1 //===-- clear_cache.c - Implement __clear_cache ---------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "int_lib.h" 10 #include <assert.h> 11 #include <stddef.h> 12 13 #if __APPLE__ 14 #include <libkern/OSCacheControl.h> 15 #endif 16 17 #if defined(_WIN32) 18 // Forward declare Win32 APIs since the GCC mode driver does not handle the 19 // newer SDKs as well as needed. 20 uint32_t FlushInstructionCache(uintptr_t hProcess, void *lpBaseAddress, 21 uintptr_t dwSize); 22 uintptr_t GetCurrentProcess(void); 23 #endif 24 25 #if defined(__FreeBSD__) && defined(__arm__) 26 #include <machine/sysarch.h> 27 #include <sys/types.h> 28 #endif 29 30 #if defined(__NetBSD__) && defined(__arm__) 31 #include <machine/sysarch.h> 32 #endif 33 34 #if defined(__OpenBSD__) && defined(__mips__) 35 #include <machine/sysarch.h> 36 #include <sys/types.h> 37 #endif 38 39 #if defined(__linux__) && defined(__mips__) 40 #include <sys/cachectl.h> 41 #include <sys/syscall.h> 42 #include <unistd.h> 43 #if defined(__ANDROID__) && defined(__LP64__) 44 // clear_mips_cache - Invalidates instruction cache for Mips. 45 static void clear_mips_cache(const void *Addr, size_t Size) { 46 __asm__ volatile( 47 ".set push\n" 48 ".set noreorder\n" 49 ".set noat\n" 50 "beq %[Size], $zero, 20f\n" // If size == 0, branch around. 51 "nop\n" 52 "daddu %[Size], %[Addr], %[Size]\n" // Calculate end address + 1 53 "rdhwr $v0, $1\n" // Get step size for SYNCI. 54 // $1 is $HW_SYNCI_Step 55 "beq $v0, $zero, 20f\n" // If no caches require 56 // synchronization, branch 57 // around. 58 "nop\n" 59 "10:\n" 60 "synci 0(%[Addr])\n" // Synchronize all caches around 61 // address. 62 "daddu %[Addr], %[Addr], $v0\n" // Add step size. 63 "sltu $at, %[Addr], %[Size]\n" // Compare current with end 64 // address. 65 "bne $at, $zero, 10b\n" // Branch if more to do. 66 "nop\n" 67 "sync\n" // Clear memory hazards. 68 "20:\n" 69 "bal 30f\n" 70 "nop\n" 71 "30:\n" 72 "daddiu $ra, $ra, 12\n" // $ra has a value of $pc here. 73 // Add offset of 12 to point to the 74 // instruction after the last nop. 75 // 76 "jr.hb $ra\n" // Return, clearing instruction 77 // hazards. 78 "nop\n" 79 ".set pop\n" 80 : [ Addr ] "+r"(Addr), [ Size ] "+r"(Size)::"at", "ra", "v0", "memory"); 81 } 82 #endif 83 #endif 84 85 // The compiler generates calls to __clear_cache() when creating 86 // trampoline functions on the stack for use with nested functions. 87 // It is expected to invalidate the instruction cache for the 88 // specified range. 89 90 void __clear_cache(void *start, void *end) { 91 #if __i386__ || __x86_64__ || defined(_M_IX86) || defined(_M_X64) 92 // Intel processors have a unified instruction and data cache 93 // so there is nothing to do 94 #elif defined(_WIN32) && (defined(__arm__) || defined(__aarch64__)) 95 FlushInstructionCache(GetCurrentProcess(), start, end - start); 96 #elif defined(__arm__) && !defined(__APPLE__) 97 #if defined(__FreeBSD__) || defined(__NetBSD__) 98 struct arm_sync_icache_args arg; 99 100 arg.addr = (uintptr_t)start; 101 arg.len = (uintptr_t)end - (uintptr_t)start; 102 103 sysarch(ARM_SYNC_ICACHE, &arg); 104 #elif defined(__linux__) 105 // We used to include asm/unistd.h for the __ARM_NR_cacheflush define, but 106 // it also brought many other unused defines, as well as a dependency on 107 // kernel headers to be installed. 