/*
* Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
#include "linux/mm.h"
#include "linux/rbtree.h"
#include "linux/slab.h"
#include "linux/vmalloc.h"
#include "linux/bootmem.h"
#include "linux/module.h"
#include "asm/types.h"
#include "asm/pgtable.h"
#include "kern_util.h"
#include "user_util.h"
#include "mode_kern.h"
#include "mem.h"
#include "mem_user.h"
#include "os.h"
#include "kern.h"
#include "init.h"
struct phys_desc {
struct rb_node rb;
int fd;
__u64 offset;
void *virt;
unsigned long phys;
struct list_head list;
};
static struct rb_root phys_mappings = RB_ROOT;
static struct rb_node **find_rb(void *virt)
{
struct rb_node **n = &phys_mappings.rb_node;
struct phys_desc *d;
while(*n != NULL){
d = rb_entry(*n, struct phys_desc, rb);
if(d->virt == virt)
return(n);
if(d->virt > virt)
n = &(*n)->rb_left;
else
n = &(*n)->rb_right;
}
return(n);
}
static struct phys_desc *find_phys_mapping(void *virt)
{
struct rb_node **n = find_rb(virt);
if(*n == NULL)
return(NULL);
return(rb_entry(*n, struct phys_desc, rb));
}
static void insert_phys_mapping(struct phys_desc *desc)
{
struct rb_node **n = find_rb(desc->virt);
if(*n != NULL)
panic("Physical remapping for %p already present",
desc->virt);
rb_link_node(&desc->rb, (*n)->rb_parent, n);
rb_insert_color(&desc->rb, &phys_mappings);
}
LIST_HEAD(descriptor_mappings);
struct desc_mapping {
int fd;
struct list_head list;
struct list_head pages;
};
static struct desc_mapping *find_mapping(int fd)
{
struct desc_mapping *desc;
struct list_head *ele;
list_for_each(ele, &descriptor_mappings){
desc = list_entry(ele, struct desc_mapping, list);
if(desc->fd == fd)
return(desc);
}
return(NULL);
}
static struct desc_mapping *descriptor_mapping(int fd)
{
struct desc_mapping *desc;
desc = find_mapping(fd);
if(desc != NULL)
return(desc);
desc = kmalloc(sizeof(*desc), GFP_ATOMIC);
if(desc == NULL)
return(NULL);
*desc = ((struct desc_mapping)
{ .fd = fd,
.list = LIST_HEAD_INIT(desc->list),
.pages = LIST_HEAD_INIT(desc->pages) });
list_add(&desc->list, &descriptor_mappings);
return(desc);
}
int physmem_subst_mapping(void *virt, int fd, __u64 offset, int w)
{
struct desc_mapping *fd_maps;
struct phys_desc *desc;
unsigned long phys;
int err;
fd_maps = descriptor_mapping(fd);
if(fd_maps == NULL)
return(-ENOMEM);
phys = __pa(virt);
desc = find_phys_mapping(virt);
if(desc != NULL)
panic("Address 0x%p is already substituted\n", virt);
err = -ENOMEM;
desc = kmalloc(sizeof(*desc), GFP_ATOMIC);
if(desc == NULL)
goto out;
*desc = ((struct phys_desc)
{ .fd = fd,
.offset = offset,
.virt = virt,
.phys = __pa(virt),
.list = LIST_HEAD_INIT(desc->list) });
insert_phys_mapping(desc);
list_add(&desc->list, &fd_maps->pages);
virt = (void *) ((unsigned long) virt & PAGE_MASK);
err = os_map_memory(virt, fd, offset, PAGE_SIZE, 1, w, 0);
if(!err)
goto out;
rb_erase(&desc->rb, &phys_mappings);
kfree(desc);
out:
return(err);
}
static int physmem_fd = -1;
static void remove_mapping(struct phys_desc *desc)
{
void *virt = desc->virt;
int err;
rb_erase(&desc->rb, &phys_mappings);
list_del(&desc->list);
kfree(desc);
err = os_map_memory(virt, physmem_fd, __pa(virt), PAGE_SIZE, 1, 1, 0);
if(err)
panic("Failed to unmap block device page from physical memory, "
"errno = %d", -err);
}
int physmem_remove_mapping(void *virt)
{
struct phys_desc *desc;
virt = (void *) ((unsigned long) virt & PAGE_MASK);
desc = find_phys_mapping(virt);
if(desc == NULL)
return(0);
remove_mapping(desc);
return(1);
}
void physmem_forget_descriptor(int fd)
{
struct desc_mapping *desc;
struct phys_desc *page;
struct list_head *ele, *next;
__u64 offset;
void *addr;
int err;
desc = find_mapping(fd);
if(desc == NULL)
return;
list_for_each_safe(ele, next, &desc->pages){
page = list_entry(ele, struct phys_desc, list);
offset = page->offset;
addr = page->virt;
remove_mapping(page);
err = os_seek_file(fd, offset);
if(err)
panic("physmem_forget_descriptor - failed to seek "
"to %lld in fd %d, error = %d\n",
offset, fd, -err);
err = os_read_file(fd, addr, PAGE_SIZE);
if(err < 0)
panic("physmem_forget_descriptor - failed to read "
"from fd %d to 0x%p, error = %d\n",
fd, addr, -err);
}
list_del(&desc->list);
kfree(desc);
}
EXPORT_SYMBOL(physmem_forget_descriptor);
EXPORT_SYMBOL(physmem_remove_mapping);
EXPORT_SYMBOL(physmem_subst_mapping);
void arch_free_page(struct page *page, int order)
{
void *virt;
int i;
for(i = 0; i < (1 << order); i++){
virt = __va(page_to_phys(page + i));
physmem_remove_mapping(virt);
}
}
int is_remapped(void *virt)
{
struct phys_desc *desc = find_phys_mapping(virt);
return(desc != NULL);
}
/* Changed during early boot */
unsigned long high_physmem;
