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 #define MTE_CTRL_TCF_ASYMM              (1UL << 18)
  25
  26 #ifndef __ASSEMBLY__
  27
  28 #include <linux/build_bug.h>
  29 #include <linux/cache.h>
  30 #include <linux/init.h>
  31 #include <linux/stddef.h>
  32 #include <linux/string.h>
  33 #include <linux/thread_info.h>
  34
  35 #include <vdso/processor.h>
  36
  37 #include <asm/alternative.h>
  38 #include <asm/cpufeature.h>
  39 #include <asm/hw_breakpoint.h>
  40 #include <asm/kasan.h>
  41 #include <asm/lse.h>
  42 #include <asm/pgtable-hwdef.h>
  43 #include <asm/pointer_auth.h>
  44 #include <asm/ptrace.h>
  45 #include <asm/spectre.h>
  46 #include <asm/types.h>
  47
  48 /*
  49  * TASK_SIZE - the maximum size of a user space task.
  50  * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
  51  */
  52
  53 #define DEFAULT_MAP_WINDOW_64   (UL(1) << VA_BITS_MIN)
  54 #define TASK_SIZE_64            (UL(1) << vabits_actual)
  55 #define TASK_SIZE_MAX           (UL(1) << VA_BITS)
  56
  57 #ifdef CONFIG_COMPAT
  58 #if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
  59 /*
  60  * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
  61  * by the compat vectors page.
  62  */
  63 #define TASK_SIZE_32            UL(0x100000000)
  64 #else
  65 #define TASK_SIZE_32            (UL(0x100000000) - PAGE_SIZE)
  66 #endif /* CONFIG_ARM64_64K_PAGES */
  67 #define TASK_SIZE               (test_thread_flag(TIF_32BIT) ? \
  68                                 TASK_SIZE_32 : TASK_SIZE_64)
  69 #define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  70                                 TASK_SIZE_32 : TASK_SIZE_64)
  71 #define DEFAULT_MAP_WINDOW      (test_thread_flag(TIF_32BIT) ? \
  72                                 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
  73 #else
  74 #define TASK_SIZE               TASK_SIZE_64
  75 #define DEFAULT_MAP_WINDOW      DEFAULT_MAP_WINDOW_64
  76 #endif /* CONFIG_COMPAT */
  77
  78 #ifdef CONFIG_ARM64_FORCE_52BIT
  79 #define STACK_TOP_MAX           TASK_SIZE_64
  80 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 4))
  81 #else
  82 #define STACK_TOP_MAX           DEFAULT_MAP_WINDOW_64
  83 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
  84 #endif /* CONFIG_ARM64_FORCE_52BIT */
  85
  86 #ifdef CONFIG_COMPAT
  87 #define AARCH32_VECTORS_BASE    0xffff0000
  88 #define STACK_TOP               (test_thread_flag(TIF_32BIT) ? \
  89                                 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
  90 #else
  91 #define STACK_TOP               STACK_TOP_MAX
  92 #endif /* CONFIG_COMPAT */
  93
  94 #ifndef CONFIG_ARM64_FORCE_52BIT
  95 #define arch_get_mmap_end(addr, len, flags) \
  96                 (((addr) > DEFAULT_MAP_WINDOW) ? TASK_SIZE : DEFAULT_MAP_WINDOW)
  97
  98 #define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
  99                                         base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
 100                                         base)
 101 #endif /* CONFIG_ARM64_FORCE_52BIT */
 102
 103 extern phys_addr_t arm64_dma_phys_limit;
 104 #define ARCH_LOW_ADDRESS_LIMIT  (arm64_dma_phys_limit - 1)
 105
 106 struct debug_info {
 107 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 108         /* Have we suspended stepping by a debugger? */
 109         int                     suspended_step;
 110         /* Allow breakpoints and watchpoints to be disabled for this thread. */
 111         int                     bps_disabled;
 112         int                     wps_disabled;
 113         /* Hardware breakpoints pinned to this task. */
 114         struct perf_event       *hbp_break[ARM_MAX_BRP];
 115         struct perf_event       *hbp_watch[ARM_MAX_WRP];
 116 #endif
 117 };
 118
 119 enum vec_type {
 120         ARM64_VEC_SVE = 0,
 121         ARM64_VEC_SME,
 122         ARM64_VEC_MAX,
 123 };
 124
 125 enum fp_type {
 126         FP_STATE_CURRENT,       /* Save based on current task state. */
 127         FP_STATE_FPSIMD,
 128         FP_STATE_SVE,
 129 };
 130
 131 struct cpu_context {
 132         unsigned long x19;
 133         unsigned long x20;
 134         unsigned long x21;
 135         unsigned long x22;
 136         unsigned long x23;
 137         unsigned long x24;
 138         unsigned long x25;
 139         unsigned long x26;
 140         unsigned long x27;
 141         unsigned long x28;
 142         unsigned long fp;
 143         unsigned long sp;
 144         unsigned long pc;
 145 };
 146
 147 struct thread_struct {
 148         struct cpu_context      cpu_context;    /* cpu context */
 149
 150         /*
 151          * Whitelisted fields for hardened usercopy:
 152          * Maintainers must ensure manually that this contains no
 153          * implicit padding.
