From: Vivek Kasireddy <vivek.kasireddy@intel.com>
To: dri-devel@lists.freedesktop.org, linux-mm@kvack.org
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>,
David Hildenbrand <david@redhat.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Hugh Dickins <hughd@google.com>, Peter Xu <peterx@redhat.com>,
Jason Gunthorpe <jgg@nvidia.com>,
Gerd Hoffmann <kraxel@redhat.com>,
Dongwon Kim <dongwon.kim@intel.com>,
Junxiao Chang <junxiao.chang@intel.com>
Subject: [PATCH v2 1/2] udmabuf: Use vmf_insert_pfn and VM_PFNMAP for handling mmap
Date: Tue, 18 Jul 2023 01:26:04 -0700 [thread overview]
Message-ID: <20230718082605.1570740-2-vivek.kasireddy@intel.com> (raw)
In-Reply-To: <20230718082605.1570740-1-vivek.kasireddy@intel.com>
Add VM_PFNMAP to vm_flags in the mmap handler to ensure that
the mappings would be managed without using struct page.
And, in the vm_fault handler, use vmf_insert_pfn to share the
page's pfn to userspace instead of directly sharing the page
(via struct page *).
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Cc: Junxiao Chang <junxiao.chang@intel.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
---
drivers/dma-buf/udmabuf.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index c40645999648..820c993c8659 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -35,12 +35,13 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf)
struct vm_area_struct *vma = vmf->vma;
struct udmabuf *ubuf = vma->vm_private_data;
pgoff_t pgoff = vmf->pgoff;
+ unsigned long pfn;
if (pgoff >= ubuf->pagecount)
return VM_FAULT_SIGBUS;
- vmf->page = ubuf->pages[pgoff];
- get_page(vmf->page);
- return 0;
+
+ pfn = page_to_pfn(ubuf->pages[pgoff]);
+ return vmf_insert_pfn(vma, vmf->address, pfn);
}
static const struct vm_operations_struct udmabuf_vm_ops = {
@@ -56,6 +57,7 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
vma->vm_ops = &udmabuf_vm_ops;
vma->vm_private_data = ubuf;
+ vm_flags_set(vma, VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
return 0;
}
--
2.39.2
next prev parent reply other threads:[~2023-07-18 8:47 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-18 8:26 [PATCH v2 0/2] udmabuf: Add back support for mapping hugetlb pages (v2) Vivek Kasireddy
2023-07-18 8:26 ` Vivek Kasireddy [this message]
2023-07-18 18:03 ` [PATCH v2 1/2] udmabuf: Use vmf_insert_pfn and VM_PFNMAP for handling mmap David Hildenbrand
2023-07-18 8:26 ` [PATCH v2 2/2] udmabuf: Add back support for mapping hugetlb pages (v2) Vivek Kasireddy
2023-07-18 18:05 ` David Hildenbrand
2023-07-18 23:44 ` Mike Kravetz
2023-07-19 5:42 ` Kasireddy, Vivek
2023-07-27 20:54 ` Peter Xu
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