arch/arm64/include/asm/processor.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Based on arch/arm/include/asm/processor.h
   4  *
   5  * Copyright (C) 1995-1999 Russell King
   6  * Copyright (C) 2012 ARM Ltd.
   7  */
   8 #ifndef __ASM_PROCESSOR_H
   9 #define __ASM_PROCESSOR_H
  10
  11 #define KERNEL_DS               UL(-1)
  12 #define USER_DS                 ((UL(1) << VA_BITS) - 1)
  13
  14 /*
  15  * On arm64 systems, unaligned accesses by the CPU are cheap, and so there is
  16  * no point in shifting all network buffers by 2 bytes just to make some IP
  17  * header fields appear aligned in memory, potentially sacrificing some DMA
  18  * performance on some platforms.
  19  */
  20 #define NET_IP_ALIGN    0
  21
  22 #ifndef __ASSEMBLY__
  23
  24 #include <linux/build_bug.h>
  25 #include <linux/cache.h>
  26 #include <linux/init.h>
  27 #include <linux/stddef.h>
  28 #include <linux/string.h>
  29 #include <linux/thread_info.h>
  30
  31 #include <asm/alternative.h>
  32 #include <asm/cpufeature.h>
  33 #include <asm/hw_breakpoint.h>
  34 #include <asm/kasan.h>
  35 #include <asm/lse.h>
  36 #include <asm/pgtable-hwdef.h>
  37 #include <asm/pointer_auth.h>
  38 #include <asm/ptrace.h>
  39 #include <asm/types.h>
  40
  41 /*
  42  * TASK_SIZE - the maximum size of a user space task.
  43  * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
  44  */
  45
  46 #define DEFAULT_MAP_WINDOW_64   (UL(1) << VA_BITS_MIN)
  47 #define TASK_SIZE_64            (UL(1) << vabits_actual)
  48
  49 #ifdef CONFIG_COMPAT
  50 #if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
  51 /*
  52  * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
  53  * by the compat vectors page.
  54  */
  55 #define TASK_SIZE_32            UL(0x100000000)
  56 #else
  57 #define TASK_SIZE_32            (UL(0x100000000) - PAGE_SIZE)
  58 #endif /* CONFIG_ARM64_64K_PAGES */
  59 #define TASK_SIZE               (test_thread_flag(TIF_32BIT) ? \
  60                                 TASK_SIZE_32 : TASK_SIZE_64)
  61 #define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  62                                 TASK_SIZE_32 : TASK_SIZE_64)
  63 #define DEFAULT_MAP_WINDOW      (test_thread_flag(TIF_32BIT) ? \
  64                                 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
  65 #else
  66 #define TASK_SIZE               TASK_SIZE_64
  67 #define DEFAULT_MAP_WINDOW      DEFAULT_MAP_WINDOW_64
  68 #endif /* CONFIG_COMPAT */
  69
  70 #ifdef CONFIG_ARM64_FORCE_52BIT
  71 #define STACK_TOP_MAX           TASK_SIZE_64
  72 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 4))
  73 #else
  74 #define STACK_TOP_MAX           DEFAULT_MAP_WINDOW_64
  75 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
  76 #endif /* CONFIG_ARM64_FORCE_52BIT */
  77
  78 #ifdef CONFIG_COMPAT
  79 #define AARCH32_VECTORS_BASE    0xffff0000
  80 #define STACK_TOP               (test_thread_flag(TIF_32BIT) ? \
  81                                 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
  82 #else
  83 #define STACK_TOP               STACK_TOP_MAX
  84 #endif /* CONFIG_COMPAT */
  85
  86 #ifndef CONFIG_ARM64_FORCE_52BIT
  87 #define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
  88                                 DEFAULT_MAP_WINDOW)
  89
  90 #define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
  91                                         base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
  92                                         base)
  93 #endif /* CONFIG_ARM64_FORCE_52BIT */
  94
  95 extern phys_addr_t arm64_dma_phys_limit;
  96 #define ARCH_LOW_ADDRESS_LIMIT  (arm64_dma_phys_limit - 1)
  97
  98 struct debug_info {
  99 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 100         /* Have we suspended stepping by a debugger? */
 101         int                     suspended_step;
 102         /* Allow breakpoints and watchpoints to be disabled for this thread. */
 103         int                     bps_disabled;
 104         int                     wps_disabled;
 105         /* Hardware breakpoints pinned to this task. */
 106         struct perf_event       *hbp_break[ARM_MAX_BRP];
 107         struct perf_event       *hbp_watch[ARM_MAX_WRP];
 108 #endif
 109 };
 110
 111 struct cpu_context {
 112         unsigned long x19;
 113         unsigned long x20;
 114         unsigned long x21;
 115         unsigned long x22;
 116         unsigned long x23;
 117         unsigned long x24;
 118         unsigned long x25;
 119         unsigned long x26;
 120         unsigned long x27;
 121         unsigned long x28;
 122         unsigned long fp;
 123         unsigned long sp;
 124         unsigned long pc;
 125 };
 126
 127 struct thread_struct {
 128         struct cpu_context      cpu_context;    /* cpu context */
 129
 130         /*
 131          * Whitelisted fields for hardened usercopy:
 132          * Maintainers must ensure manually that this contains no
 133          * implicit padding.
