LXR linux/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#define MTE_CTRL_GCR_USER_EXCL_SHIFT    0
  20#define MTE_CTRL_GCR_USER_EXCL_MASK     0xffff
  21
  22#define MTE_CTRL_TCF_SYNC               (1UL << 16)
  23#define MTE_CTRL_TCF_ASYNC              (1UL << 17)
  24
  25#ifndef __ASSEMBLY__
  26
  27#include <linux/build_bug.h>
  28#include <linux/cache.h>
  29#include <linux/init.h>
  30#include <linux/stddef.h>
  31#include <linux/string.h>
  32#include <linux/thread_info.h>
  33
  34#include <vdso/processor.h>
  35
  36#include <asm/alternative.h>
  37#include <asm/cpufeature.h>
  38#include <asm/hw_breakpoint.h>
  39#include <asm/kasan.h>
  40#include <asm/lse.h>
  41#include <asm/pgtable-hwdef.h>
  42#include <asm/pointer_auth.h>
  43#include <asm/ptrace.h>
  44#include <asm/spectre.h>
  45#include <asm/types.h>
  46
  47/*
  48 * TASK_SIZE - the maximum size of a user space task.
  49 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
  50 */
  51
  52#define DEFAULT_MAP_WINDOW_64   (UL(1) << VA_BITS_MIN)
  53#define TASK_SIZE_64            (UL(1) << vabits_actual)
  54#define TASK_SIZE_MAX           (UL(1) << VA_BITS)
  55
  56#ifdef CONFIG_COMPAT
  57#if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
  58/*
  59 * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
  60 * by the compat vectors page.
  61 */
  62#define TASK_SIZE_32            UL(0x100000000)
  63#else
  64#define TASK_SIZE_32            (UL(0x100000000) - PAGE_SIZE)
  65#endif /* CONFIG_ARM64_64K_PAGES */
  66#define TASK_SIZE               (test_thread_flag(TIF_32BIT) ? \
  67                                TASK_SIZE_32 : TASK_SIZE_64)
  68#define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  69                                TASK_SIZE_32 : TASK_SIZE_64)
  70#define DEFAULT_MAP_WINDOW      (test_thread_flag(TIF_32BIT) ? \
  71                                TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
  72#else
  73#define TASK_SIZE               TASK_SIZE_64
  74#define DEFAULT_MAP_WINDOW      DEFAULT_MAP_WINDOW_64
  75#endif /* CONFIG_COMPAT */
  76
  77#ifdef CONFIG_ARM64_FORCE_52BIT
  78#define STACK_TOP_MAX           TASK_SIZE_64
  79#define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 4))
  80#else
  81#define STACK_TOP_MAX           DEFAULT_MAP_WINDOW_64
  82#define TASK_UNMAPPED_BASE      (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
  83#endif /* CONFIG_ARM64_FORCE_52BIT */
  84
  85#ifdef CONFIG_COMPAT
  86#define AARCH32_VECTORS_BASE    0xffff0000
  87#define STACK_TOP               (test_thread_flag(TIF_32BIT) ? \
  88                                AARCH32_VECTORS_BASE : STACK_TOP_MAX)
  89#else
  90#define STACK_TOP               STACK_TOP_MAX
  91#endif /* CONFIG_COMPAT */
  92
  93#ifndef CONFIG_ARM64_FORCE_52BIT
  94#define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
  95                                DEFAULT_MAP_WINDOW)
  96
  97#define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
  98                                        base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
  99                                        base)
 100#endif /* CONFIG_ARM64_FORCE_52BIT */
 101
 102extern phys_addr_t arm64_dma_phys_limit;
 103#define ARCH_LOW_ADDRESS_LIMIT  (arm64_dma_phys_limit - 1)
 104
 105struct debug_info {
 106#ifdef CONFIG_HAVE_HW_BREAKPOINT
 107        /* Have we suspended stepping by a debugger? */
 108        int                     suspended_step;
 109        /* Allow breakpoints and watchpoints to be disabled for this thread. */
 110        int                     bps_disabled;
 111        int                     wps_disabled;
 112        /* Hardware breakpoints pinned to this task. */
 113        struct perf_event       *hbp_break[ARM_MAX_BRP];
 114        struct perf_event       *hbp_watch[ARM_MAX_WRP];
 115#endif
 116};
 117
 118struct cpu_context {
 119        unsigned long x19;
 120        unsigned long x20;
 121        unsigned long x21;
 122        unsigned long x22;
 123        unsigned long x23;
 124        unsigned long x24;
 125        unsigned long x25;
 126        unsigned long x26;
 127        unsigned long x27;
 128        unsigned long x28;
 129        unsigned long fp;
 130        unsigned long sp;
 131        unsigned long pc;
 132};
 133
 134struct thread_struct {
 135        struct cpu_context      cpu_context;    /* cpu context */
 136
 137        /*
 138         * Whitelisted fields for hardened usercopy:
 139         * Maintainers must ensure manually that this contains no
 140         * implicit padding.
