Thread (7 messages) 7 messages, 3 authors, 2017-08-23

[PATCH v2 0/3] PCI: mediatek: Add MSI support for MT2712 and MT7622

From: helgaas@kernel.org (Bjorn Helgaas)
Date: 2017-08-23 18:58:34
Also in: linux-devicetree, linux-mediatek, linux-pci, lkml
Subsystem: pci subsystem, the rest · Maintainers: Bjorn Helgaas, Linus Torvalds

On Mon, Aug 14, 2017 at 09:04:25PM +0800, honghui.zhang at mediatek.com wrote:
From: Honghui Zhang <redacted>

MT2712 and MT7622's PCIe host controller support MSI, but only 32bit MSI
address are supportted. It connect to GIC with the same IRQ number of INTx
IRQ, so it shares the same IRQ with INTx IRQ.

This patchset add MSI support for MT2712 and MT7622.
Also do some code fixup and cleanups.

Change Since V1:
 - Add the first two patches into this patchset.
 - Using -ENODEV instead of PTR_ERR if msi_domain == NULL
 - Change the error logs with consistency of lower-case
 - Using has_msi instead of support_msi to make the parameter name a bit shorter

Honghui Zhang (3):
  PCI: mediatek: Fix return value in case of error
  PCI: mediatek: take use of bus->sysdata to get host private data
  PCI: mediatek: add msi support for MT2712 and MT7622

 drivers/pci/host/pcie-mediatek.c | 157 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 151 insertions(+), 6 deletions(-)
Since "PCI: mediatek: Add controller support for MT2712 and MT7622" patch
hasn't appeared upstream yet, I folded the return value fix directly into
it.

I applied the others to pci/host-mediatek.  I modified the third one to
remove what seemed to be needless differences from the rcar and tegra
drivers.  The incremental diff is attached.  Please check to make sure I
didn't break anything.

diff --git a/drivers/pci/host/pcie-mediatek.c b/drivers/pci/host/pcie-mediatek.c
index 35ab2321ed16..8891c00bf13c 100644
--- a/drivers/pci/host/pcie-mediatek.c
+++ b/drivers/pci/host/pcie-mediatek.c
@@ -134,7 +134,7 @@ struct mtk_pcie_port;
 
 /**
  * struct mtk_pcie_soc - differentiate between host generations
- * @has_msi: whether this host support MSI interrupt or not
+ * @has_msi: whether this host supports MSI interrupts or not
  * @ops: pointer to configuration access functions
  * @startup: pointer to controller setting functions
  * @setup_irq: pointer to initialize IRQ functions
@@ -439,44 +439,51 @@ static int mtk_pcie_startup_port_v2(struct mtk_pcie_port *port)
 	return 0;
 }
 
-static int mtk_pcie_assign_msi(struct mtk_pcie_port *port)
+static int mtk_pcie_msi_alloc(struct mtk_pcie_port *port)
 {
-	int pos;
+	int msi;
 
-	pos = find_first_zero_bit(port->msi_irq_in_use, MTK_MSI_IRQS_NUM);
-	if (pos < MTK_MSI_IRQS_NUM)
-		set_bit(pos, port->msi_irq_in_use);
+	msi = find_first_zero_bit(port->msi_irq_in_use, MTK_MSI_IRQS_NUM);
+	if (msi < MTK_MSI_IRQS_NUM)
+		set_bit(msi, port->msi_irq_in_use);
 	else
 		return -ENOSPC;
 
-	return pos;
+	return msi;
+}
+
+static void mtk_pcie_msi_free(struct mtk_pcie_port *port, unsigned long hwirq)
+{
+	clear_bit(hwirq, port->msi_irq_in_use);
 }
 
 static int mtk_pcie_msi_setup_irq(struct msi_controller *chip,
-				  struct pci_dev *pdev,
-				  struct msi_desc *desc)
+				  struct pci_dev *pdev, struct msi_desc *desc)
 {
 	struct mtk_pcie_port *port;
 	struct msi_msg msg;
+	unsigned int irq;
 	int hwirq;
-	u32 irq;
 
 	port = mtk_pcie_find_port(pdev->bus, pdev->devfn);
 	if (!port)
 		return -EINVAL;
 
