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/spectre.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
  49 #define DEFAULT_MAP_WINDOW_64   (UL(1) << VA_BITS_MIN)
  50 #define TASK_SIZE_64            (UL(1) << vabits_actual)
  51
  52 #ifdef CONFIG_COMPAT
  53 #if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
  54 /*
  55  * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
  56  * by the compat vectors page.
  57  */
  58 #define TASK_SIZE_32            UL(0x100000000)
  59 #else
  60 #define TASK_SIZE_32            (UL(0x100000000) - PAGE_SIZE)
  61 #endif /* CONFIG_ARM64_64K_PAGES */
  62 #define TASK_SIZE               (test_thread_flag(TIF_32BIT) ? \
  63                                 TASK_SIZE_32 : TASK_SIZE_64)
  64 #define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  65                                 TASK_SIZE_32 : TASK_SIZE_64)
  66 #define DEFAULT_MAP_WINDOW      (test_thread_flag(TIF_32BIT) ? \
  67                                 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
  68 #else
  69 #define TASK_SIZE               TASK_SIZE_64
  70 #define DEFAULT_MAP_WINDOW      DEFAULT_MAP_WINDOW_64
  71 #endif /* CONFIG_COMPAT */
  72
  73 #ifdef CONFIG_ARM64_FORCE_52BIT
  74 #define STACK_TOP_MAX           TASK_SIZE_64
  75 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 4))
  76 #else
  77 #define STACK_TOP_MAX           DEFAULT_MAP_WINDOW_64
  78 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
  79 #endif /* CONFIG_ARM64_FORCE_52BIT */
  80
  81 #ifdef CONFIG_COMPAT
  82 #define AARCH32_VECTORS_BASE    0xffff0000
  83 #define STACK_TOP               (test_thread_flag(TIF_32BIT) ? \
  84                                 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
  85 #else
  86 #define STACK_TOP               STACK_TOP_MAX
  87 #endif /* CONFIG_COMPAT */
  88
  89 #ifndef CONFIG_ARM64_FORCE_52BIT
  90 #define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
  91                                 DEFAULT_MAP_WINDOW)
  92
  93 #define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
  94                                         base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
  95                                         base)
  96 #endif /* CONFIG_ARM64_FORCE_52BIT */
  97
  98 extern phys_addr_t arm64_dma_phys_limit;
  99 #define ARCH_LOW_ADDRESS_LIMIT  (arm64_dma_phys_limit - 1)
 100
 101 struct debug_info {
 102 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 103         /* Have we suspended stepping by a debugger? */
 104         int                     suspended_step;
 105         /* Allow breakpoints and watchpoints to be disabled for this thread. */
 106         int                     bps_disabled;
 107         int                     wps_disabled;
 108         /* Hardware breakpoints pinned to this task. */
 109         struct perf_event       *hbp_break[ARM_MAX_BRP];
 110         struct perf_event       *hbp_watch[ARM_MAX_WRP];
 111 #endif
 112 };
 113
 114 struct cpu_context {
 115         unsigned long x19;
 116         unsigned long x20;
 117         unsigned long x21;
 118         unsigned long x22;
 119         unsigned long x23;
 120         unsigned long x24;
 121         unsigned long x25;
 122         unsigned long x26;
 123         unsigned long x27;
 124         unsigned long x28;
 125         unsigned long fp;
 126         unsigned long sp;
 127         unsigned long pc;
 128 };
 129
 130 struct thread_struct {
 131         struct cpu_context      cpu_context;    /* cpu context */
 132
 133         /*
 134          * Whitelisted fields for hardened usercopy:
 135          * Maintainers must ensure manually that this contains no
 136          * implicit padding.
 137          */
 138         struct {
 139                 unsigned long   tp_value;       /* TLS register */
 140                 unsigned long   tp2_value;
 141                 struct user_fpsimd_state fpsimd_state;
 142         } uw;
 143
 144         unsigned int            fpsimd_cpu;
 145         void                    *sve_state;     /* SVE registers, if any */
 146         unsigned int            sve_vl;         /* SVE vector length */
 147         unsigned int            sve_vl_onexec;  /* SVE vl after next exec */
 148         unsigned long           fault_address;  /* fault info */
 149         unsigned long           fault_code;     /* ESR_EL1 value */
 150         struct debug_info       debug;          /* debugging */
 151 #ifdef CONFIG_ARM64_PTR_AUTH
 152         struct ptrauth_keys_user        keys_user;
 153         struct ptrauth_keys_kernel      keys_kernel;
 154 #endif
 155 #ifdef CONFIG_ARM64_MTE
 156         u64                     sctlr_tcf0;
 157         u64                     gcr_user_incl;
 158 #endif
 159 };
 160
 161 static inline void arch_thread_struct_whitelist(unsigned long *offset,
 162                                                 unsigned long *size)
 163 {
 164         /* Verify that there is no padding among the whitelisted fields: */
 165         BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
 166                      sizeof_field(struct thread_struct, uw.tp_value) +
 167                      sizeof_field(struct thread_struct, uw.tp2_value) +
 168                      sizeof_field(struct thread_struct, uw.fpsimd_state));
 169
 170         *offset = offsetof(struct thread_struct, uw);
 171         *size = sizeof_field(struct thread_struct, uw);
 172 }
 173
 174 #ifdef CONFIG_COMPAT
 175 #define task_user_tls(t)                                                \
 176 ({                                                                      \
