- 根目录:
- arch
- powerpc
- mm
- mem.c
/*
* 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
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/suspend.h>
#include <linux/memblock.h>
#include <linux/hugetlb.h>
#include <linux/slab.h>
#include <asm/pgalloc.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.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/sparsemem.h>
#include <asm/vdso.h>
#include <asm/fixmap.h>
#include <asm/swiotlb.h>
#include <asm/rtas.h>
#include "mmu_decl.h"
#ifndef CPU_FTR_COHERENT_ICACHE
#define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */
#define CPU_FTR_NOEXECUTE 0
#endif
int init_bootmem_done;
int mem_init_done;
phys_addr_t memory_limit;
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
pgprot_t kmap_prot;
EXPORT_SYMBOL(kmap_prot);
EXPORT_SYMBOL(kmap_pte);
static inline pte_t *virt_to_kpte(unsigned long vaddr)
{
return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
vaddr), vaddr), vaddr);
}
#endif
int page_is_ram(unsigned long pfn)
{
#ifndef CONFIG_PPC64 /* XXX for now */
return pfn < max_pfn;
#else
unsigned long paddr = (pfn << PAGE_SHIFT);
struct memblock_region *reg;
for_each_memblock(memory, reg)
if (paddr >= reg->base && paddr < (reg->base + reg->size))
return 1;
return 0;
#endif
}
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
if (ppc_md.phys_mem_access_prot)
return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
if (!page_is_ram(pfn))
vma_prot = pgprot_noncached(vma_prot);
return vma_prot;
}
EXPORT_SYMBOL(phys_mem_access_prot);
#ifdef CONFIG_MEMORY_HOTPLUG
#ifdef CONFIG_NUMA
int memory_add_physaddr_to_nid(u64 start)
{
return hot_add_scn_to_nid(start);
}
#endif
int arch_add_memory(int nid, u64 start, u64 size)
{
struct pglist_data *pgdata;
struct zone *zone;
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
pgdata = NODE_DATA(nid);
start = (unsigned long)__va(start);
if (create_section_mapping(start, start + size))
return -EINVAL;
/* this should work for most non-highmem platforms */
zone = pgdata->node_zones;
return __add_pages(nid, zone, start_pfn, nr_pages);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
/*
* walk_memory_resource() needs to make sure there is no holes in a given
* memory range. PPC64 does not maintain the memory layout in /proc/iomem.
* Instead it maintains it in memblock.memory structures. Walk through the
* memory regions, find holes and callback for contiguous regions.
*/
int
walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
void *arg, int (*func)(unsigned long, unsigned long, void *))
{
struct memblock_region *reg;
unsigned long end_pfn = start_pfn + nr_pages;
unsigned long tstart, tend;
int ret = -1;
for_each_memblock(memory, reg) {
tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
if (tstart >= tend)
continue;
ret = (*func)(tstart, tend - tstart, arg);
if (ret)
break;
}
return ret;
}
EXPORT_SYMBOL_GPL(walk_system_ram_range);
/*
* Initialize the bootmem system and give it all the memory we
* have available. If we are using highmem, we only put the
* lowmem into the bootmem system.
*/
#ifndef CONFIG_NEED_MULTIPLE_NODES
void __init do_init_bootmem(void)
{
unsigned long start, bootmap_pages;
unsigned long total_pages;
struct memblock_region *reg;
int boot_mapsize;
max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
total_pages = (memblock_end_of_DRAM() - memstart_addr) >> PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
total_pages = total_lowmem >> PAGE_SHIFT;
max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
#endif
/*
* Find an area to use for the bootmem bitmap. Calculate the size of
* bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
* Add 1 additional page in case the address isn't page-aligned.
*/
bootmap_pages = bootmem_bootmap_pages(total_pages);
start = memblock_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
min_low_pfn = MEMORY_START >> PAGE_SHIFT;
boot_mapsize = init_bootmem_node(NODE_DATA(0), start >> PAGE_SHIFT, min_low_pfn, max_low_pfn);
/* Add active regions with valid PFNs */
for_each_memblock(memory, reg) {
unsigned long start_pfn, end_pfn;
start_pfn = memblock_region_memory_base_pfn(reg);
end_pfn = memblock_region_memory_end_pfn(reg);
memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0);
}
/* Add all physical memory to the bootmem map, mark each area
* present.
*/
#ifdef CONFIG_HIGHMEM
free_bootmem_with_active_regions(0, lowmem_end_addr >> PAGE_SHIFT);
/* reserve the sections we're already using */
for_each_memblock(reserved, reg) {
unsigned long top = reg->base + reg->size - 1;
if (top < lowmem_end_addr)
reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
else if (reg->base < lowmem_end_addr) {
unsigned long trunc_size = lowmem_end_addr - reg->base;
reserve_bootmem(reg->base, trunc_size, BOOTMEM_DEFAULT);
}
}
#else
free_bootmem_with_active_regions(0, max_pfn);
/* reserve the sections we're already using */
for_each_memblock(reserved, reg)
reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
#endif
/* XXX need to clip this if using highmem? */
sparse_memory_present_with_active_regions(0);
init_bootmem_done = 1;
}
/* mark pages that don't exist as nosave */
static int __init mark_nonram_nosave(void)
{
struct memblock_region *reg, *prev = NULL;
for_each_memblock(memory, reg) {
if (prev &&
memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
register_nosave_region(memblock_region_memory_end_pfn(prev),
memblock_region_memory_base_pfn(reg));
prev = reg;
}
return 0;
}
/*
* paging_init() sets up the page tables - in fact we've already done this.
