[PATCH 4/6] PCI: keystone: Convert to using hierarchy domain for legacy interrupts

From: Kishon Vijay Abraham I
Date: Thu Mar 25 2021 - 05:02:14 EST


K2G provides separate IRQ lines for each of the four legacy interrupts.
Model this using hierarchy domain instead of linear domain with chained
IRQ handler.

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
drivers/pci/controller/dwc/pci-keystone.c | 214 ++++++++++++----------
1 file changed, 120 insertions(+), 94 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index 4de8c8e5e3f2..dfa9a7fcf9b7 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -69,6 +69,7 @@

#define IRQ_STATUS(n) (0x184 + ((n) << 4))
#define IRQ_ENABLE_SET(n) (0x188 + ((n) << 4))
+#define IRQ_ENABLE_CLR(n) (0x18c + ((n) << 4))
#define INTx_EN BIT(0)

#define ERR_IRQ_STATUS 0x1c4
@@ -116,7 +117,6 @@ struct keystone_pcie {
struct dw_pcie *pci;
/* PCI Device ID */
u32 device_id;
- int legacy_host_irqs[PCI_NUM_INTX];
struct device_node *legacy_intc_np;

int msi_host_irq;
@@ -125,7 +125,6 @@ struct keystone_pcie {
struct phy **phy;
struct device_link **link;
struct device_node *msi_intc_np;
- struct irq_domain *legacy_irq_domain;
struct device_node *np;

/* Application register space */
@@ -253,26 +252,6 @@ static int ks_pcie_msi_host_init(struct pcie_port *pp)
return dw_pcie_allocate_domains(pp);
}

-static void ks_pcie_handle_legacy_irq(struct keystone_pcie *ks_pcie,
- int offset)
-{
- struct dw_pcie *pci = ks_pcie->pci;
- struct device *dev = pci->dev;
- u32 pending;
- int virq;
-
- pending = ks_pcie_app_readl(ks_pcie, IRQ_STATUS(offset));
-
- if (BIT(0) & pending) {
- virq = irq_linear_revmap(ks_pcie->legacy_irq_domain, offset);
- dev_dbg(dev, ": irq: irq_offset %d, virq %d\n", offset, virq);
- generic_handle_irq(virq);
- }
-
- /* EOI the INTx interrupt */
- ks_pcie_app_writel(ks_pcie, IRQ_EOI, offset);
-}
-
static void ks_pcie_enable_error_irq(struct keystone_pcie *ks_pcie)
{
ks_pcie_app_writel(ks_pcie, ERR_IRQ_ENABLE_SET, ERR_IRQ_ALL);
@@ -310,39 +289,120 @@ static irqreturn_t ks_pcie_handle_error_irq(struct keystone_pcie *ks_pcie)
return IRQ_HANDLED;
}

-static void ks_pcie_ack_legacy_irq(struct irq_data *d)
+void ks_pcie_irq_eoi(struct irq_data *data)
{
+ struct keystone_pcie *ks_pcie = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t hwirq = data->hwirq;
+
+ ks_pcie_app_writel(ks_pcie, IRQ_EOI, hwirq);
+ irq_chip_eoi_parent(data);
}

-static void ks_pcie_mask_legacy_irq(struct irq_data *d)
+void ks_pcie_irq_enable(struct irq_data *data)
{
+ struct keystone_pcie *ks_pcie = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t hwirq = data->hwirq;
+
+ ks_pcie_app_writel(ks_pcie, IRQ_ENABLE_SET(hwirq), INTx_EN);
+ irq_chip_enable_parent(data);
}

