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/arcregs.h> /* for STATUS_E1_MASK et all */ 22 #include <asm/ptrace.h> 23 24 /* Arch specific stuff which needs to be saved per task. 25 * However these items are not so important so as to earn a place in 26 * struct thread_info 27 */ 28 struct thread_struct { 29 unsigned long ksp; /* kernel mode stack pointer */ 30 unsigned long callee_reg; /* pointer to callee regs */ 31 unsigned long fault_address; /* dbls as brkpt holder as well */ 32 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE 33 struct arc_fpu fpu; 34 #endif 35 }; 36 37 #define INIT_THREAD { \ 38 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 39 } 40 41 /* Forward declaration, a strange C thing */ 42 struct task_struct; 43 44 /* 45 * Return saved PC of a blocked thread. 46 */ 47 unsigned long thread_saved_pc(struct task_struct *t); 48 49 #define task_pt_regs(p) \ 50 ((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1) 51 52 /* Free all resources held by a thread. */ 53 #define release_thread(thread) do { } while (0) 54 55 /* Prepare to copy thread state - unlazy all lazy status */ 56 #define prepare_to_copy(tsk) do { } while (0) 57 58 /* 59 * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise 60 * get optimised away by gcc 61 */ 62 #ifdef CONFIG_SMP 63 #define cpu_relax() __asm__ __volatile__ ("" : : : "memory") 64 #else 65 #define cpu_relax() do { } while (0) 66 #endif 67 68 #define copy_segments(tsk, mm) do { } while (0) 69 #define release_segments(mm) do { } while (0) 70 71 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret) 72 73 /* 74 * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode. 75 * Look in process.c for details of kernel stack layout 76 */ 77 #define KSTK_ESP(tsk) (tsk->thread.ksp) 78 79 #define KSTK_REG(tsk, off) (*((unsigned int *)(KSTK_ESP(tsk) + \ 80 sizeof(struct callee_regs) + off))) 81 82 #define KSTK_BLINK(tsk) KSTK_REG(tsk, 4) 83 #define KSTK_FP(tsk) KSTK_REG(tsk, 0) 84 85 /* 86 * Do necessary setup to start up a newly executed thread. 87 * 88 * E1,E2 so that Interrupts are enabled in user mode 89 * L set, so Loop inhibited to begin with 90 * lp_start and lp_end seeded with bogus non-zero values so to easily catch 91 * the ARC700 sr to lp_start hardware bug 92 */ 93 #define start_thread(_regs, _pc, _usp) \ 94 do { \ 95 set_fs(USER_DS); /* reads from user space */ \ 96 (_regs)->ret = (_pc); \ 97 /* Interrupts enabled in User Mode */ \ 98 (_regs)->status32 = STATUS_U_MASK | STATUS_L_MASK \ 99 | STATUS_E1_MASK | STATUS_E2_MASK; \ 100 (_regs)->sp = (_usp); \ 101 /* bogus seed values for debugging */ \ 102 (_regs)->lp_start = 0x10; \ 103 (_regs)->lp_end = 0x80; \ 104 } while (0) 105 106 extern unsigned int get_wchan(struct task_struct *p); 107 108 /* 109 * Default implementation of macro that returns current 110 * instruction pointer ("program counter"). 111 * Should the PC register be read instead ? This macro does not seem to 112 * be used in many places so this wont be all that bad. 113 */ 114 #define current_text_addr() ({ __label__ _l; _l: &&_l; }) 115 116 #endif /* !__ASSEMBLY__ */ 117 118 /* Kernels Virtual memory area. 119 * Unlike other architectures(MIPS, sh, cris ) ARC 700 does not have a 120 * "kernel translated" region (like KSEG2 in MIPS). So we use a upper part 121 * of the translated bottom 2GB for kernel virtual memory and protect 122 * these pages from user accesses by disabling Ru, Eu and Wu. 123 */ 124 #define VMALLOC_SIZE (0x10000000) /* 256M */ 125 #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) 126 #define VMALLOC_END (PAGE_OFFSET) 127 128 /* Most of the architectures seem to be keeping some kind of padding between 129 * userspace TASK_SIZE and PAGE_OFFSET. i.e TASK_SIZE != PAGE_OFFSET. 130 */ 131 #define USER_KERNEL_GUTTER 0x10000000 132 133 /* User address space: 134 * On ARC700, CPU allows the entire lower half of 32 bit address space to be 135 * translated. Thus potentially 2G (0:0x7FFF_FFFF) could be User vaddr space. 136 * However we steal 256M for kernel addr (0x7000_0000:0x7FFF_FFFF) and another 137 * 256M (0x6000_0000:0x6FFF_FFFF) is gutter between user/kernel spaces 138 * Thus total User vaddr space is (0:0x5FFF_FFFF) 139 */ 140 #define TASK_SIZE (PAGE_OFFSET - VMALLOC_SIZE - USER_KERNEL_GUTTER) 141 142 #define STACK_TOP TASK_SIZE 143 #define STACK_TOP_MAX STACK_TOP 144 145 /* This decides where the kernel will search for a free chunk of vm 146 * space during mmap's. 147 */ 148 #define TASK_UNMAPPED_BASE (TASK_SIZE / 3) 149 150 #endif /* __KERNEL__ */ 151 152 #endif /* __ASM_ARC_PROCESSOR_H */ 153