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/*
* Initialize MMU support.
*
* Copyright (C) 1998-2001 Hewlett-Packard Co
* Copyright (C) 1998-2001 David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mm.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <asm/bitops.h>
#include <asm/dma.h>
#include <asm/efi.h>
#include <asm/ia32.h>
#include <asm/io.h>
#include <asm/machvec.h>
#include <asm/pgalloc.h>
#include <asm/sal.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/tlb.h>
mmu_gather_t mmu_gathers[NR_CPUS];
/* References to section boundaries: */
extern char _stext, _etext, _edata, __init_begin, __init_end;
extern void ia64_tlb_init (void);
unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
static unsigned long totalram_pages;
int
do_check_pgt_cache (int low, int high)
{
int freed = 0;
if (pgtable_cache_size > high) {
do {
if (pgd_quicklist)
free_page((unsigned long)pgd_alloc_one_fast(0)), ++freed;
if (pmd_quicklist)
free_page((unsigned long)pmd_alloc_one_fast(0, 0)), ++freed;
if (pte_quicklist)
free_page((unsigned long)pte_alloc_one_fast(0, 0)), ++freed;
} while (pgtable_cache_size > low);
}
return freed;
}
/*
* This performs some platform-dependent address space initialization.
* On IA-64, we want to setup the VM area for the register backing
* store (which grows upwards) and install the gateway page which is
* used for signal trampolines, etc.
*/
void
ia64_init_addr_space (void)
{
struct vm_area_struct *vma;
/*
* If we're out of memory and kmem_cache_alloc() returns NULL,
* we simply ignore the problem. When the process attempts to
* write to the register backing store for the first time, it
* will get a SEGFAULT in this case.
*/
vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (vma) {
vma->vm_mm = current->mm;
vma->vm_start = IA64_RBS_BOT;
vma->vm_end = vma->vm_start + PAGE_SIZE;
vma->vm_page_prot = PAGE_COPY;
vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE|VM_GROWSUP;
vma->vm_ops = NULL;
vma->vm_pgoff = 0;
vma->vm_file = NULL;
vma->vm_private_data = NULL;
insert_vm_struct(current->mm, vma);
}
}
void
free_initmem (void)
{
unsigned long addr;
addr = (unsigned long) &__init_begin;
for (; addr < (unsigned long) &__init_end; addr += PAGE_SIZE) {
clear_bit(PG_reserved, &virt_to_page(addr)->flags);
set_page_count(virt_to_page(addr), 1);
free_page(addr);
++totalram_pages;
}
printk ("Freeing unused kernel memory: %ldkB freed\n",
(&__init_end - &__init_begin) >> 10);
}
void
free_initrd_mem(unsigned long start, unsigned long end)
{
/*
* EFI uses 4KB pages while the kernel can use 4KB or bigger.
* Thus EFI and the kernel may have different page sizes. It is
* therefore possible to have the initrd share the same page as
* the end of the kernel (given current setup).
*
* To avoid freeing/using the wrong page (kernel sized) we:
* - align up the beginning of initrd
* - align down the end of initrd
*
* | |
* |=============| a000
* | |
* | |
* | | 9000
* |/////////////|
* |/////////////|
* |=============| 8000
* |///INITRD////|
* |/////////////|
* |/////////////| 7000
* | |
* |KKKKKKKKKKKKK|
* |=============| 6000
* |KKKKKKKKKKKKK|
* |KKKKKKKKKKKKK|
* K=kernel using 8KB pages
*
* In this example, we must free page 8000 ONLY. So we must align up
* initrd_start and keep initrd_end as is.
