arch/hexagon/include/asm/processor.h

   1 /*
   2  * Process/processor support for the Hexagon architecture
   3  *
   4  * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 and
   8  * only version 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA.
  19  */
  20
  21 #ifndef _ASM_PROCESSOR_H
  22 #define _ASM_PROCESSOR_H
  23
  24 #ifndef __ASSEMBLY__
  25
  26 #include <asm/mem-layout.h>
  27 #include <asm/registers.h>
  28 #include <asm/hexagon_vm.h>
  29
  30 /*  must be a macro  */
  31 #define current_text_addr() ({ __label__ _l; _l: &&_l; })
  32
  33 /*  task_struct, defined elsewhere, is the "process descriptor" */
  34 struct task_struct;
  35
  36 extern void start_thread(struct pt_regs *, unsigned long, unsigned long);
  37
  38 /*
  39  * thread_struct is supposed to be for context switch data.
  40  * Specifically, to hold the state necessary to perform switch_to...
  41  */
  42 struct thread_struct {
  43         void *switch_sp;
  44 };
  45
  46 /*
  47  * initializes thread_struct
  48  * The only thing we have in there is switch_sp
  49  * which doesn't really need to be initialized.
  50  */
  51
  52 #define INIT_THREAD { \
  53 }
  54
  55 #define cpu_relax() __vmyield()
  56
  57 /*
  58  * Decides where the kernel will search for a free chunk of vm space during
  59  * mmaps.
  60  * See also arch_get_unmapped_area.
  61  * Doesn't affect if you have MAX_FIXED in the page flags set though...
  62  *
  63  * Apparently the convention is that ld.so will ask for "unmapped" private
  64  * memory to be allocated SOMEWHERE, but it also asks for memory explicitly
  65  * via MAP_FIXED at the lower * addresses starting at VA=0x0.
  66  *
  67  * If the two requests collide, you get authentic segfaulting action, so
  68  * you have to kick the "unmapped" base requests higher up.
  69  */
  70 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE/3))
  71
  72
  73 #define task_pt_regs(task) \
  74         ((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE) - 1)
  75
  76 #define KSTK_EIP(tsk) (pt_elr(task_pt_regs(tsk)))
  77 #define KSTK_ESP(tsk) (pt_psp(task_pt_regs(tsk)))
  78
  79 /*  Free all resources held by a thread; defined in process.c  */
  80 extern void release_thread(struct task_struct *dead_task);
  81
  82 /* Get wait channel for task P.  */
  83 extern unsigned long get_wchan(struct task_struct *p);
  84
  85 /*  The following stuff is pretty HEXAGON specific.  */
  86
  87 /*  This is really just here for __switch_to.
  88     Offsets are pulled via asm-offsets.c  */
  89
  90 /*
  91  * No real reason why VM and native switch stacks should be different.
  92  * Ultimately this should merge.  Note that Rev C. ABI called out only
  93  * R24-27 as callee saved GPRs needing explicit attention (R29-31 being
  94  * dealt with automagically by allocframe), but the current ABI has
  95  * more, R16-R27.  By saving more, the worst case is that we waste some
  96  * cycles if building with the old compilers.
  97  */
  98
  99 struct hexagon_switch_stack {
 100         union {
 101                 struct {
 102                         unsigned long r16;
 103                         unsigned long r17;
 104                 };
 105                 unsigned long long      r1716;
 106         };
 107         union {
 108                 struct {
 109                         unsigned long r18;
 110                         unsigned long r19;
 111                 };
 112                 unsigned long long      r1918;
 113         };
 114         union {
 115                 struct {
 116                         unsigned long r20;
 117                         unsigned long r21;
 118                 };
 119                 unsigned long long      r2120;
 120         };
 121         union {
 122                 struct {
 123                         unsigned long r22;
 124                         unsigned long r23;
 125                 };
 126                 unsigned long long      r2322;
 127         };
 128         union {
 129                 struct {
 130                         unsigned long r24;
 131                         unsigned long r25;
 132                 };
 133                 unsigned long long      r2524;
 134         };
 135         union {
 136                 struct {
 137                         unsigned long r26;
 138                         unsigned long r27;
 139                 };
 140                 unsigned long long      r2726;
 141         };
 142
 143         unsigned long           fp;
 144         unsigned long           lr;
 145 };
 146
 147 #endif /* !__ASSEMBLY__ */
 148
 149 #endif