From patchwork Fri Mar 27 09:54:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vignesh Raghavendra X-Patchwork-Id: 11462129 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2F48C1667 for ; Fri, 27 Mar 2020 09:58:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0AA120717 for ; Fri, 27 Mar 2020 09:58:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="y/CXEjR4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726165AbgC0J6J (ORCPT ); Fri, 27 Mar 2020 05:58:09 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:47096 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726115AbgC0J6J (ORCPT ); Fri, 27 Mar 2020 05:58:09 -0400 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 02R9w3pL108233; Fri, 27 Mar 2020 04:58:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1585303083; bh=x646Qw6LDH3xePnNAUnlZzaXeVbRtrI4yQ8a5BcrEFA=; h=From:To:CC:Subject:Date; b=y/CXEjR4Ih5HuFF4k99W0nclHRkW/0zB/JvaZ4ja/PwmSceUXxa2w1UNwFCL4DOQG 8/T3KJdyH/CPxu90hGIjdGTXl0gWz/goxFC8+4S403LmZnee3vFJzjmxQuQndSI8g9 0mdd72+aSkmrCb+7FsrwYzDCnGcEGArvONzl1zvg= Received: from DLEE108.ent.ti.com (dlee108.ent.ti.com [157.170.170.38]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id 02R9w2vC025418; Fri, 27 Mar 2020 04:58:03 -0500 Received: from DLEE113.ent.ti.com (157.170.170.24) by DLEE108.ent.ti.com (157.170.170.38) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Fri, 27 Mar 2020 04:58:01 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE113.ent.ti.com (157.170.170.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Fri, 27 Mar 2020 04:58:01 -0500 Received: from ula0132425.ent.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 02R9vvJB057147; Fri, 27 Mar 2020 04:57:58 -0500 From: Vignesh Raghavendra To: Kishon Vijay Abraham I , Lorenzo Pieralisi , Bjorn Helgaas CC: Andrew Murray , , , , Vignesh Raghavendra Subject: [PATCH v4] PCI: dwc: pci-dra7xx: Fix MSI IRQ handling Date: Fri, 27 Mar 2020 15:24:34 +0530 Message-ID: <20200327095434.945-1-vigneshr@ti.com> X-Mailer: git-send-email 2.26.0 MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org Due an issue with PCIe wrapper around DWC PCIe IP on dra7xx, driver needs to ensure that there are no pending MSI IRQ vector set (i.e PCIE_MSI_INTR0_STATUS reads 0 at least once) before exiting IRQ handler. Else, the dra7xx PCIe wrapper will not register new MSI IRQs even though PCIE_MSI_INTR0_STATUS shows IRQs are pending. Therefore its no longer possible to use default IRQ handler provided by DWC library. So, add irqchip implementation inside pci-dra7xx.c and install new MSI IRQ handler to handle above errata. This fixes a bug, where PCIe wifi cards with 4 DMA queues like Intel 8260 used to throw following error and stall during ping/iperf3 tests. [ 97.776310] iwlwifi 0000:01:00.0: Queue 9 stuck for 2500 ms. Signed-off-by: Vignesh Raghavendra Acked-by: Kishon Vijay Abraham I Tested-by: Kishon Vijay Abraham I --- v4: Simplify dra7xx_pcie_handle_msi_irq() by spliting inner loop into separte function as suggested by Lorenzo v3: - Move loop to service all MSI IRQs into dra7xx_pcie_handle_msi_irq() - Add a warning msg when loop counter overflows drivers/pci/controller/dwc/pci-dra7xx.c | 231 ++++++++++++++++++++---- 1 file changed, 195 insertions(+), 36 deletions(-) diff --git a/drivers/pci/controller/dwc/pci-dra7xx.c b/drivers/pci/controller/dwc/pci-dra7xx.c index 9bf7fa99b103..3b0e58f2de58 100644 --- a/drivers/pci/controller/dwc/pci-dra7xx.c +++ b/drivers/pci/controller/dwc/pci-dra7xx.c @@ -215,10 +215,6 @@ static int dra7xx_pcie_host_init(struct pcie_port *pp) return 0; } -static const struct dw_pcie_host_ops dra7xx_pcie_host_ops = { - .host_init = dra7xx_pcie_host_init, -}; - static int dra7xx_pcie_intx_map(struct irq_domain *domain, unsigned int irq, irq_hw_number_t hwirq) { @@ -233,43 +229,77 @@ static const struct irq_domain_ops intx_domain_ops = { .xlate = pci_irqd_intx_xlate, }; -static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp) +static int dra7xx_pcie_handle_msi(struct pcie_port *pp, int index) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); - struct device *dev = pci->dev; - struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci); - struct device_node *node = dev->of_node; - struct device_node *pcie_intc_node = of_get_next_child(node, NULL); + unsigned long val; + int pos, irq; - if (!pcie_intc_node) { - dev_err(dev, "No PCIe Intc node found\n"); - return -ENODEV; - } + val = dw_pcie_readl_dbi(pci, PCIE_MSI_INTR0_STATUS + + (index * MSI_REG_CTRL_BLOCK_SIZE)); + if (!val) + return 0; - dra7xx->irq_domain = irq_domain_add_linear(pcie_intc_node, PCI_NUM_INTX, - &intx_domain_ops, pp); - of_node_put(pcie_intc_node); - if (!dra7xx->irq_domain) { - dev_err(dev, "Failed to get a INTx IRQ domain\n"); - return -ENODEV; + pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL, 0); + while (pos != MAX_MSI_IRQS_PER_CTRL) { + irq = irq_find_mapping(pp->irq_domain, + (index * MAX_MSI_IRQS_PER_CTRL) + pos); + generic_handle_irq(irq); + pos++; + pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL, pos); } - return 0; + return 1; } -static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg) +static void dra7xx_pcie_handle_msi_irq(struct pcie_port *pp) { - struct dra7xx_pcie *dra7xx = arg; - struct dw_pcie *pci = dra7xx->pci; - struct pcie_port *pp = &pci->pp; + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + int ret, i, count, num_ctrls; + + num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL; + + /** + * Need to make sure all MSI status bits read 0 before exiting. + * Else, new MSI IRQs are not registered by the wrapper. Have an + * upperbound for the loop and exit the IRQ in case of IRQ flood + * to avoid locking up system in interrupt context. + */ + count = 0; + do { + ret = 0; + + for (i = 0; i < num_ctrls; i++) + ret |= dra7xx_pcie_handle_msi(pp, i); + count++; + } while (ret && count <= 1000); + + if (count > 1000) + dev_warn_ratelimited(pci->dev, + "Too many MSI IRQs to handle\n"); +} + +static void dra7xx_pcie_msi_irq_handler(struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + struct dra7xx_pcie *dra7xx; + struct dw_pcie *pci; + struct pcie_port *pp; unsigned long reg; u32 virq, bit; + chained_irq_enter(chip, desc); + + pp = irq_desc_get_handler_data(desc); + pci = to_dw_pcie_from_pp(pp); + dra7xx = to_dra7xx_pcie(pci); + reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI); + dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI, reg); switch (reg) { case MSI: - dw_handle_msi_irq(pp); + dra7xx_pcie_handle_msi_irq(pp); break; case INTA: case INTB: @@ -283,9 +313,7 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg) break; } - dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI, reg); - - return IRQ_HANDLED; + chained_irq_exit(chip, desc); } static irqreturn_t dra7xx_pcie_irq_handler(int irq, void *arg) @@ -347,6 +375,145 @@ static irqreturn_t dra7xx_pcie_irq_handler(int irq, void *arg) return IRQ_HANDLED; } +static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct device *dev = pci->dev; + struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci); + struct device_node *node = dev->of_node; + struct device_node *pcie_intc_node = of_get_next_child(node, NULL); + + if (!pcie_intc_node) { + dev_err(dev, "No PCIe Intc node found\n"); + return -ENODEV; + } + + irq_set_chained_handler_and_data(pp->irq, dra7xx_pcie_msi_irq_handler, + pp); + dra7xx->irq_domain = irq_domain_add_linear(pcie_intc_node, PCI_NUM_INTX, + &intx_domain_ops, pp); + of_node_put(pcie_intc_node); + if (!dra7xx->irq_domain) { + dev_err(dev, "Failed to get a INTx IRQ domain\n"); + return -ENODEV; + } + + return 0; +} + +static void dra7xx_pcie_setup_msi_msg(struct irq_data *d, struct msi_msg *msg) +{ + struct pcie_port *pp = irq_data_get_irq_chip_data(d); + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + u64 msi_target; + + msi_target = (u64)pp->msi_data; + + msg->address_lo = lower_32_bits(msi_target); + msg->address_hi = upper_32_bits(msi_target); + + msg->data = d->hwirq; + + dev_dbg(pci->dev, "msi#%d address_hi %#x address_lo %#x\n", + (int)d->hwirq, msg->address_hi, msg->address_lo); +} + +static int dra7xx_pcie_msi_set_affinity(struct irq_data *d, + const struct cpumask *mask, + bool force) +{ + return -EINVAL; +} + +static void dra7xx_pcie_bottom_mask(struct irq_data *d) +{ + struct pcie_port *pp = irq_data_get_irq_chip_data(d); + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + unsigned int res, bit, ctrl; + unsigned long flags; + + raw_spin_lock_irqsave(&pp->lock, flags); + + ctrl = d->hwirq / MAX_MSI_IRQS_PER_CTRL; + res = ctrl * MSI_REG_CTRL_BLOCK_SIZE; + bit = d->hwirq % MAX_MSI_IRQS_PER_CTRL; + + pp->irq_mask[ctrl] |= BIT(bit); + dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_MASK + res, + pp->irq_mask[ctrl]); + + raw_spin_unlock_irqrestore(&pp->lock, flags); +} + +static void dra7xx_pcie_bottom_unmask(struct irq_data *d) +{ + struct pcie_port *pp = irq_data_get_irq_chip_data(d); + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + unsigned int res, bit, ctrl; + unsigned long flags; + + raw_spin_lock_irqsave(&pp->lock, flags); + + ctrl = d->hwirq / MAX_MSI_IRQS_PER_CTRL; + res = ctrl * MSI_REG_CTRL_BLOCK_SIZE; + bit = d->hwirq % MAX_MSI_IRQS_PER_CTRL; + + pp->irq_mask[ctrl] &= ~BIT(bit); + dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_MASK + res, + pp->irq_mask[ctrl]); + + raw_spin_unlock_irqrestore(&pp->lock, flags); +} + +static void dra7xx_pcie_bottom_ack(struct irq_data *d) +{ + struct pcie_port *pp = irq_data_get_irq_chip_data(d); + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + unsigned int res, bit, ctrl; + + ctrl = d->hwirq / MAX_MSI_IRQS_PER_CTRL; + res = ctrl * MSI_REG_CTRL_BLOCK_SIZE; + bit = d->hwirq % MAX_MSI_IRQS_PER_CTRL; + + dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_STATUS + res, BIT(bit)); +} + +static struct irq_chip dra7xx_pci_msi_bottom_irq_chip = { + .name = "DRA7XX-PCI-MSI", + .irq_ack = dra7xx_pcie_bottom_ack, + .irq_compose_msi_msg = dra7xx_pcie_setup_msi_msg, + .irq_set_affinity = dra7xx_pcie_msi_set_affinity, + .irq_mask = dra7xx_pcie_bottom_mask, + .irq_unmask = dra7xx_pcie_bottom_unmask, +}; + +static int dra7xx_pcie_msi_host_init(struct pcie_port *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + u32 ctrl, num_ctrls; + + pp->msi_irq_chip = &dra7xx_pci_msi_bottom_irq_chip; + + num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL; + /* Initialize IRQ Status array */ + for (ctrl = 0; ctrl < num_ctrls; ctrl++) { + pp->irq_mask[ctrl] = ~0; + dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_MASK + + (ctrl * MSI_REG_CTRL_BLOCK_SIZE), + pp->irq_mask[ctrl]); + dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_ENABLE + + (ctrl * MSI_REG_CTRL_BLOCK_SIZE), + ~0); + } + + return dw_pcie_allocate_domains(pp); +} + +static const struct dw_pcie_host_ops dra7xx_pcie_host_ops = { + .host_init = dra7xx_pcie_host_init, + .msi_host_init = dra7xx_pcie_msi_host_init, +}; + static void dra7xx_pcie_ep_init(struct dw_pcie_ep *ep) { struct dw_pcie *pci = to_dw_pcie_from_ep(ep); @@ -467,14 +634,6 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx, return pp->irq; } - ret = devm_request_irq(dev, pp->irq, dra7xx_pcie_msi_irq_handler, - IRQF_SHARED | IRQF_NO_THREAD, - "dra7-pcie-msi", dra7xx); - if (ret) { - dev_err(dev, "failed to request irq\n"); - return ret; - } - ret = dra7xx_pcie_init_irq_domain(pp); if (ret < 0) return ret;