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linux/arch/sh/mm/init.c
Paul Mundt d01447b319 sh: Merge legacy and dynamic PMB modes. 
This implements a bit of rework for the PMB code, which permits us to
kill off the legacy PMB mode completely. Rather than trusting the boot
loader to do the right thing, we do a quick verification of the PMB
contents to determine whether to have the kernel setup the initial
mappings or whether it needs to mangle them later on instead.

If we're booting from legacy mappings, the kernel will now take control
of them and make them match the kernel's initial mapping configuration.
This is accomplished by breaking the initialization phase out in to
multiple steps: synchronization, merging, and resizing. With the recent
rework, the synchronization code establishes page links for compound
mappings already, so we build on top of this for promoting mappings and
reclaiming unused slots.

At the same time, the changes introduced for the uncached helpers also
permit us to dynamically resize the uncached mapping without any
particular headaches. The smallest page size is more than sufficient for
mapping all of kernel text, and as we're careful not to jump to any far
off locations in the setup code the mapping can safely be resized
regardless of whether we are executing from it or not.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-02-18 18:13:51 +09:00

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/*
* linux/arch/sh/mm/init.c
*
* Copyright (C) 1999 Niibe Yutaka
* Copyright (C) 2002 - 2007 Paul Mundt
*
* Based on linux/arch/i386/mm/init.c:
* Copyright (C) 1995 Linus Torvalds
*/
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/proc_fs.h>
#include <linux/pagemap.h>
#include <linux/percpu.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <asm/mmu_context.h>
#include <asm/tlb.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
#include <asm/cache.h>
#include <asm/sizes.h>
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
pgd_t swapper_pg_dir[PTRS_PER_PGD];
#ifdef CONFIG_MMU
static pte_t *__get_pte_phys(unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = pgd_offset_k(addr);
if (pgd_none(*pgd)) {
pgd_ERROR(*pgd);
return NULL;
}
pud = pud_alloc(NULL, pgd, addr);
if (unlikely(!pud)) {
pud_ERROR(*pud);
return NULL;
}
pmd = pmd_alloc(NULL, pud, addr);
if (unlikely(!pmd)) {
pmd_ERROR(*pmd);
return NULL;
}
pte = pte_offset_kernel(pmd, addr);
return pte;
}
static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
{
pte_t *pte;
pte = __get_pte_phys(addr);
if (!pte_none(*pte)) {
pte_ERROR(*pte);
return;
}
set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
local_flush_tlb_one(get_asid(), addr);
if (pgprot_val(prot) & _PAGE_WIRED)
tlb_wire_entry(NULL, addr, *pte);
}
static void clear_pte_phys(unsigned long addr, pgprot_t prot)
{
pte_t *pte;
pte = __get_pte_phys(addr);
if (pgprot_val(prot) & _PAGE_WIRED)
tlb_unwire_entry();
set_pte(pte, pfn_pte(0, __pgprot(0)));
local_flush_tlb_one(get_asid(), addr);
}
void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
{
unsigned long address = __fix_to_virt(idx);
if (idx >= __end_of_fixed_addresses) {
BUG();
return;
}
set_pte_phys(address, phys, prot);
}
void __clear_fixmap(enum fixed_addresses idx, pgprot_t prot)
{
unsigned long address = __fix_to_virt(idx);
if (idx >= __end_of_fixed_addresses) {
BUG();
return;
}
clear_pte_phys(address, prot);
}
void __init page_table_range_init(unsigned long start, unsigned long end,
pgd_t *pgd_base)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
int i, j, k;
unsigned long vaddr;
vaddr = start;
i = __pgd_offset(vaddr);
j = __pud_offset(vaddr);
k = __pmd_offset(vaddr);
pgd = pgd_base + i;
for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
pud = (pud_t *)pgd;
for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
#ifdef __PAGETABLE_PMD_FOLDED
pmd = (pmd_t *)pud;
#else
pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
pud_populate(&init_mm, pud, pmd);
pmd += k;
#endif
for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
if (pmd_none(*pmd)) {
pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
pmd_populate_kernel(&init_mm, pmd, pte);
BUG_ON(pte != pte_offset_kernel(pmd, 0));
}
vaddr += PMD_SIZE;
}
k = 0;
}
j = 0;
}
}
#endif /* CONFIG_MMU */
/*
* paging_init() sets up the page tables
*/
void __init paging_init(void)
{
unsigned long max_zone_pfns[MAX_NR_ZONES];
unsigned long vaddr, end;
int nid;
/* We don't need to map the kernel through the TLB, as
* it is permanatly mapped using P1. So clear the
* entire pgd. */
memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
/* Set an initial value for the MMU.TTB so we don't have to
