149 lines
3.9 KiB
C
149 lines
3.9 KiB
C
/*
|
|
* Virtual Memory Map support
|
|
*
|
|
* (C) 2007 sgi. Christoph Lameter <clameter@sgi.com>.
|
|
*
|
|
* 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 memmory 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/spinlock.h>
|
|
#include <linux/vmalloc.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.
|
|
*/
|
|
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 = alloc_pages_node(node,
|
|
GFP_KERNEL | __GFP_ZERO, get_order(size));
|
|
if (page)
|
|
return page_address(page);
|
|
return NULL;
|
|
} else
|
|
return __alloc_bootmem_node(NODE_DATA(node), size, size,
|
|
__pa(MAX_DMA_ADDRESS));
|
|
}
|
|
|
|
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 (actual_node != node)
|
|
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(PAGE_SIZE, node);
|
|
if (!p)
|
|
return 0;
|
|
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 0;
|
|
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 0;
|
|
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 0;
|
|
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;
|
|
}
|