2.6.25-git19

 mm

diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 5e598c4..3e744ab 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -15,6 +15,7 @@
 #include <linux/rmap.h>
 #include <linux/sched.h>
 #include <asm/tlbflush.h>
+#include <asm/io.h>
 
 /*
  * We do use our own empty page to avoid interference with other users
@@ -42,37 +43,41 @@ static struct page *xip_sparse_page(void)
 
 /*
  * This is a file read routine for execute in place files, and uses
- * the mapping->a_ops->get_xip_page() function for the actual low-level
+ * the mapping->a_ops->get_xip_mem() function for the actual low-level
  * stuff.
  *
  * Note the struct file* is not used at all.  It may be NULL.
  */
-static void
+static ssize_t
 do_xip_mapping_read(struct address_space *mapping,
           struct file_ra_state *_ra,
           struct file *filp,
-          loff_t *ppos,
-          read_descriptor_t *desc,
-          read_actor_t actor)
+          char __user *buf,
+          size_t len,
+          loff_t *ppos)
 {
    struct inode *inode = mapping->host;
    pgoff_t index, end_index;
    unsigned long offset;
-   loff_t isize;
+   loff_t isize, pos;
+   size_t copied = 0, error = 0;
 
-   BUG_ON(!mapping->a_ops->get_xip_page);
+   BUG_ON(!mapping->a_ops->get_xip_mem);
 
-   index = *ppos >> PAGE_CACHE_SHIFT;
-   offset = *ppos & ~PAGE_CACHE_MASK;
+   pos = *ppos;
+   index = pos >> PAGE_CACHE_SHIFT;
+   offset = pos & ~PAGE_CACHE_MASK;
 
    isize = i_size_read(inode);
    if (!isize)
       goto out;
 
    end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
-   for (;;) {
-      struct page *page;
-      unsigned long nr, ret;
+   do {
+      unsigned long nr, left;
+      void *xip_mem;
+      unsigned long xip_pfn;
+      int zero = 0;
 
       /* nr is the maximum number of bytes to copy from this page */
       nr = PAGE_CACHE_SIZE;
@@ -85,19 +90,17 @@ do_xip_mapping_read(struct address_space *mapping,
          }
       }
       nr = nr - offset;
+      if (nr > len)
+         nr = len;
 
-      page = mapping->a_ops->get_xip_page(mapping,
-         index*(PAGE_SIZE/512), 0);
-      if (!page)
-         goto no_xip_page;
-      if (unlikely(IS_ERR(page))) {
-         if (PTR_ERR(page) == -ENODATA) {
+      error = mapping->a_ops->get_xip_mem(mapping, index, 0,
+                     &xip_mem, &xip_pfn);
+      if (unlikely(error)) {
+         if (error == -ENODATA) {
             /* sparse */
-            page = ZERO_PAGE(0);
-         } else {
-            desc->error = PTR_ERR(page);
+            zero = 1;
+         } else
             goto out;
-         }
       }
 
       /* If users can be writing to this page using arbitrary
@@ -105,10 +108,10 @@ do_xip_mapping_read(struct address_space *mapping,
        * before reading the page on the kernel side.
        */
       if (mapping_writably_mapped(mapping))
-         flush_dcache_page(page);
+         /* address based flush */ ;
 
       /*
-       * Ok, we have the page, so now we can copy it to user space...
+       * Ok, we have the mem, so now we can copy it to user space...
        *
        * The actor routine returns how many bytes were actually used..
        * NOTE! This may not be the same as how much of a user buffer
@@ -116,47 +119,38 @@ do_xip_mapping_read(struct address_space *mapping,
        * "pos" here (the actor routine has to update the user buffer
        * pointers and the remaining count).
        */
-      ret = actor(desc, page, offset, nr);
-      offset += ret;
-      index += offset >> PAGE_CACHE_SHIFT;
-      offset &= ~PAGE_CACHE_MASK;
+      if (!zero)
+         left = __copy_to_user(buf+copied, xip_mem+offset, nr);
+      else
+         left = __clear_user(buf + copied, nr);
 
-      if (ret == nr && desc->count)
-         continue;
-      goto out;
+      if (left) {
+         error = -EFAULT;
+         goto out;
+      }
 
