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Diffstat (limited to 'kernel/arch/um/kernel/physmem.c')
| -rw-r--r-- | kernel/arch/um/kernel/physmem.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/kernel/arch/um/kernel/physmem.c b/kernel/arch/um/kernel/physmem.c new file mode 100644 index 000000000..9034fc805 --- /dev/null +++ b/kernel/arch/um/kernel/physmem.c @@ -0,0 +1,225 @@ +/* + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#include <linux/module.h> +#include <linux/bootmem.h> +#include <linux/mm.h> +#include <linux/pfn.h> +#include <asm/page.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); + } +} + +extern int __syscall_stub_start; + +/** + * 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; + unsigned long pfn = PFN_UP(__pa(reserve_end)); + unsigned long delta = (len - reserve) >> PAGE_SHIFT; + unsigned long offset, bootmap_size; + long map_size; + int err; + + offset = uml_reserved - uml_physmem; + map_size = len - offset; + if(map_size <= 0) { + printf("Too few physical memory! Needed=%d, given=%d\n", + offset, len); + exit(1); + } + + physmem_fd = create_mem_file(len + highmem); + + err = os_map_memory((void *) uml_reserved, physmem_fd, offset, + map_size, 1, 1, 1); + if (err < 0) { + printf("setup_physmem - mapping %ld bytes of memory at 0x%p " + "failed - errno = %d\n", map_size, + (void *) uml_reserved, 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); + + bootmap_size = init_bootmem(pfn, pfn + delta); + free_bootmem(__pa(reserve_end) + bootmap_size, + len - bootmap_size - reserve); +} + +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; +} + +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 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); |