1 /* 2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * vineetg: March 2009 9 * -Implemented task_pt_regs( ) 10 * 11 * Amit Bhor, Sameer Dhavale, Ashwin Chaugule: Codito Technologies 2004 12 */ 13 14 #ifndef __ASM_ARC_PROCESSOR_H 15 #define __ASM_ARC_PROCESSOR_H 16 17 #ifdef __KERNEL__ 18 19 #ifndef __ASSEMBLY__ 20 21 #include <asm/ptrace.h> 22 23 /* Arch specific stuff which needs to be saved per task. 24 * However these items are not so important so as to earn a place in 25 * struct thread_info 26 */ 27 struct thread_struct { 28 unsigned long ksp; /* kernel mode stack pointer */ 29 unsigned long callee_reg; /* pointer to callee regs */ 30 unsigned long fault_address; /* dbls as brkpt holder as well */ 31 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE 32 struct arc_fpu fpu; 33 #endif 34 }; 35 36 #define INIT_THREAD { \ 37 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 38 } 39 40 /* Forward declaration, a strange C thing */ 41 struct task_struct; 42 43 /* Return saved PC of a blocked thread */ 44 unsigned long thread_saved_pc(struct task_struct *t); 45 46 #define task_pt_regs(p) \ 47 ((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1) 48 49 /* Free all resources held by a thread */ 50 #define release_thread(thread) do { } while (0) 51 52 /* Prepare to copy thread state - unlazy all lazy status */ 53 #define prepare_to_copy(tsk) do { } while (0) 54 55 /* 56 * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise 57 * get optimised away by gcc 58 */ 59 #ifdef CONFIG_SMP 60 #define cpu_relax() __asm__ __volatile__ ("" : : : "memory") 61 #else 62 #define cpu_relax() do { } while (0) 63 #endif 64 65 #define copy_segments(tsk, mm) do { } while (0) 66 #define release_segments(mm) do { } while (0) 67 68 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret) 69 70 /* 71 * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode. 72 * Look in process.c for details of kernel stack layout 73 */ 74 #define KSTK_ESP(tsk) (tsk->thread.ksp) 75 76 #define KSTK_REG(tsk, off) (*((unsigned int *)(KSTK_ESP(tsk) + \ 77 sizeof(struct callee_regs) + off))) 78 79 #define KSTK_BLINK(tsk) KSTK_REG(tsk, 4) 80 #define KSTK_FP(tsk) KSTK_REG(tsk, 0) 81 82 extern void start_thread(struct pt_regs * regs, unsigned long pc, 83 unsigned long usp); 84 85 extern unsigned int get_wchan(struct task_struct *p); 86 87 /* 88 * Default implementation of macro that returns current 89 * instruction pointer ("program counter"). 90 * Should the PC register be read instead ? This macro does not seem to 91 * be used in many places so this wont be all that bad. 92 */ 93 #define current_text_addr() ({ __label__ _l; _l: &&_l; }) 94 95 #endif /* !__ASSEMBLY__ */ 96 97 /* Kernels Virtual memory area. 98 * Unlike other architectures(MIPS, sh, cris ) ARC 700 does not have a 99 * "kernel translated" region (like KSEG2 in MIPS). So we use a upper part 100 * of the translated bottom 2GB for kernel virtual memory and protect 101 * these pages from user accesses by disabling Ru, Eu and Wu. 102 */ 103 #define VMALLOC_SIZE (0x10000000) /* 256M */ 104 #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) 105 #define VMALLOC_END (PAGE_OFFSET) 106 107 /* Most of the architectures seem to be keeping some kind of padding between 108 * userspace TASK_SIZE and PAGE_OFFSET. i.e TASK_SIZE != PAGE_OFFSET. 109 */ 110 #define USER_KERNEL_GUTTER 0x10000000 111 112 /* User address space: 113 * On ARC700, CPU allows the entire lower half of 32 bit address space to be 114 * translated. Thus potentially 2G (0:0x7FFF_FFFF) could be User vaddr space. 115 * However we steal 256M for kernel addr (0x7000_0000:0x7FFF_FFFF) and another 116 * 256M (0x6000_0000:0x6FFF_FFFF) is gutter between user/kernel spaces 117 * Thus total User vaddr space is (0:0x5FFF_FFFF) 118 */ 119 #define TASK_SIZE (PAGE_OFFSET - VMALLOC_SIZE - USER_KERNEL_GUTTER) 120 121 #define STACK_TOP TASK_SIZE 122 #define STACK_TOP_MAX STACK_TOP 123 124 /* This decides where the kernel will search for a free chunk of vm 125 * space during mmap's. 126 */ 127 #define TASK_UNMAPPED_BASE (TASK_SIZE / 3) 128 129 #endif /* __KERNEL__ */ 130 131 #endif /* __ASM_ARC_PROCESSOR_H */ 132