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 /* this is defined in arch/process.c */ 37 extern unsigned long thread_saved_pc(struct task_struct *tsk); 38 39 extern void start_thread(struct pt_regs *, unsigned long, unsigned long); 40 41 /* 42 * thread_struct is supposed to be for context switch data. 43 * Specifically, to hold the state necessary to perform switch_to... 44 */ 45 struct thread_struct { 46 void *switch_sp; 47 }; 48 49 /* 50 * initializes thread_struct 51 * The only thing we have in there is switch_sp 52 * which doesn't really need to be initialized. 53 */ 54 55 #define INIT_THREAD { \ 56 } 57 58 #define cpu_relax() __vmyield() 59 #define cpu_relax_lowlatency() cpu_relax() 60 61 /* 62 * Decides where the kernel will search for a free chunk of vm space during 63 * mmaps. 64 * See also arch_get_unmapped_area. 65 * Doesn't affect if you have MAX_FIXED in the page flags set though... 66 * 67 * Apparently the convention is that ld.so will ask for "unmapped" private 68 * memory to be allocated SOMEWHERE, but it also asks for memory explicitly 69 * via MAP_FIXED at the lower * addresses starting at VA=0x0. 70 * 71 * If the two requests collide, you get authentic segfaulting action, so 72 * you have to kick the "unmapped" base requests higher up. 73 */ 74 #define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE/3)) 75 76 77 #define task_pt_regs(task) \ 78 ((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE) - 1) 79 80 #define KSTK_EIP(tsk) (pt_elr(task_pt_regs(tsk))) 81 #define KSTK_ESP(tsk) (pt_psp(task_pt_regs(tsk))) 82 83 /* Free all resources held by a thread; defined in process.c */ 84 extern void release_thread(struct task_struct *dead_task); 85 86 /* Get wait channel for task P. */ 87 extern unsigned long get_wchan(struct task_struct *p); 88 89 /* The following stuff is pretty HEXAGON specific. */ 90 91 /* This is really just here for __switch_to. 92 Offsets are pulled via asm-offsets.c */ 93 94 /* 95 * No real reason why VM and native switch stacks should be different. 96 * Ultimately this should merge. Note that Rev C. ABI called out only 97 * R24-27 as callee saved GPRs needing explicit attention (R29-31 being 98 * dealt with automagically by allocframe), but the current ABI has 99 * more, R16-R27. By saving more, the worst case is that we waste some 100 * cycles if building with the old compilers. 101 */ 102 103 struct hexagon_switch_stack { 104 union { 105 struct { 106 unsigned long r16; 107 unsigned long r17; 108 }; 109 unsigned long long r1716; 110 }; 111 union { 112 struct { 113 unsigned long r18; 114 unsigned long r19; 115 }; 116 unsigned long long r1918; 117 }; 118 union { 119 struct { 120 unsigned long r20; 121 unsigned long r21; 122 }; 123 unsigned long long r2120; 124 }; 125 union { 126 struct { 127 unsigned long r22; 128 unsigned long r23; 129 }; 130 unsigned long long r2322; 131 }; 132 union { 133 struct { 134 unsigned long r24; 135 unsigned long r25; 136 }; 137 unsigned long long r2524; 138 }; 139 union { 140 struct { 141 unsigned long r26; 142 unsigned long r27; 143 }; 144 unsigned long long r2726; 145 }; 146 147 unsigned long fp; 148 unsigned long lr; 149 }; 150 151 #endif /* !__ASSEMBLY__ */ 152 153 #endif 154