Commit e08400b7 authored by Emil Tantilov's avatar Emil Tantilov Committed by Jeff Kirsher

ixgbevf: Add code to check for Tx hang

This patch adds code to allow for Tx hang checking.  The idea is to provide
more robust debug info in the event of a transmit unit hang. Similar to the
logic in ixgbe.

CC: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: default avatarEmil Tantilov <emil.s.tantilov@intel.com>
Tested-by: default avatarPhil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent d9bdb57f
......@@ -43,6 +43,13 @@
#define BP_EXTENDED_STATS
#endif
#define IXGBE_MAX_TXD_PWR 14
#define IXGBE_MAX_DATA_PER_TXD BIT(IXGBE_MAX_TXD_PWR)
/* Tx Descriptors needed, worst case */
#define TXD_USE_COUNT(S) DIV_ROUND_UP((S), IXGBE_MAX_DATA_PER_TXD)
#define DESC_NEEDED (MAX_SKB_FRAGS + 4)
/* wrapper around a pointer to a socket buffer,
* so a DMA handle can be stored along with the buffer */
struct ixgbevf_tx_buffer {
......@@ -85,6 +92,18 @@ struct ixgbevf_rx_queue_stats {
u64 csum_err;
};
enum ixgbevf_ring_state_t {
__IXGBEVF_TX_DETECT_HANG,
__IXGBEVF_HANG_CHECK_ARMED,
};
#define check_for_tx_hang(ring) \
test_bit(__IXGBEVF_TX_DETECT_HANG, &(ring)->state)
#define set_check_for_tx_hang(ring) \
set_bit(__IXGBEVF_TX_DETECT_HANG, &(ring)->state)
#define clear_check_for_tx_hang(ring) \
clear_bit(__IXGBEVF_TX_DETECT_HANG, &(ring)->state)
struct ixgbevf_ring {
struct ixgbevf_ring *next;
struct net_device *netdev;
......@@ -101,7 +120,7 @@ struct ixgbevf_ring {
struct ixgbevf_tx_buffer *tx_buffer_info;
struct ixgbevf_rx_buffer *rx_buffer_info;
};
unsigned long state;
struct ixgbevf_stats stats;
struct u64_stats_sync syncp;
union {
......
......@@ -199,14 +199,64 @@ static void ixgbevf_unmap_and_free_tx_resource(struct ixgbevf_ring *tx_ring,
/* tx_buffer must be completely set up in the transmit path */
}
#define IXGBE_MAX_TXD_PWR 14
#define IXGBE_MAX_DATA_PER_TXD (1 << IXGBE_MAX_TXD_PWR)
static u64 ixgbevf_get_tx_completed(struct ixgbevf_ring *ring)
{
return ring->stats.packets;
}
static u32 ixgbevf_get_tx_pending(struct ixgbevf_ring *ring)
{
struct ixgbevf_adapter *adapter = netdev_priv(ring->netdev);
struct ixgbe_hw *hw = &adapter->hw;
u32 head = IXGBE_READ_REG(hw, IXGBE_VFTDH(ring->reg_idx));
u32 tail = IXGBE_READ_REG(hw, IXGBE_VFTDT(ring->reg_idx));
if (head != tail)
return (head < tail) ?
tail - head : (tail + ring->count - head);
return 0;
}
static inline bool ixgbevf_check_tx_hang(struct ixgbevf_ring *tx_ring)
{
u32 tx_done = ixgbevf_get_tx_completed(tx_ring);
u32 tx_done_old = tx_ring->tx_stats.tx_done_old;
u32 tx_pending = ixgbevf_get_tx_pending(tx_ring);
clear_check_for_tx_hang(tx_ring);
/* Tx Descriptors needed, worst case */
#define TXD_USE_COUNT(S) DIV_ROUND_UP((S), IXGBE_MAX_DATA_PER_TXD)
#define DESC_NEEDED (MAX_SKB_FRAGS + 4)
/* Check for a hung queue, but be thorough. This verifies
* that a transmit has been completed since the previous
* check AND there is at least one packet pending. The
* ARMED bit is set to indicate a potential hang.
*/
if ((tx_done_old == tx_done) && tx_pending) {
/* make sure it is true for two checks in a row */
return test_and_set_bit(__IXGBEVF_HANG_CHECK_ARMED,
&tx_ring->state);
}
