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authorBjörn Töpel <bjorn.topel@intel.com>2018-08-28 14:44:25 +0200
committerAlexei Starovoitov <ast@kernel.org>2018-08-29 12:25:53 -0700
commitb0d1beeff2a97a0cf1965ea8f1d13b8973f22582 (patch)
treefe62f9152f04a26affb09ddb56fdd253f3502e82 /net/core/xdp.c
parent7d2c6cfc5411207f1094e7ca5e63e711dc76d1ff (diff)
xdp: implement convert_to_xdp_frame for MEM_TYPE_ZERO_COPY
This commit adds proper MEM_TYPE_ZERO_COPY support for convert_to_xdp_frame. Converting a MEM_TYPE_ZERO_COPY xdp_buff to an xdp_frame is done by transforming the MEM_TYPE_ZERO_COPY buffer into a MEM_TYPE_PAGE_ORDER0 frame. This is costly, and in the future it might make sense to implement a more sophisticated thread-safe alloc/free scheme for MEM_TYPE_ZERO_COPY, so that no allocation and copy is required in the fast-path. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'net/core/xdp.c')
-rw-r--r--net/core/xdp.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 89b6785cef2a..be6cb2f0e722 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -398,3 +398,42 @@ void xdp_attachment_setup(struct xdp_attachment_info *info,
info->flags = bpf->flags;
}
EXPORT_SYMBOL_GPL(xdp_attachment_setup);
+
+struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp)
+{
+ unsigned int metasize, headroom, totsize;
+ void *addr, *data_to_copy;
+ struct xdp_frame *xdpf;
+ struct page *page;
+
+ /* Clone into a MEM_TYPE_PAGE_ORDER0 xdp_frame. */
+ metasize = xdp_data_meta_unsupported(xdp) ? 0 :
+ xdp->data - xdp->data_meta;
+ headroom = xdp->data - xdp->data_hard_start;
+ totsize = xdp->data_end - xdp->data + metasize;
+
+ if (sizeof(*xdpf) + totsize > PAGE_SIZE)
+ return NULL;
+
+ page = dev_alloc_page();
+ if (!page)
+ return NULL;
+
+ addr = page_to_virt(page);
+ xdpf = addr;
+ memset(xdpf, 0, sizeof(*xdpf));
+
+ addr += sizeof(*xdpf);
+ data_to_copy = metasize ? xdp->data_meta : xdp->data;
+ memcpy(addr, data_to_copy, totsize);
+
+ xdpf->data = addr + metasize;
+ xdpf->len = totsize - metasize;
+ xdpf->headroom = 0;
+ xdpf->metasize = metasize;
+ xdpf->mem.type = MEM_TYPE_PAGE_ORDER0;
+
+ xdp_return_buff(xdp);
+ return xdpf;
+}
+EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame);