arch/mips/include/asm/thread_info.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /* thread_info.h: MIPS low-level thread information
   3  *
   4  * Copyright (C) 2002  David Howells (dhowells@redhat.com)
   5  * - Incorporating suggestions made by Linus Torvalds and Dave Miller
   6  */
   7
   8 #ifndef _ASM_THREAD_INFO_H
   9 #define _ASM_THREAD_INFO_H
  10
  11 #ifdef __KERNEL__
  12
  13
  14 #ifndef __ASSEMBLY__
  15
  16 #include <asm/processor.h>
  17
  18 /*
  19  * low level task data that entry.S needs immediate access to
  20  * - this struct should fit entirely inside of one cache line
  21  * - this struct shares the supervisor stack pages
  22  * - if the contents of this structure are changed, the assembly constants
  23  *   must also be changed
  24  */
  25 struct thread_info {
  26         struct task_struct      *task;          /* main task structure */
  27         unsigned long           flags;          /* low level flags */
  28         unsigned long           tp_value;       /* thread pointer */
  29         __u32                   cpu;            /* current CPU */
  30         int                     preempt_count;  /* 0 => preemptible, <0 => BUG */
  31         struct pt_regs          *regs;
  32         long                    syscall;        /* syscall number */
  33 };
  34
  35 /*
  36  * macros/functions for gaining access to the thread information structure
  37  */
  38 #define INIT_THREAD_INFO(tsk)                   \
  39 {                                               \
  40         .task           = &tsk,                 \
  41         .flags          = _TIF_FIXADE,          \
  42         .cpu            = 0,                    \
  43         .preempt_count  = INIT_PREEMPT_COUNT,   \
  44 }
  45
  46 /*
  47  * A pointer to the struct thread_info for the currently executing thread is
  48  * held in register $28/$gp.
  49  *
  50  * We declare __current_thread_info as a global register variable rather than a
  51  * local register variable within current_thread_info() because clang doesn't
  52  * support explicit local register variables.
  53  *
  54  * When building the VDSO we take care not to declare the global register
  55  * variable because this causes GCC to not preserve the value of $28/$gp in
  56  * functions that change its value (which is common in the PIC VDSO when
  57  * accessing the GOT). Since the VDSO shouldn't be accessing
  58  * __current_thread_info anyway we declare it extern in order to cause a link
  59  * failure if it's referenced.
  60  */
  61 #ifdef __VDSO__
  62 extern struct thread_info *__current_thread_info;
  63 #else
  64 register struct thread_info *__current_thread_info __asm__("$28");
  65 #endif
  66
  67 static inline struct thread_info *current_thread_info(void)
  68 {
  69         return __current_thread_info;
  70 }
  71
  72 #ifdef CONFIG_ARCH_HAS_CURRENT_STACK_POINTER
  73 register unsigned long current_stack_pointer __asm__("sp");
  74 #endif
  75
  76 #endif /* !__ASSEMBLY__ */
  77
  78 /* thread information allocation */
  79 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_32BIT)
  80 #define THREAD_SIZE_ORDER (1)
  81 #endif
  82 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_64BIT)
  83 #define THREAD_SIZE_ORDER (2)
  84 #endif
  85 #ifdef CONFIG_PAGE_SIZE_8KB
  86 #define THREAD_SIZE_ORDER (1)
  87 #endif
  88 #ifdef CONFIG_PAGE_SIZE_16KB
  89 #define THREAD_SIZE_ORDER (0)
  90 #endif
  91 #ifdef CONFIG_PAGE_SIZE_32KB
  92 #define THREAD_SIZE_ORDER (0)
  93 #endif
  94 #ifdef CONFIG_PAGE_SIZE_64KB
  95 #define THREAD_SIZE_ORDER (0)
  96 #endif
  97
  98 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
  99 #define THREAD_MASK (THREAD_SIZE - 1UL)
 100
 101 #define STACK_WARN      (THREAD_SIZE / 8)
 102
 103 /*
 104  * thread information flags
 105  * - these are process state flags that various assembly files may need to
 106  *   access
 107  * - pending work-to-be-done flags are in LSW
 108  * - other flags in MSW
 109  */
 110 #define TIF_SIGPENDING          1       /* signal pending */
 111 #define TIF_NEED_RESCHED        2       /* rescheduling necessary */
 112 #define TIF_SYSCALL_AUDIT       3       /* syscall auditing active */
 113 #define TIF_SECCOMP             4       /* secure computing */
 114 #define TIF_NOTIFY_RESUME       5       /* callback before returning to user */
 115 #define TIF_UPROBE              6       /* breakpointed or singlestepping */
