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Date: Tue, 3 Mar 2020 17:06:03 +0000
From: David Laight <David.Laight@...LAB.COM>
To: Network Development <netdev@...r.kernel.org>
CC: "'bruce.w.allan@...el.com'" <bruce.w.allan@...el.com>,
"'jeffrey.e.pieper@...el.com'" <jeffrey.e.pieper@...el.com>,
"'jeffrey.t.kirsher@...el.com'" <jeffrey.t.kirsher@...el.com>
Subject: [PATCH net 1/1] e1000e: Stop tx/rx setup spinning for upwards of
300us.
Instead of spinning waiting for the ME to be idle defer the ring
tail updates until one of the following:
- The next update for that ring.
- The receive frame processing.
- The next timer tick.
Reduce the delay between checks for the ME being idle from 50us
to uus.
Part fix for bdc125f7.
Signed-off-by: David Laight <david.laight@...lab.com>
---
This change probably applies as back as far as 3.16.
drivers/net/ethernet/intel/e1000e/e1000.h | 3 +
drivers/net/ethernet/intel/e1000e/ich8lan.h | 2 +-
drivers/net/ethernet/intel/e1000e/netdev.c | 131 ++++++++++++++++++++--------
3 files changed, 99 insertions(+), 37 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/e1000.h b/drivers/net/ethernet/intel/e1000e/e1000.h
index 6c51b1b..c7819e0 100644
--- a/drivers/net/ethernet/intel/e1000e/e1000.h
+++ b/drivers/net/ethernet/intel/e1000e/e1000.h
@@ -155,6 +155,8 @@ struct e1000_ring {
u16 next_to_use;
u16 next_to_clean;
+#define E1000_RING_NOT_DEFERRED 0xffff
+ u16 next_to_use_deferred;
void __iomem *head;
void __iomem *tail;
@@ -190,6 +192,7 @@ struct e1000_adapter {
struct work_struct reset_task;
struct delayed_work watchdog_task;
+ struct delayed_work delay_ring_write_task;
struct workqueue_struct *e1000_workqueue;
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.h b/drivers/net/ethernet/intel/e1000e/ich8lan.h
index 1502895..75e5a53 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.h
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.h
@@ -34,7 +34,7 @@
/* FW established a valid mode */
#define E1000_ICH_FWSM_FW_VALID 0x00008000
#define E1000_ICH_FWSM_PCIM2PCI 0x01000000 /* ME PCIm-to-PCI active */
-#define E1000_ICH_FWSM_PCIM2PCI_COUNT 2000
+#define E1000_ICH_FWSM_PCIM2PCI_COUNT 20000
#define E1000_ICH_MNG_IAMT_MODE 0x2
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index d7d56e4..299e5af 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -118,13 +118,20 @@ struct e1000_reg_info {
* an incorrect value. Workaround this by checking the FWSM register which
* has bit 24 set while ME is accessing MAC CSR registers, wait if it is set
* and try again a number of times.
+ * NB: This bit can stay set for 300us even if polled every 5us.
**/
+
+static bool __ew32_prepare_busy(struct e1000_hw *hw)
+{
+ return (er32(FWSM) & E1000_ICH_FWSM_PCIM2PCI);
+}
+
s32 __ew32_prepare(struct e1000_hw *hw)
{
s32 i = E1000_ICH_FWSM_PCIM2PCI_COUNT;
- while ((er32(FWSM) & E1000_ICH_FWSM_PCIM2PCI) && --i)
- udelay(50);
+ while (__ew32_prepare_busy(hw) && --i)
+ udelay(5);
return i;
}
@@ -603,38 +610,75 @@ static void e1000_rx_checksum(struct e1000_adapter *adapter, u32 status_err,
adapter->hw_csum_good++;
}
-static void e1000e_update_rdt_wa(struct e1000_ring *rx_ring, unsigned int i)
+static bool deferred_update_dt_wa(struct e1000_ring *ring)
{
- struct e1000_adapter *adapter = rx_ring->adapter;
- struct e1000_hw *hw = &adapter->hw;
- s32 ret_val = __ew32_prepare(hw);
-
- writel(i, rx_ring->tail);
+ struct e1000_adapter *adapter;
+ struct e1000_hw *hw;
+ unsigned long flags;
+ u32 deferred;
