1 /* 2 * Process/processor support for the Hexagon architecture 3 * 4 * Copyright (c) 2010-2011, Code Aurora Forum. 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 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags); 38 extern unsigned long thread_saved_pc(struct task_struct *tsk); 39 40 extern void start_thread(struct pt_regs *, unsigned long, unsigned long); 41 42 /* 43 * thread_struct is supposed to be for context switch data. 44 * Specifically, to hold the state necessary to perform switch_to... 45 */ 46 struct thread_struct { 47 void *switch_sp; 48 }; 49 50 /* 51 * initializes thread_struct 52 * The only thing we have in there is switch_sp 53 * which doesn't really need to be initialized. 54 */ 55 56 #define INIT_THREAD { \ 57 } 58 59 #define cpu_relax() __vmyield() 60 61 /* 62 * "Unlazying all lazy status" occurs here. 63 */ 64 static inline void prepare_to_copy(struct task_struct *tsk) 65 { 66 } 67 68 /* 69 * Decides where the kernel will search for a free chunk of vm space during 70 * mmaps. 71 * See also arch_get_unmapped_area. 72 * Doesn't affect if you have MAX_FIXED in the page flags set though... 73 * 74 * Apparently the convention is that ld.so will ask for "unmapped" private 75 * memory to be allocated SOMEWHERE, but it also asks for memory explicitly 76 * via MAP_FIXED at the lower * addresses starting at VA=0x0. 77 * 78 * If the two requests collide, you get authentic segfaulting action, so 79 * you have to kick the "unmapped" base requests higher up. 80 */ 81 #define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE/3)) 82 83 84 #define task_pt_regs(task) \ 85 ((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE) - 1) 86 87 #define KSTK_EIP(tsk) (pt_elr(task_pt_regs(tsk))) 88 #define KSTK_ESP(tsk) (pt_psp(task_pt_regs(tsk))) 89 90 /* Free all resources held by a thread; defined in process.c */ 91 extern void release_thread(struct task_struct *dead_task); 92 93 /* Get wait channel for task P. */ 94 extern unsigned long get_wchan(struct task_struct *p); 95 96 /* The following stuff is pretty HEXAGON specific. */ 97 98 /* This is really just here for __switch_to. 99 Offsets are pulled via asm-offsets.c */ 100 101 /* 102 * No real reason why VM and native switch stacks should be different. 103 * Ultimately this should merge. Note that Rev C. ABI called out only 104 * R24-27 as callee saved GPRs needing explicit attention (R29-31 being 105 * dealt with automagically by allocframe), but the current ABI has 106 * more, R16-R27. By saving more, the worst case is that we waste some 107 * cycles if building with the old compilers. 108 */ 109 110 struct hexagon_switch_stack { 111 unsigned long long r1716; 112 unsigned long long r1918; 113 unsigned long long r2120; 114 unsigned long long r2322; 115 unsigned long long r2524; 116 unsigned long long r2726; 117 unsigned long fp; 118 unsigned long lr; 119 }; 120 121 #endif /* !__ASSEMBLY__ */ 122 123 #endif 124