diff mbox series

[net-next,6/8] vmxnet3: limit number of TXDs used for TSO packet

Message ID 20220528011758.7024-7-doshir@vmware.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series vmxnet3: upgrade to version 7 | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 17 this patch: 17
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 17 this patch: 17
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 31 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Ronak Doshi May 28, 2022, 1:17 a.m. UTC 
Currently, vmxnet3 does not have a limit on number of descriptors
used for a TSO packet. However, with UPT, for hardware performance
reasons, this patch limits the number of transmit descriptors to 24
for a TSO packet.

Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
---
 drivers/net/vmxnet3/vmxnet3_defs.h |  2 ++
 drivers/net/vmxnet3/vmxnet3_drv.c  | 17 +++++++++++++++++
 2 files changed, 19 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/vmxnet3/vmxnet3_defs.h b/drivers/net/vmxnet3/vmxnet3_defs.h
index 415e4c9993ef..cb9dc72f2b3d 100644
--- a/drivers/net/vmxnet3/vmxnet3_defs.h
+++ b/drivers/net/vmxnet3/vmxnet3_defs.h
@@ -400,6 +400,8 @@  union Vmxnet3_GenericDesc {
 
 /* max # of tx descs for a non-tso pkt */
 #define VMXNET3_MAX_TXD_PER_PKT 16
+/* max # of tx descs for a tso pkt */
+#define VMXNET3_MAX_TSO_TXD_PER_PKT 24
 
 /* Max size of a single rx buffer */
 #define VMXNET3_MAX_RX_BUF_SIZE  ((1 << 14) - 1)
diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 2ba263966989..6e013ae0b5ea 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -1061,6 +1061,23 @@  vmxnet3_tq_xmit(struct sk_buff *skb, struct vmxnet3_tx_queue *tq,
 			}
 			tq->stats.copy_skb_header++;
 		}
+		if (unlikely(count > VMXNET3_MAX_TSO_TXD_PER_PKT)) {
+			/* tso pkts must not use more than
+			 * VMXNET3_MAX_TSO_TXD_PER_PKT entries
+			 */
+			if (skb_linearize(skb) != 0) {
+				tq->stats.drop_too_many_frags++;
+				goto drop_pkt;
+			}
+			tq->stats.linearized++;
+
+			/* recalculate the # of descriptors to use */
+			count = VMXNET3_TXD_NEEDED(skb_headlen(skb)) + 1;
+			if (unlikely(count > VMXNET3_MAX_TSO_TXD_PER_PKT)) {
+				tq->stats.drop_too_many_frags++;
+				goto drop_pkt;
+			}
+		}
 		if (skb->encapsulation) {
 			vmxnet3_prepare_inner_tso(skb, &ctx);
 		} else {