From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David S. Miller" Subject: [TG3]: Add tagged status support Date: Thu, 5 May 2005 21:17:35 -0700 Message-ID: <20050505211735.3829cff2.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com Return-path: To: mchan@broadcom.com Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org I've been meaning to do this for a long time. This adds tagged status support. With this, we don't need to poke the chip 10 times per second via the timer to keep from losing interrupts. Michael, I didn't know what needs to be done wrt. MSI here. So I didn't touch the MSI code until I understand things better, which likely means that this patch breaks MSI (actually, I think it will cause the MSI case to generate interrupts endlessly). My best hunch is that all MSI supporting chips support tagged status, therefore I should just make the tg3_msi() interrupt handler do the tp->last_tag stuff. We should also integrate the coalescing tweaks we did last week after we smoothe this patch out. I noticed that we were doing the 5705 status block fetch 10 times per second instead of once per second. That's fixed here too. I also removed the MAILBOX readback in the normal interrupt handling paths. Network processing overhead minded folks, particular the SGI NUMA people (hint hint) should really really check out this patch :-) It is against current 2.6.x sources. Signed-off-by: David S. Miller --- 1/drivers/net/tg3.c.~1~ 2005-05-05 17:15:59.000000000 -0700 +++ 2/drivers/net/tg3.c 2005-05-05 21:11:41.000000000 -0700 @@ -420,7 +420,8 @@ static void tg3_enable_ints(struct tg3 * { tw32(TG3PCI_MISC_HOST_CTRL, (tp->misc_host_ctrl & ~MISC_HOST_CTRL_MASK_PCI_INT)); - tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000000); + tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, + (tp->last_tag << 24)); tr32(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW); tg3_cond_int(tp); @@ -455,7 +456,8 @@ static void tg3_restart_ints(struct tg3 { tw32(TG3PCI_MISC_HOST_CTRL, (tp->misc_host_ctrl & ~MISC_HOST_CTRL_MASK_PCI_INT)); - tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000000); + tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, + tp->last_tag << 24); mmiowb(); if (tg3_has_work(tp)) @@ -2977,11 +2979,56 @@ static irqreturn_t tg3_interrupt(int irq */ tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000001); + sblk->status &= ~SD_STATUS_UPDATED; + + if (likely(tg3_has_work(tp))) + netif_rx_schedule(dev); /* schedule NAPI poll */ + else { + /* no work, shared interrupt perhaps? re-enable + * interrupts, and flush that PCI write + */ + tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, + 0x00000000); + tr32(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW); + } + } else { /* shared interrupt */ + handled = 0; + } + + spin_unlock_irqrestore(&tp->lock, flags); + + return IRQ_RETVAL(handled); +} + +static irqreturn_t tg3_interrupt_tagged(int irq, void *dev_id, struct pt_regs *regs) +{ + struct net_device *dev = dev_id; + struct tg3 *tp = netdev_priv(dev); + struct tg3_hw_status *sblk = tp->hw_status; + unsigned long flags; + unsigned int handled = 1; + + spin_lock_irqsave(&tp->lock, flags); + + /* In INTx mode, it is possible for the interrupt to arrive at + * the CPU before the status block posted prior to the interrupt. + * Reading the PCI State register will confirm whether the + * interrupt is ours and will flush the status block. + */ + if ((sblk->status & SD_STATUS_UPDATED) || + !(tr32(TG3PCI_PCISTATE) & PCISTATE_INT_NOT_ACTIVE)) { /* - * Flush PCI write. This also guarantees that our - * status block has been flushed to host memory. + * writing any value to intr-mbox-0 clears PCI INTA# and + * chip-internal interrupt pending events. + * writing non-zero to intr-mbox-0 additional tells the + * NIC to stop sending us irqs, engaging "in-intr-handler" + * event coalescing. */ - tr32(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW); + tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, + 0x00000001); + + tp->last_tag = sblk->status_tag; + sblk->status &= ~SD_STATUS_UPDATED; if (likely(tg3_has_work(tp))) @@ -2991,7 +3038,7 @@ static irqreturn_t tg3_interrupt(int irq * interrupts, and flush that PCI write */ tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, - 0x00000000); + tp->last_tag << 24); tr32(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW); } } else { /* shared interrupt */ @@ -5446,6 +5493,7 @@ static int tg3_reset_hw(struct tg3 *tp) tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0); tr32(MAILBOX_INTERRUPT_0); + tp->last_tag = 0; if (!