kernel-ark/arch/powerpc/mm/mem.c
Benjamin Herrenschmidt 8b31e49d1d powerpc: Fix up dma_alloc_coherent() on platforms without cache coherency.
The implementation we just revived has issues, such as using a
Kconfig-defined virtual address area in kernel space that nothing
actually carves out (and thus will overlap whatever is there),
or having some dependencies on being self contained in a single
PTE page which adds unnecessary constraints on the kernel virtual
address space.

This fixes it by using more classic PTE accessors and automatically
locating the area for consistent memory, carving an appropriate hole
in the kernel virtual address space, leaving only the size of that
area as a Kconfig option. It also brings some dma-mask related fixes
from the ARM implementation which was almost identical initially but
grew its own fixes.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-05-27 16:33:59 +10:00

514 lines
14 KiB
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/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.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/lmb.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 "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);
int i;
for (i=0; i < lmb.memory.cnt; i++) {
unsigned long base;
base = lmb.memory.region[i].base;
if ((paddr >= base) &&
(paddr < (base + lmb.memory.region[i].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);
create_section_mapping(start, start + size);
/* 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 lmb.memory structures. Walk through the
* memory regions, find holes and callback for contiguous regions.
*/
int
walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
int (*func)(unsigned long, unsigned long, void *))
{
struct lmb_property res;
unsigned long pfn, len;
u64 end;
int ret = -1;
res.base = (u64) start_pfn << PAGE_SHIFT;
res.size = (u64) nr_pages << PAGE_SHIFT;
end = res.base + res.size - 1;
while ((res.base < end) && (lmb_find(&res) >= 0)) {
pfn = (unsigned long)(res.base >> PAGE_SHIFT);
len = (unsigned long)(res.size >> PAGE_SHIFT);
ret = (*func)(pfn, len, arg);
if (ret)
break;
res.base += (res.size + 1);
res.size = (end - res.base + 1);
}
return ret;
}
EXPORT_SYMBOL_GPL(walk_memory_resource);
/*
* 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 i;
unsigned long start, bootmap_pages;
unsigned long total_pages;
int boot_mapsize;
max_low_pfn = max_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
total_pages = (lmb_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 = lmb_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 (i = 0; i < lmb.memory.cnt; i++) {
unsigned long start_pfn, end_pfn;
start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
add_active_range(0, start_pfn, end_pfn);
}
/* 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 (i = 0; i < lmb.reserved.cnt; i++) {
unsigned long addr = lmb.reserved.region[i].base +
lmb_size_bytes(&lmb.reserved, i) - 1;
if (addr < lowmem_end_addr)
reserve_bootmem(lmb.reserved.region[i].base,
lmb_size_bytes(&lmb.reserved, i),
BOOTMEM_DEFAULT);
else if (lmb.reserved.region[i].base < lowmem_end_addr) {
unsigned long adjusted_size = lowmem_end_addr -
lmb.reserved.region[i].base;
reserve_bootmem(lmb.reserved.region[i].base,
adjusted_size, BOOTMEM_DEFAULT);
}
}
#else
free_bootmem_with_active_regions(0, max_pfn);
/* reserve the sections we're already using */
for (i = 0; i < lmb.reserved.cnt; i++)
reserve_bootmem(lmb.reserved.region[i].base,
lmb_size_bytes(&lmb.reserved, i),
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)
{
unsigned long lmb_next_region_start_pfn,
lmb_region_max_pfn;
int i;
for (i = 0; i < lmb.memory.cnt - 1; i++) {
lmb_region_max_pfn =
(lmb.memory.region[i].base >> PAGE_SHIFT) +
(lmb.memory.region[i].size >> PAGE_SHIFT);
lmb_next_region_start_pfn =
lmb.memory.region[i+1].base >> PAGE_SHIFT;
if (lmb_region_max_pfn < lmb_next_region_start_pfn)
register_nosave_region(lmb_region_max_pfn,
lmb_next_region_start_pfn);
}
return 0;
}
/*
* paging_init() sets up the page tables - in fact we've already done this.
*/
void __init paging_init(void)
{
unsigned long total_ram = lmb_phys_mem_size();
phys_addr_t top_of_ram = lmb_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%lx\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;
num_physpages = lmb.memory.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) {
struct page *page = pfn_to_page(pfn);
if (lmb_is_reserved(pfn << PAGE_SHIFT))
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 */
printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
"%luk reserved, %luk data, %luk bss, %luk init)\n",
(unsigned long)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;
}
/*
* 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_BOOKE
void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
__flush_dcache_icache(start);
kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
#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 shouldnt 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 pte)
{
#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(pte) || 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 */
}