arch/arm64/include/asm/processor.h

   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 #ifndef __ASSEMBLY__
  28
  29 /*
  30  * Default implementation of macro that returns current
  31  * instruction pointer ("program counter").
  32  */
  33 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
  34
  35 #ifdef __KERNEL__
  36
  37 #include <linux/build_bug.h>
  38 #include <linux/cache.h>
  39 #include <linux/init.h>
  40 #include <linux/stddef.h>
  41 #include <linux/string.h>
  42
  43 #include <asm/alternative.h>
  44 #include <asm/cpufeature.h>
  45 #include <asm/hw_breakpoint.h>
  46 #include <asm/lse.h>
  47 #include <asm/pgtable-hwdef.h>
  48 #include <asm/ptrace.h>
  49 #include <asm/types.h>
  50
  51 /*
  52  * TASK_SIZE - the maximum size of a user space task.
  53  * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
  54  */
  55 #ifdef CONFIG_COMPAT
  56 #define TASK_SIZE_32            UL(0x100000000)
  57 #define TASK_SIZE               (test_thread_flag(TIF_32BIT) ? \
  58                                 TASK_SIZE_32 : TASK_SIZE_64)
  59 #define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  60                                 TASK_SIZE_32 : TASK_SIZE_64)
  61 #else
  62 #define TASK_SIZE               TASK_SIZE_64
  63 #endif /* CONFIG_COMPAT */
  64
  65 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 4))
  66
  67 #define STACK_TOP_MAX           TASK_SIZE_64
  68 #ifdef CONFIG_COMPAT
  69 #define AARCH32_VECTORS_BASE    0xffff0000
  70 #define STACK_TOP               (test_thread_flag(TIF_32BIT) ? \
  71                                 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
  72 #else
  73 #define STACK_TOP               STACK_TOP_MAX
  74 #endif /* CONFIG_COMPAT */
  75
  76 extern phys_addr_t arm64_dma_phys_limit;
  77 #define ARCH_LOW_ADDRESS_LIMIT  (arm64_dma_phys_limit - 1)
  78
  79 struct debug_info {
  80 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  81         /* Have we suspended stepping by a debugger? */
  82         int                     suspended_step;
  83         /* Allow breakpoints and watchpoints to be disabled for this thread. */
  84         int                     bps_disabled;
  85         int                     wps_disabled;
  86         /* Hardware breakpoints pinned to this task. */
  87         struct perf_event       *hbp_break[ARM_MAX_BRP];
  88         struct perf_event       *hbp_watch[ARM_MAX_WRP];
  89 #endif
  90 };
  91
  92 struct cpu_context {
  93         unsigned long x19;
  94         unsigned long x20;
  95         unsigned long x21;
  96         unsigned long x22;
  97         unsigned long x23;
  98         unsigned long x24;
  99         unsigned long x25;
 100         unsigned long x26;
 101         unsigned long x27;
 102         unsigned long x28;
 103         unsigned long fp;
 104         unsigned long sp;
 105         unsigned long pc;
 106 };
 107
 108 struct thread_struct {
 109         struct cpu_context      cpu_context;    /* cpu context */
 110
 111         /*
 112          * Whitelisted fields for hardened usercopy:
 113          * Maintainers must ensure manually that this contains no
 114          * implicit padding.
