arch/powerpc/mm/init_32.c

Source file repositories/reference/linux-study-clean/arch/powerpc/mm/init_32.c

File Facts

System
Linux kernel
Corpus path
arch/powerpc/mm/init_32.c
Extension
.c
Size
3477 bytes
Lines
135
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/memblock.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>

#include <asm/io.h>
#include <asm/mmu.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/btext.h>
#include <asm/tlb.h>
#include <asm/sections.h>
#include <asm/hugetlb.h>
#include <asm/kup.h>
#include <asm/kasan.h>
#include <asm/fixmap.h>

#include <mm/mmu_decl.h>

#if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
/* The amount of lowmem must be within 0xF0000000 - KERNELBASE. */
#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - PAGE_OFFSET))
#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_KERNEL_START"
#endif
#endif
#define MAX_LOW_MEM	CONFIG_LOWMEM_SIZE

phys_addr_t total_memory;
phys_addr_t total_lowmem;

#ifdef CONFIG_RELOCATABLE
/* Used in __va()/__pa() */
long long virt_phys_offset;
EXPORT_SYMBOL(virt_phys_offset);
#endif

phys_addr_t lowmem_end_addr;

int boot_mapsize;
#ifdef CONFIG_PPC_PMAC
unsigned long agp_special_page;
EXPORT_SYMBOL(agp_special_page);
#endif

void MMU_init(void);

/* max amount of low RAM to map in */
unsigned long __max_low_memory = MAX_LOW_MEM;

/*
 * MMU_init sets up the basic memory mappings for the kernel,
 * including both RAM and possibly some I/O regions,
 * and sets up the page tables and the MMU hardware ready to go.
 */
void __init MMU_init(void)
{
	if (ppc_md.progress)
		ppc_md.progress("MMU:enter", 0x111);

	total_lowmem = total_memory = memblock_end_of_DRAM() - memstart_addr;
	lowmem_end_addr = memstart_addr + total_lowmem;

#ifdef CONFIG_PPC_85xx
	/* Freescale Book-E parts expect lowmem to be mapped by fixed TLB

Annotation

Implementation Notes