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 /*
  12  * On arm64 systems, unaligned accesses by the CPU are cheap, and so there is
  13  * no point in shifting all network buffers by 2 bytes just to make some IP
  14  * header fields appear aligned in memory, potentially sacrificing some DMA
  15  * performance on some platforms.
  16  */
  17 #define NET_IP_ALIGN    0
  18
  19 #ifndef __ASSEMBLY__
  20
  21 #include <linux/build_bug.h>
  22 #include <linux/cache.h>
  23 #include <linux/init.h>
  24 #include <linux/stddef.h>
  25 #include <linux/string.h>
  26 #include <linux/thread_info.h>
  27
  28 #include <vdso/processor.h>
  29
  30 #include <asm/alternative.h>
  31 #include <asm/cpufeature.h>
  32 #include <asm/hw_breakpoint.h>
  33 #include <asm/kasan.h>
  34 #include <asm/lse.h>
  35 #include <asm/pgtable-hwdef.h>
  36 #include <asm/pointer_auth.h>
  37 #include <asm/ptrace.h>
  38 #include <asm/spectre.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 #define TASK_SIZE_MAX           (UL(1) << VA_BITS)
  49
  50 #ifdef CONFIG_COMPAT
  51 #if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
  52 /*
  53  * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
  54  * by the compat vectors page.
  55  */
  56 #define TASK_SIZE_32            UL(0x100000000)
  57 #else
  58 #define TASK_SIZE_32            (UL(0x100000000) - PAGE_SIZE)
  59 #endif /* CONFIG_ARM64_64K_PAGES */
  60 #define TASK_SIZE               (test_thread_flag(TIF_32BIT) ? \
  61                                 TASK_SIZE_32 : TASK_SIZE_64)
  62 #define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  63                                 TASK_SIZE_32 : TASK_SIZE_64)
  64 #define DEFAULT_MAP_WINDOW      (test_thread_flag(TIF_32BIT) ? \
  65                                 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
  66 #else
  67 #define TASK_SIZE               TASK_SIZE_64
  68 #define DEFAULT_MAP_WINDOW      DEFAULT_MAP_WINDOW_64
  69 #endif /* CONFIG_COMPAT */
  70
  71 #ifdef CONFIG_ARM64_FORCE_52BIT
  72 #define STACK_TOP_MAX           TASK_SIZE_64
  73 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 4))
  74 #else
  75 #define STACK_TOP_MAX           DEFAULT_MAP_WINDOW_64
  76 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
  77 #endif /* CONFIG_ARM64_FORCE_52BIT */
  78
  79 #ifdef CONFIG_COMPAT
  80 #define AARCH32_VECTORS_BASE    0xffff0000
  81 #define STACK_TOP               (test_thread_flag(TIF_32BIT) ? \
  82                                 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
  83 #else
  84 #define STACK_TOP               STACK_TOP_MAX
  85 #endif /* CONFIG_COMPAT */
  86
  87 #ifndef CONFIG_ARM64_FORCE_52BIT
  88 #define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
  89                                 DEFAULT_MAP_WINDOW)
  90
  91 #define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
  92                                         base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
  93                                         base)
  94 #endif /* CONFIG_ARM64_FORCE_52BIT */
  95
  96 extern phys_addr_t arm64_dma_phys_limit;
  97 #define ARCH_LOW_ADDRESS_LIMIT  (arm64_dma_phys_limit - 1)
  98
  99 struct debug_info {
 100 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 101         /* Have we suspended stepping by a debugger? */
 102         int                     suspended_step;
 103         /* Allow breakpoints and watchpoints to be disabled for this thread. */
 104         int                     bps_disabled;
 105         int                     wps_disabled;
 106         /* Hardware breakpoints pinned to this task. */
 107         struct perf_event       *hbp_break[ARM_MAX_BRP];
 108         struct perf_event       *hbp_watch[ARM_MAX_WRP];
 109 #endif
 110 };
 111
 112 struct cpu_context {
 113         unsigned long x19;
 114         unsigned long x20;
 115         unsigned long x21;
 116         unsigned long x22;
 117         unsigned long x23;
 118         unsigned long x24;
 119         unsigned long x25;
 120         unsigned long x26;
 121         unsigned long x27;
 122         unsigned long x28;
 123         unsigned long fp;
 124         unsigned long sp;
 125         unsigned long pc;
 126 };
 127
 128 struct thread_struct {
 129         struct cpu_context      cpu_context;    /* cpu context */
 130
 131         /*
 132          * Whitelisted fields for hardened usercopy:
 133          * Maintainers must ensure manually that this contains no
 134          * implicit padding.
