Messages in this thread | | | Subject | Re: [PATCH v3 2/9] arch/arm/mm/dma-mapping.c: Convert to use vm_insert_range | From | Robin Murphy <> | Date | Mon, 10 Dec 2018 16:32:06 +0000 |
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On 08/12/2018 20:01, Souptick Joarder wrote: > Hi Robin, > > On Fri, Dec 7, 2018 at 12:07 AM Souptick Joarder <jrdr.linux@gmail.com> wrote: >> >> Convert to use vm_insert_range() to map range of kernel >> memory to user vma. >> >> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> >> --- >> arch/arm/mm/dma-mapping.c | 21 +++++++-------------- >> 1 file changed, 7 insertions(+), 14 deletions(-) >> >> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c >> index 661fe48..4eec323 100644 >> --- a/arch/arm/mm/dma-mapping.c >> +++ b/arch/arm/mm/dma-mapping.c >> @@ -1582,31 +1582,24 @@ static int __arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma >> void *cpu_addr, dma_addr_t dma_addr, size_t size, >> unsigned long attrs) >> { >> - unsigned long uaddr = vma->vm_start; >> - unsigned long usize = vma->vm_end - vma->vm_start; >> + unsigned long page_count = vma_pages(vma); >> struct page **pages = __iommu_get_pages(cpu_addr, attrs); >> unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; >> unsigned long off = vma->vm_pgoff; >> + int err; >> >> if (!pages) >> return -ENXIO; >> >> - if (off >= nr_pages || (usize >> PAGE_SHIFT) > nr_pages - off) >> + if (off >= nr_pages || page_count > nr_pages - off) >> return -ENXIO; >> >> pages += off; >> + err = vm_insert_range(vma, vma->vm_start, pages, page_count); > > Just to clarify, do we need to adjust page_count with vma->vm_pgoff as > original code > have not consider it and run the loop for entire range irrespective of > vma->vm_pgoff value ?
In this instance, page_count is the size of the VMA, not the size of the pages array itself, so as I understand things this patch is true to the original code as-is.
Robin.
> >> + if (err) >> + pr_err("Remapping memory failed: %d\n", err); >> >> - do { >> - int ret = vm_insert_page(vma, uaddr, *pages++); >> - if (ret) { >> - pr_err("Remapping memory failed: %d\n", ret); >> - return ret; >> - } >> - uaddr += PAGE_SIZE; >> - usize -= PAGE_SIZE; >> - } while (usize > 0); >> - >> - return 0; >> + return err; >> } >> static int arm_iommu_mmap_attrs(struct device *dev, >> struct vm_area_struct *vma, void *cpu_addr, >> -- >> 1.9.1 >>
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