 154          */
 155         struct {
 156                 unsigned long   tp_value;       /* TLS register */
 157                 unsigned long   tp2_value;
 158                 u64             fpmr;
 159                 unsigned long   pad;
 160                 struct user_fpsimd_state fpsimd_state;
 161         } uw;
 162
 163         enum fp_type            fp_type;        /* registers FPSIMD or SVE? */
 164         unsigned int            fpsimd_cpu;
 165         void                    *sve_state;     /* SVE registers, if any */
 166         void                    *sme_state;     /* ZA and ZT state, if any */
 167         unsigned int            vl[ARM64_VEC_MAX];      /* vector length */
 168         unsigned int            vl_onexec[ARM64_VEC_MAX]; /* vl after next exec */
 169         unsigned long           fault_address;  /* fault info */
 170         unsigned long           fault_code;     /* ESR_EL1 value */
 171         struct debug_info       debug;          /* debugging */
 172
 173         struct user_fpsimd_state        kernel_fpsimd_state;
 174         unsigned int                    kernel_fpsimd_cpu;
 175 #ifdef CONFIG_ARM64_PTR_AUTH
 176         struct ptrauth_keys_user        keys_user;
 177 #ifdef CONFIG_ARM64_PTR_AUTH_KERNEL
 178         struct ptrauth_keys_kernel      keys_kernel;
 179 #endif
 180 #endif
 181 #ifdef CONFIG_ARM64_MTE
 182         u64                     mte_ctrl;
 183 #endif
 184         u64                     sctlr_user;
 185         u64                     svcr;
 186         u64                     tpidr2_el0;
 187         u64                     por_el0;
 188 #ifdef CONFIG_ARM64_GCS
 189         unsigned int            gcs_el0_mode;
 190         unsigned int            gcs_el0_locked;
 191         u64                     gcspr_el0;
 192         u64                     gcs_base;
 193         u64                     gcs_size;
 194 #endif
 195 };
 196
 197 static inline unsigned int thread_get_vl(struct thread_struct *thread,
 198                                          enum vec_type type)
 199 {
 200         return thread->vl[type];
 201 }
 202
 203 static inline unsigned int thread_get_sve_vl(struct thread_struct *thread)
 204 {
 205         return thread_get_vl(thread, ARM64_VEC_SVE);
 206 }
 207
 208 static inline unsigned int thread_get_sme_vl(struct thread_struct *thread)
 209 {
 210         return thread_get_vl(thread, ARM64_VEC_SME);
 211 }
 212
 213 static inline unsigned int thread_get_cur_vl(struct thread_struct *thread)
 214 {
 215         if (system_supports_sme() && (thread->svcr & SVCR_SM_MASK))
 216                 return thread_get_sme_vl(thread);
 217         else
 218                 return thread_get_sve_vl(thread);
 219 }
 220
 221 unsigned int task_get_vl(const struct task_struct *task, enum vec_type type);
 222 void task_set_vl(struct task_struct *task, enum vec_type type,
 223                  unsigned long vl);
 224 void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
 225                         unsigned long vl);
 226 unsigned int task_get_vl_onexec(const struct task_struct *task,
 227                                 enum vec_type type);
 228
 229 static inline unsigned int task_get_sve_vl(const struct task_struct *task)
 230 {
 231         return task_get_vl(task, ARM64_VEC_SVE);
 232 }
 233
 234 static inline unsigned int task_get_sme_vl(const struct task_struct *task)
 235 {
 236         return task_get_vl(task, ARM64_VEC_SME);
 237 }
 238
 239 static inline void task_set_sve_vl(struct task_struct *task, unsigned long vl)
 240 {