 135          */
 136         struct {
 137                 unsigned long   tp_value;       /* TLS register */
 138                 unsigned long   tp2_value;
 139                 struct user_fpsimd_state fpsimd_state;
 140         } uw;
 141
 142         unsigned int            fpsimd_cpu;
 143         void                    *sve_state;     /* SVE registers, if any */
 144         unsigned int            sve_vl;         /* SVE vector length */
 145         unsigned int            sve_vl_onexec;  /* SVE vl after next exec */
 146         unsigned long           fault_address;  /* fault info */
 147         unsigned long           fault_code;     /* ESR_EL1 value */
 148         struct debug_info       debug;          /* debugging */
 149 #ifdef CONFIG_ARM64_PTR_AUTH
 150         struct ptrauth_keys_user        keys_user;
 151         struct ptrauth_keys_kernel      keys_kernel;
 152 #endif
 153 #ifdef CONFIG_ARM64_MTE
 154         u64                     sctlr_tcf0;
 155         u64                     gcr_user_excl;
 156 #endif
 157 };
 158
 159 static inline void arch_thread_struct_whitelist(unsigned long *offset,
 160                                                 unsigned long *size)
 161 {
 162         /* Verify that there is no padding among the whitelisted fields: */
 163         BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
 164                      sizeof_field(struct thread_struct, uw.tp_value) +
 165                      sizeof_field(struct thread_struct, uw.tp2_value) +
 166                      sizeof_field(struct thread_struct, uw.fpsimd_state));
 167
 168         *offset = offsetof(struct thread_struct, uw);
 169         *size = sizeof_field(struct thread_struct, uw);
 170 }
 171
 172 #ifdef CONFIG_COMPAT
 173 #define task_user_tls(t)                                                \
 174 ({                                                                      \
 175         unsigned long *__tls;                                           \
 176         if (is_compat_thread(task_thread_info(t)))                      \
 177                 __tls = &(t)->thread.uw.tp2_value;                      \
 178         else                                                            \
 179                 __tls = &(t)->thread.uw.tp_value;                       \
 180         __tls;                                                          \
 181  })
 182 #else
 183 #define task_user_tls(t)        (&(t)->thread.uw.tp_value)
 184 #endif
 185
 186 /* Sync TPIDR_EL0 back to thread_struct for current */
 187 void tls_preserve_current_state(void);
 188
 189 #define INIT_THREAD {                           \
 190         .fpsimd_cpu = NR_CPUS,                  \
 191 }
 192
 193 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 194 {
 195         memset(regs, 0, sizeof(*regs));
 196         forget_syscall(regs);
 197         regs->pc = pc;
 198
 199         if (system_uses_irq_prio_masking())
 200                 regs->pmr_save = GIC_PRIO_IRQON;
 201 }
 202
 203 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 204                                 unsigned long sp)
 205 {
 206         start_thread_common(regs, pc);
 207         regs->pstate = PSR_MODE_EL0t;
 208         spectre_v4_enable_task_mitigation(current);
 209         regs->sp = sp;
 210 }
 211
 212 #ifdef CONFIG_COMPAT
 213 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 214                                        unsigned long sp)
 215 {
 216         start_thread_common(regs, pc);
 217         regs->pstate = PSR_AA32_MODE_USR;
 218         if (pc & 1)
 219                 regs->pstate |= PSR_AA32_T_BIT;
 220
 221 #ifdef __AARCH64EB__
 222         regs->pstate |= PSR_AA32_E_BIT;
 223 #endif
 224
 225         spectre_v4_enable_task_mitigation(current);
 226         regs->compat_sp = sp;