 177         unsigned long *__tls;                                           \
 178         if (is_compat_thread(task_thread_info(t)))                      \
 179                 __tls = &(t)->thread.uw.tp2_value;                      \
 180         else                                                            \
 181                 __tls = &(t)->thread.uw.tp_value;                       \
 182         __tls;                                                          \
 183  })
 184 #else
 185 #define task_user_tls(t)        (&(t)->thread.uw.tp_value)
 186 #endif
 187
 188 /* Sync TPIDR_EL0 back to thread_struct for current */
 189 void tls_preserve_current_state(void);
 190
 191 #define INIT_THREAD {                           \
 192         .fpsimd_cpu = NR_CPUS,                  \
 193 }
 194
 195 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 196 {
 197         memset(regs, 0, sizeof(*regs));
 198         forget_syscall(regs);
 199         regs->pc = pc;
 200
 201         if (system_uses_irq_prio_masking())
 202                 regs->pmr_save = GIC_PRIO_IRQON;
 203 }
 204
 205 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 206                                 unsigned long sp)
 207 {
 208         start_thread_common(regs, pc);
 209         regs->pstate = PSR_MODE_EL0t;
 210         spectre_v4_enable_task_mitigation(current);
 211         regs->sp = sp;
 212 }
 213
 214 #ifdef CONFIG_COMPAT
 215 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 216                                        unsigned long sp)
 217 {
 218         start_thread_common(regs, pc);
 219         regs->pstate = PSR_AA32_MODE_USR;
 220         if (pc & 1)
 221                 regs->pstate |= PSR_AA32_T_BIT;
 222
 223 #ifdef __AARCH64EB__
 224         regs->pstate |= PSR_AA32_E_BIT;
 225 #endif
 226
 227         spectre_v4_enable_task_mitigation(current);
 228         regs->compat_sp = sp;
 229 }
 230 #endif
 231
 232 static inline bool is_ttbr0_addr(unsigned long addr)
 233 {
 234         /* entry assembly clears tags for TTBR0 addrs */
 235         return addr < TASK_SIZE;
 236 }
 237
 238 static inline bool is_ttbr1_addr(unsigned long addr)
 239 {
 240         /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
 241         return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
 242 }
 243
 244 /* Forward declaration, a strange C thing */
 245 struct task_struct;
 246
 247 /* Free all resources held by a thread. */
 248 extern void release_thread(struct task_struct *);
 249
 250 unsigned long get_wchan(struct task_struct *p);
 251
 252 /* Thread switching */
 253 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
 254                                          struct task_struct *next);
 255
 256 #define task_pt_regs(p) \
 257         ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
 258
 259 #define KSTK_EIP(tsk)   ((unsigned long)task_pt_regs(tsk)->pc)
 260 #define KSTK_ESP(tsk)   user_stack_pointer(task_pt_regs(tsk))
 261
 262 /*
 263  * Prefetching support
 264  */
 265 #define ARCH_HAS_PREFETCH
 266 static inline void prefetch(const void *ptr)
 267 {
 268         asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
 269 }
 270
 271 #define ARCH_HAS_PREFETCHW
 272 static inline void prefetchw(const void *ptr)
 273 {
 274         asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
 275 }
 276
 277 #define ARCH_HAS_SPINLOCK_PREFETCH
 278 static inline void spin_lock_prefetch(const void *ptr)
 279 {
 280         asm volatile(ARM64_LSE_ATOMIC_INSN(
 281                      "prfm pstl1strm, %a0",
 282                      "nop") : : "p" (ptr));
 283 }
 284
 285 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 286 extern void __init minsigstksz_setup(void);
 287
 288 /*
 289  * Not at the top of the file due to a direct #include cycle between
 290  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
 291  * ensures that contents of processor.h are visible to fpsimd.h even if
 292  * processor.h is included first.
 293  *
 294  * These prctl helpers are the only things in this file that require
 295  * fpsimd.h.  The core code expects them to be in this header.
 296  */
 297 #include <asm/fpsimd.h>
 298
 299 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
 300 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
 301 #define SVE_GET_VL()    sve_get_current_vl()
 302
 303 /* PR_PAC_RESET_KEYS prctl */
 304 #define PAC_RESET_KEYS(tsk, arg)        ptrauth_prctl_reset_keys(tsk, arg)
 305
 306 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
 307 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
 308 long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
 309 long get_tagged_addr_ctrl(struct task_struct *task);
 310 #define SET_TAGGED_ADDR_CTRL(arg)       set_tagged_addr_ctrl(current, arg)
 311 #define GET_TAGGED_ADDR_CTRL()          get_tagged_addr_ctrl(current)
 312 #endif
 313
 314 /*
 315  * For CONFIG_GCC_PLUGIN_STACKLEAK
 316  *
 317  * These need to be macros because otherwise we get stuck in a nightmare
 318  * of header definitions for the use of task_stack_page.
 319  */
 320
 321 #define current_top_of_stack()                                                  \
 322 ({                                                                              \
 323         struct stack_info _info;                                                \
 324         BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info));   \
 325         _info.high;                                                             \
 326 })
 327 #define on_thread_stack()       (on_task_stack(current, current_stack_pointer, NULL))
 328
 329 #endif /* __ASSEMBLY__ */
 330 #endif /* __ASM_PROCESSOR_H */