[Intel-wired-lan] [next PATCH v2 5/9] igb: Limit maximum frame Rx based on MTU
Alexander Duyck
alexander.duyck at gmail.com
Tue Jan 17 16:32:26 UTC 2017
From: Alexander Duyck <alexander.h.duyck at intel.com>
In order to support the use of build_skb going forward it will be necessary
to place a maximum limit on the amount of data we can receive when jumbo
frames is not enabled. In order to do this I am adding a new upper limit
for receive based on the size of a 2K buffer minus padding.
Signed-off-by: Alexander Duyck <alexander.h.duyck at intel.com>
---
drivers/net/ethernet/intel/igb/igb.h | 10 +++++++++-
drivers/net/ethernet/intel/igb/igb_main.c | 16 ++++++++++++----
2 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index a638254f4e06..a74928cc0e58 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -143,8 +143,17 @@ struct vf_data_storage {
#define IGB_RXBUFFER_256 256
#define IGB_RXBUFFER_2048 2048
#define IGB_RX_HDR_LEN IGB_RXBUFFER_256
+#define IGB_TS_HDR_LEN 16
#define IGB_RX_BUFSZ IGB_RXBUFFER_2048
+#define IGB_SKB_PAD (NET_SKB_PAD + NET_IP_ALIGN)
+#if (PAGE_SIZE < 8192)
+#define IGB_MAX_FRAME_BUILD_SKB \
+ (SKB_WITH_OVERHEAD(IGB_RXBUFFER_2048) - IGB_SKB_PAD - IGB_TS_HDR_LEN)
+#else
+#define IGB_MAX_FRAME_BUILD_SKB (IGB_RXBUFFER_2048 - IGB_TS_HDR_LEN)
+#endif
+
/* How many Rx Buffers do we bundle into one write to the hardware ? */
#define IGB_RX_BUFFER_WRITE 16 /* Must be power of 2 */
@@ -561,7 +570,6 @@ struct igb_adapter {
#define IGB_DMCTLX_DCFLUSH_DIS 0x80000000 /* Disable DMA Coal Flush */
#define IGB_82576_TSYNC_SHIFT 19
-#define IGB_TS_HDR_LEN 16
enum e1000_state_t {
__IGB_TESTING,
__IGB_RESETTING,
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 3f3ae098e39a..d881c51ef162 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -4250,7 +4250,7 @@ static void igb_set_rx_mode(struct net_device *netdev)
struct igb_adapter *adapter = netdev_priv(netdev);
struct e1000_hw *hw = &adapter->hw;
unsigned int vfn = adapter->vfs_allocated_count;
- u32 rctl = 0, vmolr = 0;
+ u32 rctl = 0, vmolr = 0, rlpml = MAX_JUMBO_FRAME_SIZE;
int count;
/* Check for Promiscuous and All Multicast modes */
@@ -4322,12 +4322,20 @@ static void igb_set_rx_mode(struct net_device *netdev)
vmolr |= rd32(E1000_VMOLR(vfn)) &
~(E1000_VMOLR_ROPE | E1000_VMOLR_MPME | E1000_VMOLR_ROMPE);
- /* enable Rx jumbo frames, no need for restriction */
+ /* enable Rx jumbo frames, restrict as needed to support build_skb */
vmolr &= ~E1000_VMOLR_RLPML_MASK;
- vmolr |= MAX_JUMBO_FRAME_SIZE | E1000_VMOLR_LPE;
+#if (PAGE_SIZE < 8192)
+ if (adapter->max_frame_size <= IGB_MAX_FRAME_BUILD_SKB) {
+ if (!adapter->vfs_allocated_count)
+ rlpml = IGB_MAX_FRAME_BUILD_SKB;
+ vmolr |= IGB_MAX_FRAME_BUILD_SKB;
+ } else
+#endif
+ vmolr |= MAX_JUMBO_FRAME_SIZE;
+ vmolr |= E1000_VMOLR_LPE;
wr32(E1000_VMOLR(vfn), vmolr);
- wr32(E1000_RLPML, MAX_JUMBO_FRAME_SIZE);
+ wr32(E1000_RLPML, rlpml);
igb_restore_vf_multicasts(adapter);
}
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