LXR linux/arch/csky/include/asm/processor.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4#ifndef __ASM_CSKY_PROCESSOR_H
   5#define __ASM_CSKY_PROCESSOR_H
   6
   7#include <linux/bitops.h>
   8#include <asm/segment.h>
   9#include <asm/ptrace.h>
  10#include <asm/current.h>
  11#include <asm/cache.h>
  12#include <abi/reg_ops.h>
  13#include <abi/regdef.h>
  14#include <abi/switch_context.h>
  15#ifdef CONFIG_CPU_HAS_FPU
  16#include <abi/fpu.h>
  17#endif
  18
  19struct cpuinfo_csky {
  20        unsigned long asid_cache;
  21} __aligned(SMP_CACHE_BYTES);
  22
  23extern struct cpuinfo_csky cpu_data[];
  24
  25/*
  26 * User space process size: 2GB. This is hardcoded into a few places,
  27 * so don't change it unless you know what you are doing.  TASK_SIZE
  28 * for a 64 bit kernel expandable to 8192EB, of which the current CSKY
  29 * implementations will "only" be able to use 1TB ...
  30 */
  31#define TASK_SIZE       0x7fff8000UL
  32
  33#ifdef __KERNEL__
  34#define STACK_TOP       TASK_SIZE
  35#define STACK_TOP_MAX   STACK_TOP
  36#endif
  37
  38/* This decides where the kernel will search for a free chunk of vm
  39 * space during mmap's.
  40 */
  41#define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
  42
  43struct thread_struct {
  44        unsigned long  ksp;       /* kernel stack pointer */
  45        unsigned long  sr;        /* saved status register */
  46
  47        /* FPU regs */
  48        struct user_fp __aligned(16) user_fp;
  49};
  50
  51#define INIT_THREAD  { \
  52        .ksp = sizeof(init_stack) + (unsigned long) &init_stack, \
  53        .sr = DEFAULT_PSR_VALUE, \
  54}
  55
  56/*
  57 * Do necessary setup to start up a newly executed thread.
  58 *
  59 * pass the data segment into user programs if it exists,
  60 * it can't hurt anything as far as I can tell
  61 */
  62#define start_thread(_regs, _pc, _usp)                                  \
  63do {                                                                    \
  64        set_fs(USER_DS); /* reads from user space */                    \
  65        (_regs)->pc = (_pc);                                            \
  66        (_regs)->regs[1] = 0; /* ABIV1 is R7, uClibc_main rtdl arg */   \
  67        (_regs)->regs[2] = 0;                                           \
  68        (_regs)->regs[3] = 0; /* ABIV2 is R7, use it? */                \
  69        (_regs)->sr &= ~PS_S;                                           \
  70        (_regs)->usp = (_usp);                                          \
  71} while (0)
  72
  73/* Forward declaration, a strange C thing */
  74struct task_struct;
  75
  76/* Free all resources held by a thread. */
  77static inline void release_thread(struct task_struct *dead_task)
  78{
  79}
  80
  81/* Prepare to copy thread state - unlazy all lazy status */
  82#define prepare_to_copy(tsk)    do { } while (0)
  83
  84extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
  85
  86#define copy_segments(tsk, mm)          do { } while (0)
  87#define release_segments(mm)            do { } while (0)
  88#define forget_segments()               do { } while (0)
  89
  90extern unsigned long thread_saved_pc(struct task_struct *tsk);
  91
  92unsigned long get_wchan(struct task_struct *p);
  93
  94#define KSTK_EIP(tsk)           (task_pt_regs(tsk)->pc)
  95#define KSTK_ESP(tsk)           (task_pt_regs(tsk)->usp)
  96
  97#define task_pt_regs(p) \
  98        ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
  99
 100#define cpu_relax() barrier()
 101
 102#endif /* __ASM_CSKY_PROCESSOR_H */
 103