include/asm-blackfin/processor.h

   1 /*
   2  * U-boot - processor.h
   3  *
   4  * Copyright (c) 2005 blackfin.uclinux.org
   5  *
   6  * This file is based on
   7  * include/asm-m68k/processor.h
   8  * Changes made by Akbar Hussain Lineo, Inc, May 2001 for BLACKFIN
   9  * Copyright (C) 1995 Hamish Macdonald
  10  *
  11  * See file CREDITS for list of people who contributed to this
  12  * project.
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License as
  16  * published by the Free Software Foundation; either version 2 of
  17  * the License, or (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  27  * MA 02111-1307 USA
  28  */
  29
  30 #ifndef __ASM_BLACKFIN_PROCESSOR_H
  31 #define __ASM_BLACKFIN_PROCESSOR_H
  32
  33 /*
  34  * Default implementation of macro that returns current
  35  * instruction pointer ("program counter").
  36  */
  37 #define current_text_addr()     ({ __label__ _l; _l: &&_l;})
  38
  39 #include <linux/config.h>
  40 #include <asm/segment.h>
  41 #include <asm/ptrace.h>
  42 #include <asm/current.h>
  43
  44 extern inline unsigned long rdusp(void)
  45 {
  46         unsigned long usp;
  47
  48         __asm__ __volatile__("%0 = usp;\n\t":"=da"(usp));
  49         return usp;
  50 }
  51
  52 extern inline void wrusp(unsigned long usp)
  53 {
  54         __asm__ __volatile__("usp = %0;\n\t"::"da"(usp));
  55 }
  56
  57 /*
  58  * User space process size: 3.75GB. This is hardcoded into a few places,
  59  * so don't change it unless you know what you are doing.
  60  */
  61 #define TASK_SIZE               (0xF0000000UL)
  62
  63 /*
  64  * Bus types
  65  */
  66 #define EISA_bus                0
  67 #define MCA_bus                 0
  68
  69 /*  There is no pc register avaliable for BLACKFIN, so we are going to get
  70  *  it indirectly
  71  */
  72
  73 #if 0
  74 inline unsigned long obtain_pc_indirectly(void)
  75 {
  76         unsigned long pc;
  77         __asm__ __volatile__("%0 = rets;\n":"=d"(pc));
  78         return (pc - 4);        /* call pcrel24 is 4 bytes long  */
  79 }
  80 #endif
  81
  82 /*
  83  * if you change this structure, you must change the code and offsets
  84  * in m68k/machasm.S
  85  */
  86
  87 struct thread_struct {
  88         unsigned long ksp;      /* kernel stack pointer */
  89         unsigned long usp;      /* user stack pointer */
  90         unsigned short seqstat; /* saved status register */
  91         unsigned long esp0;     /* points to SR of stack frame pt_regs */
  92         unsigned long pc;       /* instruction pointer */
  93 };
  94
  95 #define INIT_MMAP { &init_mm, 0, 0x40000000, NULL, __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED), VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
  96
  97 #define INIT_THREAD  { \
  98         sizeof(init_stack) + (unsigned long) init_stack, 0, \
  99         PS_S, 0\
 100 }
 101
 102 /*
 103  * Do necessary setup to start up a newly executed thread.
 104  *
 105  * pass the data segment into user programs if it exists,
 106  * it can't hurt anything as far as I can tell
 107  */
 108 #define start_thread(_regs, _pc, _usp)           \
 109 do {                                             \
 110         set_fs(USER_DS); /* reads from user space */ \
 111         (_regs)->pc = (_pc);                         \
 112         if (current->mm)                             \
 113                 (_regs)->r5 = current->mm->start_data;   \
 114         (_regs)->seqstat &= ~0x0c00;                      \
 115         wrusp(_usp);                                 \
 116         /* Adde by HuTao, May 26, 2003 3:39PM */\
 117         if ((_regs)->ipend & 0x8000) /* check whether system in supper mode - StChen */\
 118                 (_regs)->ipend = 0x0;\
 119 } while(0)
 120
 121 /* Forward declaration, a strange C thing */
 122 struct task_struct;
 123
 124 /* Free all resources held by a thread. */
 125 static inline void release_thread(struct task_struct *dead_task)
 126 {
 127 }
 128
 129 extern int kernel_thread(int (*fn) (void *), void *arg,
 130                          unsigned long flags);
 131
 132 #define copy_segments(tsk, mm)          do { } while (0)
 133 #define release_segments(mm)            do { } while (0)
 134 #define forget_segments()               do { } while (0)
 135
 136 /*
 137  * Free current thread data structures etc..
 138  */
 139 static inline void exit_thread(void)
 140 {
 141 }
 142
 143 /*
 144  * Return saved PC of a blocked thread.
 145  */
 146 extern inline unsigned long thread_saved_pc(struct thread_struct *t)
 147 {
 148         extern void scheduling_functions_start_here(void);
 149         extern void scheduling_functions_end_here(void);
 150         return 0;
 151 }
 152
 153 unsigned long get_wchan(struct task_struct *p);
 154
 155 #define KSTK_EIP(tsk)   \
 156         ({                      \
 157         unsigned long eip = 0;   \
 158         if ((tsk)->thread.esp0 > PAGE_SIZE && \
 159                 MAP_NR((tsk)->thread.esp0) < max_mapnr) \
 160                 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
 161         eip; })
 162 #define KSTK_ESP(tsk)   ((tsk) == current ? rdusp() : (tsk)->thread.usp)
 163 #define THREAD_SIZE     (2*PAGE_SIZE)
 164
 165 /* Allocation and freeing of basic task resources. */
 166 #define alloc_task_struct() \
 167         ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
 168 #define free_task_struct(p)     free_pages((unsigned long)(p),1)
 169 #define get_task_struct(tsk)    atomic_inc(&mem_map[MAP_NR(tsk)].count)
 170
 171 #define init_task               (init_task_union.task)
 172 #define init_stack              (init_task_union.stack)
 173
 174 #endif