Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Anup Patel <apatel@ventanamicro.com>
To:     Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>
Cc:     Atish Patra <atishp@atishpatra.org>,
        Alistair Francis <Alistair.Francis@wdc.com>,
        Anup Patel <anup@brainfault.org>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        Anup Patel <apatel@ventanamicro.com>
Subject: [PATCH v3 2/6] irqchip/riscv-intc: Allow drivers to directly discover INTC hwnode
Date:   Sun, 20 Feb 2022 10:38:50 +0530
Message-Id: <20220220050854.743420-3-apatel@ventanamicro.com>
In-Reply-To: <20220220050854.743420-1-apatel@ventanamicro.com>
References: <20220220050854.743420-1-apatel@ventanamicro.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Various RISC-V drivers (such as SBI IPI, SBI Timer, SBI PMU, and
KVM RISC-V) don't have associated DT node but these drivers need
standard per-CPU (local) interrupts defined by the RISC-V privileged
specification.

We add riscv_get_intc_hwnode() in arch/riscv which allows RISC-V
drivers not having DT node to discover INTC hwnode which in-turn
helps these drivers to map per-CPU (local) interrupts provided
by the INTC driver.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 arch/riscv/include/asm/irq.h     |  4 ++++
 arch/riscv/kernel/irq.c          | 19 +++++++++++++++++++
 drivers/irqchip/irq-riscv-intc.c |  7 +++++++
 3 files changed, 30 insertions(+)

diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h
index e4c435509983..43b9ebfbd943 100644
--- a/arch/riscv/include/asm/irq.h
+++ b/arch/riscv/include/asm/irq.h
@@ -12,6 +12,10 @@
 
 #include <asm-generic/irq.h>
 
+void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void));
+
+struct fwnode_handle *riscv_get_intc_hwnode(void);
+
 extern void __init init_IRQ(void);
 
 #endif /* _ASM_RISCV_IRQ_H */
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index 7207fa08d78f..ead92432df8c 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -7,9 +7,28 @@
 
 #include <linux/interrupt.h>
 #include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
 #include <linux/seq_file.h>
 #include <asm/smp.h>
 
+static struct fwnode_handle *(*__get_intc_node)(void);
+
+void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void))
+{
+	__get_intc_node = fn;
+}
+EXPORT_SYMBOL_GPL(riscv_set_intc_hwnode_fn);
+
+struct fwnode_handle *riscv_get_intc_hwnode(void)
+{
+	if (__get_intc_node)
+		return __get_intc_node();
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(riscv_get_intc_hwnode);
+
 int arch_show_interrupts(struct seq_file *p, int prec)
 {
 	show_ipi_stats(p, prec);
diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index b65bd8878d4f..fa24ecd01d39 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -92,6 +92,11 @@ static const struct irq_domain_ops riscv_intc_domain_ops = {
 	.xlate	= irq_domain_xlate_onecell,
 };
 
+static struct fwnode_handle *riscv_intc_hwnode(void)
+{
+	return (intc_domain) ? intc_domain->fwnode : NULL;
+}
+
 static int __init riscv_intc_init(struct device_node *node,
 				  struct device_node *parent)
 {
@@ -119,6 +124,8 @@ static int __init riscv_intc_init(struct device_node *node,
 		return -ENXIO;
 	}
 
+	riscv_set_intc_hwnode_fn(riscv_intc_hwnode);
+
 	rc = set_handle_irq(&riscv_intc_irq);
 	if (rc) {
 		pr_err("failed to set irq handler\n");
-- 
2.25.1