(tp->tg3_flags2 & TG3_FLG2_5705_PLUS)) { tw32_f(DMAC_MODE, DMAC_MODE_ENABLE); @@ -5723,31 +5771,33 @@ static void tg3_timer(unsigned long __op spin_lock_irqsave(&tp->lock, flags); spin_lock(&tp->tx_lock); - /* All of this garbage is because when using non-tagged - * IRQ status the mailbox/status_block protocol the chip - * uses with the cpu is race prone. - */ - if (tp->hw_status->status & SD_STATUS_UPDATED) { - tw32(GRC_LOCAL_CTRL, - tp->grc_local_ctrl | GRC_LCLCTRL_SETINT); - } else { - tw32(HOSTCC_MODE, tp->coalesce_mode | - (HOSTCC_MODE_ENABLE | HOSTCC_MODE_NOW)); - } + if (!(tp->tg3_flags & TG3_FLAG_TAGGED_STATUS)) { + /* All of this garbage is because when using non-tagged + * IRQ status the mailbox/status_block protocol the chip + * uses with the cpu is race prone. + */ + if (tp->hw_status->status & SD_STATUS_UPDATED) { + tw32(GRC_LOCAL_CTRL, + tp->grc_local_ctrl | GRC_LCLCTRL_SETINT); + } else { + tw32(HOSTCC_MODE, tp->coalesce_mode | + (HOSTCC_MODE_ENABLE | HOSTCC_MODE_NOW)); + } - if (!(tr32(WDMAC_MODE) & WDMAC_MODE_ENABLE)) { - tp->tg3_flags2 |= TG3_FLG2_RESTART_TIMER; - spin_unlock(&tp->tx_lock); - spin_unlock_irqrestore(&tp->lock, flags); - schedule_work(&tp->reset_task); - return; + if (!(tr32(WDMAC_MODE) & WDMAC_MODE_ENABLE)) { + tp->tg3_flags2 |= TG3_FLG2_RESTART_TIMER; + spin_unlock(&tp->tx_lock); + spin_unlock_irqrestore(&tp->lock, flags); + schedule_work(&tp->reset_task); + return; + } } - if (tp->tg3_flags2 & TG3_FLG2_5705_PLUS) - tg3_periodic_fetch_stats(tp); - /* This part only runs once per second. */ if (!--tp->timer_counter) { + if (tp->tg3_flags2 & TG3_FLG2_5705_PLUS) + tg3_periodic_fetch_stats(tp); + if (tp->tg3_flags & TG3_FLAG_USE_LINKCHG_REG) { u32 mac_stat; int phy_event; @@ -5846,9 +5896,13 @@ static int tg3_test_interrupt(struct tg3 if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) err = request_irq(tp->pdev->irq, tg3_msi, SA_SAMPLE_RANDOM, dev->name, dev); - else - err = request_irq(tp->pdev->irq, tg3_interrupt, + 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); + } if (err) return err; @@ -5900,9 +5954,14 @@ static int tg3_test_msi(struct tg3 *tp) tp->tg3_flags2 &= ~TG3_FLG2_USING_MSI; - err = request_irq(tp->pdev->irq, tg3_interrupt, - SA_SHIRQ | SA_SAMPLE_RANDOM, dev->name, dev); + { + 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); + } if (err) return err; @@ -5959,9 +6018,14 @@ static int tg3_open(struct net_device *d if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) err = request_irq(tp->pdev->irq, tg3_msi, SA_SAMPLE_RANDOM, dev->name, dev); - else - err = request_irq(tp->pdev->irq, tg3_interrupt, + 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); + } if (err) { if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) { @@ -5980,9 +6044,16 @@ static int tg3_open(struct net_device *d tg3_halt(tp, 1); tg3_free_rings(tp); } else { - tp->timer_offset = HZ / 10; - tp->timer_counter = tp->timer_multiplier = 10; - tp->asf_counter = tp->asf_multiplier = (10 * 120); + if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS) + tp->timer_offset = HZ; + else + tp->timer_offset = HZ / 10; + + BUG_ON(tp->timer_offset > HZ); + tp->timer_counter = tp->timer_multiplier = + (HZ / tp->timer_offset); + tp->asf_counter = tp->asf_multiplier = + ((HZ / tp->timer_offset) * 120); init_timer(&tp->timer); tp->timer.expires = jiffies + tp->timer_offset; @@ -8422,15 +8493,7 @@ static int __devinit tg3_get_invariants( if (tp->tg3_flags2 & TG3_FLG2_5705_PLUS) tp->tg3_flags2 |= TG3_FLG2_PHY_BER_BUG; - /* Only 5701 and later support tagged irq status mode. - * Also, 5788 chips cannot use tagged irq status. - * - * However, since we are using NAPI avoid tagged irq status - * because the interrupt condition is more difficult to - * fully clear in that mode. - */ tp->coalesce_mode = 0; - if (GET_CHIP_REV(tp->pci_chip_rev_id) != CHIPREV_5700_AX && GET_CHIP_REV(tp->pci_chip_rev_id) != CHIPREV_5700_BX) tp->coalesce_mode |= HOSTCC_MODE_32BYTE; @@ -8494,6 +8557,18 @@ static int __devinit tg3_get_invariants( grc_misc_cfg == GRC_MISC_CFG_BOARD_ID_5788M)) tp->tg3_flags2 |= TG3_FLG2_IS_5788; + if (!(tp->tg3_flags2 & TG3_FLG2_IS_5788) && + (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5700)) + tp->tg3_flags |= TG3_FLAG_TAGGED_STATUS; + if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS) { + tp->coalesce_mode |= (HOSTCC_MODE_CLRTICK_RXBD | + HOSTCC_MODE_CLRTICK_TXBD); + + tp->misc_host_ctrl |= MISC_HOST_CTRL_TAGGED_STATUS; + pci_write_config_dword(tp->pdev, TG3PCI_MISC_HOST_CTRL, + tp->misc_host_ctrl); + } + /* these are limited to 10/100 only */ if ((GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5703 && (grc_misc_cfg == 0x8000 || grc_misc_cfg == 0x4000)) || --- 1/drivers/net/tg3.h.~1~ 2005-05-05 17:15:59.000000000 -0700 +++ 2/drivers/net/tg3.h 2005-05-05 20:58:56.000000000 -0700 @@ -2023,6 +2023,7 @@ struct tg3 { struct tg3_hw_status *hw_status; dma_addr_t status_mapping; + u32 last_tag; u32 msg_enable; @@ -2068,6 +2069,7 @@ struct tg3 { u32 rx_offset; u32 tg3_flags; +#define TG3_FLAG_TAGGED_STATUS 0x00000001 #define TG3_FLAG_TXD_MBOX_HWBUG 0x00000002 #define TG3_FLAG_RX_CHECKSUMS 0x00000004 #define TG3_FLAG_USE_LINKCHG_REG 0x00000008