- 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 <linux/vmalloc.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
unsigned long long memory_limit;
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
EXPORT_SYMBOL(kmap_pte);
pgprot_t kmap_prot;
EXPORT_SYMBOL(kmap_prot);
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, bool for_device)
{
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 +
zone_for_memory(nid, start, size, 0, for_device);
return __add_pages(nid, zone, start_pfn, nr_pages);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
int arch_remove_memory(u64 start, u64 size)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
struct zone *zone;
int ret;
zone = page_zone(pfn_to_page(start_pfn));
ret = __remove_pages(zone, start_pfn, nr_pages);
if (ret)
return ret;
/* Remove htab bolted mappings for this section of memory */
start = (unsigned long)__va(start);
ret = remove_section_mapping(start, start + size);
/* Ensure all vmalloc mappings are flushed in case they also
* hit that section of memory
*/
vm_unmap_aliases();
return ret;
}
#endif
#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);
#ifndef CONFIG_NEED_MULTIPLE_NODES
void __init initmem_init(void)
{
max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
min_low_pfn = MEMORY_START >> PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
#endif
/* Place all memblock_regions in the same node and merge contiguous
* memblock_regions
*/
memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
/* XXX need to clip this if using highmem? */
sparse_memory_present_with_active_regions(0);
sparse_init();
}
/* 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;
}
#else /* CONFIG_NEED_MULTIPLE_NODES */
static int __init mark_nonram_nosave(void)
{
return 0;
}
#endif
static bool zone_limits_final;
static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
[0 ... MAX_NR_ZONES - 1] = ~0UL
};
/*
* Restrict the specified zone and all more restrictive zones
* to be below the specified pfn. May not be called after
* paging_init().
*/
void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
{
int i;
if (WARN_ON(zone_limits_final))
return;
for (i = zone; i >= 0; i--) {
if (max_zone_pfns[i] > pfn_limit)
max_zone_pfns[i] = pfn_limit;
}
}
/*
* Find the least restrictive zone that is entirely below the
* specified pfn limit. Returns < 0 if no suitable zone is found.
*
* pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
* systems -- the DMA limit can be higher than any possible real pfn.
*/
int dma_pfn_limit_to_zone(u64 pfn_limit)
{
enum zone_type top_zone = ZONE_NORMAL;
int i;
#ifdef CONFIG_HIGHMEM
top_zone = ZONE_HIGHMEM;
#endif
for (i = top_zone; i >= 0; i--) {
if (max_zone_pfns[i] <= pfn_limit)
return i;
}
return -EPERM;
}
/*
* 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();
enum zone_type top_zone;
#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));
#ifdef CONFIG_HIGHMEM
top_zone = ZONE_HIGHMEM;
limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
#else
top_zone = ZONE_NORMAL;
#endif
limit_zone_pfn(top_zone, top_of_ram >> PAGE_SHIFT);
zone_limits_final = true;
free_area_init_nodes(max_zone_pfns);
mark_nonram_nosave();
}
void __init mem_init(void)
{
/*
* book3s is limited to 16 page sizes due to encoding this in
* a 4-bit field for slices.
*/
BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
#ifdef CONFIG_SWIOTLB
swiotlb_init(0);
#endif
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
set_max_mapnr(max_pfn);
free_all_bootmem();
#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))
free_highmem_page(page);
}
}
#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
mem_init_print_info(NULL);
#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 */
}
void free_initmem(void)
{
ppc_md.progress = ppc_printk_progress;
free_initmem_default(POISON_FREE_INITMEM);
}
#ifdef CONFIG_BLK_DEV_INITRD
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
free_reserved_area((void *)start, (void *)end, -1, "initrd");
}
#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
#if 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
if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
void *start = kmap_atomic(page);
__flush_dcache_icache(start);
kunmap_atomic(start);
} else {
__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
}
#endif
}
EXPORT_SYMBOL(flush_dcache_icache_page);
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
/*
* We don't need to worry about _PAGE_PRESENT here because we are
* called with either mm->page_table_lock held or ptl lock held
*/
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 __init 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 | IORESOURCE_BUSY;
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_PHYS(pfn)))
return 0;
if (!page_is_ram(pfn))
return 1;
if (page_is_rtas_user_buf(pfn))
return 1;
return 0;
}
#endif /* CONFIG_STRICT_DEVMEM */