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Commit cfbc871c authored by Alexander Duyck's avatar Alexander Duyck Committed by Jeff Kirsher
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igb: Limit maximum frame Rx based on MTU 



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: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent 7cc6fd4c

drivers/net/ethernet/intel/igb/igb.h

+9 −1
Original line number Diff line number Diff line
@@ -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,

drivers/net/ethernet/intel/igb/igb_main.c

+17 −4
Original line number Diff line number Diff line
@@ -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 */
@@ -4308,6 +4308,14 @@ static void igb_set_rx_mode(struct net_device *netdev) 
				     E1000_RCTL_VFE);

	wr32(E1000_RCTL, rctl);



#if (PAGE_SIZE < 8192)

	if (!adapter->vfs_allocated_count) {

		if (adapter->max_frame_size <= IGB_MAX_FRAME_BUILD_SKB)

			rlpml = IGB_MAX_FRAME_BUILD_SKB;

	}

#endif

	wr32(E1000_RLPML, rlpml);



	/* In order to support SR-IOV and eventually VMDq it is necessary to set

	 * the VMOLR to enable the appropriate modes.  Without this workaround

	 * we will have issues with VLAN tag stripping not being done for frames
@@ -4322,12 +4330,17 @@ 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)

		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);



	igb_restore_vf_multicasts(adapter);

}