Under certain condition, I find guest will oops on writel() in
igb_configure_tx_ring(), because hw->hw_address is NULL. While other
register access won't oops kernel because they use wr32/rd32 which have
a defense against NULL pointer. The oops message are as following:
[ 141.225449] pcieport 0000:00:1c.0: AER: Multiple Uncorrected (Fatal)
error received: id=0101
[ 141.225523] igb 0000:01:00.1: PCIe Bus Error: severity=Uncorrected
(Fatal), type=Unaccessible, id=0101(Unregistered Agent ID)
[ 141.299442] igb 0000:01:00.1: broadcast error_detected message
[ 141.300539] igb 0000:01:00.0 enp1s0f0: PCIe link lost, device now
detached
[ 141.351019] igb 0000:01:00.1 enp1s0f1: PCIe link lost, device now
detached
[ 143.465904] pcieport 0000:00:1c.0: Root Port link has been reset
[ 143.465994] igb 0000:01:00.1: broadcast slot_reset message
[ 143.466039] igb 0000:01:00.0: enabling device (0000 -> 0002)
[ 144.389078] igb 0000:01:00.1: enabling device (0000 -> 0002)
[ 145.312078] igb 0000:01:00.1: broadcast resume message
[ 145.322211] BUG: unable to handle kernel paging request at
0000000000003818
[ 145.361275] IP: [<ffffffffa02fd38d>] igb_configure_tx_ring+0x14d/0x280
[igb]
[ 145.438007] Oops: 0002 [#1] SMP
On the other hand, commit 238ac817 does some optimization which
dropped the field "head". So I think it is time to drop "tail" as well.
Signed-off-by: Cao jin <caoj.f...@cn.fujitsu.com>
---
drivers/net/ethernet/intel/igb/igb.h | 1 -
drivers/net/ethernet/intel/igb/igb_main.c | 16 +++++++++-------
2 files changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/intel/igb/igb.h
b/drivers/net/ethernet/intel/igb/igb.h
index d11093d..0df06bc 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -247,7 +247,6 @@ struct igb_ring {
};
void *desc; /* descriptor ring memory */
unsigned long flags; /* ring specific flags */
- void __iomem *tail; /* pointer to ring tail register */
dma_addr_t dma; /* phys address of the ring */
unsigned int size; /* length of desc. ring in bytes */
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c
b/drivers/net/ethernet/intel/igb/igb_main.c
index edc9a6a..e177d0e 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -3390,9 +3390,8 @@ void igb_configure_tx_ring(struct igb_adapter *adapter,
tdba & 0x00000000ffffffffULL);
wr32(E1000_TDBAH(reg_idx), tdba >> 32);
- ring->tail = hw->hw_addr + E1000_TDT(reg_idx);
wr32(E1000_TDH(reg_idx), 0);
- writel(0, ring->tail);
+ wr32(E1000_TDT(reg_idx), 0);
txdctl |= IGB_TX_PTHRESH;
txdctl |= IGB_TX_HTHRESH << 8;
@@ -3729,9 +3728,8 @@ void igb_configure_rx_ring(struct igb_adapter *adapter,
ring->count * sizeof(union e1000_adv_rx_desc));
/* initialize head and tail */
- ring->tail = hw->hw_addr + E1000_RDT(reg_idx);
wr32(E1000_RDH(reg_idx), 0);
- writel(0, ring->tail);
+ wr32(E1000_RDT(reg_idx), 0);
/* set descriptor configuration */
srrctl = IGB_RX_HDR_LEN << E1000_SRRCTL_BSIZEHDRSIZE_SHIFT;
@@ -5130,6 +5128,8 @@ static void igb_tx_map(struct igb_ring *tx_ring,
u32 tx_flags = first->tx_flags;
u32 cmd_type = igb_tx_cmd_type(skb, tx_flags);
u16 i = tx_ring->next_to_use;
+ struct igb_adapter *adapter = netdev_priv(tx_ring->netdev);
+ struct e1000_hw *hw = &adapter->hw;
tx_desc = IGB_TX_DESC(tx_ring, i);
@@ -5223,7 +5223,7 @@ static void igb_tx_map(struct igb_ring *tx_ring,
igb_maybe_stop_tx(tx_ring, DESC_NEEDED);
if (netif_xmit_stopped(txring_txq(tx_ring)) || !skb->xmit_more) {
- writel(i, tx_ring->tail);
+ wr32(E1000_TDT(tx_ring->reg_idx), i);
/* we need this if more than one processor can write to our tail
* at a time, it synchronizes IO on IA64/Altix systems
@@ -6756,7 +6756,7 @@ static bool igb_clean_tx_irq(struct igb_q_vector
*q_vector, int napi_budget)
" desc.status <%x>\n",
tx_ring->queue_index,
rd32(E1000_TDH(tx_ring->reg_idx)),
- readl(tx_ring->tail),
+ rd32(E1000_TDT(tx_ring->reg_idx)),
tx_ring->next_to_use,
tx_ring->next_to_clean,
tx_buffer->time_stamp,
@@ -7265,6 +7265,8 @@ void igb_alloc_rx_buffers(struct igb_ring *rx_ring, u16
cleaned_count)
union e1000_adv_rx_desc *rx_desc;
struct igb_rx_buffer *bi;
u16 i = rx_ring->next_to_use;
+ struct igb_adapter *adapter = netdev_priv(rx_ring->netdev);
+ struct e1000_hw *hw = &adapter->hw;
/* nothing to do */
if (!cleaned_count)
@@ -7313,7 +7315,7 @@ void igb_alloc_rx_buffers(struct igb_ring *rx_ring, u16
cleaned_count)
* such as IA-64).
*/
wmb();
- writel(i, rx_ring->tail);
+ wr32(E1000_RDT(rx_ring->reg_idx), i);
}
}
--
2.1.0
