PCI: microchip: Add event irqchip field to host port and add PLDA irqchip

As the PLDA DT binding doc (Documentation/devicetree/bindings/pci/
plda,xpressrich3-axi-common.yaml) shows, PLDA PCIe contains an interrupt
controller.

Microchip PolarFire PCIe event IRQs include PLDA interrupts and PolarFire
additional interrupts. The interrupt irqchip ops includes ack/mask/unmask
interrupt ops, which will write correct registers.  Microchip PolarFire
PCIe additional interrupts require to write PolarFire SoC self-defined
registers. So Microchip PCIe event irqchip ops can not be re-used.

Microchip PolarFire PCIe additional interrupts (defined in
drivers/pci/controller/plda/pcie-microchip-host.c):

  EVENT_PCIE_L2_EXIT
  EVENT_PCIE_HOTRST_EXIT
  EVENT_PCIE_DLUP_EXIT
  EVENT_SEC_TX_RAM_SEC_ERR
  EVENT_SEC_RX_RAM_SEC_ERR
  ...

To support PLDA its own event IRQ process, implements PLDA irqchip ops and
add event irqchip field to struct pcie_plda_rp.

[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20240328091835.14797-16-minda.chen@starfivetech.comSigned-off-by: Minda Chen <minda.chen@starfivetech.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>

drivers/pci/controller/plda/pcie-microchip-host.c

@@ -770,6 +770,64 @@ static struct irq_chip mc_event_irq_chip = {
 	.irq_unmask = mc_unmask_event_irq,
 };
 
+static u32 plda_hwirq_to_mask(int hwirq)
+{
+	u32 mask;
+
+	/* hwirq 23 - 0 are the same with register */
+	if (hwirq < EVENT_PM_MSI_INT_INTX)
+		mask = BIT(hwirq);
+	else if (hwirq == EVENT_PM_MSI_INT_INTX)
+		mask = PM_MSI_INT_INTX_MASK;
+	else
+		mask = BIT(hwirq + PCI_NUM_INTX - 1);
+
+	return mask;
+}
+
+static void plda_ack_event_irq(struct irq_data *data)
+{
+	struct plda_pcie_rp *port = irq_data_get_irq_chip_data(data);
+
+	writel_relaxed(plda_hwirq_to_mask(data->hwirq),
+		       port->bridge_addr + ISTATUS_LOCAL);
+}
+
+static void plda_mask_event_irq(struct irq_data *data)
+{
+	struct plda_pcie_rp *port = irq_data_get_irq_chip_data(data);
+	u32 mask, val;
+
+	mask = plda_hwirq_to_mask(data->hwirq);
+
+	raw_spin_lock(&port->lock);
+	val = readl_relaxed(port->bridge_addr + IMASK_LOCAL);
+	val &= ~mask;
+	writel_relaxed(val, port->bridge_addr + IMASK_LOCAL);
+	raw_spin_unlock(&port->lock);
+}
+
+static void plda_unmask_event_irq(struct irq_data *data)
+{
+	struct plda_pcie_rp *port = irq_data_get_irq_chip_data(data);
+	u32 mask, val;
+
+	mask = plda_hwirq_to_mask(data->hwirq);
+
+	raw_spin_lock(&port->lock);
+	val = readl_relaxed(port->bridge_addr + IMASK_LOCAL);
+	val |= mask;
+	writel_relaxed(val, port->bridge_addr + IMASK_LOCAL);
+	raw_spin_unlock(&port->lock);
+}
+
+static struct irq_chip plda_event_irq_chip = {
+	.name = "PLDA PCIe EVENT",
+	.irq_ack = plda_ack_event_irq,
+	.irq_mask = plda_mask_event_irq,
+	.irq_unmask = plda_unmask_event_irq,
+};
+
 static const struct plda_event_ops plda_event_ops = {
 	.get_events = plda_get_events,
 };
@@ -777,7 +835,9 @@ static const struct plda_event_ops plda_event_ops = {
 static int plda_pcie_event_map(struct irq_domain *domain, unsigned int irq,
 			       irq_hw_number_t hwirq)
 {
-	irq_set_chip_and_handler(irq, &mc_event_irq_chip, handle_level_irq);
+	struct plda_pcie_rp *port = (void *)domain->host_data;
+
+	irq_set_chip_and_handler(irq, port->event_irq_chip, handle_level_irq);
 	irq_set_chip_data(irq, domain->host_data);
 
 	return 0;
@@ -962,6 +1022,9 @@ static int plda_init_interrupts(struct platform_device *pdev,
 	if (!port->event_ops)
 		port->event_ops = &plda_event_ops;
 