 141         */
 142        struct {
 143                unsigned long   tp_value;       /* TLS register */
 144                unsigned long   tp2_value;
 145                struct user_fpsimd_state fpsimd_state;
 146        } uw;
 147
 148        unsigned int            fpsimd_cpu;
 149        void                    *sve_state;     /* SVE registers, if any */
 150        unsigned int            sve_vl;         /* SVE vector length */
 151        unsigned int            sve_vl_onexec;  /* SVE vl after next exec */
 152        unsigned long           fault_address;  /* fault info */
 153        unsigned long           fault_code;     /* ESR_EL1 value */
 154        struct debug_info       debug;          /* debugging */
 155#ifdef CONFIG_ARM64_PTR_AUTH
 156        struct ptrauth_keys_user        keys_user;
 157#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL
 158        struct ptrauth_keys_kernel      keys_kernel;
 159#endif
 160#endif
 161#ifdef CONFIG_ARM64_MTE
 162        u64                     mte_ctrl;
 163#endif
 164        u64                     sctlr_user;
 165};
 166
 167#define SCTLR_USER_MASK                                                        \
 168        (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | SCTLR_ELx_ENDA | SCTLR_ELx_ENDB |   \
 169         SCTLR_EL1_TCF0_MASK)
 170
 171static inline void arch_thread_struct_whitelist(unsigned long *offset,
 172                                                unsigned long *size)
 173{
 174        /* Verify that there is no padding among the whitelisted fields: */
 175        BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
 176                     sizeof_field(struct thread_struct, uw.tp_value) +
 177                     sizeof_field(struct thread_struct, uw.tp2_value) +
 178                     sizeof_field(struct thread_struct, uw.fpsimd_state));
 179
 180        *offset = offsetof(struct thread_struct, uw);
 181        *size = sizeof_field(struct thread_struct, uw);
 182}
 183
 184#ifdef CONFIG_COMPAT
 185#define task_user_tls(t)                                                \
 186({                                                                      \
 187        unsigned long *__tls;                                           \
 188        if (is_compat_thread(task_thread_info(t)))                      \
 189                __tls = &(t)->thread.uw.tp2_value;                      \
 190        else                                                            \
 191                __tls = &(t)->thread.uw.tp_value;                       \
 192        __tls;                                                          \
 193 })
 194#else
 195#define task_user_tls(t)        (&(t)->thread.uw.tp_value)
 196#endif
 197
 198/* Sync TPIDR_EL0 back to thread_struct for current */
 199void tls_preserve_current_state(void);
 200
 201#define INIT_THREAD {                           \
 202        .fpsimd_cpu = NR_CPUS,                  \
 203}
 204
 205static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 206{
 207        memset(regs, 0, sizeof(*regs));
 208        forget_syscall(regs);
 209        regs->pc = pc;
 210
 211        if (system_uses_irq_prio_masking())
 212                regs->pmr_save = GIC_PRIO_IRQON;
 213}
 214
 215static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 216                                unsigned long sp)
 217{
 218        start_thread_common(regs, pc);
 219        regs->pstate = PSR_MODE_EL0t;
 220        spectre_v4_enable_task_mitigation(current);
 221        regs->sp = sp;
 222}
 223
 224#ifdef CONFIG_COMPAT
 225static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 226                                       unsigned long sp)
 227{
 228        start_thread_common(regs, pc);
 229        regs->pstate = PSR_AA32_MODE_USR;
 230        if (pc & 1)
 231                regs->pstate |= PSR_AA32_T_BIT;
 232
 233#ifdef __AARCH64EB__
 234        regs->pstate |= PSR_AA32_E_BIT;
 235#endif
 236
 237        spectre_v4_enable_task_mitigation(current);
 238        regs->compat_sp = sp;
 239}
 240#endif
 241
 242static inline bool is_ttbr0_addr(unsigned long addr)
 243{
 244        /* entry assembly clears tags for TTBR0 addrs */
 245        return addr < TASK_SIZE;
 246}
 247
 248static inline bool is_ttbr1_addr(unsigned long addr)
 249{
 250        /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
 251        return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
 252}
 253
 254/* Forward declaration, a strange C thing */
 255struct task_struct;
 256
 257/* Free all resources held by a thread. */
 258extern void release_thread(struct task_struct *);
 259
 260unsigned long get_wchan(struct task_struct *p);
 261
 262void update_sctlr_el1(u64 sctlr);
 263
 264/* Thread switching */
 265extern 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
 278static inline void prefetch(const void *ptr)
 279{
 280        asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
 281}
 282
 283#define ARCH_HAS_PREFETCHW
 284static inline void prefetchw(const void *ptr)
 285{
 286        asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
 287}
 288
 289#define ARCH_HAS_SPINLOCK_PREFETCH
 290static 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
 297extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 298extern 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/* PR_PAC_{SET,GET}_ENABLED_KEYS prctl */
 319#define PAC_SET_ENABLED_KEYS(tsk, keys, enabled)                                \
 320        ptrauth_set_enabled_keys(tsk, keys, enabled)
 321#define PAC_GET_ENABLED_KEYS(tsk) ptrauth_get_enabled_keys(tsk)
 322
 323#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
 324/* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
 325long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
 326long get_tagged_addr_ctrl(struct task_struct *task);
 327#define SET_TAGGED_ADDR_CTRL(arg)       set_tagged_addr_ctrl(current, arg)
 328#define GET_TAGGED_ADDR_CTRL()          get_tagged_addr_ctrl(current)
 329#endif
 330
 331/*
 332 * For CONFIG_GCC_PLUGIN_STACKLEAK
 333 *
 334 * These need to be macros because otherwise we get stuck in a nightmare
 335 * of header definitions for the use of task_stack_page.
 336 */
 337
 338#define current_top_of_stack()                                                          \
 339({                                                                                      \
 340        struct stack_info _info;                                                        \
 341        BUG_ON(!on_accessible_stack(current, current_stack_pointer, 1, &_info));        \
 342        _info.high;                                                                     \
 343})
 344#define on_thread_stack()       (on_task_stack(current, current_stack_pointer, 1, NULL))
 345
 346#endif /* __ASSEMBLY__ */
 347#endif /* __ASM_PROCESSOR_H */
 348