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-rw-r--r--arch/um/kernel/physmem.c478
1 files changed, 478 insertions, 0 deletions
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
new file mode 100644
index 00000000000..420e6d51fa0
--- /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:
+ */