- if (unlikely(!ret_val && (i != readl(rx_ring->tail)))) {
- u32 rctl = er32(RCTL);
+ adapter = ring->adapter;
+ hw = &adapter->hw;
+ spin_lock_irqsave(&adapter->systim_lock, flags);
+ deferred = ring->next_to_use_deferred;
+ if (deferred != E1000_RING_NOT_DEFERRED) {
+ if (__ew32_prepare_busy(hw)) {
+ spin_unlock_irqrestore(&adapter->systim_lock, flags);
+ /* Caller needs to ensure timer running */
+ return true;
+ }
- ew32(RCTL, rctl & ~E1000_RCTL_EN);
- e_err("ME firmware caused invalid RDT - resetting\n");
- schedule_work(&adapter->reset_task);
+ writel(deferred, ring->tail);
+ ring->next_to_use_deferred = E1000_RING_NOT_DEFERRED;
}
+ spin_unlock_irqrestore(&adapter->systim_lock, flags);
+ return false;
}
-static void e1000e_update_tdt_wa(struct e1000_ring *tx_ring, unsigned int i)
+/* Inline the cheap unlocked test */
+#define e1000e_deferred_update_dt_wa(ring) \
+ (likely(READ_ONCE(ring->next_to_use_deferred) == \
+ E1000_RING_NOT_DEFERRED) ? false : \
+ deferred_update_dt_wa(ring))
+
+static void e1000e_delay_ring_write_task(struct work_struct *work)
{
- struct e1000_adapter *adapter = tx_ring->adapter;
- struct e1000_hw *hw = &adapter->hw;
- s32 ret_val = __ew32_prepare(hw);
+ struct e1000_adapter *adapter;
- writel(i, tx_ring->tail);
+ adapter = container_of(work, struct e1000_adapter,
+ delay_ring_write_task.work);
- if (unlikely(!ret_val && (i != readl(tx_ring->tail)))) {
- u32 tctl = er32(TCTL);
+ if (e1000e_deferred_update_dt_wa(adapter->tx_ring) |
+ e1000e_deferred_update_dt_wa(adapter->rx_ring))
+ mod_delayed_work(adapter->e1000_workqueue,
+ &adapter->delay_ring_write_task, 1);
+}
- ew32(TCTL, tctl & ~E1000_TCTL_EN);
- e_err("ME firmware caused invalid TDT - resetting\n");
- schedule_work(&adapter->reset_task);
+static void e1000e_update_dt_wa(struct e1000_ring *ring, unsigned int i)
+{
+ struct e1000_adapter *adapter = ring->adapter;
+ struct e1000_hw *hw = &adapter->hw;
+ unsigned long flags;
+ u32 deferred;
+
+ deferred = READ_ONCE(ring->next_to_use_deferred);
+ if (unlikely(deferred != E1000_RING_NOT_DEFERRED)) {
+ /* previous write was deferred - forget about it */
+ spin_lock_irqsave(&adapter->systim_lock, flags);
+ ring->next_to_use_deferred = E1000_RING_NOT_DEFERRED;
+ spin_unlock_irqrestore(&adapter->systim_lock, flags);
+ }
+
+ if (!__ew32_prepare_busy(hw)) {
+ writel(i, ring->tail);
+ return;
}
+
+ /* We can't write now, defer to rx clean or timeout */
+ WRITE_ONCE(ring->next_to_use_deferred, i);
+
+ mod_delayed_work(adapter->e1000_workqueue,
+ &adapter->delay_ring_write_task, 1);
}
/**
@@ -692,7 +736,7 @@ static void e1000_alloc_rx_buffers(struct e1000_ring *rx_ring,
*/
wmb();
if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
- e1000e_update_rdt_wa(rx_ring, i);
+ e1000e_update_dt_wa(rx_ring, i);
else
writel(i, rx_ring->tail);
}
@@ -792,7 +836,7 @@ static void e1000_alloc_rx_buffers_ps(struct e1000_ring *rx_ring,
*/
wmb();
if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
- e1000e_update_rdt_wa(rx_ring, i << 1);
+ e1000e_update_dt_wa(rx_ring, i << 1);
else
writel(i << 1, rx_ring->tail);
}
@@ -884,7 +928,7 @@ static void e1000_alloc_jumbo_rx_buffers(struct e1000_ring *rx_ring,
*/
wmb();
if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
- e1000e_update_rdt_wa(rx_ring, i);
+ e1000e_update_dt_wa(rx_ring, i);
else
writel(i, rx_ring->tail);
}
@@ -1256,6 +1300,8 @@ static bool e1000_clean_tx_irq(struct e1000_ring *tx_ring)
tx_ring->next_to_clean = i;
+ e1000e_deferred_update_dt_wa(tx_ring);