-	chip->dev = &pdev->dev;
-	hwirq = mtk_pcie_assign_msi(port);
+	hwirq = mtk_pcie_msi_alloc(port);
 	if (hwirq < 0)
 		return hwirq;
 
 	irq = irq_create_mapping(port->msi_domain, hwirq);
-	if (!irq)
+	if (!irq) {
+		mtk_pcie_msi_free(port, hwirq);
 		return -EINVAL;
+	}
+
+	chip->dev = &pdev->dev;
 
 	irq_set_msi_desc(irq, desc);
 
-	/* MT2712/MT7622 only support 32 bit MSI address */
+	/* MT2712/MT7622 only support 32-bit MSI addresses */
 	msg.address_hi = 0;
 	msg.address_lo = lower_32_bits((u64)(port->base + PCIE_MSI_VECTOR));
 	msg.data = hwirq;
@@ -497,10 +504,8 @@ static void mtk_msi_teardown_irq(struct msi_controller *chip, unsigned int irq)
 	if (!port)
 		return;
 
-	if (!test_bit(hwirq, port->msi_irq_in_use))
-		dev_err(&pdev->dev, "trying to free unused MSI#%d\n", irq);
-	else
-		clear_bit(hwirq, port->msi_irq_in_use);
+	irq_dispose_mapping(irq);
+	mtk_pcie_msi_free(port, hwirq);
 }
 
 static struct msi_controller mtk_pcie_msi_chip = {
@@ -529,16 +534,26 @@ static const struct irq_domain_ops msi_domain_ops = {
 	.map = mtk_pcie_msi_map,
 };
 
-static void mtk_pcie_enable_msi(struct mtk_pcie_port *port)
+static int mtk_pcie_enable_msi(struct mtk_pcie_port *port)
 {
 	u32 val;
 
+	port->msi_domain = irq_domain_add_linear(node, MTK_MSI_IRQS_NUM,
+						 &msi_domain_ops,
+						 &mtk_pcie_msi_chip);
+	if (!port->msi_domain) {
+		dev_err(dev, "failed to create MSI IRQ domain\n");
+		return -ENOMEM;
+	}
+
 	val = lower_32_bits((u64)(port->base + PCIE_MSI_VECTOR));
 	writel(val, port->base + PCIE_IMSI_ADDR);
 
 	val = readl(port->base + PCIE_INT_MASK);
 	val &= ~MSI_MASK;
 	writel(val, port->base + PCIE_INT_MASK);
+
+	return 0;
 }
 
 static int mtk_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
@@ -559,6 +574,7 @@ static int mtk_pcie_init_irq_domain(struct mtk_pcie_port *port,
 {
 	struct device *dev = port->pcie->dev;
 	struct device_node *pcie_intc_node;
+	int err;
 
 	/* Setup INTx */
 	pcie_intc_node = of_get_next_child(node, NULL);
@@ -574,16 +590,10 @@ static int mtk_pcie_init_irq_domain(struct mtk_pcie_port *port,
 		return -ENODEV;
 	}
 
-	/* Setup MSI */
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
-		port->msi_domain = irq_domain_add_linear(node, MTK_MSI_IRQS_NUM,
-							 &msi_domain_ops,
-							 &mtk_pcie_msi_chip);
-		if (!port->msi_domain) {
-			dev_err(dev, "failed to get MSI IRQ domain\n");
-			return -ENODEV;
-		}
-		mtk_pcie_enable_msi(port);
+		err = mtk_pcie_enable_msi(port);
+		if (err < 0)
+			return err;
 	}
 
 	return 0;
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