linux/arch/s390/mm/vmem.c
Heiko Carstens 8fc6365868 [S390] vmemmap: use clear_table to initialise page tables.
Always use clear_table to initialise page tables. The overlapping
memcpy is just a leftover of a previous version that wasn't fully
converted to clear_table.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-04-30 13:38:46 +02:00

412 lines
8.9 KiB
C

/*
* arch/s390/mm/vmem.c
*
* Copyright IBM Corp. 2006
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#include <linux/bootmem.h>
#include <linux/pfn.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/list.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/setup.h>
#include <asm/tlbflush.h>
static DEFINE_MUTEX(vmem_mutex);
struct memory_segment {
struct list_head list;
unsigned long start;
unsigned long size;
};
static LIST_HEAD(mem_segs);
void __meminit memmap_init(unsigned long size, int nid, unsigned long zone,
unsigned long start_pfn)
{
struct page *start, *end;
struct page *map_start, *map_end;
int i;
start = pfn_to_page(start_pfn);
end = start + size;
for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
unsigned long cstart, cend;
cstart = PFN_DOWN(memory_chunk[i].addr);
cend = cstart + PFN_DOWN(memory_chunk[i].size);
map_start = mem_map + cstart;
map_end = mem_map + cend;
if (map_start < start)
map_start = start;
if (map_end > end)
map_end = end;
map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1))
/ sizeof(struct page);
map_end += ((PFN_ALIGN((unsigned long) map_end)
- (unsigned long) map_end)
/ sizeof(struct page));
if (map_start < map_end)
memmap_init_zone((unsigned long)(map_end - map_start),
nid, zone, page_to_pfn(map_start),
MEMMAP_EARLY);
}
}
static void __ref *vmem_alloc_pages(unsigned int order)
{
if (slab_is_available())
return (void *)__get_free_pages(GFP_KERNEL, order);
return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
}
static inline pud_t *vmem_pud_alloc(void)
{
pud_t *pud = NULL;
#ifdef CONFIG_64BIT
pud = vmem_alloc_pages(2);
if (!pud)
return NULL;
clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
#endif
return pud;
}
static inline pmd_t *vmem_pmd_alloc(void)
{
pmd_t *pmd = NULL;
#ifdef CONFIG_64BIT
pmd = vmem_alloc_pages(2);
if (!pmd)
return NULL;
clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
#endif
return pmd;
}
static pte_t __init_refok *vmem_pte_alloc(void)
{
pte_t *pte;
if (slab_is_available())
pte = (pte_t *) page_table_alloc(&init_mm);
else
pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
if (!pte)
return NULL;
clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY,
PTRS_PER_PTE * sizeof(pte_t));
return pte;
}
/*
* Add a physical memory range to the 1:1 mapping.
*/
static int vmem_add_range(unsigned long start, unsigned long size)
{
unsigned long address;
pgd_t *pg_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
pte_t *pt_dir;
pte_t pte;
int ret = -ENOMEM;
for (address = start; address < start + size; address += PAGE_SIZE) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
pu_dir = vmem_pud_alloc();
if (!pu_dir)
goto out;
pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
}
pu_dir = pud_offset(pg_dir, address);
if (pud_none(*pu_dir)) {
pm_dir = vmem_pmd_alloc();
if (!pm_dir)
goto out;
pud_populate_kernel(&init_mm, pu_dir, pm_dir);
}
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir)) {
pt_dir = vmem_pte_alloc();
if (!pt_dir)
goto out;
pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
}
pt_dir = pte_offset_kernel(pm_dir, address);
pte = pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL);
*pt_dir = pte;
}
ret = 0;
out:
flush_tlb_kernel_range(start, start + size);
return ret;
}
/*
* Remove a physical memory range from the 1:1 mapping.
* Currently only invalidates page table entries.
*/
static void vmem_remove_range(unsigned long start, unsigned long size)
{
unsigned long address;
pgd_t *pg_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
pte_t *pt_dir;
pte_t pte;
pte_val(pte) = _PAGE_TYPE_EMPTY;
for (address = start; address < start + size; address += PAGE_SIZE) {
pg_dir = pgd_offset_k(address);
pu_dir = pud_offset(pg_dir, address);
if (pud_none(*pu_dir))
continue;
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir))
continue;
pt_dir = pte_offset_kernel(pm_dir, address);
*pt_dir = pte;
}
flush_tlb_kernel_range(start, start + size);
}
/*
* Add a backed mem_map array to the virtual mem_map array.