 134          */
 135         struct {
 136                 unsigned long   tp_value;       /* TLS register */
 137                 unsigned long   tp2_value;
 138                 struct user_fpsimd_state fpsimd_state;
 139         } uw;
 140
 141         unsigned int            fpsimd_cpu;
 142         void                    *sve_state;     /* SVE registers, if any */
 143         unsigned int            sve_vl;         /* SVE vector length */
 144         unsigned int            sve_vl_onexec;  /* SVE vl after next exec */
 145         unsigned long           fault_address;  /* fault info */
 146         unsigned long           fault_code;     /* ESR_EL1 value */
 147         struct debug_info       debug;          /* debugging */
 148 #ifdef CONFIG_ARM64_PTR_AUTH
 149         struct ptrauth_keys     keys_user;
 150 #endif
 151 };
 152
 153 static inline void arch_thread_struct_whitelist(unsigned long *offset,
 154                                                 unsigned long *size)
 155 {
 156         /* Verify that there is no padding among the whitelisted fields: */
 157         BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
 158                      sizeof_field(struct thread_struct, uw.tp_value) +
 159                      sizeof_field(struct thread_struct, uw.tp2_value) +
 160                      sizeof_field(struct thread_struct, uw.fpsimd_state));
 161
 162         *offset = offsetof(struct thread_struct, uw);
 163         *size = sizeof_field(struct thread_struct, uw);
 164 }
 165
 166 #ifdef CONFIG_COMPAT
 167 #define task_user_tls(t)                                                \
 168 ({                                                                      \
 169         unsigned long *__tls;                                           \
 170         if (is_compat_thread(task_thread_info(t)))                      \
 171                 __tls = &(t)->thread.uw.tp2_value;                      \
 172         else                                                            \
 173                 __tls = &(t)->thread.uw.tp_value;                       \
 174         __tls;                                                          \
 175  })
 176 #else
 177 #define task_user_tls(t)        (&(t)->thread.uw.tp_value)
 178 #endif
 179
 180 /* Sync TPIDR_EL0 back to thread_struct for current */
 181 void tls_preserve_current_state(void);
 182
 183 #define INIT_THREAD {                           \
 184         .fpsimd_cpu = NR_CPUS,                  \
 185 }
 186
 187 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 188 {
 189         memset(regs, 0, sizeof(*regs));
 190         forget_syscall(regs);
 191         regs->pc = pc;
 192
 193         if (system_uses_irq_prio_masking())
 194                 regs->pmr_save = GIC_PRIO_IRQON;
 195 }
 196
 197 static inline void set_ssbs_bit(struct pt_regs *regs)
 198 {
 199         regs->pstate |= PSR_SSBS_BIT;
 200 }
 201
 202 static inline void set_compat_ssbs_bit(struct pt_regs *regs)
 203 {
 204         regs->pstate |= PSR_AA32_SSBS_BIT;
 205 }
 206
 207 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 208                                 unsigned long sp)
 209 {
 210         start_thread_common(regs, pc);
 211         regs->pstate = PSR_MODE_EL0t;
 212
 213         if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
 214                 set_ssbs_bit(regs);
 215
 216         regs->sp = sp;
 217 }
 218
 219 static inline bool is_ttbr0_addr(unsigned long addr)
 220 {
 221         /* entry assembly clears tags for TTBR0 addrs */
 222         return addr < TASK_SIZE;
 223 }
 224
 225 static inline bool is_ttbr1_addr(unsigned long addr)
 226 {
 227         /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
 228         return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
 229 }
 230
 231 #ifdef CONFIG_COMPAT
 232 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 233                                        unsigned long sp)