 115          */
 116         struct {
 117                 unsigned long   tp_value;       /* TLS register */
 118                 unsigned long   tp2_value;
 119                 struct user_fpsimd_state fpsimd_state;
 120         } uw;
 121
 122         unsigned int            fpsimd_cpu;
 123         void                    *sve_state;     /* SVE registers, if any */
 124         unsigned int            sve_vl;         /* SVE vector length */
 125         unsigned int            sve_vl_onexec;  /* SVE vl after next exec */
 126         unsigned long           fault_address;  /* fault info */
 127         unsigned long           fault_code;     /* ESR_EL1 value */
 128         struct debug_info       debug;          /* debugging */
 129 };
 130
 131 static inline void arch_thread_struct_whitelist(unsigned long *offset,
 132                                                 unsigned long *size)
 133 {
 134         /* Verify that there is no padding among the whitelisted fields: */
 135         BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
 136                      sizeof_field(struct thread_struct, uw.tp_value) +
 137                      sizeof_field(struct thread_struct, uw.tp2_value) +
 138                      sizeof_field(struct thread_struct, uw.fpsimd_state));
 139
 140         *offset = offsetof(struct thread_struct, uw);
 141         *size = sizeof_field(struct thread_struct, uw);
 142 }
 143
 144 #ifdef CONFIG_COMPAT
 145 #define task_user_tls(t)                                                \
 146 ({                                                                      \
 147         unsigned long *__tls;                                           \
 148         if (is_compat_thread(task_thread_info(t)))                      \
 149                 __tls = &(t)->thread.uw.tp2_value;                      \
 150         else                                                            \
 151                 __tls = &(t)->thread.uw.tp_value;                       \
 152         __tls;                                                          \
 153  })
 154 #else
 155 #define task_user_tls(t)        (&(t)->thread.uw.tp_value)
 156 #endif
 157
 158 /* Sync TPIDR_EL0 back to thread_struct for current */
 159 void tls_preserve_current_state(void);
 160
 161 #define INIT_THREAD {                           \
 162         .fpsimd_cpu = NR_CPUS,                  \
 163 }
 164
 165 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 166 {
 167         memset(regs, 0, sizeof(*regs));
 168         forget_syscall(regs);
 169         regs->pc = pc;
 170 }
 171
 172 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 173                                 unsigned long sp)
 174 {
 175         start_thread_common(regs, pc);
 176         regs->pstate = PSR_MODE_EL0t;
 177         regs->sp = sp;
 178 }
 179
 180 #ifdef CONFIG_COMPAT
 181 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 182                                        unsigned long sp)
 183 {
 184         start_thread_common(regs, pc);
 185         regs->pstate = PSR_AA32_MODE_USR;
 186         if (pc & 1)
 187                 regs->pstate |= PSR_AA32_T_BIT;
 188
 189 #ifdef __AARCH64EB__
 190         regs->pstate |= PSR_AA32_E_BIT;
 191 #endif
 192
 193         regs->compat_sp = sp;
 194 }
 195 #endif
 196
 197 /* Forward declaration, a strange C thing */
 198 struct task_struct;
 199
 200 /* Free all resources held by a thread. */
 201 extern void release_thread(struct task_struct *);
 202
 203 unsigned long get_wchan(struct task_struct *p);
 204
 205 static inline void cpu_relax(void)
 206 {
 207         asm volatile("yield" ::: "memory");
 208 }
 209
 210 /* Thread switching */
 211 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
 212                                          struct task_struct *next);
 213
 214 #define task_pt_regs(p) \
 215         ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
 216
 217 #define KSTK_EIP(tsk)   ((unsigned long)task_pt_regs(tsk)->pc)
 218 #define KSTK_ESP(tsk)   user_stack_pointer(task_pt_regs(tsk))
 219
 220 /*
 221  * Prefetching support
 222  */
 223 #define ARCH_HAS_PREFETCH
 224 static inline void prefetch(const void *ptr)
 225 {
 226         asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
 227 }
 228
 229 #define ARCH_HAS_PREFETCHW
 230 static inline void prefetchw(const void *ptr)
 231 {
 232         asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
 233 }
 234
 235 #define ARCH_HAS_SPINLOCK_PREFETCH
 236 static inline void spin_lock_prefetch(const void *ptr)
 237 {
 238         asm volatile(ARM64_LSE_ATOMIC_INSN(
 239                      "prfm pstl1strm, %a0",
 240                      "nop") : : "p" (ptr));
 241 }
 242
 243 #define HAVE_ARCH_PICK_MMAP_LAYOUT
 244
 245 #endif
 246
 247 void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused);
 248 void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused);
 249 void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused);
 250
 251 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 252 extern void __init minsigstksz_setup(void);
 253
 254 /*
 255  * Not at the top of the file due to a direct #include cycle between
 256  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
 257  * ensures that contents of processor.h are visible to fpsimd.h even if
 258  * processor.h is included first.
 259  *
 260  * These prctl helpers are the only things in this file that require
 261  * fpsimd.h.  The core code expects them to be in this header.
 262  */
 263 #include <asm/fpsimd.h>
 264
 265 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
 266 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
 267 #define SVE_GET_VL()    sve_get_current_vl()
 268
 269 /*
 270  * For CONFIG_GCC_PLUGIN_STACKLEAK
 271  *
 272  * These need to be macros because otherwise we get stuck in a nightmare
 273  * of header definitions for the use of task_stack_page.
 274  */
 275
 276 #define current_top_of_stack()                                                  \
 277 ({                                                                              \
 278         struct stack_info _info;                                                \
 279         BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info));   \
 280         _info.high;                                                             \
 281 })
 282 #define on_thread_stack()       (on_task_stack(current, current_stack_pointer, NULL))
 283
 284 #endif /* __ASSEMBLY__ */
 285 #endif /* __ASM_PROCESSOR_H */