/* SPDX-License-Identifier: GPL-2.0 */
/* thread_info.h: MIPS low-level thread information
 *
 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
 */

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

#ifdef __KERNEL__


#ifndef __ASSEMBLER__

#include <asm/processor.h>

/*
 * low level task data that entry.S needs immediate access to
 * - this struct should fit entirely inside of one cache line
 * - this struct shares the supervisor stack pages
 * - if the contents of this structure are changed, the assembly constants
 *   must also be changed
 */
struct thread_info {
        struct task_struct      *task;          /* main task structure */
        unsigned long           flags;          /* low level flags */
        unsigned long           tp_value;       /* thread pointer */
        __u32                   cpu;            /* current CPU */
        int                     preempt_count;  /* 0 => preemptible, <0 => BUG */
        struct pt_regs          *regs;
        long                    syscall;        /* syscall number */
};

/*
 * macros/functions for gaining access to the thread information structure
 */
#define INIT_THREAD_INFO(tsk)                   \
{                                               \
        .task           = &tsk,                 \
        .flags          = _TIF_FIXADE,          \
        .cpu            = 0,                    \
        .preempt_count  = INIT_PREEMPT_COUNT,   \
}

/*
 * A pointer to the struct thread_info for the currently executing thread is
 * held in register $28/$gp.
 *
 * We declare __current_thread_info as a global register variable rather than a
 * local register variable within current_thread_info() because clang doesn't
 * support explicit local register variables.
 *
 * When building the VDSO we take care not to declare the global register
 * variable because this causes GCC to not preserve the value of $28/$gp in
 * functions that change its value (which is common in the PIC VDSO when
 * accessing the GOT). Since the VDSO shouldn't be accessing
 * __current_thread_info anyway we declare it extern in order to cause a link
 * failure if it's referenced.
 */
#ifdef __VDSO__
extern struct thread_info *__current_thread_info;
#else
register struct thread_info *__current_thread_info __asm__("$28");
#endif

static inline struct thread_info *current_thread_info(void)
{
        return __current_thread_info;
}

#ifdef CONFIG_ARCH_HAS_CURRENT_STACK_POINTER
register unsigned long current_stack_pointer __asm__("sp");
#endif

#endif /* !__ASSEMBLER__ */

/* thread information allocation */
#if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_32BIT)
#define THREAD_SIZE_ORDER (1)
#endif
#if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_64BIT)
#define THREAD_SIZE_ORDER (2)
#endif
#ifdef CONFIG_PAGE_SIZE_8KB
#define THREAD_SIZE_ORDER (1)
#endif
#ifdef CONFIG_PAGE_SIZE_16KB
#define THREAD_SIZE_ORDER (0)
#endif
#ifdef CONFIG_PAGE_SIZE_32KB
#define THREAD_SIZE_ORDER (0)
#endif
#ifdef CONFIG_PAGE_SIZE_64KB
#define THREAD_SIZE_ORDER (0)
#endif

#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#define THREAD_MASK (THREAD_SIZE - 1UL)

#define STACK_WARN      (THREAD_SIZE / 8)

/*
 * thread information flags
 * - these are process state flags that various assembly files may need to
 *   access
 * - pending work-to-be-done flags are in LSW
 * - other flags in MSW
 */
#define TIF_SIGPENDING          1       /* signal pending */
#define TIF_NEED_RESCHED        2       /* rescheduling necessary */
#define TIF_SYSCALL_AUDIT       3       /* syscall auditing active */
#define TIF_SECCOMP             4       /* secure computing */
#define TIF_NOTIFY_RESUME       5       /* callback before returning to user */
#define TIF_UPROBE              6       /* breakpointed or singlestepping */
#define TIF_NOTIFY_SIGNAL       7       /* signal notifications exist */
#define TIF_RESTORE_SIGMASK     9       /* restore signal mask in do_signal() */
#define TIF_USEDFPU             16      /* FPU was used by this task this quantum (SMP) */
#define TIF_MEMDIE              18      /* is terminating due to OOM killer */
#define TIF_NOHZ                19      /* in adaptive nohz mode */
#define TIF_FIXADE              20      /* Fix address errors in software */
#define TIF_LOGADE              21      /* Log address errors to syslog */
#define TIF_32BIT_REGS          22      /* 32-bit general purpose registers */
#define TIF_32BIT_ADDR          23      /* 32-bit address space (o32/n32) */
#define TIF_FPUBOUND            24      /* thread bound to FPU-full CPU set */
#define TIF_LOAD_WATCH          25      /* If set, load watch registers */
#define TIF_SYSCALL_TRACEPOINT  26      /* syscall tracepoint instrumentation */
#define TIF_32BIT_FPREGS        27      /* 32-bit floating point registers */
#define TIF_HYBRID_FPREGS       28      /* 64b FP registers, odd singles in bits 63:32 of even doubles */
#define TIF_USEDMSA             29      /* MSA has been used this quantum */
#define TIF_MSA_CTX_LIVE        30      /* MSA context must be preserved */
#define TIF_SYSCALL_TRACE       31      /* syscall trace active */