/* reset the countdown */
clear_bit(__IXGBEVF_HANG_CHECK_ARMED, &tx_ring->state);
/* update completed stats and continue */
tx_ring->tx_stats.tx_done_old = tx_done;
return false;
}
/**
* ixgbevf_tx_timeout - Respond to a Tx Hang
* @netdev: network interface device structure
**/
static void ixgbevf_tx_timeout(struct net_device *netdev)
{
struct ixgbevf_adapter *adapter = netdev_priv(netdev);
static void ixgbevf_tx_timeout(struct net_device *netdev);
/* Do the reset outside of interrupt context */
schedule_work(&adapter->reset_task);
}
/**
* ixgbevf_clean_tx_irq - Reclaim resources after transmit completes
......@@ -311,6 +361,37 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_q_vector *q_vector,
q_vector->tx.total_bytes += total_bytes;
q_vector->tx.total_packets += total_packets;
if (check_for_tx_hang(tx_ring) && ixgbevf_check_tx_hang(tx_ring)) {
struct ixgbe_hw *hw = &adapter->hw;
union ixgbe_adv_tx_desc *eop_desc;
eop_desc = tx_ring->tx_buffer_info[i].next_to_watch;
pr_err("Detected Tx Unit Hang\n"
" Tx Queue <%d>\n"
" TDH, TDT <%x>, <%x>\n"
" next_to_use <%x>\n"
" next_to_clean <%x>\n"
"tx_buffer_info[next_to_clean]\n"
" next_to_watch <%p>\n"
" eop_desc->wb.status <%x>\n"
" time_stamp <%lx>\n"
" jiffies <%lx>\n",
tx_ring->queue_index,
IXGBE_READ_REG(hw, IXGBE_VFTDH(tx_ring->reg_idx)),
IXGBE_READ_REG(hw, IXGBE_VFTDT(tx_ring->reg_idx)),
tx_ring->next_to_use, i,
eop_desc, (eop_desc ? eop_desc->wb.status : 0),
tx_ring->tx_buffer_info[i].time_stamp, jiffies);
netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
/* schedule immediate reset if we believe we hung */
schedule_work(&adapter->reset_task);
return true;
}
#define TX_WAKE_THRESHOLD (DESC_NEEDED * 2)
if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
(ixgbevf_desc_unused(tx_ring) >= TX_WAKE_THRESHOLD))) {
......@@ -1479,6 +1560,8 @@ static void ixgbevf_configure_tx_ring(struct ixgbevf_adapter *adapter,
txdctl |= (1 << 8) | /* HTHRESH = 1 */
32; /* PTHRESH = 32 */
clear_bit(__IXGBEVF_HANG_CHECK_ARMED, &ring->state);
IXGBE_WRITE_REG(hw, IXGBE_VFTXDCTL(reg_idx), txdctl);
/* poll to verify queue is enabled */
......@@ -2643,6 +2726,12 @@ static void ixgbevf_watchdog(unsigned long data)
if (test_bit(__IXGBEVF_DOWN, &adapter->state))
goto watchdog_short_circuit;
/* Force detection of hung controller */
if (netif_carrier_ok(adapter->netdev)) {
for (i = 0; i < adapter->num_tx_queues; i++)
set_check_for_tx_hang(adapter->tx_ring[i]);
}
/* get one bit for every active tx/rx interrupt vector */
for (i = 0; i < adapter->num_msix_vectors - NON_Q_VECTORS; i++) {
struct ixgbevf_q_vector *qv = adapter->q_vector[i];
......@@ -2656,18 +2745,6 @@ static void ixgbevf_watchdog(unsigned long data)
schedule_work(&adapter->watchdog_task);
}
/**
* ixgbevf_tx_timeout - Respond to a Tx Hang
* @netdev: network interface device structure
**/
static void ixgbevf_tx_timeout(struct net_device *netdev)
{
struct ixgbevf_adapter *adapter = netdev_priv(netdev);
/* Do the reset outside of interrupt context */
schedule_work(&adapter->reset_task);
}
static void ixgbevf_reset_task(struct work_struct *work)
{
struct ixgbevf_adapter *adapter;
......
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