+	if (!port->event_irq_chip)
+		port->event_irq_chip = &plda_event_irq_chip;
+
 	ret = plda_pcie_init_irq_domains(port);
 	if (ret) {
 		dev_err(dev, "failed creating IRQ domains\n");
@@ -1038,6 +1101,7 @@ static int mc_platform_init(struct pci_config_window *cfg)
 		return ret;
 
 	port->plda.event_ops = &mc_event_ops;
+	port->plda.event_irq_chip = &mc_event_irq_chip;
 
 	/* Address translation is up; safe to enable interrupts */
 	ret = plda_init_interrupts(pdev, &port->plda, &mc_event);

drivers/pci/controller/plda/pcie-plda.h

@@ -107,6 +107,8 @@ enum plda_int_event {
 
 #define PLDA_NUM_DMA_EVENTS			16
 
+#define EVENT_PM_MSI_INT_INTX			(PLDA_NUM_DMA_EVENTS + PLDA_INTX)
+#define EVENT_PM_MSI_INT_MSI			(PLDA_NUM_DMA_EVENTS + PLDA_MSI)
 #define PLDA_MAX_EVENT_NUM			(PLDA_NUM_DMA_EVENTS + PLDA_INT_EVENT_NUM)
 
 /*
@@ -116,21 +118,22 @@ enum plda_int_event {
  * +--+--+--+-+------+-+-+-+-+-+-+-+-+-----------+-----------+
  * |12|11|10|9| intx |7|6|5|4|3|2|1|0| DMA error | DMA end   |
  * +--+--+--+-+------+-+-+-+-+-+-+-+-+-----------+-----------+
- * bit 0-7  DMA interrupt end : reserved for vendor implement
- * bit 8-15 DMA error : reserved for vendor implement
- * 0:  AXI post error (PLDA_AXI_POST_ERR)
- * 1:  AXI fetch error (PLDA_AXI_FETCH_ERR)
- * 2:  AXI discard error (PLDA_AXI_DISCARD_ERR)
- * 3:  AXI doorbell (PLDA_PCIE_DOORBELL)
- * 4:  PCIe post error (PLDA_PCIE_POST_ERR)
- * 5:  PCIe fetch error (PLDA_PCIE_FETCH_ERR)
- * 6:  PCIe discard error (PLDA_PCIE_DISCARD_ERR)
- * 7:  PCIe doorbell (PLDA_PCIE_DOORBELL)
- * 8:  4 INTx interruts (PLDA_INTX)
- * 9:  MSI interrupt (PLDA_MSI)
- * 10: AER event (PLDA_AER_EVENT)
- * 11: PM/LTR/Hotplug (PLDA_MISC_EVENTS)
- * 12: System error (PLDA_SYS_ERR)
+ * event  bit
+ * 0-7   (0-7)   DMA interrupt end : reserved for vendor implement
+ * 8-15  (8-15)  DMA error : reserved for vendor implement
+ * 16    (16)    AXI post error (PLDA_AXI_POST_ERR)
+ * 17    (17)    AXI fetch error (PLDA_AXI_FETCH_ERR)
+ * 18    (18)    AXI discard error (PLDA_AXI_DISCARD_ERR)
+ * 19    (19)    AXI doorbell (PLDA_PCIE_DOORBELL)
+ * 20    (20)    PCIe post error (PLDA_PCIE_POST_ERR)
+ * 21    (21)    PCIe fetch error (PLDA_PCIE_FETCH_ERR)
+ * 22    (22)    PCIe discard error (PLDA_PCIE_DISCARD_ERR)
+ * 23    (23)    PCIe doorbell (PLDA_PCIE_DOORBELL)
+ * 24    (27-24) INTx interruts (PLDA_INTX)
+ * 25    (28):   MSI interrupt (PLDA_MSI)
+ * 26    (29):   AER event (PLDA_AER_EVENT)
+ * 27    (30):   PM/LTR/Hotplug (PLDA_MISC_EVENTS)
+ * 28    (31):   System error (PLDA_SYS_ERR)
  */
 
 struct plda_pcie_rp;
@@ -155,6 +158,7 @@ struct plda_pcie_rp {
 	raw_spinlock_t lock;
 	struct plda_msi msi;
 	const struct plda_event_ops *event_ops;
+	const struct irq_chip *event_irq_chip;
 	void __iomem *bridge_addr;
 	int num_events;
 };