#define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
#define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP            (1<<TIF_SECCOMP)
#define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
#define _TIF_UPROBE             (1<<TIF_UPROBE)
#define _TIF_NOTIFY_SIGNAL      (1<<TIF_NOTIFY_SIGNAL)
#define _TIF_USEDFPU            (1<<TIF_USEDFPU)
#define _TIF_NOHZ               (1<<TIF_NOHZ)
#define _TIF_FIXADE             (1<<TIF_FIXADE)
#define _TIF_LOGADE             (1<<TIF_LOGADE)
#define _TIF_32BIT_REGS         (1<<TIF_32BIT_REGS)
#define _TIF_32BIT_ADDR         (1<<TIF_32BIT_ADDR)
#define _TIF_FPUBOUND           (1<<TIF_FPUBOUND)
#define _TIF_LOAD_WATCH         (1<<TIF_LOAD_WATCH)
#define _TIF_32BIT_FPREGS       (1<<TIF_32BIT_FPREGS)
#define _TIF_HYBRID_FPREGS      (1<<TIF_HYBRID_FPREGS)
#define _TIF_USEDMSA            (1<<TIF_USEDMSA)
#define _TIF_MSA_CTX_LIVE       (1<<TIF_MSA_CTX_LIVE)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)

#define _TIF_WORK_SYSCALL_ENTRY (_TIF_NOHZ | _TIF_SYSCALL_TRACE |       \
                                 _TIF_SYSCALL_AUDIT | \
                                 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)

/* work to do in syscall_trace_leave() */
#define _TIF_WORK_SYSCALL_EXIT  (_TIF_NOHZ | _TIF_SYSCALL_TRACE |       \
                                 _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)

/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK          \
        (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME |     \
         _TIF_UPROBE | _TIF_NOTIFY_SIGNAL)
/* work to do on any return to u-space */
#define _TIF_ALLWORK_MASK       (_TIF_NOHZ | _TIF_WORK_MASK |           \
                                 _TIF_WORK_SYSCALL_EXIT |               \
                                 _TIF_SYSCALL_TRACEPOINT)

/*
 * We stash processor id into a COP0 register to retrieve it fast
 * at kernel exception entry.
 */
#if   defined(CONFIG_MIPS_PGD_C0_CONTEXT)
#define SMP_CPUID_REG           20, 0   /* XCONTEXT */
#define ASM_SMP_CPUID_REG       $20
#define SMP_CPUID_PTRSHIFT      48
#else
#define SMP_CPUID_REG           4, 0    /* CONTEXT */
#define ASM_SMP_CPUID_REG       $4
#define SMP_CPUID_PTRSHIFT      23
#endif

#ifdef CONFIG_64BIT
#define SMP_CPUID_REGSHIFT      (SMP_CPUID_PTRSHIFT + 3)
#else
#define SMP_CPUID_REGSHIFT      (SMP_CPUID_PTRSHIFT + 2)
#endif

#define ASM_CPUID_MFC0          MFC0
#define UASM_i_CPUID_MFC0       UASM_i_MFC0

#endif /* __KERNEL__ */
#endif /* _ASM_THREAD_INFO_H */