lkml.org 
[lkml]   [2021]   [Jun]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH] swiotlb-xen: override common mmap and get_sgtable dma ops
    From
    Date

    On 6/11/21 5:55 AM, Roman Skakun wrote:
    >
    > +static int
    > +xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma,
    > + void *cpu_addr, dma_addr_t dma_addr, size_t size,
    > + unsigned long attrs)
    > +{
    > + unsigned long user_count = vma_pages(vma);
    > + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
    > + unsigned long off = vma->vm_pgoff;
    > + struct page *page;
    > +
    > + if (is_vmalloc_addr(cpu_addr))
    > + page = vmalloc_to_page(cpu_addr);
    > + else
    > + page = virt_to_page(cpu_addr);
    > +
    > + vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
    > +
    > + if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
    > + return -ENXIO;
    > +
    > + if (off >= count || user_count > count - off)
    > + return -ENXIO;
    > +
    > + return remap_pfn_range(vma, vma->vm_start,
    > + page_to_pfn(page) + vma->vm_pgoff,
    > + user_count << PAGE_SHIFT, vma->vm_page_prot);
    > +}


    I suggest you create a helper for computing page value and then revert 922659ea771b3fd728149262c5ea15608fab9719 and pass result of the helper instead of cpu_addr. Here and in xen_swiotlb_dma_get_sgtable().


    And use this new helper in xen_swiotlb_free_coherent() too. I am curious though why this was not a problem when Stefano was looking at the problem that introduced this vmalloc check (i.e. 8b1e868f66076490189a36d984fcce286cdd6295). Stefano?


    -boris

    \
     
     \ /
      Last update: 2021-06-11 17:20    [W:3.899 / U:0.092 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site