-no_xip_page:
-      /* Did not get the page. Report it */
-      desc->error = -EIO;
-      goto out;
-   }
+      copied += (nr - left);
+      offset += (nr - left);
+      index += offset >> PAGE_CACHE_SHIFT;
+      offset &= ~PAGE_CACHE_MASK;
+   } while (copied < len);
 
 out:
-   *ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset;
+   *ppos = pos + copied;
    if (filp)
       file_accessed(filp);
+
+   return (copied ? copied : error);
 }
 
 ssize_t
 xip_file_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
 {
-   read_descriptor_t desc;
-
    if (!access_ok(VERIFY_WRITE, buf, len))
       return -EFAULT;
 
-   desc.written = 0;
-   desc.arg.buf = buf;
-   desc.count = len;
-   desc.error = 0;
-
-   do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
-             ppos, &desc, file_read_actor);
-
-   if (desc.written)
-      return desc.written;
-   else
-      return desc.error;
+   return do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
+             buf, len, ppos);
 }
 EXPORT_SYMBOL_GPL(xip_file_read);
 
@@ -211,13 +205,16 @@ __xip_unmap (struct address_space * mapping,
  *
  * This function is derived from filemap_fault, but used for execute in place
  */
-static int xip_file_fault(struct vm_area_struct *area, struct vm_fault *vmf)
+static int xip_file_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-   struct file *file = area->vm_file;
+   struct file *file = vma->vm_file;
    struct address_space *mapping = file->f_mapping;
    struct inode *inode = mapping->host;
-   struct page *page;
    pgoff_t size;
+   void *xip_mem;
+   unsigned long xip_pfn;
+   struct page *page;
+   int error;
 
    /* XXX: are VM_FAULT_ codes OK? */
 
@@ -225,35 +222,44 @@ static int xip_file_fault(struct vm_area_struct *area, struct vm_fault *vmf)
    if (vmf->pgoff >= size)
       return VM_FAULT_SIGBUS;
 
-   page = mapping->a_ops->get_xip_page(mapping,
-               vmf->pgoff*(PAGE_SIZE/512), 0);
-   if (!IS_ERR(page))
-      goto out;
-   if (PTR_ERR(page) != -ENODATA)
+   error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 0,
+                  &xip_mem, &xip_pfn);
+   if (likely(!error))
+      goto found;
+   if (error != -ENODATA)
       return VM_FAULT_OOM;
 
    /* sparse block */
-   if ((area->vm_flags & (VM_WRITE | VM_MAYWRITE)) &&
-       (area->vm_flags & (VM_SHARED| VM_MAYSHARE)) &&
+   if ((vma->vm_flags & (VM_WRITE | VM_MAYWRITE)) &&
+       (vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) &&
        (!(mapping->host->i_sb->s_flags & MS_RDONLY))) {
+      int err;
+
       /* maybe shared writable, allocate new block */
-      page = mapping->a_ops->get_xip_page(mapping,
-               vmf->pgoff*(PAGE_SIZE/512), 1);
-      if (IS_ERR(page))
+      error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 1,
+                     &xip_mem, &xip_pfn);
+      if (error)
          return VM_FAULT_SIGBUS;
-      /* unmap page at pgoff from all other vmas */
+      /* unmap sparse mappings at pgoff from all other vmas */
       __xip_unmap(mapping, vmf->pgoff);
+
+found:
+      err = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
+                     xip_pfn);
+      if (err == -ENOMEM)
+         return VM_FAULT_OOM;
+      BUG_ON(err);
+      return VM_FAULT_NOPAGE;
    } else {
       /* not shared and writable, use xip_sparse_page() */
       page = xip_sparse_page();
       if (!page)
          return VM_FAULT_OOM;
-   }
 
