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From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
To: Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Jingoo Han <jingoohan1@gmail.com>,
	Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Stanimir Varbanov <svarbanov@mm-sol.com>,
	Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Vinod Koul <vkoul@kernel.org>,
	linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org,
	devicetree@vger.kernel.org, Johan Hovold <johan@kernel.org>
Subject: [PATCH v11 4/7] PCI: dwc: Implement special ISR handler for split MSI IRQ setup
Date: Fri, 20 May 2022 21:31:11 +0300	[thread overview]
Message-ID: <20220520183114.1356599-5-dmitry.baryshkov@linaro.org> (raw)
In-Reply-To: <20220520183114.1356599-1-dmitry.baryshkov@linaro.org>

If the PCIe DWC controller uses split MSI IRQs for reporting MSI
vectors, it is possible to detect, which group triggered the interrupt.
Provide an optimized version of MSI ISR handler that will handle just a
single MSI group instead of handling all of them.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 .../pci/controller/dwc/pcie-designware-host.c | 85 ++++++++++++++-----
 1 file changed, 64 insertions(+), 21 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 381bc24d5715..20ab8a0c6359 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -52,34 +52,42 @@ static struct msi_domain_info dw_pcie_msi_domain_info = {
 	.chip	= &dw_pcie_msi_irq_chip,
 };
 
+static inline irqreturn_t dw_handle_single_msi_group(struct pcie_port *pp, int i)
+{
+	int pos;
+	unsigned long val;
+	u32 status;
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+
+	status = dw_pcie_readl_dbi(pci, PCIE_MSI_INTR0_STATUS +
+				   (i * MSI_REG_CTRL_BLOCK_SIZE));
+	if (!status)
+		return IRQ_NONE;
+
+	val = status;
+	pos = 0;
+	while ((pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL,
+				    pos)) != MAX_MSI_IRQS_PER_CTRL) {
+		generic_handle_domain_irq(pp->irq_domain,
+					  (i * MAX_MSI_IRQS_PER_CTRL) +
+					  pos);
+		pos++;
+	}
+
+	return IRQ_HANDLED;
+}
+
 /* MSI int handler */
 irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
 {
-	int i, pos;
-	unsigned long val;
-	u32 status, num_ctrls;
+	int i;
+	u32 num_ctrls;
 	irqreturn_t ret = IRQ_NONE;
-	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 
 	num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
 
-	for (i = 0; i < num_ctrls; i++) {
-		status = dw_pcie_readl_dbi(pci, PCIE_MSI_INTR0_STATUS +
-					   (i * MSI_REG_CTRL_BLOCK_SIZE));
-		if (!status)
-			continue;
-
-		ret = IRQ_HANDLED;
-		val = status;
-		pos = 0;
-		while ((pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL,
-					    pos)) != MAX_MSI_IRQS_PER_CTRL) {
-			generic_handle_domain_irq(pp->irq_domain,
-						  (i * MAX_MSI_IRQS_PER_CTRL) +
-						  pos);
-			pos++;
-		}
-	}
+	for (i = 0; i < num_ctrls; i++)
+		ret |= dw_handle_single_msi_group(pp, i);
 
 	return ret;
 }
@@ -98,6 +106,38 @@ static void dw_chained_msi_isr(struct irq_desc *desc)
 	chained_irq_exit(chip, desc);
 }
 
+static void dw_split_msi_isr(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	int irq = irq_desc_get_irq(desc);
+	struct pcie_port *pp;
+	int i;
+	u32 num_ctrls;
+	struct dw_pcie *pci;
+
+	chained_irq_enter(chip, desc);
+
+	pp = irq_desc_get_handler_data(desc);
+	pci = to_dw_pcie_from_pp(pp);
+
+	/*
+	 * Unlike generic dw_handle_msi_irq(), we can determine which group of
+	 * MSIs triggered the IRQ, so process just that group.
+	 */
+	num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
+
+	for (i = 0; i < num_ctrls; i++) {
+		if (pp->msi_irq[i] == irq) {
+			dw_handle_single_msi_group(pp, i);
+			break;
+		}
+	}
+
+	WARN_ON_ONCE(i == num_ctrls);
+
+	chained_irq_exit(chip, desc);
+}
+
 static void dw_pci_setup_msi_msg(struct irq_data *d, struct msi_msg *msg)
 {
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
@@ -341,6 +381,8 @@ static int dw_pcie_msi_host_init(struct pcie_port *pp)
 		ret = dw_pcie_parse_split_msi_irq(pp);
 		if (ret < 0 && ret != -ENXIO)
 			return ret;
+		else if (!ret)
+			has_split_msi_irq = true;
 	}
 
 	if (!pp->num_vectors)
@@ -369,6 +411,7 @@ static int dw_pcie_msi_host_init(struct pcie_port *pp)
 	for (ctrl = 0; ctrl < num_ctrls; ctrl++)
 		if (pp->msi_irq[ctrl] > 0)
 			irq_set_chained_handler_and_data(pp->msi_irq[ctrl],
+							 has_split_msi_irq ? dw_split_msi_isr :
 							 dw_chained_msi_isr,
 							 pp);
 
-- 
2.35.1


  parent reply	other threads:[~2022-05-20 18:32 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-20 18:31 [PATCH v11 0/7] PCI: qcom: Fix higher MSI vectors handling Dmitry Baryshkov
2022-05-20 18:31 ` [PATCH v11 1/7] PCI: dwc: Convert msi_irq to the array Dmitry Baryshkov
2022-05-20 18:31 ` [PATCH v11 2/7] PCI: dwc: split MSI IRQ parsing/allocation to a separate function Dmitry Baryshkov
2022-05-20 18:31 ` [PATCH v11 3/7] PCI: dwc: Handle MSIs routed to multiple GIC interrupts Dmitry Baryshkov
2022-05-23  7:53   ` Johan Hovold
2022-05-23 13:39     ` Dmitry Baryshkov
2022-05-23 14:02       ` Johan Hovold
2022-05-23 15:17         ` Dmitry Baryshkov
2022-05-23 15:32           ` Johan Hovold
2022-05-23 15:36             ` Dmitry Baryshkov
2022-05-20 18:31 ` Dmitry Baryshkov [this message]
2022-05-20 18:31 ` [PATCH v11 5/7] dt-bindings: PCI: qcom: Support additional MSI interrupts Dmitry Baryshkov
2022-05-20 18:31 ` [PATCH v11 6/7] arm64: dts: qcom: sm8250: provide " Dmitry Baryshkov
2022-05-20 18:31 ` [PATCH v11 7/7] dt-bindings: mfd: qcom,qca639x: add binding for QCA639x defvice Dmitry Baryshkov
2022-05-23  7:42 ` [PATCH v11 0/7] PCI: qcom: Fix higher MSI vectors handling Johan Hovold
2022-05-23 13:03   ` Dmitry Baryshkov

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