108 // 109 // This value is stable at least since Linux 3.13 and should remain so for 110 // compatibility reasons, warranting it's re-definition here. 111 #define __ARM_NR_cacheflush 0x0f0002 112 register int start_reg __asm("r0") = (int)(intptr_t)start; 113 const register int end_reg __asm("r1") = (int)(intptr_t)end; 114 const register int flags __asm("r2") = 0; 115 const register int syscall_nr __asm("r7") = __ARM_NR_cacheflush; 116 __asm __volatile("svc 0x0" 117 : "=r"(start_reg) 118 : "r"(syscall_nr), "r"(start_reg), "r"(end_reg), "r"(flags)); 119 assert(start_reg == 0 && "Cache flush syscall failed."); 120 #else 121 compilerrt_abort(); 122 #endif 123 #elif defined(__linux__) && defined(__mips__) 124 const uintptr_t start_int = (uintptr_t)start; 125 const uintptr_t end_int = (uintptr_t)end; 126 #if defined(__ANDROID__) && defined(__LP64__) 127 // Call synci implementation for short address range. 128 const uintptr_t address_range_limit = 256; 129 if ((end_int - start_int) <= address_range_limit) { 130 clear_mips_cache(start, (end_int - start_int)); 131 } else { 132 syscall(__NR_cacheflush, start, (end_int - start_int), BCACHE); 133 } 134 #else 135 syscall(__NR_cacheflush, start, (end_int - start_int), BCACHE); 136 #endif 137 #elif defined(__mips__) && defined(__OpenBSD__) 138 cacheflush(start, (uintptr_t)end - (uintptr_t)start, BCACHE); 139 #elif defined(__aarch64__) && !defined(__APPLE__) 140 uint64_t xstart = (uint64_t)(uintptr_t)start; 141 uint64_t xend = (uint64_t)(uintptr_t)end; 142 uint64_t addr; 143 144 // Get Cache Type Info 145 uint64_t ctr_el0; 146 __asm __volatile("mrs %0, ctr_el0" : "=r"(ctr_el0)); 147 148 // dc & ic instructions must use 64bit registers so we don't use 149 // uintptr_t in case this runs in an IPL32 environment. 150 const size_t dcache_line_size = 4 << ((ctr_el0 >> 16) & 15); 151 for (addr = xstart & ~(dcache_line_size - 1); addr < xend; 152 addr += dcache_line_size) 153 __asm __volatile("dc cvau, %0" ::"r"(addr)); 154 __asm __volatile("dsb ish"); 155 156 const size_t icache_line_size = 4 << ((ctr_el0 >> 0) & 15); 157 for (addr = xstart & ~(icache_line_size - 1); addr < xend; 158 addr += icache_line_size) 159 __asm __volatile("ic ivau, %0" ::"r"(addr)); 160 __asm __volatile("isb sy"); 161 #elif defined(__powerpc64__) 162 const size_t line_size = 32; 163 const size_t len = (uintptr_t)end - (uintptr_t)start; 164 165 const uintptr_t mask = ~(line_size - 1); 166 const uintptr_t start_line = ((uintptr_t)start) & mask; 167 const uintptr_t end_line = ((uintptr_t)start + len + line_size - 1) & mask; 168 169 for (uintptr_t line = start_line; line < end_line; line += line_size) 170 __asm__ volatile("dcbf 0, %0" : : "r"(line)); 171 __asm__ volatile("sync"); 172 173 for (uintptr_t line = start_line; line < end_line; line += line_size) 174 __asm__ volatile("icbi 0, %0" : : "r"(line)); 175 __asm__ volatile("isync"); 176 #else 177 #if __APPLE__ 178 // On Darwin, sys_icache_invalidate() provides this functionality 179 sys_icache_invalidate(start, end - start); 180 #else 181 compilerrt_abort(); 182 #endif 183 #endif 184 } 185