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