Messages in this thread Patch in this message | | | From | Magnus Damm <> | Date | Fri, 18 Jul 2008 14:04:51 +0900 | Subject | [PATCH 06/06] uio: Support multiple UIO_MEM_LOGICAL/VIRTUAL pages |
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From: Magnus Damm <damm@igel.co.jp>
This patch improves the UIO_MEM_LOGICAL and UIO_MEM_VIRTUAL page fault code to support more than one page of data. Memory allocated from the slab is however not supported, so a check for that is added and the documentation gets a little update.
Signed-off-by: Magnus Damm <damm@igel.co.jp> ---
Documentation/DocBook/uio-howto.tmpl | 2 +- drivers/uio/uio.c | 10 ++++++++-- 2 files changed, 9 insertions(+), 3 deletions(-)
--- 0001/Documentation/DocBook/uio-howto.tmpl +++ work/Documentation/DocBook/uio-howto.tmpl 2008-07-18 12:45:22.000000000 +0900 @@ -376,7 +376,7 @@ Here's a description of the fields of <v <varname>int memtype</varname>: Required if the mapping is used. Set this to <varname>UIO_MEM_PHYS</varname> if you you have physical memory on your card to be mapped. Use <varname>UIO_MEM_LOGICAL</varname> for logical -memory (e.g. allocated with <function>kmalloc()</function>). There's also +memory (e.g. allocated with <function>alloc_pages()</function>). There's also <varname>UIO_MEM_VIRTUAL</varname> for virtual memory. </para></listitem> --- 0006/drivers/uio/uio.c +++ work/drivers/uio/uio.c 2008-07-18 12:49:38.000000000 +0900 @@ -455,12 +455,15 @@ static void uio_vma_close(struct vm_area static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct uio_mem *imem = vma->vm_private_data; + unsigned long vaddr = imem->addr; struct page *page; + vaddr += (vmf->pgoff - vma->vm_pgoff) << PAGE_SHIFT; + if (imem->memtype == UIO_MEM_LOGICAL) - page = virt_to_page(imem->addr); + page = virt_to_page(vaddr); else - page = vmalloc_to_page((void *)imem->addr); + page = vmalloc_to_page((void *)vaddr); get_page(page); vmf->page = page; return 0; @@ -521,6 +524,9 @@ static int uio_mmap(struct file *filep, case UIO_MEM_PHYS: return uio_mmap_physical(vma, imem); case UIO_MEM_LOGICAL: + if (virt_to_page(imem->addr)->flags & (1 << PG_slab)) + return -EINVAL; /* kmalloc() not supported */ + /* fall-through */ case UIO_MEM_VIRTUAL: return uio_mmap_logical(vma, imem); default:
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