 234 {
 235         start_thread_common(regs, pc);
 236         regs->pstate = PSR_AA32_MODE_USR;
 237         if (pc & 1)
 238                 regs->pstate |= PSR_AA32_T_BIT;
 239
 240 #ifdef __AARCH64EB__
 241         regs->pstate |= PSR_AA32_E_BIT;
 242 #endif
 243
 244         if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
 245                 set_compat_ssbs_bit(regs);
 246
 247         regs->compat_sp = sp;
 248 }
 249 #endif
 250
 251 /* Forward declaration, a strange C thing */
 252 struct task_struct;
 253
 254 /* Free all resources held by a thread. */
 255 extern void release_thread(struct task_struct *);
 256
 257 unsigned long get_wchan(struct task_struct *p);
 258
 259 static inline void cpu_relax(void)
 260 {
 261         asm volatile("yield" ::: "memory");
 262 }
 263
 264 /* Thread switching */
 265 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
 266                                          struct task_struct *next);
 267
 268 #define task_pt_regs(p) \
 269         ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
 270
 271 #define KSTK_EIP(tsk)   ((unsigned long)task_pt_regs(tsk)->pc)
 272 #define KSTK_ESP(tsk)   user_stack_pointer(task_pt_regs(tsk))
 273
 274 /*
 275  * Prefetching support
 276  */
 277 #define ARCH_HAS_PREFETCH
 278 static inline void prefetch(const void *ptr)
 279 {
 280         asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
 281 }
 282
 283 #define ARCH_HAS_PREFETCHW
 284 static inline void prefetchw(const void *ptr)
 285 {
 286         asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
 287 }
 288
 289 #define ARCH_HAS_SPINLOCK_PREFETCH
 290 static inline void spin_lock_prefetch(const void *ptr)
 291 {
 292         asm volatile(ARM64_LSE_ATOMIC_INSN(
 293                      "prfm pstl1strm, %a0",
 294                      "nop") : : "p" (ptr));
 295 }
 296
 297 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 298 extern void __init minsigstksz_setup(void);
 299
 300 /*
 301  * Not at the top of the file due to a direct #include cycle between
 302  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
 303  * ensures that contents of processor.h are visible to fpsimd.h even if
 304  * processor.h is included first.
 305  *
 306  * These prctl helpers are the only things in this file that require
 307  * fpsimd.h.  The core code expects them to be in this header.
 308  */
 309 #include <asm/fpsimd.h>
 310
 311 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
 312 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
 313 #define SVE_GET_VL()    sve_get_current_vl()
 314
 315 /* PR_PAC_RESET_KEYS prctl */
 316 #define PAC_RESET_KEYS(tsk, arg)        ptrauth_prctl_reset_keys(tsk, arg)
 317
 318 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
 319 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
 320 long set_tagged_addr_ctrl(unsigned long arg);
 321 long get_tagged_addr_ctrl(void);
 322 #define SET_TAGGED_ADDR_CTRL(arg)       set_tagged_addr_ctrl(arg)
 323 #define GET_TAGGED_ADDR_CTRL()          get_tagged_addr_ctrl()
 324 #endif
 325
 326 /*
 327  * For CONFIG_GCC_PLUGIN_STACKLEAK
 328  *
 329  * These need to be macros because otherwise we get stuck in a nightmare
 330  * of header definitions for the use of task_stack_page.
 331  */
 332
 333 #define current_top_of_stack()                                                  \
 334 ({                                                                              \
 335         struct stack_info _info;                                                \
 336         BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info));   \
 337         _info.high;                                                             \
 338 })
 339 #define on_thread_stack()       (on_task_stack(current, current_stack_pointer, NULL))
 340
 341 #endif /* __ASSEMBLY__ */
 342 #endif /* __ASM_PROCESSOR_H */