[TG3]: Add new one-shot MSI handler
Support one-shot MSI on 5787.
This one-shot MSI idea is credited to David Miller. In this mode, MSI
disables itself automatically after it is generated, saving the driver
a register access to disable it for NAPI.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 5182a3b..40f5289 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -546,6 +546,9 @@
(tp->misc_host_ctrl & ~MISC_HOST_CTRL_MASK_PCI_INT));
tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
(tp->last_tag << 24));
+ if (tp->tg3_flags2 & TG3_FLG2_1SHOT_MSI)
+ tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
+ (tp->last_tag << 24));
tg3_cond_int(tp);
}
@@ -3365,6 +3368,23 @@
spin_unlock_bh(&tp->lock);
}
+/* One-shot MSI handler - Chip automatically disables interrupt
+ * after sending MSI so driver doesn't have to do it.
+ */
+static irqreturn_t tg3_msi_1shot(int irq, void *dev_id, struct pt_regs *regs)
+{
+ struct net_device *dev = dev_id;
+ struct tg3 *tp = netdev_priv(dev);
+
+ prefetch(tp->hw_status);
+ prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
+
+ if (likely(!tg3_irq_sync(tp)))
+ netif_rx_schedule(dev); /* schedule NAPI poll */
+
+ return IRQ_HANDLED;
+}
+
/* MSI ISR - No need to check for interrupt sharing and no need to
* flush status block and interrupt mailbox. PCI ordering rules
* guarantee that MSI will arrive after the status block.
@@ -6511,6 +6531,26 @@
add_timer(&tp->timer);
}
+int tg3_request_irq(struct tg3 *tp)
+{
+ irqreturn_t (*fn)(int, void *, struct pt_regs *);
+ unsigned long flags;
+ struct net_device *dev = tp->dev;
+
+ if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) {
+ fn = tg3_msi;
+ if (tp->tg3_flags2 & TG3_FLG2_1SHOT_MSI)
+ fn = tg3_msi_1shot;
+ flags = SA_SAMPLE_RANDOM;
+ } else {
+ fn = tg3_interrupt;
+ if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS)
+ fn = tg3_interrupt_tagged;
+ flags = SA_SHIRQ | SA_SAMPLE_RANDOM;
+ }
+ return (request_irq(tp->pdev->irq, fn, flags, dev->name, dev));
+}
+
static int tg3_test_interrupt(struct tg3 *tp)
{
struct net_device *dev = tp->dev;
@@ -6547,16 +6587,7 @@
free_irq(tp->pdev->irq, dev);
- if (tp->tg3_flags2 & TG3_FLG2_USING_MSI)
- err = request_irq(tp->pdev->irq, tg3_msi,
- SA_SAMPLE_RANDOM, dev->name, dev);
- else {
- irqreturn_t (*fn)(int, void *, struct pt_regs *)=tg3_interrupt;
- if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS)
- fn = tg3_interrupt_tagged;
- err = request_irq(tp->pdev->irq, fn,
- SA_SHIRQ | SA_SAMPLE_RANDOM, dev->name, dev);
- }
+ err = tg3_request_irq(tp);
if (err)
return err;
@@ -6608,14 +6639,7 @@
tp->tg3_flags2 &= ~TG3_FLG2_USING_MSI;
- {
- irqreturn_t (*fn)(int, void *, struct pt_regs *)=tg3_interrupt;
- if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS)
- fn = tg3_interrupt_tagged;
-
- err = request_irq(tp->pdev->irq, fn,
- SA_SHIRQ | SA_SAMPLE_RANDOM, dev->name, dev);
- }
+ err = tg3_request_irq(tp);
if (err)
return err;
@@ -6677,17 +6701,7 @@
tp->tg3_flags2 |= TG3_FLG2_USING_MSI;
}
}
- if (tp->tg3_flags2 & TG3_FLG2_USING_MSI)
- err = request_irq(tp->pdev->irq, tg3_msi,
- SA_SAMPLE_RANDOM, dev->name, dev);
- else {
- irqreturn_t (*fn)(int, void *, struct pt_regs *)=tg3_interrupt;
- if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS)
- fn = tg3_interrupt_tagged;
-
- err = request_irq(tp->pdev->irq, fn,
- SA_SHIRQ | SA_SAMPLE_RANDOM, dev->name, dev);
- }
+ err = tg3_request_irq(tp);
if (err) {
if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) {
@@ -6752,6 +6766,14 @@
return err;
}
+
+ if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) {
+ if (tp->tg3_flags2 & TG3_FLG2_1SHOT_MSI) {
+ u32 val = tr32(0x7c04);
+
+ tw32(0x7c04, val | (1 << 29));
+ }
+ }
}
tg3_full_lock(tp, 0);
@@ -9940,9 +9962,10 @@
tp->tg3_flags2 |= TG3_FLG2_5705_PLUS;
if (tp->tg3_flags2 & TG3_FLG2_5750_PLUS) {
- if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5787)
+ if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5787) {
tp->tg3_flags2 |= TG3_FLG2_HW_TSO_2;
- else
+ tp->tg3_flags2 |= TG3_FLG2_1SHOT_MSI;
+ } else
tp->tg3_flags2 |= TG3_FLG2_HW_TSO_1;
}