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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>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc:     Atish Patra <atishp@atishpatra.org>,
        Andrew Jones <ajones@ventanamicro.com>,
        Sunil V L <sunilvl@ventanamicro.com>,
        Conor Dooley <conor@kernel.org>,
        Saravana Kannan <saravanak@google.com>,
        Anup Patel <anup@brainfault.org>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, Anup Patel <apatel@ventanamicro.com>
Subject: [PATCH v5 1/9] RISC-V: Add riscv_fw_parent_hartid() function
Date:   Mon, 10 Jul 2023 15:13:13 +0530
Message-Id: <20230710094321.1378351-2-apatel@ventanamicro.com>
In-Reply-To: <20230710094321.1378351-1-apatel@ventanamicro.com>
References: <20230710094321.1378351-1-apatel@ventanamicro.com>
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We add common riscv_fw_parent_hartid() which help device drivers
to get parent hartid of the INTC (i.e. local interrupt controller)
fwnode. This should work for both DT and ACPI.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 arch/riscv/include/asm/processor.h |  3 +++
 arch/riscv/kernel/cpu.c            | 16 ++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index c950a8d9edef..39dc23a18f88 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -81,6 +81,9 @@ int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
 
+struct fwnode_handle;
+int riscv_fw_parent_hartid(struct fwnode_handle *node, unsigned long *hartid);
+
 extern void riscv_fill_hwcap(void);
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index a2fc952318e9..9be9b3b1f333 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -96,6 +96,22 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
 	return -1;
 }
 
+/* Find hart ID of the CPU fwnode under which given fwnode falls. */
+int riscv_fw_parent_hartid(struct fwnode_handle *node, unsigned long *hartid)
+{
+	int rc;
+	u64 temp;
+
+	if (!is_of_node(node)) {
+		rc = fwnode_property_read_u64_array(node, "hartid", &temp, 1);
+		if (!rc)
+			*hartid = temp;
+	} else
+		rc = riscv_of_parent_hartid(to_of_node(node), hartid);
+
+	return rc;
+}
+
 DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
 
 unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
-- 
2.34.1