diff options
Diffstat (limited to 'mm/filemap_xip.c')
-rw-r--r-- | mm/filemap_xip.c | 200 |
1 files changed, 100 insertions, 100 deletions
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c index 5e598c42afd..3e744abcce9 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); |