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 #ifdef __KERNEL__
  29
  30 #include <linux/build_bug.h>
  31 #include <linux/cache.h>
  32 #include <linux/init.h>
  33 #include <linux/stddef.h>
  34 #include <linux/string.h>
  35
  36 #include <asm/alternative.h>
  37 #include <asm/cpufeature.h>
  38 #include <asm/hw_breakpoint.h>
  39 #include <asm/lse.h>
  40 #include <asm/pgtable-hwdef.h>
  41 #include <asm/ptrace.h>
  42 #include <asm/types.h>
  43
  44 /*
  45  * TASK_SIZE - the maximum size of a user space task.
  46  * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
  47  */
  48 #ifdef CONFIG_COMPAT
  49 #define TASK_SIZE_32            UL(0x100000000)
  50 #define TASK_SIZE               (test_thread_flag(TIF_32BIT) ? \
  51                                 TASK_SIZE_32 : TASK_SIZE_64)
  52 #define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  53                                 TASK_SIZE_32 : TASK_SIZE_64)
  54 #else
  55 #define TASK_SIZE               TASK_SIZE_64
  56 #endif /* CONFIG_COMPAT */
  57
  58 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 4))
  59
  60 #define STACK_TOP_MAX           TASK_SIZE_64
  61 #ifdef CONFIG_COMPAT
  62 #define AARCH32_VECTORS_BASE    0xffff0000
  63 #define STACK_TOP               (test_thread_flag(TIF_32BIT) ? \
  64                                 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
  65 #else
  66 #define STACK_TOP               STACK_TOP_MAX
  67 #endif /* CONFIG_COMPAT */
  68
  69 extern phys_addr_t arm64_dma_phys_limit;
  70 #define ARCH_LOW_ADDRESS_LIMIT  (arm64_dma_phys_limit - 1)
  71
  72 struct debug_info {
  73 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  74         /* Have we suspended stepping by a debugger? */
  75         int                     suspended_step;
  76         /* Allow breakpoints and watchpoints to be disabled for this thread. */
  77         int                     bps_disabled;
  78         int                     wps_disabled;
  79         /* Hardware breakpoints pinned to this task. */
  80         struct perf_event       *hbp_break[ARM_MAX_BRP];
  81         struct perf_event       *hbp_watch[ARM_MAX_WRP];
  82 #endif
  83 };
  84
  85 struct cpu_context {
  86         unsigned long x19;
  87         unsigned long x20;
  88         unsigned long x21;
  89         unsigned long x22;
  90         unsigned long x23;
  91         unsigned long x24;
  92         unsigned long x25;
  93         unsigned long x26;
  94         unsigned long x27;
  95         unsigned long x28;
  96         unsigned long fp;
  97         unsigned long sp;
  98         unsigned long pc;
  99 };
 100
 101 struct thread_struct {
 102         struct cpu_context      cpu_context;    /* cpu context */
 103
 104         /*
 105          * Whitelisted fields for hardened usercopy:
 106          * Maintainers must ensure manually that this contains no
 107          * implicit padding.
 108          */
 109         struct {
 110                 unsigned long   tp_value;       /* TLS register */
 111                 unsigned long   tp2_value;
 112                 struct user_fpsimd_state fpsimd_state;
 113         } uw;
 114
 115         unsigned int            fpsimd_cpu;
 116         void                    *sve_state;     /* SVE registers, if any */
 117         unsigned int            sve_vl;         /* SVE vector length */
 118         unsigned int            sve_vl_onexec;  /* SVE vl after next exec */
 119         unsigned long           fault_address;  /* fault info */
 120         unsigned long           fault_code;     /* ESR_EL1 value */
 121         struct debug_info       debug;          /* debugging */
 122 };
 123
 124 static inline void arch_thread_struct_whitelist(unsigned long *offset,
 125                                                 unsigned long *size)
 126 {
 127         /* Verify that there is no padding among the whitelisted fields: */
 128         BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
 129                      sizeof_field(struct thread_struct, uw.tp_value) +
 130                      sizeof_field(struct thread_struct, uw.tp2_value) +
 131                      sizeof_field(struct thread_struct, uw.fpsimd_state));
 132
 133         *offset = offsetof(struct thread_struct, uw);
 134         *size = sizeof_field(struct thread_struct, uw);
 135 }
 136
 137 #ifdef CONFIG_COMPAT
 138 #define task_user_tls(t)                                                \
 139 ({                                                                      \
 140         unsigned long *__tls;                                           \
 141         if (is_compat_thread(task_thread_info(t)))                      \
 142                 __tls = &(t)->thread.uw.tp2_value;                      \
 143         else                                                            \
 144                 __tls = &(t)->thread.uw.tp_value;                       \
 145         __tls;                                                          \
 146  })
 147 #else
 148 #define task_user_tls(t)        (&(t)->thread.uw.tp_value)
 149 #endif
 150
 151 /* Sync TPIDR_EL0 back to thread_struct for current */
 152 void tls_preserve_current_state(void);
 153
 154 #define INIT_THREAD {                           \
 155         .fpsimd_cpu = NR_CPUS,                  \
 156 }
 157
 158 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 159 {
 160         memset(regs, 0, sizeof(*regs));
 161         forget_syscall(regs);
 162         regs->pc = pc;
 163 }
 164
 165 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 166                                 unsigned long sp)
 167 {
 168         start_thread_common(regs, pc);
 169         regs->pstate = PSR_MODE_EL0t;
 170
 171         if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
 172                 regs->pstate |= PSR_SSBS_BIT;
 173
 174         regs->sp = sp;
 175 }
 176
 177 #ifdef CONFIG_COMPAT
 178 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 179                                        unsigned long sp)
 180 {
 181         start_thread_common(regs, pc);
 182         regs->pstate = PSR_AA32_MODE_USR;
 183         if (pc & 1)
 184                 regs->pstate |= PSR_AA32_T_BIT;
 185
 186 #ifdef __AARCH64EB__
 187         regs->pstate |= PSR_AA32_E_BIT;
 188 #endif
 189
 190         if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
 191                 regs->pstate |= PSR_AA32_SSBS_BIT;
 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 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 248 extern void __init minsigstksz_setup(void);
 249
 250 /*
 251  * Not at the top of the file due to a direct #include cycle between
 252  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
 253  * ensures that contents of processor.h are visible to fpsimd.h even if
 254  * processor.h is included first.
 255  *
 256  * These prctl helpers are the only things in this file that require
 257  * fpsimd.h.  The core code expects them to be in this header.
 258  */
 259 #include <asm/fpsimd.h>
 260
 261 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
 262 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
 263 #define SVE_GET_VL()    sve_get_current_vl()
 264
 265 /*
 266  * For CONFIG_GCC_PLUGIN_STACKLEAK
 267  *
 268  * These need to be macros because otherwise we get stuck in a nightmare
 269  * of header definitions for the use of task_stack_page.
 270  */
 271
 272 #define current_top_of_stack()                                                  \
 273 ({                                                                              \
 274         struct stack_info _info;                                                \
 275         BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info));   \
 276         _info.high;                                                             \
 277 })
 278 #define on_thread_stack()       (on_task_stack(current, current_stack_pointer, NULL))
 279
 280 #endif /* __ASSEMBLY__ */
 281 #endif /* __ASM_PROCESSOR_H */