[PATCH v7 2/2] PCI: mediatek: Using chained IRQ to setup IRQ handle

From: honghui.zhang
Date: Fri May 04 2018 - 01:48:17 EST


From: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx>

Using irq_chip solution to setup IRQs in order to consist
with IRQ framework.

Signed-off-by: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx>
Acked-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
---
drivers/pci/host/pcie-mediatek.c | 206 ++++++++++++++++++++++-----------------
1 file changed, 115 insertions(+), 91 deletions(-)

diff --git a/drivers/pci/host/pcie-mediatek.c b/drivers/pci/host/pcie-mediatek.c
index c3dc549..dabf1086 100644
--- a/drivers/pci/host/pcie-mediatek.c
+++ b/drivers/pci/host/pcie-mediatek.c
@@ -11,8 +11,10 @@
#include <linux/delay.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
+#include <linux/msi.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
@@ -130,14 +132,12 @@ struct mtk_pcie_port;
/**
* struct mtk_pcie_soc - differentiate between host generations
* @need_fix_class_id: whether this host's class ID needed to be fixed 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
*/
struct mtk_pcie_soc {
bool need_fix_class_id;
- bool has_msi;
struct pci_ops *ops;
int (*startup)(struct mtk_pcie_port *port);
int (*setup_irq)(struct mtk_pcie_port *port, struct device_node *node);
@@ -161,7 +161,9 @@ struct mtk_pcie_soc {
* @lane: lane count
* @slot: port slot
* @irq_domain: legacy INTx IRQ domain
+ * @inner_domain: inner IRQ domain
* @msi_domain: MSI IRQ domain
+ * @lock: protect the msi_irq_in_use bitmap
* @msi_irq_in_use: bit map for assigned MSI IRQ
*/
struct mtk_pcie_port {
@@ -179,7 +181,9 @@ struct mtk_pcie_port {
u32 lane;
u32 slot;
struct irq_domain *irq_domain;
+ struct irq_domain *inner_domain;
struct irq_domain *msi_domain;
+ struct mutex lock;
DECLARE_BITMAP(msi_irq_in_use, MTK_MSI_IRQS_NUM);
};

@@ -446,103 +450,130 @@ static int mtk_pcie_startup_port_v2(struct mtk_pcie_port *port)
return 0;
}

-static int mtk_pcie_msi_alloc(struct mtk_pcie_port *port)
+static void mtk_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
{
- int msi;
+ struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+ phys_addr_t addr;

- 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;
+ /* MT2712/MT7622 only support 32-bit MSI addresses */
+ addr = virt_to_phys(port->base + PCIE_MSI_VECTOR);
+ msg->address_hi = 0;
+ msg->address_lo = lower_32_bits(addr);
+
+ msg->data = data->hwirq;

- return msi;
+ dev_dbg(port->pcie->dev, "msi#%d address_hi %#x address_lo %#x\n",
+ (int)data->hwirq, msg->address_hi, msg->address_lo);
}

-static void mtk_pcie_msi_free(struct mtk_pcie_port *port, unsigned long hwirq)
+static int mtk_msi_set_affinity(struct irq_data *irq_data,
+ const struct cpumask *mask, bool force)
{
- clear_bit(hwirq, port->msi_irq_in_use);
+ return -EINVAL;
}

-static int mtk_pcie_msi_setup_irq(struct msi_controller *chip,
- struct pci_dev *pdev, struct msi_desc *desc)
+static void mtk_msi_ack_irq(struct irq_data *data)
{
- struct mtk_pcie_port *port;
- struct msi_msg msg;
- unsigned int irq;
- int hwirq;
- phys_addr_t msg_addr;
+ struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+ u32 hwirq = data->hwirq;

- port = mtk_pcie_find_port(pdev->bus, pdev->devfn);
- if (!port)
- return -EINVAL;
+ writel(1 << hwirq, port->base + PCIE_IMSI_STATUS);
+}

- hwirq = mtk_pcie_msi_alloc(port);
- if (hwirq < 0)
- return hwirq;
+static struct irq_chip mtk_msi_bottom_irq_chip = {
+ .name = "MTK MSI",
+ .irq_compose_msi_msg = mtk_compose_msi_msg,
+ .irq_set_affinity = mtk_msi_set_affinity,
+ .irq_ack = mtk_msi_ack_irq,
+};

- irq = irq_create_mapping(port->msi_domain, hwirq);
- if (!irq) {
- mtk_pcie_msi_free(port, hwirq);
- return -EINVAL;
- }
+static int mtk_pcie_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *args)
+{
+ struct mtk_pcie_port *port = domain->host_data;
+ unsigned long bit;

