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linux/arch/s390/mm/init.c
Heiko Carstens 3e03a2fcb2 [S390] kernel page table allocation. 
Don't waste DMA capable pages for identity mapping page tables.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-08-16 13:49:37 +02:00

322 lines
9.3 KiB
C
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/*
* arch/s390/mm/init.c
*
* S390 version
* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Hartmut Penner (hp@de.ibm.com)
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1995 Linus Torvalds
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/bootmem.h>
#include <linux/pfn.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/lowcore.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
char empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
void diag10(unsigned long addr)
{
if (addr >= 0x7ff00000)
return;
#ifdef CONFIG_64BIT
asm volatile (
" sam31\n"
" diag %0,%0,0x10\n"
"0: sam64\n"
".section __ex_table,\"a\"\n"
" .align 8\n"
" .quad 0b, 0b\n"
".previous\n"
: : "a" (addr));
#else
asm volatile (
" diag %0,%0,0x10\n"
"0:\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 0b, 0b\n"
".previous\n"
: : "a" (addr));
#endif
}
void show_mem(void)
{
int i, total = 0, reserved = 0;
int shared = 0, cached = 0;
printk("Mem-info:\n");
show_free_areas();
printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
i = max_mapnr;
while (i-- > 0) {
total++;
if (PageReserved(mem_map+i))
reserved++;
else if (PageSwapCache(mem_map+i))
cached++;
else if (page_count(mem_map+i))
shared += page_count(mem_map+i) - 1;
}
printk("%d pages of RAM\n",total);
printk("%d reserved pages\n",reserved);
printk("%d pages shared\n",shared);
printk("%d pages swap cached\n",cached);
}
extern unsigned long __initdata zholes_size[];
/*
* paging_init() sets up the page tables
*/
#ifndef CONFIG_64BIT
void __init paging_init(void)
{
pgd_t * pg_dir;
pte_t * pg_table;
pte_t pte;
int i;
unsigned long tmp;
unsigned long pfn = 0;
unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
static const int ssm_mask = 0x04000000L;
unsigned long ro_start_pfn, ro_end_pfn;
ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
/* unmap whole virtual address space */
pg_dir = swapper_pg_dir;
for (i=0;i<KERNEL_PGD_PTRS;i++)
pmd_clear((pmd_t*)pg_dir++);
/*
* map whole physical memory to virtual memory (identity mapping)
*/
pg_dir = swapper_pg_dir;
while (pfn < max_low_pfn) {
/*
* pg_table is physical at this point
*/
pg_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
pg_dir->pgd0 = (_PAGE_TABLE | __pa(pg_table));
pg_dir->pgd1 = (_PAGE_TABLE | (__pa(pg_table)+1024));
pg_dir->pgd2 = (_PAGE_TABLE | (__pa(pg_table)+2048));
pg_dir->pgd3 = (_PAGE_TABLE | (__pa(pg_table)+3072));
pg_dir++;
for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
else
pte = pfn_pte(pfn, PAGE_KERNEL);
if (pfn >= max_low_pfn)
pte_clear(&init_mm, 0, &pte);
set_pte(pg_table, pte);
pfn++;
}
}
S390_lowcore.kernel_asce = pgdir_k;
/* enable virtual mapping in kernel mode */
__asm__ __volatile__(" LCTL 1,1,%0\n"
" LCTL 7,7,%0\n"
" LCTL 13,13,%0\n"
" SSM %1"
: : "m" (pgdir_k), "m" (ssm_mask));
local_flush_tlb();
{
unsigned long zones_size[MAX_NR_ZONES];
memset(zones_size, 0, sizeof(zones_size));
zones_size[ZONE_DMA] = max_low_pfn;
free_area_init_node(0, &contig_page_data, zones_size,
__pa(PAGE_OFFSET) >> PAGE_SHIFT,
zholes_size);
}
return;
}
#else /* CONFIG_64BIT */
void __init paging_init(void)
{
pgd_t * pg_dir;
pmd_t * pm_dir;
pte_t * pt_dir;
pte_t pte;
int i,j,k;
unsigned long pfn = 0;
unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
_KERN_REGION_TABLE;
static const int ssm_mask = 0x04000000L;
unsigned long zones_size[MAX_NR_ZONES];
unsigned long dma_pfn, high_pfn;
unsigned long ro_start_pfn, ro_end_pfn;
memset(zones_size, 0, sizeof(zones_size));
dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
high_pfn = max_low_pfn;
ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
if (dma_pfn > high_pfn)
zones_size[ZONE_DMA] = high_pfn;
else {
zones_size[ZONE_DMA] = dma_pfn;
zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
}
/* Initialize mem_map[]. */
free_area_init_node(0, &contig_page_data, zones_size,
__pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
/*
* map whole physical memory to virtual memory (identity mapping)
*/
pg_dir = swapper_pg_dir;
for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
if (pfn >= max_low_pfn) {
pgd_clear(pg_dir);
continue;
}
pm_dir = (pmd_t *) alloc_bootmem_pages(PAGE_SIZE * 4);
pgd_populate(&init_mm, pg_dir, pm_dir);
for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
if (pfn >= max_low_pfn) {
pmd_clear(pm_dir);
continue;
}
pt_dir = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
else
pte = pfn_pte(pfn, PAGE_KERNEL);
if (pfn >= max_low_pfn) {
pte_clear(&init_mm, 0, &pte);
continue;
}
set_pte(pt_dir, pte);
pfn++;
}
}
}
S390_lowcore.kernel_asce = pgdir_k;
/* enable virtual mapping in kernel mode */
__asm__ __volatile__("lctlg 1,1,%0\n\t"
"lctlg 7,7,%0\n\t"
"lctlg 13,13,%0\n\t"
"ssm %1"
: :"m" (pgdir_k), "m" (ssm_mask));
local_flush_tlb();
return;
}
#endif /* CONFIG_64BIT */
void __init mem_init(void)
{
unsigned long codesize, reservedpages, datasize, initsize;
max_mapnr = num_physpages = max_low_pfn;
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
/* clear the zero-page */
memset(empty_zero_page, 0, PAGE_SIZE);
/* this will put all low memory onto the freelists */
totalram_pages += free_all_bootmem();
reservedpages = 0;
codesize = (unsigned long) &_etext - (unsigned long) &_text;
datasize = (unsigned long) &_edata - (unsigned long) &_etext;
initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
max_mapnr << (PAGE_SHIFT-10),
codesize >> 10,
reservedpages << (PAGE_SHIFT-10),
datasize >>10,
initsize >> 10);
printk("Write protected kernel read-only data: %#lx - %#lx\n",
(unsigned long)&__start_rodata,
PFN_ALIGN((unsigned long)&__end_rodata) - 1);
}
void free_initmem(void)
{
unsigned long addr;
addr = (unsigned long)(&__init_begin);
for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
free_page(addr);
totalram_pages++;
}
printk ("Freeing unused kernel memory: %ldk freed\n",
((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
if (start < end)
printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
for (; start < end; start += PAGE_SIZE) {
ClearPageReserved(virt_to_page(start));
init_page_count(virt_to_page(start));
free_page(start);
totalram_pages++;
}
}
#endif
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