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 #ifdef CONFIG_KASAN
  17 #define KASAN_STACK_ORDER       1
  18 #else
  19 #define KASAN_STACK_ORDER       0
  20 #endif
  21 #define THREAD_SIZE_ORDER       (CONFIG_THREAD_SIZE_ORDER + KASAN_STACK_ORDER)
  22 #define THREAD_SIZE             (PAGE_SIZE << THREAD_SIZE_ORDER)
  23
  24 /*
  25  * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
  26  * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
  27  * assembly.
  28  */
  29 #ifdef CONFIG_VMAP_STACK
  30 #define THREAD_ALIGN            (2 * THREAD_SIZE)
  31 #else
  32 #define THREAD_ALIGN            THREAD_SIZE
  33 #endif
  34
  35 #define THREAD_SHIFT            (PAGE_SHIFT + THREAD_SIZE_ORDER)
  36 #define OVERFLOW_STACK_SIZE     SZ_4K
  37
  38 #define IRQ_STACK_SIZE          THREAD_SIZE
  39
  40 #ifndef __ASSEMBLY__
  41
  42 #include <asm/processor.h>
  43 #include <asm/csr.h>
  44
  45 /*
  46  * low level task data that entry.S needs immediate access to
  47  * - this struct should fit entirely inside of one cache line
  48  * - if the members of this struct changes, the assembly constants
  49  *   in asm-offsets.c must be updated accordingly
  50  * - thread_info is included in task_struct at an offset of 0.  This means that
  51  *   tp points to both thread_info and task_struct.
  52  */
  53 struct thread_info {
  54         unsigned long           flags;          /* low level flags */
  55         int                     preempt_count;  /* 0=>preemptible, <0=>BUG */
  56         /*
  57          * These stack pointers are overwritten on every system call or
  58          * exception.  SP is also saved to the stack it can be recovered when
  59          * overwritten.
  60          */
  61         long                    kernel_sp;      /* Kernel stack pointer */
  62         long                    user_sp;        /* User stack pointer */
  63         int                     cpu;
  64         unsigned long           syscall_work;   /* SYSCALL_WORK_ flags */
  65 #ifdef CONFIG_SHADOW_CALL_STACK
  66         void                    *scs_base;
  67         void                    *scs_sp;
  68 #endif
  69 #ifdef CONFIG_64BIT
  70         /*
  71          * Used in handle_exception() to save a0, a1 and a2 before knowing if we
  72          * can access the kernel stack.
  73          */
  74         unsigned long           a0, a1, a2;
  75 #endif
  76 };
  77
  78 #ifdef CONFIG_SHADOW_CALL_STACK
  79 #define INIT_SCS                                                        \
  80         .scs_base       = init_shadow_call_stack,                       \
  81         .scs_sp         = init_shadow_call_stack,
  82 #else
  83 #define INIT_SCS
  84 #endif
  85
  86 /*
  87  * macros/functions for gaining access to the thread information structure
  88  *
  89  * preempt_count needs to be 1 initially, until the scheduler is functional.
  90  */
  91 #define INIT_THREAD_INFO(tsk)                   \
  92 {                                               \
  93         .flags          = 0,                    \
  94         .preempt_count  = INIT_PREEMPT_COUNT,   \
  95         INIT_SCS                                \
  96 }
  97
  98 void arch_release_task_struct(struct task_struct *tsk);
  99 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 100
 101 #endif /* !__ASSEMBLY__ */
 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 lowest half-word
 108  * - other flags in upper half-word(s)
 109  */
 110 #define TIF_NEED_RESCHED        0       /* rescheduling necessary */
 111 #define TIF_NEED_RESCHED_LAZY   1       /* Lazy rescheduling needed */
 112 #define TIF_NOTIFY_RESUME       2       /* callback before returning to user */
 113 #define TIF_SIGPENDING          3       /* signal pending */
 114 #define TIF_RESTORE_SIGMASK     4       /* restore signal mask in do_signal() */
 115 #define TIF_MEMDIE              5       /* is terminating due to OOM killer */
 116 #define TIF_NOTIFY_SIGNAL       9       /* signal notifications exist */
 117 #define TIF_UPROBE              10      /* uprobe breakpoint or singlestep */
 118 #define TIF_32BIT               11      /* compat-mode 32bit process */
 119 #define TIF_RISCV_V_DEFER_RESTORE       12 /* restore Vector before returing to user */
 120
 121 #define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
 122 #define _TIF_NEED_RESCHED_LAZY  (1 << TIF_NEED_RESCHED_LAZY)
 123 #define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
 124 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 125 #define _TIF_NOTIFY_SIGNAL      (1 << TIF_NOTIFY_SIGNAL)
 126 #define _TIF_UPROBE             (1 << TIF_UPROBE)
 127 #define _TIF_RISCV_V_DEFER_RESTORE      (1 << TIF_RISCV_V_DEFER_RESTORE)
 128
 129 #endif /* _ASM_RISCV_THREAD_INFO_H */