-static void ks_pcie_unmask_legacy_irq(struct irq_data *d)
+void ks_pcie_irq_disable(struct irq_data *data)
{
+ struct keystone_pcie *ks_pcie = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t hwirq = data->hwirq;
+
+ ks_pcie_app_writel(ks_pcie, IRQ_ENABLE_CLR(hwirq), INTx_EN);
+ irq_chip_disable_parent(data);
}

static struct irq_chip ks_pcie_legacy_irq_chip = {
- .name = "Keystone-PCI-Legacy-IRQ",
- .irq_ack = ks_pcie_ack_legacy_irq,
- .irq_mask = ks_pcie_mask_legacy_irq,
- .irq_unmask = ks_pcie_unmask_legacy_irq,
+ .name = "Keystone-PCI-Legacy-IRQ",
+ .irq_enable = ks_pcie_irq_enable,
+ .irq_disable = ks_pcie_irq_disable,
+ .irq_eoi = ks_pcie_irq_eoi,
+ .irq_mask = irq_chip_mask_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_retrigger = irq_chip_retrigger_hierarchy,
+ .irq_set_type = irq_chip_set_type_parent,
+ .irq_set_affinity = irq_chip_set_affinity_parent,
};

-static int ks_pcie_init_legacy_irq_map(struct irq_domain *d,
- unsigned int irq,
- irq_hw_number_t hw_irq)
+static int ks_pcie_legacy_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *data)
{
- irq_set_chip_and_handler(irq, &ks_pcie_legacy_irq_chip,
- handle_level_irq);
- irq_set_chip_data(irq, d->host_data);
+ struct keystone_pcie *ks_pcie = domain->host_data;
+ struct device_node *np = ks_pcie->legacy_intc_np;
+ struct irq_fwspec parent_fwspec, *fwspec = data;
+ struct of_phandle_args out_irq;
+ int ret;
+
+ if (nr_irqs != 1)
+ return -EINVAL;
+
+ /*
+ * Get the correct interrupt from legacy-interrupt-controller node
+ * corresponding to INTA/INTB/INTC/INTD (passed in fwspec->param[0])
+ * after performing mapping specified in "interrupt-map".
+ * interrupt-map = <0 0 0 1 &pcie_intc0 0>, INTA (4th cell in
+ * interrupt-map) corresponds to 1st entry in "interrupts" (6th cell
+ * in interrupt-map)
+ */
+ ret = of_irq_parse_one(np, fwspec->param[0], &out_irq);
+ if (ret < 0) {
+ pr_err("Failed to parse interrupt node\n");
+ return ret;
+ }
+
+ of_phandle_args_to_fwspec(np, out_irq.args, out_irq.args_count, &parent_fwspec);
+
+ ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
+ if (ret < 0) {
+ pr_err("Failed to allocate parent irq %u: %d\n",
+ parent_fwspec.param[0], ret);
+ return ret;
+ }
+
+ ret = irq_domain_set_hwirq_and_chip(domain, virq, fwspec->param[0],
+ &ks_pcie_legacy_irq_chip, ks_pcie);
+ if (ret < 0) {
+ pr_err("Failed to set hwirq and chip\n");
+ goto err_set_hwirq_and_chip;
+ }

return 0;
+
+err_set_hwirq_and_chip:
+ irq_domain_free_irqs_parent(domain, virq, 1);
+
+ return ret;
+}
+
+static int ks_pcie_irq_domain_translate(struct irq_domain *domain,
+ struct irq_fwspec *fwspec,
+ unsigned long *hwirq,
+ unsigned int *type)
+{
+ if (is_of_node(fwspec->fwnode)) {
+ if (fwspec->param_count != 2)
+ return -EINVAL;
+
+ if (fwspec->param[0] >= PCI_NUM_INTX)
+ return -EINVAL;
+
+ *hwirq = fwspec->param[0];
+ *type = fwspec->param[1];
+
+ return 0;
+ }
+
+ return -EINVAL;
}

static const struct irq_domain_ops ks_pcie_legacy_irq_domain_ops = {
- .map = ks_pcie_init_legacy_irq_map,
- .xlate = irq_domain_xlate_onetwocell,
+ .alloc = ks_pcie_legacy_irq_domain_alloc,
+ .free = irq_domain_free_irqs_common,
+ .translate = ks_pcie_irq_domain_translate,
};

/**
@@ -614,35 +674,6 @@ static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
chained_irq_exit(chip, desc);
}

