Commit d111e8f9 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[ARM] Split ARM MM initialisation for !mmu 



Move the MMU specific code from init.c into mmu.c, and add nommu
fixups to nommu.c

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 456335e2

arch/arm/mm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ obj-y := consistent.o extable.o fault.o init.o \ 
				   iomap.o



obj-$(CONFIG_MMU)		+= fault-armv.o flush.o ioremap.o mmap.o \

				   mm-armv.o

				   mm-armv.o mmu.o



ifneq ($(CONFIG_MMU),y)

obj-y				+= nommu.o

arch/arm/mm/init.c

+4 −205
Original line number Diff line number Diff line
@@ -27,10 +27,7 @@ 


#include "mm.h"



DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);



extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

extern void _stext, _text, _etext, __data_start, _end, __init_begin, __init_end;

extern void _text, _etext, __data_start, _end, __init_begin, __init_end;

extern unsigned long phys_initrd_start;

extern unsigned long phys_initrd_size;
@@ -40,17 +37,6 @@ extern unsigned long phys_initrd_size; 
 */

static struct meminfo meminfo __initdata = { 0, };



/*

 * empty_zero_page is a special page that is used for

 * zero-initialized data and COW.

 */

struct page *empty_zero_page;



/*

 * The pmd table for the upper-most set of pages.

 */

pmd_t *top_pmd;



void show_mem(void)

{

	int free = 0, total = 0, reserved = 0;
@@ -173,87 +159,9 @@ static int __init check_initrd(struct meminfo *mi) 
	return initrd_node;

}



/*

 * Reserve the various regions of node 0

 */

static __init void reserve_node_zero(pg_data_t *pgdat)

{

	unsigned long res_size = 0;



	/*

	 * Register the kernel text and data with bootmem.

	 * Note that this can only be in node 0.

	 */

#ifdef CONFIG_XIP_KERNEL

	reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);

#else

	reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);

#endif



	/*

	 * Reserve the page tables.  These are already in use,

	 * and can only be in node 0.

	 */

	reserve_bootmem_node(pgdat, __pa(swapper_pg_dir),

			     PTRS_PER_PGD * sizeof(pgd_t));



	/*

	 * Hmm... This should go elsewhere, but we really really need to

	 * stop things allocating the low memory; ideally we need a better

	 * implementation of GFP_DMA which does not assume that DMA-able

	 * memory starts at zero.

	 */

	if (machine_is_integrator() || machine_is_cintegrator())

		res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;



	/*

	 * These should likewise go elsewhere.  They pre-reserve the

	 * screen memory region at the start of main system memory.

	 */

	if (machine_is_edb7211())

		res_size = 0x00020000;

	if (machine_is_p720t())

		res_size = 0x00014000;



#ifdef CONFIG_SA1111

	/*

	 * Because of the SA1111 DMA bug, we want to preserve our

	 * precious DMA-able memory...

	 */

	res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;

#endif

	if (res_size)

		reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size);

}



static inline void prepare_page_table(struct meminfo *mi)

{

	unsigned long addr;



	/*

	 * Clear out all the mappings below the kernel image.

	 */

	for (addr = 0; addr < MODULE_START; addr += PGDIR_SIZE)

		pmd_clear(pmd_off_k(addr));



#ifdef CONFIG_XIP_KERNEL

	/* The XIP kernel is mapped in the module area -- skip over it */

	addr = ((unsigned long)&_etext + PGDIR_SIZE - 1) & PGDIR_MASK;

#endif

	for ( ; addr < PAGE_OFFSET; addr += PGDIR_SIZE)

		pmd_clear(pmd_off_k(addr));



	/*

	 * Clear out all the kernel space mappings, except for the first

	 * memory bank, up to the end of the vmalloc region.