*/
void __init paging_init(void)
{
unsigned long long total_ram = memblock_phys_mem_size();
phys_addr_t top_of_ram = memblock_end_of_DRAM();
unsigned long max_zone_pfns[MAX_NR_ZONES];
#ifdef CONFIG_PPC32
unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
unsigned long end = __fix_to_virt(FIX_HOLE);
for (; v < end; v += PAGE_SIZE)
map_page(v, 0, 0); /* XXX gross */
#endif
#ifdef CONFIG_HIGHMEM
map_page(PKMAP_BASE, 0, 0); /* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
kmap_prot = PAGE_KERNEL;
#endif /* CONFIG_HIGHMEM */
printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
(unsigned long long)top_of_ram, total_ram);
printk(KERN_DEBUG "Memory hole size: %ldMB\n",
(long int)((top_of_ram - total_ram) >> 20));
memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
#ifdef CONFIG_HIGHMEM
max_zone_pfns[ZONE_DMA] = lowmem_end_addr >> PAGE_SHIFT;
max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
#else
max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
#endif
free_area_init_nodes(max_zone_pfns);
mark_nonram_nosave();
}
#endif /* ! CONFIG_NEED_MULTIPLE_NODES */
void __init mem_init(void)
{
#ifdef CONFIG_NEED_MULTIPLE_NODES
int nid;
#endif
pg_data_t *pgdat;
unsigned long i;
struct page *page;
unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
#ifdef CONFIG_SWIOTLB
if (ppc_swiotlb_enable)
swiotlb_init(1);
#endif
num_physpages = memblock_phys_mem_size() >> PAGE_SHIFT;
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
#ifdef CONFIG_NEED_MULTIPLE_NODES
for_each_online_node(nid) {
if (NODE_DATA(nid)->node_spanned_pages != 0) {
printk("freeing bootmem node %d\n", nid);
totalram_pages +=
free_all_bootmem_node(NODE_DATA(nid));
}
}
#else
max_mapnr = max_pfn;
totalram_pages += free_all_bootmem();
#endif
for_each_online_pgdat(pgdat) {
for (i = 0; i < pgdat->node_spanned_pages; i++) {
if (!pfn_valid(pgdat->node_start_pfn + i))
continue;
page = pgdat_page_nr(pgdat, i);
if (PageReserved(page))
reservedpages++;
}
}
codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
#ifdef CONFIG_HIGHMEM
{
unsigned long pfn, highmem_mapnr;
highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
struct page *page = pfn_to_page(pfn);
if (memblock_is_reserved(paddr))
continue;
ClearPageReserved(page);
init_page_count(page);
__free_page(page);
totalhigh_pages++;
reservedpages--;
}
totalram_pages += totalhigh_pages;
printk(KERN_DEBUG "High memory: %luk\n",
totalhigh_pages << (PAGE_SHIFT-10));
}
#endif /* CONFIG_HIGHMEM */
#if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
/*
* If smp is enabled, next_tlbcam_idx is initialized in the cpu up
* functions.... do it here for the non-smp case.
*/
per_cpu(next_tlbcam_idx, smp_processor_id()) =
(mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
#endif
printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
"%luk reserved, %luk data, %luk bss, %luk init)\n",
nr_free_pages() << (PAGE_SHIFT-10),
num_physpages << (PAGE_SHIFT-10),
codesize >> 10,
reservedpages << (PAGE_SHIFT-10),
datasize >> 10,
bsssize >> 10,
initsize >> 10);
#ifdef CONFIG_PPC32
pr_info("Kernel virtual memory layout:\n");
pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
#ifdef CONFIG_HIGHMEM
pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
#endif /* CONFIG_HIGHMEM */
#ifdef CONFIG_NOT_COHERENT_CACHE
pr_info(" * 0x%08lx..0x%08lx : consistent mem\n",
IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
#endif /* CONFIG_NOT_COHERENT_CACHE */
pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
ioremap_bot, IOREMAP_TOP);
pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
VMALLOC_START, VMALLOC_END);
#endif /* CONFIG_PPC32 */
mem_init_done = 1;
}
void free_initmem(void)
{
unsigned long addr;
ppc_md.progress = ppc_printk_progress;
addr = (unsigned long)__init_begin;
for (; addr < (unsigned long)__init_end; addr += PAGE_SIZE) {
memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
free_page(addr);
totalram_pages++;
}
pr_info("Freeing unused kernel memory: %luk freed\n",
((unsigned long)__init_end -
(unsigned long)__init_begin) >> 10);
}
#ifdef CONFIG_BLK_DEV_INITRD
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
if (start >= end)
return;
start = _ALIGN_DOWN(start, PAGE_SIZE);
end = _ALIGN_UP(end, PAGE_SIZE);
pr_info("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
for (; start < end; start += PAGE_SIZE) {
ClearPageReserved(virt_to_page(start));
init_page_count(virt_to_page(start));
free_page(start);
totalram_pages++;
}
}
#endif
/*
* This is called when a page has been modified by the kernel.
