1 /* 2 * Based on arch/arm/include/asm/processor.h 3 * 4 * Copyright (C) 1995-1999 Russell King 5 * Copyright (C) 2012 ARM Ltd. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 #ifndef __ASM_PROCESSOR_H 20 #define __ASM_PROCESSOR_H 21 22 #define TASK_SIZE_64 (UL(1) << VA_BITS) 23 24 #define KERNEL_DS UL(-1) 25 #define USER_DS (TASK_SIZE_64 - 1) 26 27 /* 28 * On arm64 systems, unaligned accesses by the CPU are cheap, and so there is 29 * no point in shifting all network buffers by 2 bytes just to make some IP 30 * header fields appear aligned in memory, potentially sacrificing some DMA 31 * performance on some platforms. 32 */ 33 #define NET_IP_ALIGN 0 34 35 #ifndef __ASSEMBLY__ 36 #ifdef __KERNEL__ 37 38 #include <linux/build_bug.h> 39 #include <linux/cache.h> 40 #include <linux/init.h> 41 #include <linux/stddef.h> 42 #include <linux/string.h> 43 44 #include <asm/alternative.h> 45 #include <asm/cpufeature.h> 46 #include <asm/hw_breakpoint.h> 47 #include <asm/lse.h> 48 #include <asm/pgtable-hwdef.h> 49 #include <asm/ptrace.h> 50 #include <asm/types.h> 51 52 /* 53 * TASK_SIZE - the maximum size of a user space task. 54 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area. 55 */ 56 #ifdef CONFIG_COMPAT 57 #define TASK_SIZE_32 UL(0x100000000) 58 #define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \ 59 TASK_SIZE_32 : TASK_SIZE_64) 60 #define TASK_SIZE_OF(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT) ? \ 61 TASK_SIZE_32 : TASK_SIZE_64) 62 #else 63 #define TASK_SIZE TASK_SIZE_64 64 #endif /* CONFIG_COMPAT */ 65 66 #define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4)) 67 68 #define STACK_TOP_MAX TASK_SIZE_64 69 #ifdef CONFIG_COMPAT 70 #define AARCH32_VECTORS_BASE 0xffff0000 71 #define STACK_TOP (test_thread_flag(TIF_32BIT) ? \ 72 AARCH32_VECTORS_BASE : STACK_TOP_MAX) 73 #else 74 #define STACK_TOP STACK_TOP_MAX 75 #endif /* CONFIG_COMPAT */ 76 77 extern phys_addr_t arm64_dma_phys_limit; 78 #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1) 79 80 struct debug_info { 81 #ifdef CONFIG_HAVE_HW_BREAKPOINT 82 /* Have we suspended stepping by a debugger? */ 83 int suspended_step; 84 /* Allow breakpoints and watchpoints to be disabled for this thread. */ 85 int bps_disabled; 86 int wps_disabled; 87 /* Hardware breakpoints pinned to this task. */ 88 struct perf_event *hbp_break[ARM_MAX_BRP]; 89 struct perf_event *hbp_watch[ARM_MAX_WRP]; 90 #endif 91 }; 92 93 struct cpu_context { 94 unsigned long x19; 95 unsigned long x20; 96 unsigned long x21; 97 unsigned long x22; 98 unsigned long x23; 99 unsigned long x24; 100 unsigned long x25; 101 unsigned long x26; 102 unsigned long x27; 103 unsigned long x28; 104 unsigned long fp; 105 unsigned long sp; 106 unsigned long pc; 107 }; 108 109 struct thread_struct { 110 struct cpu_context cpu_context; /* cpu context */ 111 112 /* 113 * Whitelisted fields for hardened usercopy: 114 * Maintainers must ensure manually that this contains no 115 * implicit padding. 116 */ 117 struct { 118 unsigned long tp_value; /* TLS register */ 119 unsigned long tp2_value; 120 struct user_fpsimd_state fpsimd_state; 121 } uw; 122 123 unsigned int fpsimd_cpu; 124 void *sve_state; /* SVE registers, if any */ 125 unsigned int sve_vl; /* SVE vector length */ 126 unsigned int sve_vl_onexec; /* SVE vl after next exec */ 127 unsigned long fault_address; /* fault info */ 128 unsigned long fault_code; /* ESR_EL1 value */ 129 struct debug_info debug; /* debugging */ 130 }; 131 132 static inline void arch_thread_struct_whitelist(unsigned long *offset, 133 unsigned long *size) 134 { 135 /* Verify that there is no padding among the whitelisted fields: */ 136 BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) != 137 sizeof_field(struct thread_struct, uw.tp_value) + 138 sizeof_field(struct thread_struct, uw.tp2_value) + 139 sizeof_field(struct thread_struct, uw.fpsimd_state)); 140 141 *offset = offsetof(struct thread_struct, uw); 142 *size = sizeof_field(struct thread_struct, uw); 143 } 144 145 #ifdef CONFIG_COMPAT 146 #define task_user_tls(t) \ 147 ({ \ 148 unsigned long *__tls; \ 149 if (is_compat_thread(task_thread_info(t))) \ 150 __tls = &(t)->thread.uw.tp2_value; \ 151 else \ 152 __tls = &(t)->thread.uw.tp_value; \ 153 __tls; \ 154 }) 155 #else 156 #define task_user_tls(t) (&(t)->thread.uw.tp_value) 157 #endif 158 159 /* Sync TPIDR_EL0 back to thread_struct for current */ 160 void tls_preserve_current_state(void); 161 162 #define INIT_THREAD { \ 163 .fpsimd_cpu = NR_CPUS, \ 164 } 165 166 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc) 167 { 168 memset(regs, 0, sizeof(*regs)); 169 forget_syscall(regs); 170 regs->pc = pc; 171 } 172 173 static inline void start_thread(struct pt_regs *regs, unsigned long pc, 174 unsigned long sp) 175 { 176 start_thread_common(regs, pc); 177 regs->pstate = PSR_MODE_EL0t; 178 179 if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE) 180 regs->pstate |= PSR_SSBS_BIT; 181 182 regs->sp = sp; 183 } 184 185 #ifdef CONFIG_COMPAT 186 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc, 187 unsigned long sp) 188 { 189 start_thread_common(regs, pc); 190 regs->pstate = PSR_AA32_MODE_USR; 191 if (pc & 1) 192 regs->pstate |= PSR_AA32_T_BIT; 193 194 #ifdef __AARCH64EB__ 195 regs->pstate |= PSR_AA32_E_BIT; 196 #endif 197 198 if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE) 199 regs->pstate |= PSR_AA32_SSBS_BIT; 200 201 regs->compat_sp = sp; 202 } 203 #endif 204 205 /* Forward declaration, a strange C thing */ 206 struct task_struct; 207 208 /* Free all resources held by a thread. */ 209 extern void release_thread(struct task_struct *); 210 211 unsigned long get_wchan(struct task_struct *p); 212 213 static inline void cpu_relax(void) 214 { 215 asm volatile("yield" ::: "memory"); 216 } 217 218 /* Thread switching */ 219 extern struct task_struct *cpu_switch_to(struct task_struct *prev, 220 struct task_struct *next); 221 222 #define task_pt_regs(p) \ 223 ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1) 224 225 #define KSTK_EIP(tsk) ((unsigned long)task_pt_regs(tsk)->pc) 226 #define KSTK_ESP(tsk) user_stack_pointer(task_pt_regs(tsk)) 227 228 /* 229 * Prefetching support 230 */ 231 #define ARCH_HAS_PREFETCH 232 static inline void prefetch(const void *ptr) 233 { 234 asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr)); 235 } 236 237 #define ARCH_HAS_PREFETCHW 238 static inline void prefetchw(const void *ptr) 239 { 240 asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr)); 241 } 242 243 #define ARCH_HAS_SPINLOCK_PREFETCH 244 static inline void spin_lock_prefetch(const void *ptr) 245 { 246 asm volatile(ARM64_LSE_ATOMIC_INSN( 247 "prfm pstl1strm, %a0", 248 "nop") : : "p" (ptr)); 249 } 250 251 #define HAVE_ARCH_PICK_MMAP_LAYOUT 252 253 #endif 254 255 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */ 256 extern void __init minsigstksz_setup(void); 257 258 /* 259 * Not at the top of the file due to a direct #include cycle between 260 * <asm/fpsimd.h> and <asm/processor.h>. Deferring this #include 261 * ensures that contents of processor.h are visible to fpsimd.h even if 262 * processor.h is included first. 263 * 264 * These prctl helpers are the only things in this file that require 265 * fpsimd.h. The core code expects them to be in this header. 266 */ 267 #include <asm/fpsimd.h> 268 269 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */ 270 #define SVE_SET_VL(arg) sve_set_current_vl(arg) 271 #define SVE_GET_VL() sve_get_current_vl() 272 273 /* 274 * For CONFIG_GCC_PLUGIN_STACKLEAK 275 * 276 * These need to be macros because otherwise we get stuck in a nightmare 277 * of header definitions for the use of task_stack_page. 278 */ 279 280 #define current_top_of_stack() \ 281 ({ \ 282 struct stack_info _info; \ 283 BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info)); \ 284 _info.high; \ 285 }) 286 #define on_thread_stack() (on_task_stack(current, current_stack_pointer, NULL)) 287 288 #endif /* __ASSEMBLY__ */ 289 #endif /* __ASM_PROCESSOR_H */ 290