	 */

	for (addr = __phys_to_virt(mi->bank[0].start + mi->bank[0].size);

	     addr < VMALLOC_END; addr += PGDIR_SIZE)

		pmd_clear(pmd_off_k(addr));

}



static inline void map_memory_bank(struct membank *bank)

{

#ifdef CONFIG_MMU

	struct map_desc map;



	map.pfn = __phys_to_pfn(bank->start);
@@ -262,6 +170,7 @@ static inline void map_memory_bank(struct membank *bank) 
	map.type = MT_MEMORY;



	create_mapping(&map);

#endif

}



static unsigned long __init
@@ -373,7 +282,7 @@ bootmem_init_node(int node, int initrd_node, struct meminfo *mi) 
	return end_pfn;

}



static void __init bootmem_init(struct meminfo *mi)

void __init bootmem_init(struct meminfo *mi)

{

	unsigned long memend_pfn = 0;

	int node, initrd_node, i;
@@ -387,8 +296,6 @@ static void __init bootmem_init(struct meminfo *mi) 


	memcpy(&meminfo, mi, sizeof(meminfo));



	prepare_page_table(mi);



	/*

	 * Locate which node contains the ramdisk image, if any.

	 */
@@ -422,114 +329,6 @@ static void __init bootmem_init(struct meminfo *mi) 
	max_pfn = max_low_pfn = memend_pfn - PHYS_PFN_OFFSET;

}



/*

 * Set up device the mappings.  Since we clear out the page tables for all

 * mappings above VMALLOC_END, we will remove any debug device mappings.

 * This means you have to be careful how you debug this function, or any

 * called function.  This means you can't use any function or debugging

 * method which may touch any device, otherwise the kernel _will_ crash.

 */

static void __init devicemaps_init(struct machine_desc *mdesc)

{

	struct map_desc map;

	unsigned long addr;

	void *vectors;



	/*

	 * Allocate the vector page early.

	 */

	vectors = alloc_bootmem_low_pages(PAGE_SIZE);

	BUG_ON(!vectors);



	for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE)

		pmd_clear(pmd_off_k(addr));



	/*

	 * Map the kernel if it is XIP.

	 * It is always first in the modulearea.

	 */

#ifdef CONFIG_XIP_KERNEL

	map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);

	map.virtual = MODULE_START;

	map.length = ((unsigned long)&_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;

	map.type = MT_ROM;

	create_mapping(&map);

#endif



	/*

	 * Map the cache flushing regions.

	 */

#ifdef FLUSH_BASE

	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS);

	map.virtual = FLUSH_BASE;

	map.length = SZ_1M;

	map.type = MT_CACHECLEAN;

	create_mapping(&map);

#endif

#ifdef FLUSH_BASE_MINICACHE

	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M);

	map.virtual = FLUSH_BASE_MINICACHE;

	map.length = SZ_1M;

	map.type = MT_MINICLEAN;

	create_mapping(&map);

#endif



	/*

	 * Create a mapping for the machine vectors at the high-vectors

	 * location (0xffff0000).  If we aren't using high-vectors, also

	 * create a mapping at the low-vectors virtual address.

	 */

	map.pfn = __phys_to_pfn(virt_to_phys(vectors));

	map.virtual = 0xffff0000;

	map.length = PAGE_SIZE;

	map.type = MT_HIGH_VECTORS;

	create_mapping(&map);



	if (!vectors_high()) {

		map.virtual = 0;

		map.type = MT_LOW_VECTORS;

		create_mapping(&map);

	}



	/*

	 * Ask the machine support to map in the statically mapped devices.

	 */

	if (mdesc->map_io)

		mdesc->map_io();



	/*

	 * Finally flush the caches and tlb to ensure that we're in a

	 * consistent state wrt the writebuffer.  This also ensures that

	 * any write-allocated cache lines in the vector page are written

	 * back.  After this point, we can start to touch devices again.

	 */

	local_flush_tlb_all();

	flush_cache_all();

}



/*

 * paging_init() sets up the page tables, initialises the zone memory

 * maps, and sets up the zero page, bad page and bad page tables.

 */

void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)

{

	void *zero_page;



	build_mem_type_table();

	bootmem_init(mi);

	devicemaps_init(mdesc);



	top_pmd = pmd_off_k(0xffff0000);



	/*

	 * allocate the zero page.  Note that we count on this going ok.