* check for a null value. */
set_TTB(swapper_pg_dir);
/*
* Populate the relevant portions of swapper_pg_dir so that
* we can use the fixmap entries without calling kmalloc.
* pte's will be filled in by __set_fixmap().
*/
vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
page_table_range_init(vaddr, end, swapper_pg_dir);
kmap_coherent_init();
memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
for_each_online_node(nid) {
pg_data_t *pgdat = NODE_DATA(nid);
unsigned long low, start_pfn;
start_pfn = pgdat->bdata->node_min_pfn;
low = pgdat->bdata->node_low_pfn;
if (max_zone_pfns[ZONE_NORMAL] < low)
max_zone_pfns[ZONE_NORMAL] = low;
printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
nid, start_pfn, low);
}
free_area_init_nodes(max_zone_pfns);
}
/*
* Early initialization for any I/O MMUs we might have.
*/
static void __init iommu_init(void)
{
no_iommu_init();
}
unsigned int mem_init_done = 0;
void __init mem_init(void)
{
int codesize, datasize, initsize;
int nid;
iommu_init();
num_physpages = 0;
high_memory = NULL;
for_each_online_node(nid) {
pg_data_t *pgdat = NODE_DATA(nid);
unsigned long node_pages = 0;
void *node_high_memory;
num_physpages += pgdat->node_present_pages;
if (pgdat->node_spanned_pages)
node_pages = free_all_bootmem_node(pgdat);
totalram_pages += node_pages;
node_high_memory = (void *)__va((pgdat->node_start_pfn +
pgdat->node_spanned_pages) <<
PAGE_SHIFT);
if (node_high_memory > high_memory)
high_memory = node_high_memory;
}
/* Set this up early, so we can take care of the zero page */
cpu_cache_init();
/* clear the zero-page */
memset(empty_zero_page, 0, PAGE_SIZE);
__flush_wback_region(empty_zero_page, PAGE_SIZE);
vsyscall_init();
codesize = (unsigned long) &_etext - (unsigned long) &_text;
datasize = (unsigned long) &_edata - (unsigned long) &_etext;
initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
"%dk data, %dk init)\n",
nr_free_pages() << (PAGE_SHIFT-10),
num_physpages << (PAGE_SHIFT-10),
codesize >> 10,
datasize >> 10,
initsize >> 10);
printk(KERN_INFO "virtual kernel memory layout:\n"
" fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
#ifdef CONFIG_HIGHMEM
" pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
#endif
" vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
" lowmem : 0x%08lx - 0x%08lx (%4ld MB) (cached)\n"
#ifdef CONFIG_UNCACHED_MAPPING
" : 0x%08lx - 0x%08lx (%4ld MB) (uncached)\n"
#endif
" .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
" .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
" .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
FIXADDR_START, FIXADDR_TOP,
(FIXADDR_TOP - FIXADDR_START) >> 10,
#ifdef CONFIG_HIGHMEM
PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
(LAST_PKMAP*PAGE_SIZE) >> 10,
#endif
(unsigned long)VMALLOC_START, VMALLOC_END,
(VMALLOC_END - VMALLOC_START) >> 20,
(unsigned long)memory_start, (unsigned long)high_memory,
((unsigned long)high_memory - (unsigned long)memory_start) >> 20,
#ifdef CONFIG_UNCACHED_MAPPING
uncached_start, uncached_end, uncached_size >> 20,
#endif
(unsigned long)&__init_begin, (unsigned long)&__init_end,
((unsigned long)&__init_end -
(unsigned long)&__init_begin) >> 10,
(unsigned long)&_etext, (unsigned long)&_edata,
((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
(unsigned long)&_text, (unsigned long)&_etext,
((unsigned long)&_etext - (unsigned long)&_text) >> 10);
mem_init_done = 1;
}
void free_initmem(void)
{
unsigned long addr;
addr = (unsigned long)(&__init_begin);
for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
free_page(addr);
totalram_pages++;
}
printk("Freeing unused kernel memory: %ldk freed\n",
((unsigned long)&__init_end -
(unsigned long)&__init_begin) >> 10);
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
unsigned long p;
for (p = start; p < end; p += PAGE_SIZE) {
ClearPageReserved(virt_to_page(p));
init_page_count(virt_to_page(p));
free_page(p);
totalram_pages++;
}
printk("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
}
#endif
#ifdef CONFIG_MEMORY_HOTPLUG
int arch_add_memory(int nid, u64 start, u64 size)
{
pg_data_t *pgdat;
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
int ret;
pgdat = NODE_DATA(nid);
/* We only have ZONE_NORMAL, so this is easy.. */
ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL,
start_pfn, nr_pages);
if (unlikely(ret))
printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
return ret;
}
EXPORT_SYMBOL_GPL(arch_add_memory);
#ifdef CONFIG_NUMA
int memory_add_physaddr_to_nid(u64 addr)
{
/* Node 0 for now.. */
return 0;
}
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif
#endif /* CONFIG_MEMORY_HOTPLUG */
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