arch/c6x/include/asm/processor.h

   1 /*
   2  *  Port on Texas Instruments TMS320C6x architecture
   3  *
   4  *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
   5  *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
   6  *
   7  *  Updated for 2.6.34: Mark Salter <msalter@redhat.com>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2 as
  11  *  published by the Free Software Foundation.
  12  */
  13 #ifndef _ASM_C6X_PROCESSOR_H
  14 #define _ASM_C6X_PROCESSOR_H
  15
  16 #include <asm/ptrace.h>
  17 #include <asm/page.h>
  18 #include <asm/current.h>
  19
  20 /*
  21  * Default implementation of macro that returns current
  22  * instruction pointer ("program counter").
  23  */
  24 #define current_text_addr()                     \
  25 ({                                              \
  26         void *__pc;                             \
  27         asm("mvc .S2 pce1,%0\n" : "=b"(__pc));  \
  28         __pc;                                   \
  29 })
  30
  31 /*
  32  * User space process size. This is mostly meaningless for NOMMU
  33  * but some C6X processors may have RAM addresses up to 0xFFFFFFFF.
  34  * Since calls like mmap() can return an address or an error, we
  35  * have to allow room for error returns when code does something
  36  * like:
  37  *
  38  *       addr = do_mmap(...)
  39  *       if ((unsigned long)addr >= TASK_SIZE)
  40  *            ... its an error code, not an address ...
  41  *
  42  * Here, we allow for 4096 error codes which means we really can't
  43  * use the last 4K page on systems with RAM extending all the way
  44  * to the end of the 32-bit address space.
  45  */
  46 #define TASK_SIZE       0xFFFFF000
  47
  48 /*
  49  * This decides where the kernel will search for a free chunk of vm
  50  * space during mmap's. We won't be using it
  51  */
  52 #define TASK_UNMAPPED_BASE      0
  53
  54 struct thread_struct {
  55         unsigned long long b15_14;
  56         unsigned long long a15_14;
  57         unsigned long long b13_12;
  58         unsigned long long a13_12;
  59         unsigned long long b11_10;
  60         unsigned long long a11_10;
  61         unsigned long long ricl_icl;
  62         unsigned long  usp;             /* user stack pointer */
  63         unsigned long  pc;              /* kernel pc */
  64         unsigned long  wchan;
  65 };
  66
  67 #define INIT_THREAD                                     \
  68 {                                                       \
  69         .usp = 0,                                       \
  70         .wchan = 0,                                     \
  71 }
  72
  73 #define INIT_MMAP { \
  74         &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, \
  75         NULL, NULL }
  76
  77 #define task_pt_regs(task) \
  78         ((struct pt_regs *)(THREAD_START_SP + task_stack_page(task)) - 1)
  79
  80 #define alloc_kernel_stack()    __get_free_page(GFP_KERNEL)
  81 #define free_kernel_stack(page) free_page((page))
  82
  83
  84 /* Forward declaration, a strange C thing */
  85 struct task_struct;
  86
  87 extern void start_thread(struct pt_regs *regs, unsigned int pc,
  88                          unsigned long usp);
  89
  90 /* Free all resources held by a thread. */
  91 static inline void release_thread(struct task_struct *dead_task)
  92 {
  93 }
  94
  95 /* Prepare to copy thread state - unlazy all lazy status */
  96 #define prepare_to_copy(tsk)    do { } while (0)
  97
  98 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
  99
 100 #define copy_segments(tsk, mm)          do { } while (0)
 101 #define release_segments(mm)            do { } while (0)
 102
 103 /*
 104  * saved PC of a blocked thread.
 105  */
 106 #define thread_saved_pc(tsk) (task_pt_regs(tsk)->pc)
 107
 108 /*
 109  * saved kernel SP and DP of a blocked thread.
 110  */
 111 #ifdef _BIG_ENDIAN
 112 #define thread_saved_ksp(tsk) \
 113         (*(unsigned long *)&(tsk)->thread.b15_14)
 114 #define thread_saved_dp(tsk) \
 115         (*(((unsigned long *)&(tsk)->thread.b15_14) + 1))
 116 #else
 117 #define thread_saved_ksp(tsk) \
 118         (*(((unsigned long *)&(tsk)->thread.b15_14) + 1))
 119 #define thread_saved_dp(tsk) \
 120         (*(unsigned long *)&(tsk)->thread.b15_14)
 121 #endif
 122
 123 extern unsigned long get_wchan(struct task_struct *p);
 124
 125 #define KSTK_EIP(task)  (task_pt_regs(task)->pc)
 126 #define KSTK_ESP(task)  (task_pt_regs(task)->sp)
 127
 128 #define cpu_relax()             do { } while (0)
 129
 130 extern const struct seq_operations cpuinfo_op;
 131
 132 #endif /* ASM_C6X_PROCESSOR_H */