	 */

	zero_page = alloc_bootmem_low_pages(PAGE_SIZE);

	memzero(zero_page, PAGE_SIZE);

	empty_zero_page = virt_to_page(zero_page);

	flush_dcache_page(empty_zero_page);

}



static inline void free_area(unsigned long addr, unsigned long end, char *s)

{

	unsigned int size = (end - addr) >> 10;

arch/arm/mm/mm.h

+4 −0
Original line number Diff line number Diff line
@@ -14,6 +14,10 @@ static inline pmd_t *pmd_off_k(unsigned long virt) 
}



struct map_desc;

struct meminfo;

struct pglist_data;



void __init build_mem_type_table(void);

void __init create_mapping(struct map_desc *md);

void __init bootmem_init(struct meminfo *mi);

void reserve_node_zero(struct pglist_data *pgdat);

arch/arm/mm/mmu.c

0 → 100644
+229 −0
Original line number Diff line number Diff line 
/*

 *  linux/arch/arm/mm/mmu.c

 *

 *  Copyright (C) 1995-2005 Russell King

 *

 * 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.

 */

#include <linux/kernel.h>

#include <linux/errno.h>

#include <linux/init.h>

#include <linux/bootmem.h>

#include <linux/mman.h>

#include <linux/nodemask.h>



#include <asm/mach-types.h>

#include <asm/setup.h>

#include <asm/sizes.h>

#include <asm/tlb.h>



#include <asm/mach/arch.h>

#include <asm/mach/map.h>



#include "mm.h"



DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);



extern void _stext, __data_start, _end;

extern pgd_t swapper_pg_dir[PTRS_PER_PGD];



/*

 * empty_zero_page is a special page that is used for

 * zero-initialized data and COW.

 */

struct page *empty_zero_page;



/*

 * The pmd table for the upper-most set of pages.

 */

pmd_t *top_pmd;



static inline void prepare_page_table(struct meminfo *mi)

{

	unsigned long addr;



	/*

	 * Clear out all the mappings below the kernel image.

	 */

	for (addr = 0; addr < MODULE_START; addr += PGDIR_SIZE)

		pmd_clear(pmd_off_k(addr));



#ifdef CONFIG_XIP_KERNEL

	/* The XIP kernel is mapped in the module area -- skip over it */

	addr = ((unsigned long)&_etext + PGDIR_SIZE - 1) & PGDIR_MASK;

#endif

	for ( ; addr < PAGE_OFFSET; addr += PGDIR_SIZE)

		pmd_clear(pmd_off_k(addr));



	/*

	 * Clear out all the kernel space mappings, except for the first

	 * memory bank, up to the end of the vmalloc region.

	 */

	for (addr = __phys_to_virt(mi->bank[0].start + mi->bank[0].size);

	     addr < VMALLOC_END; addr += PGDIR_SIZE)

		pmd_clear(pmd_off_k(addr));

}



/*

 * Reserve the various regions of node 0

 */

void __init reserve_node_zero(pg_data_t *pgdat)

{

	unsigned long res_size = 0;



	/*

	 * Register the kernel text and data with bootmem.

	 * Note that this can only be in node 0.

	 */

#ifdef CONFIG_XIP_KERNEL

	reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);

#else

	reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);

#endif



	/*

	 * Reserve the page tables.  These are already in use,

	 * and can only be in node 0.

	 */

	reserve_bootmem_node(pgdat, __pa(swapper_pg_dir),

			     PTRS_PER_PGD * sizeof(pgd_t));



	/*

	 * Hmm... This should go elsewhere, but we really really need to

	 * stop things allocating the low memory; ideally we need a better

	 * implementation of GFP_DMA which does not assume that DMA-able

	 * memory starts at zero.

	 */

	if (machine_is_integrator() || machine_is_cintegrator())

		res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;



	/*

	 * These should likewise go elsewhere.  They pre-reserve the

	 * screen memory region at the start of main system memory.

	 */

	if (machine_is_edb7211())

		res_size = 0x00020000;

	if (machine_is_p720t())

		res_size = 0x00014000;



#ifdef CONFIG_SA1111

	/*

	 * Because of the SA1111 DMA bug, we want to preserve our

	 * precious DMA-able memory...

	 */

	res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;

#endif

	if (res_size)

		reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size);

}



/*

 * Set up device the mappings.  Since we clear out the page tables for all

 * mappings above VMALLOC_END, we will remove any debug device mappings.

