uml: more page fault path trimming
[powerpc.git] / arch / um / kernel / physmem.c
index 166cb09..3ba6e4c 100644 (file)
@@ -13,7 +13,7 @@
 #include "asm/types.h"
 #include "asm/pgtable.h"
 #include "kern_util.h"
-#include "user_util.h"
+#include "as-layout.h"
 #include "mode_kern.h"
 #include "mem.h"
 #include "mem_user.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, 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;
 
@@ -276,7 +55,7 @@ int init_maps(unsigned long physmem, unsigned long iomem, unsigned long highmem)
        else map = alloc_bootmem_low_pages(total_len);
 
        if(map == NULL)
-               return(-ENOMEM);
+               return -ENOMEM;
 
        for(i = 0; i < total_pages; i++){
                p = &map[i];
@@ -286,7 +65,7 @@ int init_maps(unsigned long physmem, unsigned long iomem, unsigned long highmem)
        }
 
        max_mapnr = total_pages;
-       return(0);
+       return 0;
 }
 
 /* Changed during early boot */
@@ -296,7 +75,7 @@ unsigned long get_kmem_end(void)
 {
        if(kmem_top == 0)
                kmem_top = CHOOSE_MODE(kmem_end_tt, kmem_end_skas);
-       return(kmem_top);
+       return kmem_top;
 }
 
 void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
@@ -317,7 +96,7 @@ void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
        }
 }
 
-extern int __syscall_stub_start, __binary_start;
+extern int __syscall_stub_start;
 
 void setup_physmem(unsigned long start, unsigned long reserve_end,
                   unsigned long len, unsigned long long highmem)
@@ -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;
        }
@@ -379,7 +153,7 @@ int phys_mapping(unsigned long phys, __u64 *offset_out)
                *offset_out = phys - iomem_size;
        }
 
-       return(fd);
+       return fd;
 }
 
 static int __init uml_mem_setup(char *line, int *add)
@@ -398,6 +172,23 @@ __uml_setup("mem=", uml_mem_setup,
 "      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 = NULL;
+
+/* Initialized in parse_iomem */
+int iomem_size = 0;
+
 unsigned long find_iomem(char *driver, unsigned long *len_out)
 {
        struct iomem_region *region = iomem_regions;
@@ -405,13 +196,13 @@ unsigned long find_iomem(char *driver, unsigned long *len_out)
        while(region != NULL){
                if(!strcmp(region->driver, driver)){
                        *len_out = region->size;
-                       return(region->virt);
+                       return region->virt;
                }
 
                region = region->next;
        }
 
-       return(0);
+       return 0;
 }
 
 int setup_iomem(void)
@@ -435,18 +226,7 @@ int setup_iomem(void)
                region = region->next;
        }
 
-       return(0);
+       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:
- */