 241         task_set_vl(task, ARM64_VEC_SVE, vl);
 242 }
 243
 244 static inline unsigned int task_get_sve_vl_onexec(const struct task_struct *task)
 245 {
 246         return task_get_vl_onexec(task, ARM64_VEC_SVE);
 247 }
 248
 249 static inline void task_set_sve_vl_onexec(struct task_struct *task,
 250                                           unsigned long vl)
 251 {
 252         task_set_vl_onexec(task, ARM64_VEC_SVE, vl);
 253 }
 254
 255 #define SCTLR_USER_MASK                                                        \
 256         (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | SCTLR_ELx_ENDA | SCTLR_ELx_ENDB |   \
 257          SCTLR_EL1_TCF0_MASK)
 258
 259 static inline void arch_thread_struct_whitelist(unsigned long *offset,
 260                                                 unsigned long *size)
 261 {
 262         /* Verify that there is no padding among the whitelisted fields: */
 263         BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
 264                      sizeof_field(struct thread_struct, uw.tp_value) +
 265                      sizeof_field(struct thread_struct, uw.tp2_value) +
 266                      sizeof_field(struct thread_struct, uw.fpmr) +
 267                      sizeof_field(struct thread_struct, uw.pad) +
 268                      sizeof_field(struct thread_struct, uw.fpsimd_state));
 269
 270         *offset = offsetof(struct thread_struct, uw);
 271         *size = sizeof_field(struct thread_struct, uw);
 272 }
 273
 274 #ifdef CONFIG_COMPAT
 275 #define task_user_tls(t)                                                \
 276 ({                                                                      \
 277         unsigned long *__tls;                                           \
 278         if (is_compat_thread(task_thread_info(t)))                      \
 279                 __tls = &(t)->thread.uw.tp2_value;                      \
 280         else                                                            \
 281                 __tls = &(t)->thread.uw.tp_value;                       \
 282         __tls;                                                          \
 283  })
 284 #else
 285 #define task_user_tls(t)        (&(t)->thread.uw.tp_value)
 286 #endif
 287
 288 /* Sync TPIDR_EL0 back to thread_struct for current */
 289 void tls_preserve_current_state(void);
 290
 291 #define INIT_THREAD {                           \
 292         .fpsimd_cpu = NR_CPUS,                  \
 293 }
 294
 295 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc,
 296                                        unsigned long pstate)
 297 {
 298         /*
 299          * Ensure all GPRs are zeroed, and initialize PC + PSTATE.
 300          * The SP (or compat SP) will be initialized later.
 301          */
 302         regs->user_regs = (struct user_pt_regs) {
 303                 .pc = pc,
 304                 .pstate = pstate,
 305         };
 306
 307         /*
 308          * To allow the syscalls:sys_exit_execve tracepoint we need to preserve
 309          * syscallno, but do not need orig_x0 or the original GPRs.
 310          */
 311         regs->orig_x0 = 0;
 312
 313         /*
 314          * An exec from a kernel thread won't have an existing PMR value.
 315          */
 316         if (system_uses_irq_prio_masking())
 317                 regs->pmr = GIC_PRIO_IRQON;
 318
 319         /*
 320          * The pt_regs::stackframe field must remain valid throughout this
 321          * function as a stacktrace can be taken at any time. Any user or
 322          * kernel task should have a valid final frame.
