Revision 140d0b2108faebc77c6523296e211e509cb9f5f9 authored by Linus Torvalds on 05 August 2011, 05:35:59 UTC, committed by Linus Torvalds on 05 August 2011, 05:35:59 UTC
This isn't really critical any more, since other patches (commit 298507d4d2cf: "shm: optimize exit_shm()") have caused us to not actually need to touch the rw_mutex unless there are actual shm segments associated with the namespace, but we really should do tne shm_init_ns() earlier than we do now. This, together with commit 288d5abec831 ("Boot up with usermodehelper disabled") will mean that we really do initialize the initial ipc namespace data structure before we run any tasks. Tested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 24f0eed
sparse-vmemmap.c
/*
* Virtual Memory Map support
*
* (C) 2007 sgi. Christoph Lameter.
*
* Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
* virt_to_page, page_address() to be implemented as a base offset
* calculation without memory access.
*
* However, virtual mappings need a page table and TLBs. Many Linux
* architectures already map their physical space using 1-1 mappings
* via TLBs. For those arches the virtual memory map is essentially
* for free if we use the same page size as the 1-1 mappings. In that
* case the overhead consists of a few additional pages that are
* allocated to create a view of memory for vmemmap.
*
* The architecture is expected to provide a vmemmap_populate() function
* to instantiate the mapping.
*/
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <linux/sched.h>
#include <asm/dma.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
/*
* Allocate a block of memory to be used to back the virtual memory map
* or to back the page tables that are used to create the mapping.
* Uses the main allocators if they are available, else bootmem.
*/
static void * __init_refok __earlyonly_bootmem_alloc(int node,
unsigned long size,
unsigned long align,
unsigned long goal)
{
return __alloc_bootmem_node_high(NODE_DATA(node), size, align, goal);
}
static void *vmemmap_buf;
static void *vmemmap_buf_end;
void * __meminit vmemmap_alloc_block(unsigned long size, int node)
{
/* If the main allocator is up use that, fallback to bootmem. */
if (slab_is_available()) {
struct page *page;
if (node_state(node, N_HIGH_MEMORY))
page = alloc_pages_node(node,
GFP_KERNEL | __GFP_ZERO, get_order(size));
else
page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
get_order(size));
if (page)
return page_address(page);
return NULL;
} else
return __earlyonly_bootmem_alloc(node, size, size,
__pa(MAX_DMA_ADDRESS));
}
/* need to make sure size is all the same during early stage */
void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
{
void *ptr;
if (!vmemmap_buf)
return vmemmap_alloc_block(size, node);
/* take the from buf */
ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
if (ptr + size > vmemmap_buf_end)
return vmemmap_alloc_block(size, node);
vmemmap_buf = ptr + size;
return ptr;
}
void __meminit vmemmap_verify(pte_t *pte, int node,
unsigned long start, unsigned long end)
{
unsigned long pfn = pte_pfn(*pte);
int actual_node = early_pfn_to_nid(pfn);
if (node_distance(actual_node, node) > LOCAL_DISTANCE)
printk(KERN_WARNING "[%lx-%lx] potential offnode "
"page_structs\n", start, end - 1);
}
pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
{
pte_t *pte = pte_offset_kernel(pmd, addr);
if (pte_none(*pte)) {
pte_t entry;
void *p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
if (!p)
return NULL;
entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
set_pte_at(&init_mm, addr, pte, entry);
}
return pte;
}
pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
{
pmd_t *pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd)) {
void *p = vmemmap_alloc_block(PAGE_SIZE, node);
if (!p)
return NULL;
pmd_populate_kernel(&init_mm, pmd, p);
}
return pmd;
}
pud_t * __meminit vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node)
{
pud_t *pud = pud_offset(pgd, addr);
if (pud_none(*pud)) {
void *p = vmemmap_alloc_block(PAGE_SIZE, node);
if (!p)
return NULL;
pud_populate(&init_mm, pud, p);
}
return pud;
}
pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
{
pgd_t *pgd = pgd_offset_k(addr);
if (pgd_none(*pgd)) {
void *p = vmemmap_alloc_block(PAGE_SIZE, node);
if (!p)
return NULL;
pgd_populate(&init_mm, pgd, p);
}
return pgd;
}
int __meminit vmemmap_populate_basepages(struct page *start_page,
unsigned long size, int node)
{
unsigned long addr = (unsigned long)start_page;
unsigned long end = (unsigned long)(start_page + size);
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
for (; addr < end; addr += PAGE_SIZE) {
pgd = vmemmap_pgd_populate(addr, node);
if (!pgd)
return -ENOMEM;
pud = vmemmap_pud_populate(pgd, addr, node);
if (!pud)
return -ENOMEM;
pmd = vmemmap_pmd_populate(pud, addr, node);
if (!pmd)
return -ENOMEM;
pte = vmemmap_pte_populate(pmd, addr, node);
if (!pte)
return -ENOMEM;
vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
}
return 0;
}
struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid)
{
struct page *map = pfn_to_page(pnum * PAGES_PER_SECTION);
int error = vmemmap_populate(map, PAGES_PER_SECTION, nid);
if (error)
return NULL;
return map;
}
void __init sparse_mem_maps_populate_node(struct page **map_map,
unsigned long pnum_begin,
unsigned long pnum_end,
unsigned long map_count, int nodeid)
{
unsigned long pnum;
unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
void *vmemmap_buf_start;
size = ALIGN(size, PMD_SIZE);
vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
PMD_SIZE, __pa(MAX_DMA_ADDRESS));
if (vmemmap_buf_start) {
vmemmap_buf = vmemmap_buf_start;
vmemmap_buf_end = vmemmap_buf_start + size * map_count;
}
for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
struct mem_section *ms;
if (!present_section_nr(pnum))
continue;
map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
if (map_map[pnum])
continue;
ms = __nr_to_section(pnum);
printk(KERN_ERR "%s: sparsemem memory map backing failed "
"some memory will not be available.\n", __func__);
ms->section_mem_map = 0;
}
if (vmemmap_buf_start) {
/* need to free left buf */
free_bootmem(__pa(vmemmap_buf), vmemmap_buf_end - vmemmap_buf);
vmemmap_buf = NULL;
vmemmap_buf_end = NULL;
}
}
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