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 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 unsigned long cause_code; /* Exception Cause Code (ECR) */ 32 }; 33 34 #define INIT_THREAD { \ 35 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 36 } 37 38 /* Forward declaration, a strange C thing */ 39 struct task_struct; 40 41 /* 42 * Return saved PC of a blocked thread. 43 */ 44 unsigned long thread_saved_pc(struct task_struct *t); 45 46 #define task_pt_regs(p) \ 47 ((struct pt_regs *)(THREAD_SIZE - 4 + (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 #define cpu_relax() do { } while (0) 56 57 /* 58 * Create a new kernel thread 59 */ 60 61 extern int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags); 62 63 #define copy_segments(tsk, mm) do { } while (0) 64 #define release_segments(mm) do { } while (0) 65 66 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret) 67 68 /* 69 * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode. 70 * These can't be derived from pt_regs as that would give correp user-mode val 71 */ 72 #define KSTK_ESP(tsk) (tsk->thread.ksp) 73 #define KSTK_BLINK(tsk) (*((unsigned int *)((KSTK_ESP(tsk)) + (13+1+1)*4))) 74 #define KSTK_FP(tsk) (*((unsigned int *)((KSTK_ESP(tsk)) + (13+1)*4))) 75 76 /* 77 * Do necessary setup to start up a newly executed thread. 78 * 79 * E1,E2 so that Interrupts are enabled in user mode 80 * L set, so Loop inhibited to begin with 81 * lp_start and lp_end seeded with bogus non-zero values so to easily catch 82 * the ARC700 sr to lp_start hardware bug 83 */ 84 #define start_thread(_regs, _pc, _usp) \ 85 do { \ 86 set_fs(USER_DS); /* reads from user space */ \ 87 (_regs)->ret = (_pc); \ 88 /* Interrupts enabled in User Mode */ \ 89 (_regs)->status32 = STATUS_U_MASK | STATUS_L_MASK \ 90 | STATUS_E1_MASK | STATUS_E2_MASK; \ 91 (_regs)->sp = (_usp); \ 92 /* bogus seed values for debugging */ \ 93 (_regs)->lp_start = 0x10; \ 94 (_regs)->lp_end = 0x80; \ 95 } while (0) 96 97 extern unsigned int get_wchan(struct task_struct *p); 98 99 /* 100 * Default implementation of macro that returns current 101 * instruction pointer ("program counter"). 102 * Should the PC register be read instead ? This macro does not seem to 103 * be used in many places so this wont be all that bad. 104 */ 105 #define current_text_addr() ({ __label__ _l; _l: &&_l; }) 106 107 #endif /* !__ASSEMBLY__ */ 108 109 /* Kernels Virtual memory area. 110 * Unlike other architectures(MIPS, sh, cris ) ARC 700 does not have a 111 * "kernel translated" region (like KSEG2 in MIPS). So we use a upper part 112 * of the translated bottom 2GB for kernel virtual memory and protect 113 * these pages from user accesses by disabling Ru, Eu and Wu. 114 */ 115 #define VMALLOC_SIZE (0x10000000) /* 256M */ 116 #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) 117 #define VMALLOC_END (PAGE_OFFSET) 118 119 /* Most of the architectures seem to be keeping some kind of padding between 120 * userspace TASK_SIZE and PAGE_OFFSET. i.e TASK_SIZE != PAGE_OFFSET. 121 */ 122 #define USER_KERNEL_GUTTER 0x10000000 123 124 /* User address space: 125 * On ARC700, CPU allows the entire lower half of 32 bit address space to be 126 * translated. Thus potentially 2G (0:0x7FFF_FFFF) could be User vaddr space. 127 * However we steal 256M for kernel addr (0x7000_0000:0x7FFF_FFFF) and another 128 * 256M (0x6000_0000:0x6FFF_FFFF) is gutter between user/kernel spaces 129 * Thus total User vaddr space is (0:0x5FFF_FFFF) 130 */ 131 #define TASK_SIZE (PAGE_OFFSET - VMALLOC_SIZE - USER_KERNEL_GUTTER) 132 133 #define STACK_TOP TASK_SIZE 134 #define STACK_TOP_MAX STACK_TOP 135 136 /* This decides where the kernel will search for a free chunk of vm 137 * space during mmap's. 138 */ 139 #define TASK_UNMAPPED_BASE (TASK_SIZE / 3) 140 141 #endif /* __KERNEL__ */ 142 143 #endif /* __ASM_ARC_PROCESSOR_H */ 144