irqchip: Add RISC-V advanced PLIC driver for direct-mode

The RISC-V advanced interrupt architecture (AIA) specification defines
advanced platform-level interrupt controller (APLIC) which has two modes
of operation: 1) Direct mode and 2) MSI mode.
(For more details, refer https://github.com/riscv/riscv-aia)

In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
as a local external interrupt.

Add a platform irqchip driver for the RISC-V APLIC direct-mode to
support RISC-V platforms having only wired interrupts.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240307140307.646078-7-apatel@ventanamicro.com

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
new file mode 100644
index 000000000000..4cfbadf37ddc
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-main.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#ifndef _IRQ_RISCV_APLIC_MAIN_H
+#define _IRQ_RISCV_APLIC_MAIN_H
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/fwnode.h>
+
+#define APLIC_DEFAULT_PRIORITY		1
+
+struct aplic_msicfg {
+	phys_addr_t		base_ppn;
+	u32			hhxs;
+	u32			hhxw;
+	u32			lhxs;
+	u32			lhxw;
+};
+
+struct aplic_priv {
+	struct device		*dev;
+	u32			gsi_base;
+	u32			nr_irqs;
+	u32			nr_idcs;
+	void __iomem		*regs;
+	struct aplic_msicfg	msicfg;
+};
+
+void aplic_irq_unmask(struct irq_data *d);
+void aplic_irq_mask(struct irq_data *d);
+int aplic_irq_set_type(struct irq_data *d, unsigned int type);
+int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
+			      unsigned long *hwirq, unsigned int *type);
+void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
+int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs);
+int aplic_direct_setup(struct device *dev, void __iomem *regs);
+
+#endif