 * This means you have to be careful how you debug this function, or any

 * called function.  This means you can't use any function or debugging

 * method which may touch any device, otherwise the kernel _will_ crash.

 */

static void __init devicemaps_init(struct machine_desc *mdesc)

{

	struct map_desc map;

	unsigned long addr;

	void *vectors;



	/*

	 * Allocate the vector page early.

	 */

	vectors = alloc_bootmem_low_pages(PAGE_SIZE);

	BUG_ON(!vectors);



	for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE)

		pmd_clear(pmd_off_k(addr));



	/*

	 * Map the kernel if it is XIP.

	 * It is always first in the modulearea.

	 */

#ifdef CONFIG_XIP_KERNEL

	map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);

	map.virtual = MODULE_START;

	map.length = ((unsigned long)&_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;

	map.type = MT_ROM;

	create_mapping(&map);

#endif



	/*

	 * Map the cache flushing regions.

	 */

#ifdef FLUSH_BASE

	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS);

	map.virtual = FLUSH_BASE;

	map.length = SZ_1M;

	map.type = MT_CACHECLEAN;

	create_mapping(&map);

#endif

#ifdef FLUSH_BASE_MINICACHE

	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M);

	map.virtual = FLUSH_BASE_MINICACHE;

	map.length = SZ_1M;

	map.type = MT_MINICLEAN;

	create_mapping(&map);

#endif



	/*

	 * Create a mapping for the machine vectors at the high-vectors

	 * location (0xffff0000).  If we aren't using high-vectors, also

	 * create a mapping at the low-vectors virtual address.

	 */

	map.pfn = __phys_to_pfn(virt_to_phys(vectors));

	map.virtual = 0xffff0000;

	map.length = PAGE_SIZE;

	map.type = MT_HIGH_VECTORS;

	create_mapping(&map);



	if (!vectors_high()) {

		map.virtual = 0;

		map.type = MT_LOW_VECTORS;

		create_mapping(&map);

	}



	/*

	 * Ask the machine support to map in the statically mapped devices.

	 */

	if (mdesc->map_io)

		mdesc->map_io();



	/*

	 * Finally flush the caches and tlb to ensure that we're in a

	 * consistent state wrt the writebuffer.  This also ensures that

	 * any write-allocated cache lines in the vector page are written

	 * back.  After this point, we can start to touch devices again.

	 */

	local_flush_tlb_all();

	flush_cache_all();

}



/*

 * paging_init() sets up the page tables, initialises the zone memory

 * maps, and sets up the zero page, bad page and bad page tables.

 */

void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)

{

	void *zero_page;



	build_mem_type_table();

	prepare_page_table(mi);

	bootmem_init(mi);

	devicemaps_init(mdesc);



	top_pmd = pmd_off_k(0xffff0000);



	/*

	 * allocate the zero page.  Note that we count on this going ok.

	 */

	zero_page = alloc_bootmem_low_pages(PAGE_SIZE);

	memzero(zero_page, PAGE_SIZE);

	empty_zero_page = virt_to_page(zero_page);

	flush_dcache_page(empty_zero_page);

}

arch/arm/mm/nommu.c

+36 −0
Original line number Diff line number Diff line
@@ -11,6 +11,42 @@ 
#include <asm/io.h>

#include <asm/page.h>



#include "mm.h"



extern void _stext, __data_start, _end;



/*

 * Reserve the various regions of node 0

 */

void __init reserve_node_zero(pg_data_t *pgdat)

{

	/*

	 * Register the kernel text and data with bootmem.

	 * Note that this can only be in node 0.

	 */

#ifdef CONFIG_XIP_KERNEL

	reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);

#else

	reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);

#endif



	/*

	 * Register the exception vector page.

	 * some architectures which the DRAM is the exception vector to trap,

	 * alloc_page breaks with error, although it is not NULL, but "0."

	 */

	reserve_bootmem_node(pgdat, CONFIG_VECTORS_BASE, PAGE_SIZE);

}



/*

 * paging_init() sets up the page tables, initialises the zone memory

 * maps, and sets up the zero page, bad page and bad page tables.

 */

void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)

{

	bootmem_init(mi);

}



void flush_dcache_page(struct page *page)

{

	__cpuc_flush_dcache_page(page_address(page));