 323          */
 324         WARN_ON_ONCE(regs->stackframe.record.fp != 0);
 325         WARN_ON_ONCE(regs->stackframe.record.lr != 0);
 326         WARN_ON_ONCE(regs->stackframe.type != FRAME_META_TYPE_FINAL);
 327 }
 328
 329 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 330                                 unsigned long sp)
 331 {
 332         start_thread_common(regs, pc, PSR_MODE_EL0t);
 333         spectre_v4_enable_task_mitigation(current);
 334         regs->sp = sp;
 335 }
 336
 337 #ifdef CONFIG_COMPAT
 338 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 339                                        unsigned long sp)
 340 {
 341         unsigned long pstate = PSR_AA32_MODE_USR;
 342         if (pc & 1)
 343                 pstate |= PSR_AA32_T_BIT;
 344         if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 345                 pstate |= PSR_AA32_E_BIT;
 346
 347         start_thread_common(regs, pc, pstate);
 348         spectre_v4_enable_task_mitigation(current);
 349         regs->compat_sp = sp;
 350 }
 351 #endif
 352
 353 static __always_inline bool is_ttbr0_addr(unsigned long addr)
 354 {
 355         /* entry assembly clears tags for TTBR0 addrs */
 356         return addr < TASK_SIZE;
 357 }
 358
 359 static __always_inline bool is_ttbr1_addr(unsigned long addr)
 360 {
 361         /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
 362         return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
 363 }
 364
 365 /* Forward declaration, a strange C thing */
 366 struct task_struct;
 367
 368 unsigned long __get_wchan(struct task_struct *p);
 369
 370 void update_sctlr_el1(u64 sctlr);
 371
 372 /* Thread switching */
 373 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
 374                                          struct task_struct *next);
 375
 376 #define task_pt_regs(p) \
 377         ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
 378
 379 #define KSTK_EIP(tsk)   ((unsigned long)task_pt_regs(tsk)->pc)
 380 #define KSTK_ESP(tsk)   user_stack_pointer(task_pt_regs(tsk))
 381
 382 /*
 383  * Prefetching support
 384  */
 385 #define ARCH_HAS_PREFETCH
 386 static inline void prefetch(const void *ptr)
 387 {
 388         asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
 389 }
 390
 391 #define ARCH_HAS_PREFETCHW
 392 static inline void prefetchw(const void *ptr)
 393 {
 394         asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
 395 }
 396
 397 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 398 extern void __init minsigstksz_setup(void);
 399
 400 /*
 401  * Not at the top of the file due to a direct #include cycle between
 402  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
 403  * ensures that contents of processor.h are visible to fpsimd.h even if
 404  * processor.h is included first.
 405  *
 406  * These prctl helpers are the only things in this file that require
 407  * fpsimd.h.  The core code expects them to be in this header.
 408  */
 409 #include <asm/fpsimd.h>
 410
 411 /* Userspace interface for PR_S[MV]E_{SET,GET}_VL prctl()s: */
 412 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
 413 #define SVE_GET_VL()    sve_get_current_vl()
 414 #define SME_SET_VL(arg) sme_set_current_vl(arg)
 415 #define SME_GET_VL()    sme_get_current_vl()
 416
 417 /* PR_PAC_RESET_KEYS prctl */
 418 #define PAC_RESET_KEYS(tsk, arg)        ptrauth_prctl_reset_keys(tsk, arg)
 419
 420 /* PR_PAC_{SET,GET}_ENABLED_KEYS prctl */
 421 #define PAC_SET_ENABLED_KEYS(tsk, keys, enabled)                                \
 422         ptrauth_set_enabled_keys(tsk, keys, enabled)
 423 #define PAC_GET_ENABLED_KEYS(tsk) ptrauth_get_enabled_keys(tsk)
 424
 425 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
 426 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
 427 long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
 428 long get_tagged_addr_ctrl(struct task_struct *task);
 429 #define SET_TAGGED_ADDR_CTRL(arg)       set_tagged_addr_ctrl(current, arg)
 430 #define GET_TAGGED_ADDR_CTRL()          get_tagged_addr_ctrl(current)
 431 #endif
 432
 433 int get_tsc_mode(unsigned long adr);
 434 int set_tsc_mode(unsigned int val);
 435 #define GET_TSC_CTL(adr)        get_tsc_mode((adr))
 436 #define SET_TSC_CTL(val)        set_tsc_mode((val))
 437
 438 #endif /* __ASSEMBLY__ */
 439 #endif /* __ASM_PROCESSOR_H */