 116 #define TIF_NOTIFY_SIGNAL       7       /* signal notifications exist */
 117 #define TIF_RESTORE_SIGMASK     9       /* restore signal mask in do_signal() */
 118 #define TIF_USEDFPU             16      /* FPU was used by this task this quantum (SMP) */
 119 #define TIF_MEMDIE              18      /* is terminating due to OOM killer */
 120 #define TIF_NOHZ                19      /* in adaptive nohz mode */
 121 #define TIF_FIXADE              20      /* Fix address errors in software */
 122 #define TIF_LOGADE              21      /* Log address errors to syslog */
 123 #define TIF_32BIT_REGS          22      /* 32-bit general purpose registers */
 124 #define TIF_32BIT_ADDR          23      /* 32-bit address space (o32/n32) */
 125 #define TIF_FPUBOUND            24      /* thread bound to FPU-full CPU set */
 126 #define TIF_LOAD_WATCH          25      /* If set, load watch registers */
 127 #define TIF_SYSCALL_TRACEPOINT  26      /* syscall tracepoint instrumentation */
 128 #define TIF_32BIT_FPREGS        27      /* 32-bit floating point registers */
 129 #define TIF_HYBRID_FPREGS       28      /* 64b FP registers, odd singles in bits 63:32 of even doubles */
 130 #define TIF_USEDMSA             29      /* MSA has been used this quantum */
 131 #define TIF_MSA_CTX_LIVE        30      /* MSA context must be preserved */
 132 #define TIF_SYSCALL_TRACE       31      /* syscall trace active */
 133
 134 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 135 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 136 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 137 #define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
 138 #define _TIF_SECCOMP            (1<<TIF_SECCOMP)
 139 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 140 #define _TIF_UPROBE             (1<<TIF_UPROBE)
 141 #define _TIF_NOTIFY_SIGNAL      (1<<TIF_NOTIFY_SIGNAL)
 142 #define _TIF_USEDFPU            (1<<TIF_USEDFPU)
 143 #define _TIF_NOHZ               (1<<TIF_NOHZ)
 144 #define _TIF_FIXADE             (1<<TIF_FIXADE)
 145 #define _TIF_LOGADE             (1<<TIF_LOGADE)
 146 #define _TIF_32BIT_REGS         (1<<TIF_32BIT_REGS)
 147 #define _TIF_32BIT_ADDR         (1<<TIF_32BIT_ADDR)
 148 #define _TIF_FPUBOUND           (1<<TIF_FPUBOUND)
 149 #define _TIF_LOAD_WATCH         (1<<TIF_LOAD_WATCH)
 150 #define _TIF_32BIT_FPREGS       (1<<TIF_32BIT_FPREGS)
 151 #define _TIF_HYBRID_FPREGS      (1<<TIF_HYBRID_FPREGS)
 152 #define _TIF_USEDMSA            (1<<TIF_USEDMSA)
 153 #define _TIF_MSA_CTX_LIVE       (1<<TIF_MSA_CTX_LIVE)
 154 #define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
 155
 156 #define _TIF_WORK_SYSCALL_ENTRY (_TIF_NOHZ | _TIF_SYSCALL_TRACE |       \
 157                                  _TIF_SYSCALL_AUDIT | \
 158                                  _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)
 159
 160 /* work to do in syscall_trace_leave() */
 161 #define _TIF_WORK_SYSCALL_EXIT  (_TIF_NOHZ | _TIF_SYSCALL_TRACE |       \
 162                                  _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)
 163
 164 /* work to do on interrupt/exception return */
 165 #define _TIF_WORK_MASK          \
 166         (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME |     \
 167          _TIF_UPROBE | _TIF_NOTIFY_SIGNAL)
 168 /* work to do on any return to u-space */
 169 #define _TIF_ALLWORK_MASK       (_TIF_NOHZ | _TIF_WORK_MASK |           \
 170                                  _TIF_WORK_SYSCALL_EXIT |               \
 171                                  _TIF_SYSCALL_TRACEPOINT)
 172
 173 /*
 174  * We stash processor id into a COP0 register to retrieve it fast
 175  * at kernel exception entry.
 176  */
 177 #if   defined(CONFIG_MIPS_PGD_C0_CONTEXT)
 178 #define SMP_CPUID_REG           20, 0   /* XCONTEXT */
 179 #define ASM_SMP_CPUID_REG       $20
 180 #define SMP_CPUID_PTRSHIFT      48
 181 #else
 182 #define SMP_CPUID_REG           4, 0    /* CONTEXT */
 183 #define ASM_SMP_CPUID_REG       $4
 184 #define SMP_CPUID_PTRSHIFT      23
 185 #endif
 186
 187 #ifdef CONFIG_64BIT
 188 #define SMP_CPUID_REGSHIFT      (SMP_CPUID_PTRSHIFT + 3)
 189 #else
 190 #define SMP_CPUID_REGSHIFT      (SMP_CPUID_PTRSHIFT + 2)
 191 #endif
 192
 193 #define ASM_CPUID_MFC0          MFC0
 194 #define UASM_i_CPUID_MFC0       UASM_i_MFC0
 195
 196 #endif /* __KERNEL__ */
 197 #endif /* _ASM_THREAD_INFO_H */