diff options
Diffstat (limited to 'arch/um/kernel/physmem.c')
-rw-r--r-- | arch/um/kernel/physmem.c | 228 |
1 files changed, 1 insertions, 227 deletions
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c index df1ad3b..3ba6e4c 100644 --- a/arch/um/kernel/physmem.c +++ b/arch/um/kernel/physmem.c @@ -21,229 +21,8 @@ #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, rb_parent(*n), 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; @@ -350,14 +129,9 @@ void setup_physmem(unsigned long start, unsigned long reserve_end, 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){ + if(phys < physmem_size){ fd = physmem_fd; *offset_out = phys; } |