arch/riscv/include/asm/thread_info.h

root/arch/riscv/include/asm/thread_info.h
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
 * Copyright (C) 2012 Regents of the University of California
 * Copyright (C) 2017 SiFive
 */

#ifndef _ASM_RISCV_THREAD_INFO_H
#define _ASM_RISCV_THREAD_INFO_H

#include <asm/page.h>
#include <linux/const.h>
#include <linux/sizes.h>

/* thread information allocation */
#ifdef CONFIG_KASAN
#define KASAN_STACK_ORDER       1
#else
#define KASAN_STACK_ORDER       0
#endif
#define THREAD_SIZE_ORDER       (CONFIG_THREAD_SIZE_ORDER + KASAN_STACK_ORDER)
#define THREAD_SIZE             (PAGE_SIZE << THREAD_SIZE_ORDER)

/*
 * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
 * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
 * assembly.
 */
#ifdef CONFIG_VMAP_STACK
#define THREAD_ALIGN            (2 * THREAD_SIZE)
#else
#define THREAD_ALIGN            THREAD_SIZE
#endif

#define THREAD_SHIFT            (PAGE_SHIFT + THREAD_SIZE_ORDER)
#define OVERFLOW_STACK_SIZE     SZ_4K

#define IRQ_STACK_SIZE          THREAD_SIZE

#ifndef __ASSEMBLER__

#include <asm/processor.h>
#include <asm/csr.h>

/*
 * low level task data that entry.S needs immediate access to
 * - this struct should fit entirely inside of one cache line
 * - if the members of this struct changes, the assembly constants
 *   in asm-offsets.c must be updated accordingly
 * - thread_info is included in task_struct at an offset of 0.  This means that
 *   tp points to both thread_info and task_struct.
 */
struct thread_info {
        unsigned long           flags;          /* low level flags */
        int                     preempt_count;  /* 0=>preemptible, <0=>BUG */
        /*
         * These stack pointers are overwritten on every system call or
         * exception.  SP is also saved to the stack it can be recovered when
         * overwritten.
         */
        long                    kernel_sp;      /* Kernel stack pointer */
        long                    user_sp;        /* User stack pointer */
        int                     cpu;
        unsigned long           syscall_work;   /* SYSCALL_WORK_ flags */
#ifdef CONFIG_SHADOW_CALL_STACK
        void                    *scs_base;
        void                    *scs_sp;
#endif
#ifdef CONFIG_64BIT
        /*
         * Used in handle_exception() to save a0, a1 and a2 before knowing if we
         * can access the kernel stack.
         */
        unsigned long           a0, a1, a2;
#endif
#ifdef CONFIG_RISCV_USER_CFI
        struct cfi_state        user_cfi_state;
#endif
};

#ifdef CONFIG_SHADOW_CALL_STACK
#define INIT_SCS                                                        \
        .scs_base       = init_shadow_call_stack,                       \
        .scs_sp         = init_shadow_call_stack,
#else
#define INIT_SCS
#endif

/*
 * macros/functions for gaining access to the thread information structure
 *
 * preempt_count needs to be 1 initially, until the scheduler is functional.
 */
#define INIT_THREAD_INFO(tsk)                   \
{                                               \
        .flags          = 0,                    \
        .preempt_count  = INIT_PREEMPT_COUNT,   \
        INIT_SCS                                \
}

void arch_release_task_struct(struct task_struct *tsk);
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);

#endif /* !__ASSEMBLER__ */

/*
 * thread information flags
 * - these are process state flags that various assembly files may need to
 *   access
 * - pending work-to-be-done flags are in lowest half-word
 * - other flags in upper half-word(s)
 */

/*
 * Tell the generic TIF infrastructure which bits riscv supports
 */
#define HAVE_TIF_NEED_RESCHED_LAZY
#define HAVE_TIF_RESTORE_SIGMASK

#include <asm-generic/thread_info_tif.h>

#define TIF_32BIT                       16      /* compat-mode 32bit process */
#define TIF_RISCV_V_DEFER_RESTORE       17      /* restore Vector before returing to user */

#define _TIF_RISCV_V_DEFER_RESTORE      BIT(TIF_RISCV_V_DEFER_RESTORE)

#endif /* _ASM_RISCV_THREAD_INFO_H */
Linux