-out:
-   page_cache_get(page);
-   vmf->page = page;
-   return 0;
+      page_cache_get(page);
+      vmf->page = page;
+      return 0;
+   }
 }
 
 static struct vm_operations_struct xip_file_vm_ops = {
@@ -262,11 +268,11 @@ static struct vm_operations_struct xip_file_vm_ops = {
 
 int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
 {
-   BUG_ON(!file->f_mapping->a_ops->get_xip_page);
+   BUG_ON(!file->f_mapping->a_ops->get_xip_mem);
 
    file_accessed(file);
    vma->vm_ops = &xip_file_vm_ops;
-   vma->vm_flags |= VM_CAN_NONLINEAR;
+   vma->vm_flags |= VM_CAN_NONLINEAR | VM_MIXEDMAP;
    return 0;
 }
 EXPORT_SYMBOL_GPL(xip_file_mmap);
@@ -279,17 +285,17 @@ __xip_file_write(struct file *filp, const char __user *buf,
    const struct address_space_operations *a_ops = mapping->a_ops;
    struct inode    *inode = mapping->host;
    long      status = 0;
-   struct page   *page;
    size_t      bytes;
    ssize_t      written = 0;
 
-   BUG_ON(!mapping->a_ops->get_xip_page);
+   BUG_ON(!mapping->a_ops->get_xip_mem);
 
    do {
       unsigned long index;
       unsigned long offset;
       size_t copied;
-      char *kaddr;
+      void *xip_mem;
+      unsigned long xip_pfn;
 
       offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
       index = pos >> PAGE_CACHE_SHIFT;
@@ -297,28 +303,22 @@ __xip_file_write(struct file *filp, const char __user *buf,
       if (bytes > count)
          bytes = count;
 
-      page = a_ops->get_xip_page(mapping,
-                  index*(PAGE_SIZE/512), 0);
-      if (IS_ERR(page) && (PTR_ERR(page) == -ENODATA)) {
+      status = a_ops->get_xip_mem(mapping, index, 0,
+                  &xip_mem, &xip_pfn);
+      if (status == -ENODATA) {
          /* we allocate a new page unmap it */
-         page = a_ops->get_xip_page(mapping,
-                     index*(PAGE_SIZE/512), 1);
-         if (!IS_ERR(page))
+         status = a_ops->get_xip_mem(mapping, index, 1,
+                     &xip_mem, &xip_pfn);
+         if (!status)
             /* unmap page at pgoff from all other vmas */
             __xip_unmap(mapping, index);
       }
 
-      if (IS_ERR(page)) {
-         status = PTR_ERR(page);
+      if (status)
          break;
-      }
 
-      fault_in_pages_readable(buf, bytes);
-      kaddr = kmap_atomic(page, KM_USER0);
       copied = bytes -
-         __copy_from_user_inatomic_nocache(kaddr + offset, buf, bytes);
-      kunmap_atomic(kaddr, KM_USER0);
-      flush_dcache_page(page);
+         __copy_from_user_nocache(xip_mem + offset, buf, bytes);
 
       if (likely(copied > 0)) {
          status = copied;
@@ -398,7 +398,7 @@ EXPORT_SYMBOL_GPL(xip_file_write);
 
 /*
  * truncate a page used for execute in place
- * functionality is analog to block_truncate_page but does use get_xip_page
+ * functionality is analog to block_truncate_page but does use get_xip_mem
  * to get the page instead of page cache
  */
 int
@@ -408,9 +408,11 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
    unsigned offset = from & (PAGE_CACHE_SIZE-1);
    unsigned blocksize;
    unsigned length;
-   struct page *page;
+   void *xip_mem;
+   unsigned long xip_pfn;
+   int err;
 
-   BUG_ON(!mapping->a_ops->get_xip_page);
+   BUG_ON(!mapping->a_ops->get_xip_mem);
 
    blocksize = 1 << mapping->host->i_blkbits;
    length = offset & (blocksize - 1);
@@ -421,18 +423,16 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
 
    length = blocksize - length;
 
-   page = mapping->a_ops->get_xip_page(mapping,
-                   index*(PAGE_SIZE/512), 0);
-   if (!page)
-      return -ENOMEM;
-   if (unlikely(IS_ERR(page))) {
-      if (PTR_ERR(page) == -ENODATA)
+   err = mapping->a_ops->get_xip_mem(mapping, index, 0,
+                  &xip_mem, &xip_pfn);
+   if (unlikely(err)) {
+      if (err == -ENODATA)
          /* Hole? No need to truncate */
          return 0;
       else
-         return PTR_ERR(page);
+         return err;
    }
-   zero_user(page, offset, length);
+   memset(xip_mem + offset, 0, length);
    return 0;
 }
 EXPORT_SYMBOL_GPL(xip_truncate_page);