include/asm-nios2/bits/shadow.h

   1 /*
   2  * Copyright (C) 2009 Philippe Gerum <rpm@xenomai.org>.
   3  *
   4  * Xenomai is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Xenomai is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Xenomai; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  17  * 02111-1307, USA.
  18  */
  19
  20 #ifndef _XENO_ASM_NIOS2_BITS_SHADOW_H
  21 #define _XENO_ASM_NIOS2_BITS_SHADOW_H
  22
  23 #ifndef __KERNEL__
  24 #error "Pure kernel header included from user-space!"
  25 #endif
  26
  27 #include <asm/cacheflush.h>
  28
  29 static inline void xnarch_init_shadow_tcb(xnarchtcb_t * tcb,
  30                                           struct xnthread *thread,
  31                                           const char *name)
  32 {
  33         struct task_struct *task = current;
  34
  35         tcb->user_task = task;
  36         tcb->active_task = NULL;
  37         tcb->tsp = &task->thread;
  38         tcb->mm = task->mm;
  39         tcb->active_mm = NULL;
  40 #ifdef CONFIG_XENO_HW_UNLOCKED_SWITCH
  41         tcb->tip = task_thread_info(task);
  42 #endif
  43         tcb->entry = NULL;
  44         tcb->cookie = NULL;
  45         tcb->self = thread;
  46         tcb->imask = 0;
  47         tcb->name = name;
  48 }
  49
  50 static inline int xnarch_local_syscall(struct pt_regs *regs)
  51 {
  52         unsigned long ptr, x, r;
  53
  54         switch (__xn_reg_arg1(regs)) {
  55         case __xn_lsys_xchg:
  56
  57                 /* lsys_xchg(ptr,newval,&oldval) */
  58                 ptr = __xn_reg_arg2(regs);
  59                 x = __xn_reg_arg3(regs);
  60                 r = xchg((unsigned long *)ptr, x);
  61                 __xn_put_user(r, (unsigned long *)__xn_reg_arg4(regs));
  62                 break;
  63
  64         default:
  65
  66                 return -ENOSYS;
  67         }
  68
  69         return 0;
  70 }
  71
  72 #define xnarch_schedule_tail(prev) do { } while(0)
  73
  74 #ifdef XNARCH_HAVE_MAYDAY
  75
  76 static inline void xnarch_setup_mayday_page(void *page)
  77 {
  78         /*
  79          * We want this code to appear at the top of the MAYDAY page:
  80          *
  81          *      00c00334        movhi   r3,#__xn_sys_mayday
  82          *      18c08ac4        addi    r3,r3,#__xn_sys_mux
  83          *      00800004        movi    r2,0
  84          *      003b683a        trap
  85          *      003fff06        br      .
  86          */
  87         static const struct {
  88                 u32 movhi_r3h;
  89                 u32 addi_r3l;
  90                 u32 movi_r2;
  91                 u32 syscall;
  92                 u32 bug;
  93         } code = {
  94                 .movhi_r3h = 0x00c00334,
  95                 .addi_r3l = 0x18c08ac4,
  96                 .movi_r2 = 0x00800004,
  97                 .syscall = 0x003b683a,
  98                 .bug = 0x003fff06
  99         };
 100
 101         memcpy(page, &code, sizeof(code));
 102
 103         flush_dcache_range((unsigned long)page,
 104                            (unsigned long)page + sizeof(code));
 105 }
 106
 107 static inline void xnarch_call_mayday(struct task_struct *p)
 108 {
 109         rthal_return_intercept(p);
 110 }
 111
 112 static inline void xnarch_handle_mayday(struct xnarchtcb *tcb,
 113                                         struct pt_regs *regs,
 114                                         unsigned long tramp)
 115 {
 116         tcb->mayday.ea = regs->ea;
 117         tcb->mayday.r2 = regs->r2;
 118         tcb->mayday.r3 = regs->r3;
 119         regs->ea = tramp;
 120 }
 121
 122 static inline void xnarch_fixup_mayday(struct xnarchtcb *tcb,
 123                                        struct pt_regs *regs)
 124 {
 125         regs->ea = tcb->mayday.ea;
 126         regs->r2 = tcb->mayday.r2;
 127         regs->r3 = tcb->mayday.r3;
 128 }
 129
 130 #endif /* XNARCH_HAVE_MAYDAY */
 131
 132 #endif /* !_XENO_ASM_NIOS2_BITS_SHADOW_H */