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authorJakub Kicinski <jakub.kicinski@netronome.com>2018-09-07 10:18:46 +0200
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2018-09-25 13:13:15 -0700
commitf5bd91388e26557f64ca999e0006038c7a919308 (patch)
tree28d868b5c3ed674e3bc2e18cd179657d4301bd9d /net/xdp
parenti40e: clean zero-copy XDP Tx ring on shutdown/reset (diff)
downloadlinux-dev-f5bd91388e26557f64ca999e0006038c7a919308.tar.xz
linux-dev-f5bd91388e26557f64ca999e0006038c7a919308.zip
net: xsk: add a simple buffer reuse queue
XSK UMEM is strongly single producer single consumer so reuse of frames is challenging. Add a simple "stash" of FILL packets to reuse for drivers to optionally make use of. This is useful when driver has to free (ndo_stop) or resize a ring with an active AF_XDP ZC socket. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Tested-by: Andrew Bowers <andrewx.bowers@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'net/xdp')
-rw-r--r--net/xdp/xdp_umem.c2
-rw-r--r--net/xdp/xsk_queue.c55
-rw-r--r--net/xdp/xsk_queue.h3
3 files changed, 60 insertions, 0 deletions
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index b3b632c5aeae..555427b3e0fe 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -165,6 +165,8 @@ static void xdp_umem_release(struct xdp_umem *umem)
umem->cq = NULL;
}
+ xsk_reuseq_destroy(umem);
+
xdp_umem_unpin_pages(umem);
task = get_pid_task(umem->pid, PIDTYPE_PID);
diff --git a/net/xdp/xsk_queue.c b/net/xdp/xsk_queue.c
index 2dc1384d9f27..b66504592d9b 100644
--- a/net/xdp/xsk_queue.c
+++ b/net/xdp/xsk_queue.c
@@ -3,7 +3,9 @@
* Copyright(c) 2018 Intel Corporation.
*/
+#include <linux/log2.h>
#include <linux/slab.h>
+#include <linux/overflow.h>
#include "xsk_queue.h"
@@ -62,3 +64,56 @@ void xskq_destroy(struct xsk_queue *q)
page_frag_free(q->ring);
kfree(q);
}
+
+struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries)
+{
+ struct xdp_umem_fq_reuse *newq;
+
+ /* Check for overflow */
+ if (nentries > (u32)roundup_pow_of_two(nentries))
+ return NULL;
+ nentries = roundup_pow_of_two(nentries);
+
+ newq = kvmalloc(struct_size(newq, handles, nentries), GFP_KERNEL);
+ if (!newq)
+ return NULL;
+ memset(newq, 0, offsetof(typeof(*newq), handles));
+
+ newq->nentries = nentries;
+ return newq;
+}
+EXPORT_SYMBOL_GPL(xsk_reuseq_prepare);
+
+struct xdp_umem_fq_reuse *xsk_reuseq_swap(struct xdp_umem *umem,
+ struct xdp_umem_fq_reuse *newq)
+{
+ struct xdp_umem_fq_reuse *oldq = umem->fq_reuse;
+
+ if (!oldq) {
+ umem->fq_reuse = newq;
+ return NULL;
+ }
+
+ if (newq->nentries < oldq->length)
+ return newq;
+
+ memcpy(newq->handles, oldq->handles,
+ array_size(oldq->length, sizeof(u64)));
+ newq->length = oldq->length;
+
+ umem->fq_reuse = newq;
+ return oldq;
+}
+EXPORT_SYMBOL_GPL(xsk_reuseq_swap);
+
+void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq)
+{
+ kvfree(rq);
+}
+EXPORT_SYMBOL_GPL(xsk_reuseq_free);
+
+void xsk_reuseq_destroy(struct xdp_umem *umem)
+{
+ xsk_reuseq_free(umem->fq_reuse);
+ umem->fq_reuse = NULL;
+}
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index 82252cccb4e0..bcb5cbb40419 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -258,4 +258,7 @@ void xskq_set_umem(struct xsk_queue *q, u64 size, u64 chunk_mask);
struct xsk_queue *xskq_create(u32 nentries, bool umem_queue);
void xskq_destroy(struct xsk_queue *q_ops);
+/* Executed by the core when the entire UMEM gets freed */
+void xsk_reuseq_destroy(struct xdp_umem *umem);
+
#endif /* _LINUX_XSK_QUEUE_H */