*/
start = PAGE_ALIGN(start);
end = end & PAGE_MASK;
if (start < end)
printk ("Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
for (; start < end; start += PAGE_SIZE) {
if (!VALID_PAGE(virt_to_page(start)))
continue;
clear_bit(PG_reserved, &virt_to_page(start)->flags);
set_page_count(virt_to_page(start), 1);
free_page(start);
++totalram_pages;
}
}
void
si_meminfo (struct sysinfo *val)
{
val->totalram = totalram_pages;
val->sharedram = 0;
val->freeram = nr_free_pages();
val->bufferram = atomic_read(&buffermem_pages);
val->totalhigh = 0;
val->freehigh = 0;
val->mem_unit = PAGE_SIZE;
return;
}
void
show_mem(void)
{
int i, total = 0, reserved = 0;
int shared = 0, cached = 0;
printk("Mem-info:\n");
show_free_areas();
#ifdef CONFIG_DISCONTIGMEM
{
pg_data_t *pgdat = pgdat_list;
printk("Free swap: %6dkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
do {
printk("Node ID: %d\n", pgdat->node_id);
for(i = 0; i < pgdat->node_size; i++) {
if (PageReserved(pgdat->node_mem_map+i))
reserved++;
else if (PageSwapCache(pgdat->node_mem_map+i))
cached++;
else if (page_count(pgdat->node_mem_map + i))
shared += page_count(pgdat->node_mem_map + i) - 1;
}
printk("\t%d pages of RAM\n", pgdat->node_size);
printk("\t%d reserved pages\n", reserved);
printk("\t%d pages shared\n", shared);
printk("\t%d pages swap cached\n", cached);
pgdat = pgdat->node_next;
} while (pgdat);
printk("Total of %ld pages in page table cache\n", pgtable_cache_size);
show_buffers();
printk("%d free buffer pages\n", nr_free_buffer_pages());
}
#else /* !CONFIG_DISCONTIGMEM */
printk("Free swap: %6dkB\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);
printk("%ld pages in page table cache\n", pgtable_cache_size);
show_buffers();
#endif /* !CONFIG_DISCONTIGMEM */
}
/*
* This is like put_dirty_page() but installs a clean page with PAGE_GATE protection
* (execute-only, typically).
*/
struct page *
put_gate_page (struct page *page, unsigned long address)
{
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
if (!PageReserved(page))
printk("put_gate_page: gate page at 0x%p not in reserved memory\n",
page_address(page));
pgd = pgd_offset_k(address); /* note: this is NOT pgd_offset()! */
spin_lock(&init_mm.page_table_lock);
{
pmd = pmd_alloc(&init_mm, pgd, address);
if (!pmd)
goto out;
pte = pte_alloc(&init_mm, pmd, address);
if (!pte)
goto out;
if (!pte_none(*pte)) {
pte_ERROR(*pte);
goto out;
}
flush_page_to_ram(page);
set_pte(pte, mk_pte(page, PAGE_GATE));
}
out: spin_unlock(&init_mm.page_table_lock);
/* no need for flush_tlb */
return page;
}
void __init
ia64_mmu_init (void *my_cpu_data)
{
unsigned long flags, rid, pta, impl_va_bits;
extern void __init tlb_init (void);
#ifdef CONFIG_DISABLE_VHPT
# define VHPT_ENABLE_BIT 0
#else
# define VHPT_ENABLE_BIT 1
#endif
/*
* Set up the kernel identity mapping for regions 6 and 5. The mapping for region
* 7 is setup up in _start().
*/
ia64_clear_ic(flags);
rid = ia64_rid(IA64_REGION_ID_KERNEL, __IA64_UNCACHED_OFFSET);
ia64_set_rr(__IA64_UNCACHED_OFFSET, (rid << 8) | (IA64_GRANULE_SHIFT << 2));
rid = ia64_rid(IA64_REGION_ID_KERNEL, VMALLOC_START);
ia64_set_rr(VMALLOC_START, (rid << 8) | (PAGE_SHIFT << 2) | 1);
/* ensure rr6 is up-to-date before inserting the PERCPU_ADDR translation: */
ia64_srlz_d();
ia64_itr(0x2, IA64_TR_PERCPU_DATA, PERCPU_ADDR,
pte_val(mk_pte_phys(__pa(my_cpu_data), PAGE_KERNEL)), PAGE_SHIFT);
__restore_flags(flags);
ia64_srlz_i();
/*
* Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
* address space. The IA-64 architecture guarantees that at least 50 bits of
* virtual address space are implemented but if we pick a large enough page size
* (e.g., 64KB), the mapped address space is big enough that it will overlap with
* VMLPT. I assume that once we run on machines big enough to warrant 64KB pages,
* IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
* problem in practice. Alternatively, we could truncate the top of the mapped
* address space to not permit mappings that would overlap with the VMLPT.
* --davidm 00/12/06
*/
# define pte_bits 3
# define mapped_space_bits (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
/*
* The virtual page table has to cover the entire implemented address space within
* a region even though not all of this space may be mappable. The reason for
* this is that the Access bit and Dirty bit fault handlers perform
* non-speculative accesses to the virtual page table, so the address range of the
* virtual page table itself needs to be covered by virtual page table.
*/
# define vmlpt_bits (impl_va_bits - PAGE_SHIFT + pte_bits)
# define POW2(n) (1ULL << (n))
impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
if (impl_va_bits < 51 || impl_va_bits > 61)
panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
/* place the VMLPT at the end of each page-table mapped region: */
pta = POW2(61) - POW2(vmlpt_bits);
if (POW2(mapped_space_bits) >= pta)
panic("mm/init: overlap between virtually mapped linear page table and "
"mapped kernel space!");
/*
* Set the (virtually mapped linear) page table address. Bit
* 8 selects between the short and long format, bits 2-7 the
* size of the table, and bit 0 whether the VHPT walker is
* enabled.
*/
ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
ia64_tlb_init();
}
/*
* Set up the page tables.
*/
void
paging_init (void)
{
unsigned long max_dma, zones_size[MAX_NR_ZONES];
clear_page((void *) ZERO_PAGE_ADDR);
/* initialize mem_map[] */
memset(zones_size, 0, sizeof(zones_size));
max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
if (max_low_pfn < max_dma)
zones_size[ZONE_DMA] = max_low_pfn;
else {
zones_size[ZONE_DMA] = max_dma;
zones_size[ZONE_NORMAL] = max_low_pfn - max_dma;
}
free_area_init(zones_size);
}
static int
count_pages (u64 start, u64 end, void *arg)
{
unsigned long *count = arg;
*count += (end - start) >> PAGE_SHIFT;
return 0;
}
static int
count_reserved_pages (u64 start, u64 end, void *arg)
{
unsigned long num_reserved = 0;
unsigned long *count = arg;
struct page *pg;
for (pg = virt_to_page(start); pg < virt_to_page(end); ++pg)
if (PageReserved(pg))
++num_reserved;
*count += num_reserved;
return 0;
}
void
mem_init (void)
{
extern char __start_gate_section[];
long reserved_pages, codesize, datasize, initsize;
unsigned long num_pgt_pages;
#ifdef CONFIG_PCI
/*
* This needs to be called _after_ the command line has been parsed but _before_
* any drivers that may need the PCI DMA interface are initialized or bootmem has
* been freed.
*/
platform_pci_dma_init();
#endif
if (!mem_map)
BUG();
num_physpages = 0;
efi_memmap_walk(count_pages, &num_physpages);
max_mapnr = max_low_pfn;
high_memory = __va(max_low_pfn * PAGE_SIZE);
totalram_pages += free_all_bootmem();
reserved_pages = 0;
efi_memmap_walk(count_reserved_pages, &reserved_pages);
codesize = (unsigned long) &_etext - (unsigned long) &_stext;
datasize = (unsigned long) &_edata - (unsigned long) &_etext;
initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
printk("Memory: %luk/%luk available (%luk code, %luk reserved, %luk data, %luk init)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT - 10),
max_mapnr << (PAGE_SHIFT - 10), codesize >> 10, reserved_pages << (PAGE_SHIFT - 10),
datasize >> 10, initsize >> 10);
/*
* Allow for enough (cached) page table pages so that we can map the entire memory
* at least once. Each task also needs a couple of page tables pages, so add in a
* fudge factor for that (don't use "threads-max" here; that would be wrong!).
* Don't allow the cache to be more than 10% of total memory, though.
*/
# define NUM_TASKS 500 /* typical number of tasks */
num_pgt_pages = nr_free_pages() / PTRS_PER_PGD + NUM_TASKS;
if (num_pgt_pages > nr_free_pages() / 10)
num_pgt_pages = nr_free_pages() / 10;
if (num_pgt_pages > pgt_cache_water[1])
pgt_cache_water[1] = num_pgt_pages;
/* install the gate page in the global page table: */
put_gate_page(virt_to_page(__start_gate_section), GATE_ADDR);
#ifdef CONFIG_IA32_SUPPORT
ia32_gdt_init();
#endif
}
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