linux/arch/arc/include/asm/processor.h
Vineet Gupta 4db27dca60 ARC: mm: document system mem map clearly
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:29 +05:30

133 lines
3.8 KiB
C

/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* vineetg: March 2009
* -Implemented task_pt_regs( )
*
* Amit Bhor, Sameer Dhavale, Ashwin Chaugule: Codito Technologies 2004
*/
#ifndef __ASM_ARC_PROCESSOR_H
#define __ASM_ARC_PROCESSOR_H
#ifndef __ASSEMBLY__
#include <asm/ptrace.h>
#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
/* These DPFP regs need to be saved/restored across ctx-sw */
struct arc_fpu {
struct {
unsigned int l, h;
} aux_dpfp[2];
};
#endif
/* Arch specific stuff which needs to be saved per task.
* However these items are not so important so as to earn a place in
* struct thread_info
*/
struct thread_struct {
unsigned long ksp; /* kernel mode stack pointer */
unsigned long callee_reg; /* pointer to callee regs */
unsigned long fault_address; /* dbls as brkpt holder as well */
#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
struct arc_fpu fpu;
#endif
};
#define INIT_THREAD { \
.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
}
/* Forward declaration, a strange C thing */
struct task_struct;
#define task_pt_regs(p) \
((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
/* Free all resources held by a thread */
#define release_thread(thread) do { } while (0)
/*
* A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
* get optimised away by gcc
*/
#ifdef CONFIG_SMP
#define cpu_relax() __asm__ __volatile__ ("" : : : "memory")
#else
#define cpu_relax() do { } while (0)
#endif
#define cpu_relax_lowlatency() cpu_relax()
#define copy_segments(tsk, mm) do { } while (0)
#define release_segments(mm) do { } while (0)
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp)
/*
* Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
* Look in process.c for details of kernel stack layout
*/
#define TSK_K_ESP(tsk) (tsk->thread.ksp)
#define TSK_K_REG(tsk, off) (*((unsigned long *)(TSK_K_ESP(tsk) + \
sizeof(struct callee_regs) + off)))
#define TSK_K_BLINK(tsk) TSK_K_REG(tsk, 4)
#define TSK_K_FP(tsk) TSK_K_REG(tsk, 0)
#define thread_saved_pc(tsk) TSK_K_BLINK(tsk)
extern void start_thread(struct pt_regs * regs, unsigned long pc,
unsigned long usp);
extern unsigned int get_wchan(struct task_struct *p);
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
* Should the PC register be read instead ? This macro does not seem to
* be used in many places so this wont be all that bad.
*/
#define current_text_addr() ({ __label__ _l; _l: &&_l; })
#endif /* !__ASSEMBLY__ */
/*
* System Memory Map on ARC
*
* ---------------------------- (lower 2G, Translated) -------------------------
* 0x0000_0000 0x5FFF_FFFF (user vaddr: TASK_SIZE)
* 0x6000_0000 0x6FFF_FFFF (reserved gutter between U/K)
* 0x7000_0000 0x7FFF_FFFF (kvaddr: vmalloc/modules/pkmap..)
*
* PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
* 0x8000_0000 0xBFFF_FFFF (kernel direct mapped)
* 0xC000_0000 0xFFFF_FFFF (peripheral uncached space)
* -----------------------------------------------------------------------------
*/
#define VMALLOC_START 0x70000000
#define VMALLOC_SIZE (PAGE_OFFSET - VMALLOC_START)
#define VMALLOC_END (VMALLOC_START + VMALLOC_SIZE)
#define USER_KERNEL_GUTTER 0x10000000
#define TASK_SIZE (VMALLOC_START - USER_KERNEL_GUTTER)
#define STACK_TOP TASK_SIZE
#define STACK_TOP_MAX STACK_TOP
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
#endif /* __ASM_ARC_PROCESSOR_H */