-/**
- * ks_pcie_legacy_irq_handler() - Handle legacy interrupt
- * @irq: IRQ line for legacy interrupts
- * @desc: Pointer to irq descriptor
- *
- * Traverse through pending legacy interrupts and invoke handler for each. Also
- * takes care of interrupt controller level mask/ack operation.
- */
-static void ks_pcie_legacy_irq_handler(struct irq_desc *desc)
-{
- unsigned int irq = irq_desc_get_irq(desc);
- struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
- struct dw_pcie *pci = ks_pcie->pci;
- struct device *dev = pci->dev;
- u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0];
- struct irq_chip *chip = irq_desc_get_chip(desc);
-
- dev_dbg(dev, ": Handling legacy irq %d\n", irq);
-
- /*
- * The chained irq handler installation would have replaced normal
- * interrupt driver handler so we need to take care of mask/unmask and
- * ack operation.
- */
- chained_irq_enter(chip, desc);
- ks_pcie_handle_legacy_irq(ks_pcie, irq_offset);
- chained_irq_exit(chip, desc);
-}
-
static int ks_pcie_config_msi_irq(struct keystone_pcie *ks_pcie)
{
struct device *dev = ks_pcie->pci->dev;
@@ -702,20 +733,33 @@ static int ks_pcie_config_legacy_irq(struct keystone_pcie *ks_pcie)
struct device *dev = ks_pcie->pci->dev;
struct irq_domain *legacy_irq_domain;
struct device_node *np = ks_pcie->np;
+ struct irq_domain *parent_domain;
+ struct device_node *parent_node;
struct device_node *intc_np;
- int irq_count, irq, ret = 0, i;
+ int irq_count, ret = 0;

- intc_np = of_get_child_by_name(np, "legacy-interrupt-controller");
+ intc_np = of_get_child_by_name(np, "interrupt-controller");
if (!intc_np) {
- /*
- * Since legacy interrupts are modeled as edge-interrupts in
- * AM6, keep it disabled for now.
- */
- if (ks_pcie->is_am6)
- return 0;
dev_warn(dev, "legacy-interrupt-controller node is absent\n");
return -EINVAL;
}
+ ks_pcie->legacy_intc_np = intc_np;
+
+ parent_node = of_irq_find_parent(intc_np);
+ if (!parent_node) {
+ dev_err(dev, "unable to obtain parent node\n");
+ ret = -ENXIO;
+ goto err;
+ }
+
+ parent_domain = irq_find_host(parent_node);
+ if (!parent_domain) {
+ dev_err(dev, "unable to obtain parent domain\n");
+ ret = -ENXIO;
+ goto err;
+ }
+
+ of_node_put(parent_node);

irq_count = of_irq_count(intc_np);
if (!irq_count) {
@@ -724,31 +768,13 @@ static int ks_pcie_config_legacy_irq(struct keystone_pcie *ks_pcie)
goto err;
}

- for (i = 0; i < irq_count; i++) {
- irq = irq_of_parse_and_map(intc_np, i);
- if (!irq) {
- ret = -EINVAL;
- goto err;
- }
- ks_pcie->legacy_host_irqs[i] = irq;
-
- irq_set_chained_handler_and_data(irq,
- ks_pcie_legacy_irq_handler,
- ks_pcie);
- }
-
- legacy_irq_domain =
- irq_domain_add_linear(intc_np, PCI_NUM_INTX,
- &ks_pcie_legacy_irq_domain_ops, NULL);
+ legacy_irq_domain = irq_domain_add_hierarchy(parent_domain, 0, PCI_NUM_INTX, intc_np,
+ &ks_pcie_legacy_irq_domain_ops, ks_pcie);
if (!legacy_irq_domain) {
dev_err(dev, "Failed to add irq domain for legacy irqs\n");
ret = -EINVAL;
goto err;
}
- ks_pcie->legacy_irq_domain = legacy_irq_domain;
-
- for (i = 0; i < PCI_NUM_INTX; i++)
- ks_pcie_app_writel(ks_pcie, IRQ_ENABLE_SET(i), INTx_EN);

err:
of_node_put(intc_np);
--
2.17.1