+
netdev_completed_queue(netdev, pkts_compl, bytes_compl);
#define TX_WAKE_THRESHOLD 32
@@ -1729,6 +1775,7 @@ static void e1000_clean_rx_ring(struct e1000_ring *rx_ring)
rx_ring->next_to_clean = 0;
rx_ring->next_to_use = 0;
+ rx_ring->next_to_use_deferred = E1000_RING_NOT_DEFERRED;
adapter->flags2 &= ~FLAG2_IS_DISCARDING;
}
@@ -2342,6 +2389,7 @@ int e1000e_setup_tx_resources(struct e1000_ring *tx_ring)
tx_ring->next_to_use = 0;
tx_ring->next_to_clean = 0;
+ tx_ring->next_to_use_deferred = E1000_RING_NOT_DEFERRED;
return 0;
err:
@@ -2388,6 +2436,7 @@ int e1000e_setup_rx_resources(struct e1000_ring *rx_ring)
rx_ring->next_to_clean = 0;
rx_ring->next_to_use = 0;
+ rx_ring->next_to_use_deferred = E1000_RING_NOT_DEFERRED;
rx_ring->rx_skb_top = NULL;
return 0;
@@ -2427,6 +2476,7 @@ static void e1000_clean_tx_ring(struct e1000_ring *tx_ring)
tx_ring->next_to_use = 0;
tx_ring->next_to_clean = 0;
+ tx_ring->next_to_use_deferred = E1000_RING_NOT_DEFERRED;
}
/**
@@ -2666,6 +2716,9 @@ static int e1000e_poll(struct napi_struct *napi, int budget)
adapter = netdev_priv(poll_dev);
+ e1000e_deferred_update_dt_wa(adapter->tx_ring);
+ e1000e_deferred_update_dt_wa(adapter->rx_ring);
+
if (!adapter->msix_entries ||
(adapter->rx_ring->ims_val & adapter->tx_ring->ims_val))
tx_cleaned = e1000_clean_tx_irq(adapter->tx_ring);
@@ -2930,10 +2983,11 @@ static void e1000_configure_tx(struct e1000_adapter *adapter)
tx_ring->tail = adapter->hw.hw_addr + E1000_TDT(0);
writel(0, tx_ring->head);
- if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
- e1000e_update_tdt_wa(tx_ring, 0);
- else
- writel(0, tx_ring->tail);
+ if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA) {
+ while (__ew32_prepare_busy(hw))
+ usleep_range(50, 100);
+ }
+ writel(0, tx_ring->tail);
/* Set the Tx Interrupt Delay register */
ew32(TIDV, adapter->tx_int_delay);
@@ -3254,10 +3308,11 @@ static void e1000_configure_rx(struct e1000_adapter *adapter)
rx_ring->tail = adapter->hw.hw_addr + E1000_RDT(0);
writel(0, rx_ring->head);
- if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
- e1000e_update_rdt_wa(rx_ring, 0);
- else
- writel(0, rx_ring->tail);
+ if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA) {
+ while (__ew32_prepare_busy(hw))
+ usleep_range(50, 100);
+ }
+ writel(0, rx_ring->tail);
/* Enable Receive Checksum Offload for TCP and UDP */
rxcsum = er32(RXCSUM);
@@ -5908,8 +5963,8 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,
if (!netdev_xmit_more() ||
netif_xmit_stopped(netdev_get_tx_queue(netdev, 0))) {
if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
- e1000e_update_tdt_wa(tx_ring,
- tx_ring->next_to_use);
+ e1000e_update_dt_wa(tx_ring,
+ tx_ring->next_to_use);
else
writel(tx_ring->next_to_use, tx_ring->tail);
}
@@ -7271,6 +7326,9 @@ static int e1000_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
queue_delayed_work(adapter->e1000_workqueue, &adapter->watchdog_task,
0);
+ INIT_DELAYED_WORK(&adapter->delay_ring_write_task,
+ e1000e_delay_ring_write_task);
+
timer_setup(&adapter->phy_info_timer, e1000_update_phy_info, 0);
INIT_WORK(&adapter->reset_task, e1000_reset_task);
@@ -7424,6 +7482,7 @@ static void e1000_remove(struct pci_dev *pdev)
cancel_work_sync(&adapter->print_hang_task);
cancel_delayed_work(&adapter->watchdog_task);
+ cancel_delayed_work(&adapter->delay_ring_write_task);
flush_workqueue(adapter->e1000_workqueue);
destroy_workqueue(adapter->e1000_workqueue);
--
1.8.1.2
-
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