extern unsigned long physmem_size;
int init_maps(unsigned long physmem, unsigned long iomem, unsigned long highmem)
{
struct page *p, *map;
unsigned long phys_len, phys_pages, highmem_len, highmem_pages;
unsigned long iomem_len, iomem_pages, total_len, total_pages;
int i;
phys_pages = physmem >> PAGE_SHIFT;
phys_len = phys_pages * sizeof(struct page);
iomem_pages = iomem >> PAGE_SHIFT;
iomem_len = iomem_pages * sizeof(struct page);
highmem_pages = highmem >> PAGE_SHIFT;
highmem_len = highmem_pages * sizeof(struct page);
total_pages = phys_pages + iomem_pages + highmem_pages;
total_len = phys_len + iomem_pages + highmem_len;
if(kmalloc_ok){
map = kmalloc(total_len, GFP_KERNEL);
if(map == NULL)
map = vmalloc(total_len);
}
else map = alloc_bootmem_low_pages(total_len);
if(map == NULL)
return(-ENOMEM);
for(i = 0; i < total_pages; i++){
p = &map[i];
set_page_count(p, 0);
SetPageReserved(p);
INIT_LIST_HEAD(&p->lru);
}
max_mapnr = total_pages;
return(0);
}
/* Changed during early boot */
static unsigned long kmem_top = 0;
unsigned long get_kmem_end(void)
{
if(kmem_top == 0)
kmem_top = CHOOSE_MODE(kmem_end_tt, kmem_end_skas);
return(kmem_top);
}
void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
int r, int w, int x)
{
__u64 offset;
int fd, err;
fd = phys_mapping(phys, &offset);
err = os_map_memory((void *) virt, fd, offset, len, r, w, x);
if(err) {
if(err == -ENOMEM)
printk("try increasing the host's "
"/proc/sys/vm/max_map_count to <physical "
"memory size>/4096\n");
panic("map_memory(0x%lx, %d, 0x%llx, %ld, %d, %d, %d) failed, "
"err = %d\n", virt, fd, offset, len, r, w, x, err);
}
}
#define PFN_UP(x) (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
extern int __syscall_stub_start, __binary_start;
void setup_physmem(unsigned long start, unsigned long reserve_end,
unsigned long len, unsigned long highmem)
{
unsigned long reserve = reserve_end - start;
int pfn = PFN_UP(__pa(reserve_end));
int delta = (len - reserve) >> PAGE_SHIFT;
int err, offset, bootmap_size;
physmem_fd = create_mem_file(len + highmem);
offset = uml_reserved - uml_physmem;
err = os_map_memory((void *) uml_reserved, physmem_fd, offset,
len - offset, 1, 1, 0);
if(err < 0){
os_print_error(err, "Mapping memory");
exit(1);
}
/* Special kludge - This page will be mapped in to userspace processes
* from physmem_fd, so it needs to be written out there.
*/
os_seek_file(physmem_fd, __pa(&__syscall_stub_start));
os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE);
bootmap_size = init_bootmem(pfn, pfn + delta);
free_bootmem(__pa(reserve_end) + bootmap_size,
len - bootmap_size - reserve);
}
int phys_mapping(unsigned long phys, __u64 *offset_out)
{
struct phys_desc *desc = find_phys_mapping(__va(phys & PAGE_MASK));
int fd = -1;
if(desc != NULL){
fd = desc->fd;
*offset_out = desc->offset;
}
else if(phys < physmem_size){
fd = physmem_fd;
*offset_out = phys;
}
else if(phys < __pa(end_iomem)){
struct iomem_region *region = iomem_regions;
while(region != NULL){
if((phys >= region->phys) &&
(phys < region->phys + region->size)){
fd = region->fd;
*offset_out = phys - region->phys;
break;
}
region = region->next;
}
}
else if(phys < __pa(end_iomem) + highmem){
fd = physmem_fd;
*offset_out = phys - iomem_size;
}
return(fd);
}
static int __init uml_mem_setup(char *line, int *add)
{
char *retptr;
physmem_size = memparse(line,&retptr);
return 0;
}
__uml_setup("mem=", uml_mem_setup,
"mem=<Amount of desired ram>\n"
" This controls how much \"physical\" memory the kernel allocates\n"
" for the system. The size is specified as a number followed by\n"
" one of 'k', 'K', 'm', 'M', which have the obvious meanings.\n"
" This is not related to the amount of memory in the host. It can\n"
" be more, and the excess, if it's ever used, will just be swapped out.\n"
" Example: mem=64M\n\n"
);
unsigned long find_iomem(char *driver, unsigned long *len_out)
{
struct iomem_region *region = iomem_regions;
while(region != NULL){
if(!strcmp(region->driver, driver)){
*len_out = region->size;
return(region->virt);
}
}
return(0);
}
int setup_iomem(void)
{
struct iomem_region *region = iomem_regions;
unsigned long iomem_start = high_physmem + PAGE_SIZE;
int err;
while(region != NULL){
err = os_map_memory((void *) iomem_start, region->fd, 0,
region->size, 1, 1, 0);
if(err)
printk("Mapping iomem region for driver '%s' failed, "
"errno = %d\n", region->driver, -err);
else {
region->virt = iomem_start;
region->phys = __pa(region->virt);
}
iomem_start += region->size + PAGE_SIZE;
region = region->next;
}
return(0);
}
__initcall(setup_iomem);
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/