- chip->dev = &pdev->dev;
+ WARN_ON(nr_irqs != 1);
+ mutex_lock(&port->lock);

- irq_set_msi_desc(irq, desc);
+ bit = find_first_zero_bit(port->msi_irq_in_use, MTK_MSI_IRQS_NUM);
+ if (bit >= MTK_MSI_IRQS_NUM) {
+ mutex_unlock(&port->lock);
+ return -ENOSPC;
+ }

- /* MT2712/MT7622 only support 32-bit MSI addresses */
- msg_addr = virt_to_phys(port->base + PCIE_MSI_VECTOR);
- msg.address_hi = 0;
- msg.address_lo = lower_32_bits(msg_addr);
- msg.data = hwirq;
+ __set_bit(bit, port->msi_irq_in_use);
+
+ mutex_unlock(&port->lock);

- pci_write_msi_msg(irq, &msg);
+ irq_domain_set_info(domain, virq, bit, &mtk_msi_bottom_irq_chip,
+ domain->host_data, handle_edge_irq,
+ NULL, NULL);

return 0;
}

-static void mtk_msi_teardown_irq(struct msi_controller *chip, unsigned int irq)
+static void mtk_pcie_irq_domain_free(struct irq_domain *domain,
+ unsigned int virq, unsigned int nr_irqs)
{
- struct pci_dev *pdev = to_pci_dev(chip->dev);
- struct irq_data *d = irq_get_irq_data(irq);
- irq_hw_number_t hwirq = irqd_to_hwirq(d);
- struct mtk_pcie_port *port;
+ struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+ struct mtk_pcie_port *port = irq_data_get_irq_chip_data(d);

- port = mtk_pcie_find_port(pdev->bus, pdev->devfn);
- if (!port)
- return;
+ mutex_lock(&port->lock);
+
+ if (!test_bit(d->hwirq, port->msi_irq_in_use))
+ dev_err(port->pcie->dev, "trying to free unused MSI#%lu\n",
+ d->hwirq);
+ else
+ __clear_bit(d->hwirq, port->msi_irq_in_use);
+
+ mutex_unlock(&port->lock);

- irq_dispose_mapping(irq);
- mtk_pcie_msi_free(port, hwirq);
+ irq_domain_free_irqs_parent(domain, virq, nr_irqs);
}

-static struct msi_controller mtk_pcie_msi_chip = {
- .setup_irq = mtk_pcie_msi_setup_irq,
- .teardown_irq = mtk_msi_teardown_irq,
+static const struct irq_domain_ops msi_domain_ops = {
+ .alloc = mtk_pcie_irq_domain_alloc,
+ .free = mtk_pcie_irq_domain_free,
};

static struct irq_chip mtk_msi_irq_chip = {
- .name = "MTK PCIe MSI",
- .irq_enable = pci_msi_unmask_irq,
- .irq_disable = pci_msi_mask_irq,
- .irq_mask = pci_msi_mask_irq,
- .irq_unmask = pci_msi_unmask_irq,
+ .name = "MTK PCIe MSI",
+ .irq_ack = irq_chip_ack_parent,
+ .irq_mask = pci_msi_mask_irq,
+ .irq_unmask = pci_msi_unmask_irq,
};

-static int mtk_pcie_msi_map(struct irq_domain *domain, unsigned int irq,
- irq_hw_number_t hwirq)
+static struct msi_domain_info mtk_msi_domain_info = {
+ .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_PCI_MSIX),
+ .chip = &mtk_msi_irq_chip,
+};
+
+static int mtk_pcie_allocate_msi_domains(struct mtk_pcie_port *port)
{
- irq_set_chip_and_handler(irq, &mtk_msi_irq_chip, handle_simple_irq);
- irq_set_chip_data(irq, domain->host_data);
+ struct fwnode_handle *fwnode = of_node_to_fwnode(port->pcie->dev->of_node);
+
+ mutex_init(&port->lock);
+
+ port->inner_domain = irq_domain_create_linear(fwnode, MTK_MSI_IRQS_NUM,
+ &msi_domain_ops, port);
+ if (!port->inner_domain) {
+ dev_err(port->pcie->dev, "failed to create IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ port->msi_domain = pci_msi_create_irq_domain(fwnode, &mtk_msi_domain_info,
+ port->inner_domain);
+ if (!port->msi_domain) {
+ dev_err(port->pcie->dev, "failed to create MSI domain\n");
+ irq_domain_remove(port->inner_domain);
+ return -ENOMEM;
+ }

return 0;
}

-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)
{
u32 val;
@@ -575,6 +606,7 @@ 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 ret;

