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
  19 struct cpuinfo_csky {
  20         unsigned long asid_cache;
  21 } __aligned(SMP_CACHE_BYTES);
  22
  23 extern 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
  43 struct thread_struct {
  44         unsigned long  ksp;       /* kernel stack pointer */
  45         unsigned long  sr;        /* saved status register */
  46         unsigned long  trap_no;   /* saved status register */
  47
  48         /* FPU regs */
  49         struct user_fp __aligned(16) user_fp;
  50 };
  51
  52 #define INIT_THREAD  { \
  53         .ksp = sizeof(init_stack) + (unsigned long) &init_stack, \
  54         .sr = DEFAULT_PSR_VALUE, \
  55 }
  56
  57 /*
  58  * Do necessary setup to start up a newly executed thread.
  59  *
  60  * pass the data segment into user programs if it exists,
  61  * it can't hurt anything as far as I can tell
  62  */
  63 #define start_thread(_regs, _pc, _usp)                                  \
  64 do {                                                                    \
  65         set_fs(USER_DS); /* reads from user space */                    \
  66         (_regs)->pc = (_pc);                                            \
  67         (_regs)->regs[1] = 0; /* ABIV1 is R7, uClibc_main rtdl arg */   \
  68         (_regs)->regs[2] = 0;                                           \
  69         (_regs)->regs[3] = 0; /* ABIV2 is R7, use it? */                \
  70         (_regs)->sr &= ~PS_S;                                           \
  71         (_regs)->usp = (_usp);                                          \
  72 } while (0)
  73
  74 /* Forward declaration, a strange C thing */
  75 struct task_struct;
  76
  77 /* Free all resources held by a thread. */
  78 static inline void release_thread(struct task_struct *dead_task)
  79 {
  80 }
  81
  82 /* Prepare to copy thread state - unlazy all lazy status */
  83 #define prepare_to_copy(tsk)    do { } while (0)
  84
  85 extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
  86
  87 #define copy_segments(tsk, mm)          do { } while (0)
  88 #define release_segments(mm)            do { } while (0)
  89 #define forget_segments()               do { } while (0)
  90
  91 extern unsigned long thread_saved_pc(struct task_struct *tsk);
  92
  93 unsigned long get_wchan(struct task_struct *p);
  94
  95 #define KSTK_EIP(tsk)           (task_pt_regs(tsk)->pc)
  96 #define KSTK_ESP(tsk)           (task_pt_regs(tsk)->usp)
  97
  98 #define task_pt_regs(p) \
  99         ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
 100
 101 #define cpu_relax() barrier()
 102
 103 #endif /* __ASM_CSKY_PROCESSOR_H */