*/
static int vmem_add_mem_map(unsigned long start, unsigned long size)
{
unsigned long address, start_addr, end_addr;
struct page *map_start, *map_end;
pgd_t *pg_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
pte_t *pt_dir;
pte_t pte;
int ret = -ENOMEM;
map_start = VMEM_MAP + PFN_DOWN(start);
map_end = VMEM_MAP + PFN_DOWN(start + size);
start_addr = (unsigned long) map_start & PAGE_MASK;
end_addr = PFN_ALIGN((unsigned long) map_end);
for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
pu_dir = vmem_pud_alloc();
if (!pu_dir)
goto out;
pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
}
pu_dir = pud_offset(pg_dir, address);
if (pud_none(*pu_dir)) {
pm_dir = vmem_pmd_alloc();
if (!pm_dir)
goto out;
pud_populate_kernel(&init_mm, pu_dir, pm_dir);
}
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir)) {
pt_dir = vmem_pte_alloc();
if (!pt_dir)
goto out;
pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
}
pt_dir = pte_offset_kernel(pm_dir, address);
if (pte_none(*pt_dir)) {
unsigned long new_page;
new_page =__pa(vmem_alloc_pages(0));
if (!new_page)
goto out;
pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
*pt_dir = pte;
}
}
ret = 0;
out:
flush_tlb_kernel_range(start_addr, end_addr);
return ret;
}
static int vmem_add_mem(unsigned long start, unsigned long size)
{
int ret;
ret = vmem_add_mem_map(start, size);
if (ret)
return ret;
return vmem_add_range(start, size);
}
/*
* Add memory segment to the segment list if it doesn't overlap with
* an already present segment.
*/
static int insert_memory_segment(struct memory_segment *seg)
{
struct memory_segment *tmp;
if (seg->start + seg->size >= VMEM_MAX_PHYS ||
seg->start + seg->size < seg->start)
return -ERANGE;
list_for_each_entry(tmp, &mem_segs, list) {
if (seg->start >= tmp->start + tmp->size)
continue;
if (seg->start + seg->size <= tmp->start)
continue;
return -ENOSPC;
}
list_add(&seg->list, &mem_segs);
return 0;
}
/*
* Remove memory segment from the segment list.
*/
static void remove_memory_segment(struct memory_segment *seg)
{
list_del(&seg->list);
}
static void __remove_shared_memory(struct memory_segment *seg)
{
remove_memory_segment(seg);
vmem_remove_range(seg->start, seg->size);
}
int remove_shared_memory(unsigned long start, unsigned long size)
{
struct memory_segment *seg;
int ret;
mutex_lock(&vmem_mutex);
ret = -ENOENT;
list_for_each_entry(seg, &mem_segs, list) {
if (seg->start == start && seg->size == size)
break;
}
if (seg->start != start || seg->size != size)
goto out;
ret = 0;
__remove_shared_memory(seg);
kfree(seg);
out:
mutex_unlock(&vmem_mutex);
return ret;
}
int add_shared_memory(unsigned long start, unsigned long size)
{
struct memory_segment *seg;
struct page *page;
unsigned long pfn, num_pfn, end_pfn;
int ret;
mutex_lock(&vmem_mutex);
ret = -ENOMEM;
seg = kzalloc(sizeof(*seg), GFP_KERNEL);
if (!seg)
goto out;
seg->start = start;
seg->size = size;
ret = insert_memory_segment(seg);
if (ret)
goto out_free;
ret = vmem_add_mem(start, size);
if (ret)
goto out_remove;
pfn = PFN_DOWN(start);
num_pfn = PFN_DOWN(size);
end_pfn = pfn + num_pfn;
page = pfn_to_page(pfn);
memset(page, 0, num_pfn * sizeof(struct page));
for (; pfn < end_pfn; pfn++) {
page = pfn_to_page(pfn);
init_page_count(page);
reset_page_mapcount(page);
SetPageReserved(page);
INIT_LIST_HEAD(&page->lru);
}
goto out;
out_remove:
__remove_shared_memory(seg);
out_free:
kfree(seg);
out:
mutex_unlock(&vmem_mutex);
return ret;
}
/*
* map whole physical memory to virtual memory (identity mapping)
* we reserve enough space in the vmalloc area for vmemmap to hotplug
* additional memory segments.
*/
void __init vmem_map_init(void)
{
int i;
INIT_LIST_HEAD(&init_mm.context.crst_list);
INIT_LIST_HEAD(&init_mm.context.pgtable_list);
init_mm.context.noexec = 0;
NODE_DATA(0)->node_mem_map = VMEM_MAP;
for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++)
vmem_add_mem(memory_chunk[i].addr, memory_chunk[i].size);
}
/*
* Convert memory chunk array to a memory segment list so there is a single
* list that contains both r/w memory and shared memory segments.
*/
static int __init vmem_convert_memory_chunk(void)
{
struct memory_segment *seg;
int i;
mutex_lock(&vmem_mutex);
for (i = 0; i < MEMORY_CHUNKS; i++) {
if (!memory_chunk[i].size)
continue;
seg = kzalloc(sizeof(*seg), GFP_KERNEL);
if (!seg)
panic("Out of memory...\n");
seg->start = memory_chunk[i].addr;
seg->size = memory_chunk[i].size;
insert_memory_segment(seg);
}
mutex_unlock(&vmem_mutex);
return 0;
}
core_initcall(vmem_convert_memory_chunk);