/* Setup INTx */
pcie_intc_node = of_get_next_child(node, NULL);
@@ -591,27 +623,28 @@ static int mtk_pcie_init_irq_domain(struct mtk_pcie_port *port,
}

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 create MSI IRQ domain\n");
- return -ENODEV;
- }
+ ret = mtk_pcie_allocate_msi_domains(port);
+ if (ret)
+ return ret;
+
mtk_pcie_enable_msi(port);
}

return 0;
}

-static irqreturn_t mtk_pcie_intr_handler(int irq, void *data)
+static void mtk_pcie_intr_handler(struct irq_desc *desc)
{
- struct mtk_pcie_port *port = (struct mtk_pcie_port *)data;
+ struct mtk_pcie_port *port = irq_desc_get_handler_data(desc);
+ struct irq_chip *irqchip = irq_desc_get_chip(desc);
unsigned long status;
u32 virq;
u32 bit = INTX_SHIFT;

- while ((status = readl(port->base + PCIE_INT_STATUS)) & INTX_MASK) {
+ chained_irq_enter(irqchip, desc);
+
+ status = readl(port->base + PCIE_INT_STATUS);
+ if (status & INTX_MASK) {
for_each_set_bit_from(bit, &status, PCI_NUM_INTX + INTX_SHIFT) {
/* Clear the INTx */
writel(1 << bit, port->base + PCIE_INT_STATUS);
@@ -622,14 +655,12 @@ static irqreturn_t mtk_pcie_intr_handler(int irq, void *data)
}

if (IS_ENABLED(CONFIG_PCI_MSI)) {
- while ((status = readl(port->base + PCIE_INT_STATUS)) & MSI_STATUS) {
+ if (status & MSI_STATUS){
unsigned long imsi_status;

while ((imsi_status = readl(port->base + PCIE_IMSI_STATUS))) {
for_each_set_bit(bit, &imsi_status, MTK_MSI_IRQS_NUM) {
- /* Clear the MSI */
- writel(1 << bit, port->base + PCIE_IMSI_STATUS);
- virq = irq_find_mapping(port->msi_domain, bit);
+ virq = irq_find_mapping(port->inner_domain, bit);
generic_handle_irq(virq);
}
}
@@ -638,7 +669,9 @@ static irqreturn_t mtk_pcie_intr_handler(int irq, void *data)
}
}

- return IRQ_HANDLED;
+ chained_irq_exit(irqchip, desc);
+
+ return;
}

static int mtk_pcie_setup_irq(struct mtk_pcie_port *port,
@@ -649,20 +682,15 @@ static int mtk_pcie_setup_irq(struct mtk_pcie_port *port,
struct platform_device *pdev = to_platform_device(dev);
int err, irq;

- irq = platform_get_irq(pdev, port->slot);
- err = devm_request_irq(dev, irq, mtk_pcie_intr_handler,
- IRQF_SHARED, "mtk-pcie", port);
- if (err) {
- dev_err(dev, "unable to request IRQ %d\n", irq);
- return err;
- }
-
err = mtk_pcie_init_irq_domain(port, node);
if (err) {
dev_err(dev, "failed to init PCIe IRQ domain\n");
return err;
}

+ irq = platform_get_irq(pdev, port->slot);
+ irq_set_chained_handler_and_data(irq, mtk_pcie_intr_handler, port);
+
return 0;
}

@@ -1096,8 +1124,6 @@ static int mtk_pcie_register_host(struct pci_host_bridge *host)
host->map_irq = of_irq_parse_and_map_pci;
host->swizzle_irq = pci_common_swizzle;
host->sysdata = pcie;
- if (IS_ENABLED(CONFIG_PCI_MSI) && pcie->soc->has_msi)
- host->msi = &mtk_pcie_msi_chip;

err = pci_scan_root_bus_bridge(host);
if (err < 0)
@@ -1159,7 +1185,6 @@ static const struct mtk_pcie_soc mtk_pcie_soc_v1 = {
};

static const struct mtk_pcie_soc mtk_pcie_soc_mt2712 = {
- .has_msi = true,
.ops = &mtk_pcie_ops_v2,
.startup = mtk_pcie_startup_port_v2,
.setup_irq = mtk_pcie_setup_irq,
@@ -1167,7 +1192,6 @@ static const struct mtk_pcie_soc mtk_pcie_soc_mt2712 = {

static const struct mtk_pcie_soc mtk_pcie_soc_mt7622 = {
.need_fix_class_id = true,
- .has_msi = true,
.ops = &mtk_pcie_ops_v2,
.startup = mtk_pcie_startup_port_v2,
.setup_irq = mtk_pcie_setup_irq,
--
2.6.4