LXR linux/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" */
  34struct task_struct;
  35
  36extern 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 */
  42struct 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  */
  80extern void release_thread(struct task_struct *dead_task);
  81
  82/* Get wait channel for task P.  */
  83extern 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
  99struct 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
 150