* It just marks the page as not i-cache clean. We do the i-cache
* flush later when the page is given to a user process, if necessary.
*/
void flush_dcache_page(struct page *page)
{
if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
return;
/* avoid an atomic op if possible */
if (test_bit(PG_arch_1, &page->flags))
clear_bit(PG_arch_1, &page->flags);
}
EXPORT_SYMBOL(flush_dcache_page);
void flush_dcache_icache_page(struct page *page)
{
#ifdef CONFIG_HUGETLB_PAGE
if (PageCompound(page)) {
flush_dcache_icache_hugepage(page);
return;
}
#endif
#ifdef CONFIG_BOOKE
{
void *start = kmap_atomic(page);
__flush_dcache_icache(start);
kunmap_atomic(start);
}
#elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
/* On 8xx there is no need to kmap since highmem is not supported */
__flush_dcache_icache(page_address(page));
#else
__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
#endif
}
void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
{
clear_page(page);
/*
* We shouldn't have to do this, but some versions of glibc
* require it (ld.so assumes zero filled pages are icache clean)
* - Anton
*/
flush_dcache_page(pg);
}
EXPORT_SYMBOL(clear_user_page);
void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
struct page *pg)
{
copy_page(vto, vfrom);
/*
* We should be able to use the following optimisation, however
* there are two problems.
* Firstly a bug in some versions of binutils meant PLT sections
* were not marked executable.
* Secondly the first word in the GOT section is blrl, used
* to establish the GOT address. Until recently the GOT was
* not marked executable.
* - Anton
*/
#if 0
if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
return;
#endif
flush_dcache_page(pg);
}
void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
unsigned long addr, int len)
{
unsigned long maddr;
maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
flush_icache_range(maddr, maddr + len);
kunmap(page);
}
EXPORT_SYMBOL(flush_icache_user_range);
/*
* This is called at the end of handling a user page fault, when the
* fault has been handled by updating a PTE in the linux page tables.
* We use it to preload an HPTE into the hash table corresponding to
* the updated linux PTE.
*
* This must always be called with the pte lock held.
*/
void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
pte_t *ptep)
{
#ifdef CONFIG_PPC_STD_MMU
unsigned long access = 0, trap;
/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
if (!pte_young(*ptep) || address >= TASK_SIZE)
return;
/* We try to figure out if we are coming from an instruction
* access fault and pass that down to __hash_page so we avoid
* double-faulting on execution of fresh text. We have to test
* for regs NULL since init will get here first thing at boot
*
* We also avoid filling the hash if not coming from a fault
*/
if (current->thread.regs == NULL)
return;
trap = TRAP(current->thread.regs);
if (trap == 0x400)
access |= _PAGE_EXEC;
else if (trap != 0x300)
return;
hash_preload(vma->vm_mm, address, access, trap);
#endif /* CONFIG_PPC_STD_MMU */
#if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
&& defined(CONFIG_HUGETLB_PAGE)
if (is_vm_hugetlb_page(vma))
book3e_hugetlb_preload(vma, address, *ptep);
#endif
}
/*
* System memory should not be in /proc/iomem but various tools expect it
* (eg kdump).
*/
static int add_system_ram_resources(void)
{
struct memblock_region *reg;
for_each_memblock(memory, reg) {
struct resource *res;
unsigned long base = reg->base;
unsigned long size = reg->size;
res = kzalloc(sizeof(struct resource), GFP_KERNEL);
WARN_ON(!res);
if (res) {
res->name = "System RAM";
res->start = base;
res->end = base + size - 1;
res->flags = IORESOURCE_MEM;
WARN_ON(request_resource(&iomem_resource, res) < 0);
}
}
return 0;
}
subsys_initcall(add_system_ram_resources);
#ifdef CONFIG_STRICT_DEVMEM
/*
* devmem_is_allowed(): check to see if /dev/mem access to a certain address
* is valid. The argument is a physical page number.
*
* Access has to be given to non-kernel-ram areas as well, these contain the
* PCI mmio resources as well as potential bios/acpi data regions.
*/
int devmem_is_allowed(unsigned long pfn)
{
if (iomem_is_exclusive(pfn << PAGE_SHIFT))
return 0;
if (!page_is_ram(pfn))
return 1;
if (page_is_rtas_user_buf(pfn))
return 1;
return 0;
}
#endif /* CONFIG_STRICT_DEVMEM */