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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#include <linux/module.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/pfn.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <as-layout.h>
#include <init.h>
#include <kern.h>
#include <mem_user.h>
#include <os.h>
static int physmem_fd = -1;
/* Changed during early boot */
unsigned long high_physmem;
EXPORT_SYMBOL(high_physmem);
extern unsigned long long physmem_size;
void __init mem_total_pages(unsigned long physmem, unsigned long iomem,
unsigned long highmem)
{
unsigned long phys_pages, highmem_pages;
unsigned long iomem_pages, total_pages;
phys_pages = physmem >> PAGE_SHIFT;
iomem_pages = iomem >> PAGE_SHIFT;
highmem_pages = highmem >> PAGE_SHIFT;
total_pages = phys_pages + iomem_pages + highmem_pages;
max_mapnr = total_pages;
}
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(KERN_ERR "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);
}
}
/**
* setup_physmem() - Setup physical memory for UML
* @start: Start address of the physical kernel memory,
* i.e start address of the executable image.
* @reserve_end: end address of the physical kernel memory.
* @len: Length of total physical memory that should be mapped/made
* available, in bytes.
* @highmem: Number of highmem bytes that should be mapped/made available.
*
* Creates an unlinked temporary file of size (len + highmem) and memory maps
* it on the last executable image address (uml_reserved).
*
* The offset is needed as the length of the total physical memory
* (len + highmem) includes the size of the memory used be the executable image,
* but the mapped-to address is the last address of the executable image
* (uml_reserved == end address of executable image).
*
* The memory mapped memory of the temporary file is used as backing memory
* of all user space processes/kernel tasks.
*/
void __init setup_physmem(unsigned long start, unsigned long reserve_end,
unsigned long len, unsigned long long highmem)
{
unsigned long reserve = reserve_end - start;
long map_size = len - reserve;
int err;
if(map_size <= 0) {
os_warn("Too few physical memory! Needed=%lu, given=%lu\n",
reserve, len);
exit(1);
}
physmem_fd = create_mem_file(len + highmem);
err = os_map_memory((void *) reserve_end, physmem_fd, reserve,
map_size, 1, 1, 1);
if (err < 0) {
os_warn("setup_physmem - mapping %ld bytes of memory at 0x%p "
"failed - errno = %d\n", map_size,
(void *) reserve_end, err);
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);
os_fsync_file(physmem_fd);
memblock_add(__pa(start), len + highmem);
memblock_reserve(__pa(start), reserve);
min_low_pfn = PFN_UP(__pa(reserve_end));
max_low_pfn = min_low_pfn + (map_size >> PAGE_SHIFT);
}
int phys_mapping(unsigned long phys, unsigned long long *offset_out)
{
int fd = -1;
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;
}
EXPORT_SYMBOL(phys_mapping);
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"
);
extern int __init parse_iomem(char *str, int *add);
__uml_setup("iomem=", parse_iomem,
"iomem=<name>,<file>\n"
" Configure <file> as an IO memory region named <name>.\n\n"
);
/*
* This list is constructed in parse_iomem and addresses filled in
* setup_iomem, both of which run during early boot. Afterwards, it's
* unchanged.
*/
struct iomem_region *iomem_regions;
/* Initialized in parse_iomem and unchanged thereafter */
int iomem_size;
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;
}
region = region->next;
}
return 0;
}
EXPORT_SYMBOL(find_iomem);
static 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(KERN_ERR "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);
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