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 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:
+ */