arch/riscv/include/asm/thread_info.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
   4  * Copyright (C) 2012 Regents of the University of California
   5  * Copyright (C) 2017 SiFive
   6  */
   7
   8 #ifndef _ASM_RISCV_THREAD_INFO_H
   9 #define _ASM_RISCV_THREAD_INFO_H
  10
  11 #include <asm/page.h>
  12 #include <linux/const.h>
  13 #include <linux/sizes.h>
  14
  15 /* thread information allocation */
  16 #define THREAD_SIZE_ORDER       CONFIG_THREAD_SIZE_ORDER
  17 #define THREAD_SIZE             (PAGE_SIZE << THREAD_SIZE_ORDER)
  18
  19 /*
  20  * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
  21  * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
  22  * assembly.
  23  */
  24 #ifdef CONFIG_VMAP_STACK
  25 #define THREAD_ALIGN            (2 * THREAD_SIZE)
  26 #else
  27 #define THREAD_ALIGN            THREAD_SIZE
  28 #endif
  29
  30 #define THREAD_SHIFT            (PAGE_SHIFT + THREAD_SIZE_ORDER)
  31 #define OVERFLOW_STACK_SIZE     SZ_4K
  32
  33 #define IRQ_STACK_SIZE          THREAD_SIZE
  34
  35 #ifndef __ASSEMBLY__
  36
  37 #include <asm/processor.h>
  38 #include <asm/csr.h>
  39
  40 /*
  41  * low level task data that entry.S needs immediate access to
  42  * - this struct should fit entirely inside of one cache line
  43  * - if the members of this struct changes, the assembly constants
  44  *   in asm-offsets.c must be updated accordingly
  45  * - thread_info is included in task_struct at an offset of 0.  This means that
  46  *   tp points to both thread_info and task_struct.
  47  */
  48 struct thread_info {
  49         unsigned long           flags;          /* low level flags */
  50         int                     preempt_count;  /* 0=>preemptible, <0=>BUG */
  51         /*
  52          * These stack pointers are overwritten on every system call or
  53          * exception.  SP is also saved to the stack it can be recovered when
  54          * overwritten.
  55          */
  56         long                    kernel_sp;      /* Kernel stack pointer */
  57         long                    user_sp;        /* User stack pointer */
  58         int                     cpu;
  59         unsigned long           syscall_work;   /* SYSCALL_WORK_ flags */
  60 #ifdef CONFIG_SHADOW_CALL_STACK
  61         void                    *scs_base;
  62         void                    *scs_sp;
  63 #endif
  64 #ifdef CONFIG_64BIT
  65         /*
  66          * Used in handle_exception() to save a0, a1 and a2 before knowing if we
  67          * can access the kernel stack.
  68          */
  69         unsigned long           a0, a1, a2;
  70 #endif
  71 };
  72
  73 #ifdef CONFIG_SHADOW_CALL_STACK
  74 #define INIT_SCS                                                        \
  75         .scs_base       = init_shadow_call_stack,                       \
  76         .scs_sp         = init_shadow_call_stack,
  77 #else
  78 #define INIT_SCS
  79 #endif
  80
  81 /*
  82  * macros/functions for gaining access to the thread information structure
  83  *
  84  * preempt_count needs to be 1 initially, until the scheduler is functional.
  85  */
  86 #define INIT_THREAD_INFO(tsk)                   \
  87 {                                               \
  88         .flags          = 0,                    \
  89         .preempt_count  = INIT_PREEMPT_COUNT,   \
  90         INIT_SCS                                \
  91 }
  92
  93 void arch_release_task_struct(struct task_struct *tsk);
  94 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
  95
  96 #endif /* !__ASSEMBLY__ */
  97
  98 /*
  99  * thread information flags
 100  * - these are process state flags that various assembly files may need to
 101  *   access
 102  * - pending work-to-be-done flags are in lowest half-word
 103  * - other flags in upper half-word(s)
 104  */
 105 #define TIF_NOTIFY_RESUME       1       /* callback before returning to user */
 106 #define TIF_SIGPENDING          2       /* signal pending */
 107 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
 108 #define TIF_RESTORE_SIGMASK     4       /* restore signal mask in do_signal() */
 109 #define TIF_MEMDIE              5       /* is terminating due to OOM killer */
 110 #define TIF_NOTIFY_SIGNAL       9       /* signal notifications exist */
 111 #define TIF_UPROBE              10      /* uprobe breakpoint or singlestep */
 112 #define TIF_32BIT               11      /* compat-mode 32bit process */
 113 #define TIF_RISCV_V_DEFER_RESTORE       12 /* restore Vector before returing to user */
 114
 115 #define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
 116 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 117 #define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
 118 #define _TIF_NOTIFY_SIGNAL      (1 << TIF_NOTIFY_SIGNAL)
 119 #define _TIF_UPROBE             (1 << TIF_UPROBE)
 120 #define _TIF_RISCV_V_DEFER_RESTORE      (1 << TIF_RISCV_V_DEFER_RESTORE)
 121
 122 #endif /* _ASM_RISCV_THREAD_INFO_H */