From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds <torvalds@ppc970.osdl.org> Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- arch/um/kernel/physmem.c | 478 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 478 insertions(+) create mode 100644 arch/um/kernel/physmem.c (limited to 'arch/um/kernel/physmem.c') diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c new file mode 100644 index 000000000000..420e6d51fa0f --- /dev/null +++ b/arch/um/kernel/physmem.c @@ -0,0 +1,478 @@ +/* + * 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; + +void *to_virt(unsigned long phys) +{ + return((void *) uml_physmem + phys); +} + +unsigned long to_phys(void *virt) +{ + return(((unsigned long) virt) - uml_physmem); +} + +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); +} + +struct page *phys_to_page(const unsigned long phys) +{ + return(&mem_map[phys >> PAGE_SHIFT]); +} + +struct page *__virt_to_page(const unsigned long virt) +{ + return(&mem_map[__pa(virt) >> PAGE_SHIFT]); +} + +phys_t page_to_phys(struct page *page) +{ + return((page - mem_map) << PAGE_SHIFT); +} + +pte_t mk_pte(struct page *page, pgprot_t pgprot) +{ + pte_t pte; + + pte_set_val(pte, page_to_phys(page), pgprot); + if(pte_present(pte)) + pte_mknewprot(pte_mknewpage(pte)); + return(pte); +} + +/* 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) + +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); + } + + 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: + */ -- cgit v1.2.2