1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  4 *
  5 * vineetg: March 2009
  6 *  -Implemented task_pt_regs( )
  7 *
  8 * Amit Bhor, Sameer Dhavale, Ashwin Chaugule: Codito Technologies 2004
  9 */
 10
 11#ifndef __ASM_ARC_PROCESSOR_H
 12#define __ASM_ARC_PROCESSOR_H
 13
 14#ifndef __ASSEMBLY__
 15
 16#include <asm/ptrace.h>
 17#include <asm/dsp.h>
 18#include <asm/fpu.h>
 19
 20/* Arch specific stuff which needs to be saved per task.
 21 * However these items are not so important so as to earn a place in
 22 * struct thread_info
 23 */
 24struct thread_struct {
 25	unsigned long callee_reg;	/* pointer to callee regs */
 26	unsigned long fault_address;	/* dbls as brkpt holder as well */
 27#ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
 28	struct dsp_callee_regs dsp;
 29#endif
 30#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
 31	struct arc_fpu fpu;
 32#endif
 33};
 34
 35#define INIT_THREAD  { }
 36
 37/* Forward declaration, a strange C thing */
 38struct task_struct;
 39
 40#define task_pt_regs(p) \
 41	((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
 42
 43/*
 44 * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
 45 * get optimised away by gcc
 46 */
 47#define cpu_relax()		barrier()
 48
 49#define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
 50#define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
 51
 52/*
 53 * Where about of Task's sp, fp, blink when it was last seen in kernel mode.
 54 * Look in process.c for details of kernel stack layout
 55 */
 56#define TSK_K_ESP(tsk)		(task_thread_info(tsk)->ksp)
 57
 58#define TSK_K_REG(tsk, off)	(*((unsigned long *)(TSK_K_ESP(tsk) + \
 59					sizeof(struct callee_regs) + off)))
 60
 61#define TSK_K_BLINK(tsk)	TSK_K_REG(tsk, 4)
 62#define TSK_K_FP(tsk)		TSK_K_REG(tsk, 0)
 63
 64extern void start_thread(struct pt_regs * regs, unsigned long pc,
 65			 unsigned long usp);
 66
 67extern unsigned int __get_wchan(struct task_struct *p);
 68
 69#endif /* !__ASSEMBLY__ */
 70
 71/*
 72 * Default System Memory Map on ARC
 73 *
 74 * ---------------------------- (lower 2G, Translated) -------------------------
 75 * 0x0000_0000		0x5FFF_FFFF	(user vaddr: TASK_SIZE)
 76 * 0x6000_0000		0x6FFF_FFFF	(reserved gutter between U/K)
 77 * 0x7000_0000		0x7FFF_FFFF	(kvaddr: vmalloc/modules/pkmap..)
 78 *
 79 * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
 80 * 0x8000_0000		0xBFFF_FFFF	(kernel direct mapped)
 81 * 0xC000_0000		0xFFFF_FFFF	(peripheral uncached space)
 82 * -----------------------------------------------------------------------------
 83 */
 84
 85#define TASK_SIZE	0x60000000
 86
 87#define VMALLOC_START	(PAGE_OFFSET - (CONFIG_ARC_KVADDR_SIZE << 20))
 88
 89/* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter (see asm/highmem.h) */
 90#define VMALLOC_SIZE	((CONFIG_ARC_KVADDR_SIZE << 20) - PMD_SIZE * 4)
 91
 92#define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
 93
 94#define USER_KERNEL_GUTTER    (VMALLOC_START - TASK_SIZE)
 95
 96#define STACK_TOP       TASK_SIZE
 97#define STACK_TOP_MAX   STACK_TOP
 98
 99/* This decides where the kernel will search for a free chunk of vm
100 * space during mmap's.
101 */
102#define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
103
104#endif /* __ASM_ARC_PROCESSOR_H */