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 cpu_relax_lowlatency() cpu_relax() 66 67 #define copy_segments(tsk, mm) do { } while (0) 68 #define release_segments(mm) do { } while (0) 69 70 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret) 71 72 /* 73 * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode. 74 * Look in process.c for details of kernel stack layout 75 */ 76 #define KSTK_ESP(tsk) (tsk->thread.ksp) 77 78 #define KSTK_REG(tsk, off) (*((unsigned int *)(KSTK_ESP(tsk) + \ 79 sizeof(struct callee_regs) + off))) 80 81 #define KSTK_BLINK(tsk) KSTK_REG(tsk, 4) 82 #define KSTK_FP(tsk) KSTK_REG(tsk, 0) 83 84 extern void start_thread(struct pt_regs * regs, unsigned long pc, 85 unsigned long usp); 86 87 extern unsigned int get_wchan(struct task_struct *p); 88 89 /* 90 * Default implementation of macro that returns current 91 * instruction pointer ("program counter"). 92 * Should the PC register be read instead ? This macro does not seem to 93 * be used in many places so this wont be all that bad. 94 */ 95 #define current_text_addr() ({ __label__ _l; _l: &&_l; }) 96 97 #endif /* !__ASSEMBLY__ */ 98 99 /* Kernels Virtual memory area. 100 * Unlike other architectures(MIPS, sh, cris ) ARC 700 does not have a 101 * "kernel translated" region (like KSEG2 in MIPS). So we use a upper part 102 * of the translated bottom 2GB for kernel virtual memory and protect 103 * these pages from user accesses by disabling Ru, Eu and Wu. 104 */ 105 #define VMALLOC_SIZE (0x10000000) /* 256M */ 106 #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) 107 #define VMALLOC_END (PAGE_OFFSET) 108 109 /* Most of the architectures seem to be keeping some kind of padding between 110 * userspace TASK_SIZE and PAGE_OFFSET. i.e TASK_SIZE != PAGE_OFFSET. 111 */ 112 #define USER_KERNEL_GUTTER 0x10000000 113 114 /* User address space: 115 * On ARC700, CPU allows the entire lower half of 32 bit address space to be 116 * translated. Thus potentially 2G (0:0x7FFF_FFFF) could be User vaddr space. 117 * However we steal 256M for kernel addr (0x7000_0000:0x7FFF_FFFF) and another 118 * 256M (0x6000_0000:0x6FFF_FFFF) is gutter between user/kernel spaces 119 * Thus total User vaddr space is (0:0x5FFF_FFFF) 120 */ 121 #define TASK_SIZE (PAGE_OFFSET - VMALLOC_SIZE - USER_KERNEL_GUTTER) 122 123 #define STACK_TOP TASK_SIZE 124 #define STACK_TOP_MAX STACK_TOP 125 126 /* This decides where the kernel will search for a free chunk of vm 127 * space during mmap's. 128 */ 129 #define TASK_UNMAPPED_BASE (TASK_SIZE / 3) 130 131 #endif /* __KERNEL__ */ 132 133 #endif /* __ASM_ARC_PROCESSOR_H */ 134