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 #ifndef __ASSEMBLY__ 18 19 #include <asm/ptrace.h> 20 21 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE 22 /* These DPFP regs need to be saved/restored across ctx-sw */ 23 struct arc_fpu { 24 struct { 25 unsigned int l, h; 26 } aux_dpfp[2]; 27 }; 28 #endif 29 30 /* Arch specific stuff which needs to be saved per task. 31 * However these items are not so important so as to earn a place in 32 * struct thread_info 33 */ 34 struct thread_struct { 35 unsigned long ksp; /* kernel mode stack pointer */ 36 unsigned long callee_reg; /* pointer to callee regs */ 37 unsigned long fault_address; /* dbls as brkpt holder as well */ 38 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE 39 struct arc_fpu fpu; 40 #endif 41 }; 42 43 #define INIT_THREAD { \ 44 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 45 } 46 47 /* Forward declaration, a strange C thing */ 48 struct task_struct; 49 50 /* Return saved PC of a blocked thread */ 51 unsigned long thread_saved_pc(struct task_struct *t); 52 53 #define task_pt_regs(p) \ 54 ((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1) 55 56 /* Free all resources held by a thread */ 57 #define release_thread(thread) do { } while (0) 58 59 /* Prepare to copy thread state - unlazy all lazy status */ 60 #define prepare_to_copy(tsk) do { } while (0) 61 62 /* 63 * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise 64 * get optimised away by gcc 65 */ 66 #ifdef CONFIG_SMP 67 #define cpu_relax() __asm__ __volatile__ ("" : : : "memory") 68 #else 69 #define cpu_relax() do { } while (0) 70 #endif 71 72 #define cpu_relax_lowlatency() cpu_relax() 73 74 #define copy_segments(tsk, mm) do { } while (0) 75 #define release_segments(mm) do { } while (0) 76 77 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret) 78 79 /* 80 * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode. 81 * Look in process.c for details of kernel stack layout 82 */ 83 #define KSTK_ESP(tsk) (tsk->thread.ksp) 84 85 #define KSTK_REG(tsk, off) (*((unsigned int *)(KSTK_ESP(tsk) + \ 86 sizeof(struct callee_regs) + off))) 87 88 #define KSTK_BLINK(tsk) KSTK_REG(tsk, 4) 89 #define KSTK_FP(tsk) KSTK_REG(tsk, 0) 90 91 extern void start_thread(struct pt_regs * regs, unsigned long pc, 92 unsigned long usp); 93 94 extern unsigned int get_wchan(struct task_struct *p); 95 96 /* 97 * Default implementation of macro that returns current 98 * instruction pointer ("program counter"). 99 * Should the PC register be read instead ? This macro does not seem to 100 * be used in many places so this wont be all that bad. 101 */ 102 #define current_text_addr() ({ __label__ _l; _l: &&_l; }) 103 104 #endif /* !__ASSEMBLY__ */ 105 106 /* Kernels Virtual memory area. 107 * Unlike other architectures(MIPS, sh, cris ) ARC 700 does not have a 108 * "kernel translated" region (like KSEG2 in MIPS). So we use a upper part 109 * of the translated bottom 2GB for kernel virtual memory and protect 110 * these pages from user accesses by disabling Ru, Eu and Wu. 111 */ 112 #define VMALLOC_SIZE (0x10000000) /* 256M */ 113 #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) 114 #define VMALLOC_END (PAGE_OFFSET) 115 116 /* Most of the architectures seem to be keeping some kind of padding between 117 * userspace TASK_SIZE and PAGE_OFFSET. i.e TASK_SIZE != PAGE_OFFSET. 118 */ 119 #define USER_KERNEL_GUTTER 0x10000000 120 121 /* User address space: 122 * On ARC700, CPU allows the entire lower half of 32 bit address space to be 123 * translated. Thus potentially 2G (0:0x7FFF_FFFF) could be User vaddr space. 124 * However we steal 256M for kernel addr (0x7000_0000:0x7FFF_FFFF) and another 125 * 256M (0x6000_0000:0x6FFF_FFFF) is gutter between user/kernel spaces 126 * Thus total User vaddr space is (0:0x5FFF_FFFF) 127 */ 128 #define TASK_SIZE (PAGE_OFFSET - VMALLOC_SIZE - USER_KERNEL_GUTTER) 129 130 #define STACK_TOP TASK_SIZE 131 #define STACK_TOP_MAX STACK_TOP 132 133 /* This decides where the kernel will search for a free chunk of vm 134 * space during mmap's. 135 */ 136 #define TASK_UNMAPPED_BASE (TASK_SIZE / 3) 137 138 #endif /* __ASM_ARC_PROCESSOR_H */ 139