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[ARM] Split ARM MM initialisation for !mmu
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Move the MMU specific code from init.c into mmu.c, and add nommu
fixups to nommu.c

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Russell King authored and Russell King committed Sep 27, 2006
1 parent 456335e commit d111e8f
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Showing 5 changed files with 274 additions and 206 deletions.
2 changes: 1 addition & 1 deletion arch/arm/mm/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -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
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209 changes: 4 additions & 205 deletions arch/arm/mm/init.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;

Expand All @@ -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;
Expand Down Expand Up @@ -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);
Expand All @@ -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
Expand Down Expand Up @@ -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;
Expand All @@ -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.
*/
Expand Down Expand Up @@ -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;
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4 changes: 4 additions & 0 deletions arch/arm/mm/mm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
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