 227 }
 228 #endif
 229
 230 static inline bool is_ttbr0_addr(unsigned long addr)
 231 {
 232         /* entry assembly clears tags for TTBR0 addrs */
 233         return addr < TASK_SIZE;
 234 }
 235
 236 static inline bool is_ttbr1_addr(unsigned long addr)
 237 {
 238         /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
 239         return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
 240 }
 241
 242 /* Forward declaration, a strange C thing */
 243 struct task_struct;
 244
 245 /* Free all resources held by a thread. */
 246 extern void release_thread(struct task_struct *);
 247
 248 unsigned long get_wchan(struct task_struct *p);
 249
 250 /* Thread switching */
 251 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
 252                                          struct task_struct *next);
 253
 254 #define task_pt_regs(p) \
 255         ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
 256
 257 #define KSTK_EIP(tsk)   ((unsigned long)task_pt_regs(tsk)->pc)
 258 #define KSTK_ESP(tsk)   user_stack_pointer(task_pt_regs(tsk))
 259
 260 /*
 261  * Prefetching support
 262  */
 263 #define ARCH_HAS_PREFETCH
 264 static inline void prefetch(const void *ptr)
 265 {
 266         asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
 267 }
 268
 269 #define ARCH_HAS_PREFETCHW
 270 static inline void prefetchw(const void *ptr)
 271 {
 272         asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
 273 }
 274
 275 #define ARCH_HAS_SPINLOCK_PREFETCH
 276 static inline void spin_lock_prefetch(const void *ptr)
 277 {
 278         asm volatile(ARM64_LSE_ATOMIC_INSN(
 279                      "prfm pstl1strm, %a0",
 280                      "nop") : : "p" (ptr));
 281 }
 282
 283 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 284 extern void __init minsigstksz_setup(void);
 285
 286 /*
 287  * Not at the top of the file due to a direct #include cycle between
 288  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
 289  * ensures that contents of processor.h are visible to fpsimd.h even if
 290  * processor.h is included first.
 291  *
 292  * These prctl helpers are the only things in this file that require
 293  * fpsimd.h.  The core code expects them to be in this header.
 294  */
 295 #include <asm/fpsimd.h>
 296
 297 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
 298 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
 299 #define SVE_GET_VL()    sve_get_current_vl()
 300
 301 /* PR_PAC_RESET_KEYS prctl */
 302 #define PAC_RESET_KEYS(tsk, arg)        ptrauth_prctl_reset_keys(tsk, arg)
 303
 304 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
 305 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
 306 long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
 307 long get_tagged_addr_ctrl(struct task_struct *task);
 308 #define SET_TAGGED_ADDR_CTRL(arg)       set_tagged_addr_ctrl(current, arg)
 309 #define GET_TAGGED_ADDR_CTRL()          get_tagged_addr_ctrl(current)
 310 #endif
 311
 312 /*
 313  * For CONFIG_GCC_PLUGIN_STACKLEAK
 314  *
 315  * These need to be macros because otherwise we get stuck in a nightmare
 316  * of header definitions for the use of task_stack_page.
 317  */
 318
 319 #define current_top_of_stack()                                                  \
 320 ({                                                                              \
 321         struct stack_info _info;                                                \
 322         BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info));   \
 323         _info.high;                                                             \
 324 })
 325 #define on_thread_stack()       (on_task_stack(current, current_stack_pointer, NULL))
 326
 327 #endif /* __ASSEMBLY__ */
 328 #endif /* __ASM_PROCESSOR_H */