daddu %[Addr], %[Addr], $v0\n" /* Add step size. */ 61 "sltu $at, %[Addr], %[Size]\n" /* Compare current with end 62 address. */ 63 "bne $at, $zero, 10b\n" /* Branch if more to do. */ 64 "nop\n" 65 "sync\n" /* Clear memory hazards. */ 66 "20:\n" 67 "bal 30f\n" 68 "nop\n" 69 "30:\n" 70 "daddiu $ra, $ra, 12\n" /* $ra has a value of $pc here. 71 Add offset of 12 to point to the 72 instruction after the last nop. 73 */ 74 "jr.hb $ra\n" /* Return, clearing instruction 75 hazards. */ 76 "nop\n" 77 ".set pop\n" 78 : [Addr] "+r"(Addr), [Size] "+r"(Size) 79 :: "at", "ra", "v0", "memory" 80 ); 81 } 82 #endif 83 #endif 84 85 /* 86 * The compiler generates calls to __clear_cache() when creating 87 * trampoline functions on the stack for use with nested functions. 88 * It is expected to invalidate the instruction cache for the 89 * specified range. 90 */ 91 92 void __clear_cache(void *start, void *end) { 93 #if __i386__ || __x86_64__ 94 /* 95 * Intel processors have a unified instruction and data cache 96 * so there is nothing to do 97 */ 98 #elif defined(__arm__) && !defined(__APPLE__) 99 #if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__Bitrig__) 100 struct arm_sync_icache_args arg; 101 102 arg.addr = (uintptr_t)start; 103 arg.len = (uintptr_t)end - (uintptr_t)start; 104 105 sysarch(ARM_SYNC_ICACHE, &arg); 106 #elif defined(__linux__) 107 /* 108 * We used to include asm/unistd.h for the __ARM_NR_cacheflush define, but 109 * it also brought many other unused defines, as well as a dependency on 110 * kernel headers to be installed. 111 * 112 * This value is stable at least since Linux 3.13 and should remain so for 113 * compatibility reasons, warranting it's re-definition here. 114 */ 115 #define __ARM_NR_cacheflush 0x0f0002 116 register int start_reg __asm("r0") = (int) (intptr_t) start; 117 const register int end_reg __asm("r1") = (int) (intptr_t) end; 118 const register int flags __asm("r2") = 0; 119 const register int syscall_nr __asm("r7") = __ARM_NR_cacheflush; 120 __asm __volatile("svc 0x0" 121 : "=r"(start_reg) 122 : "r"(syscall_nr), "r"(start_reg), "r"(end_reg), 123 "r"(flags)); 124 if (start_reg != 0) { 125 compilerrt_abort(); 126 } 127 #elif defined(_WIN32) 128 FlushInstructionCache(GetCurrentProcess(), start, end - start); 129 #else 130 compilerrt_abort(); 131 #endif 132 #elif defined(__mips__) 133 const uintptr_t start_int = (uintptr_t) start; 134 const uintptr_t end_int = (uintptr_t) end; 135 #if defined(__ANDROID__) && defined(__LP64__) 136 // Call synci implementation for short address range. 137 const uintptr_t address_range_limit = 256; 138 if ((end_int - start_int) <= address_range_limit) { 139 clear_mips_cache(start, (end_int - start_int)); 140 } else { 141 syscall(__NR_cacheflush, start, (end_int - start_int), BCACHE); 142 } 143 #else 144 syscall(__NR_cacheflush, start, (end_int - start_int), BCACHE); 145 #endif 146 #elif defined(__aarch64__) && !defined(__APPLE__) 147 uint64_t xstart = (uint64_t)(uintptr_t) start; 148 uint64_t xend = (uint64_t)(uintptr_t) end; 149 uint64_t addr; 150 151 // Get Cache Type Info 152 uint64_t ctr_el0; 153 __asm __volatile("mrs %0, ctr_el0" : "=r"(ctr_el0)); 154 155 /* 156 * dc & ic instructions must use 64bit registers so we don't use 157 * uintptr_t in case this runs in an IPL32 environment. 158 */ 159 const size_t dcache_line_size = 4 << ((ctr_el0 >> 16) & 15); 160 for (addr = xstart; addr < xend; addr += dcache_line_size) 161 __asm __volatile("dc cvau, %0" :: "r"(addr)); 162 __asm __volatile("dsb ish"); 163 164 const size_t icache_line_size = 4 << ((ctr_el0 >> 0) & 15); 165 for (addr = xstart; addr < xend; addr += icache_line_size) 166 __asm __volatile("ic ivau, %0" :: "r"(addr)); 167 __asm __volatile("isb sy"); 168 #else 169 #if __APPLE__ 170 /* On Darwin, sys_icache_invalidate() provides this functionality */ 171 sys_icache_invalidate(start, end-start); 172 #else 173 compilerrt_abort(); 174 #endif 175 #endif 176 } 177 178