mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
2dde02ab6d
ARCv2 MMU is software walked and Linux implements 2 levels of paging: pgd/pte.
Forthcoming hw will have multiple levels, so this change preps mm code
for same. It is also fun to try multi levels even on soft-walked code to
ensure generic mm code is robust to handle.
overview
________
2 levels {pgd, pte} : pmd is folded but pmd_* macros are valid and operate on pgd
3 levels {pgd, pmd, pte}:
- pud is folded and pud_* macros point to pgd
- pmd_* macros operate on actual pmd
code changes
____________
1. #include <asm-generic/pgtable-nopud.h>
2. Define CONFIG_PGTABLE_LEVELS 3
3a. Define PMD_SHIFT, PMD_SIZE, PMD_MASK, pmd_t
3b. Define pmd_val() which actually deals with pmd
(pmd_offset(), pmd_index() are provided by generic code)
3c. pmd_alloc_one()/pmd_free() also provided by generic code
(pmd_populate/pmd_free already exist)
4. Define pud_none(), pud_bad() macros based on generic pud_val() which
internally pertains to pgd now.
4b. define pud_populate() to just setup pgd
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
110 lines
3.2 KiB
C
110 lines
3.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
|
|
*
|
|
* 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>
|
|
#include <asm/dsp.h>
|
|
#include <asm/fpu.h>
|
|
|
|
/* 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_DSP_SAVE_RESTORE_REGS
|
|
struct dsp_callee_regs dsp;
|
|
#endif
|
|
#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
|
|
*/
|
|
#define cpu_relax() barrier()
|
|
|
|
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret)
|
|
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp)
|
|
|
|
/*
|
|
* Where about 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)
|
|
|
|
extern void start_thread(struct pt_regs * regs, unsigned long pc,
|
|
unsigned long usp);
|
|
|
|
extern unsigned int get_wchan(struct task_struct *p);
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
/*
|
|
* Default 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 TASK_SIZE 0x60000000
|
|
|
|
#define VMALLOC_START (PAGE_OFFSET - (CONFIG_ARC_KVADDR_SIZE << 20))
|
|
|
|
/* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter (see asm/highmem.h) */
|
|
#define VMALLOC_SIZE ((CONFIG_ARC_KVADDR_SIZE << 20) - PMD_SIZE * 4)
|
|
|
|
#define VMALLOC_END (VMALLOC_START + VMALLOC_SIZE)
|
|
|
|
#define USER_KERNEL_GUTTER (VMALLOC_START - TASK_SIZE)
|
|
|
|
#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 */
|