1 files changed, 118 insertions, 0 deletions
diff --git a/arch/riscv/lib/smp.c b/arch/riscv/lib/smp.c
new file mode 100644
index 0000000..caa292c
--- /dev/null
+++ b/arch/riscv/lib/smp.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Fraunhofer AISEC,
+ * Lukas Auer <lukas.auer@aisec.fraunhofer.de>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/barrier.h>
+#include <asm/smp.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * riscv_send_ipi() - Send inter-processor interrupt (IPI)
+ *
+ * Platform code must provide this function.
+ *
+ * @hart: Hart ID of receiving hart
+ * @return 0 if OK, -ve on error
+ */
+extern int riscv_send_ipi(int hart);
+
+/**
+ * riscv_clear_ipi() - Clear inter-processor interrupt (IPI)
+ *
+ * Platform code must provide this function.
+ *
+ * @hart: Hart ID of hart to be cleared
+ * @return 0 if OK, -ve on error
+ */
+extern int riscv_clear_ipi(int hart);
+
+static int send_ipi_many(struct ipi_data *ipi)
+{
+	ofnode node, cpus;
+	u32 reg;
+	int ret;
+
+	cpus = ofnode_path("/cpus");
+	if (!ofnode_valid(cpus)) {
+		pr_err("Can't find cpus node!\n");
+		return -EINVAL;
+	}
+
+	ofnode_for_each_subnode(node, cpus) {
+		/* skip if hart is marked as not available in the device tree */
+		if (!ofnode_is_available(node))
+			continue;
+
+		/* read hart ID of CPU */
+		ret = ofnode_read_u32(node, "reg", &reg);
+		if (ret)
+			continue;
+
+		/* skip if it is the hart we are running on */
+		if (reg == gd->arch.boot_hart)
+			continue;
+
+		if (reg >= CONFIG_NR_CPUS) {
+			pr_err("Hart ID %d is out of range, increase CONFIG_NR_CPUS\n",
+			       reg);
+			continue;
+		}
+
+		/* skip if hart is not available */
+		if (!(gd->arch.available_harts & (1 << reg)))
+			continue;
+
+		gd->arch.ipi[reg].addr = ipi->addr;
+		gd->arch.ipi[reg].arg0 = ipi->arg0;
+		gd->arch.ipi[reg].arg1 = ipi->arg1;
+
+		ret = riscv_send_ipi(reg);
+		if (ret) {
+			pr_err("Cannot send IPI to hart %d\n", reg);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+void handle_ipi(ulong hart)
+{
+	int ret;
+	void (*smp_function)(ulong hart, ulong arg0, ulong arg1);
+
+	if (hart >= CONFIG_NR_CPUS)
+		return;
+
+	ret = riscv_clear_ipi(hart);
+	if (ret) {
+		pr_err("Cannot clear IPI of hart %ld\n", hart);
+		return;
+	}
+
+	__smp_mb();
+
+	smp_function = (void (*)(ulong, ulong, ulong))gd->arch.ipi[hart].addr;
+	invalidate_icache_all();
+
+	smp_function(hart, gd->arch.ipi[hart].arg0, gd->arch.ipi[hart].arg1);
+}
+
+int smp_call_function(ulong addr, ulong arg0, ulong arg1)
+{
+	int ret = 0;
+	struct ipi_data ipi;
+
+	ipi.addr = addr;
+	ipi.arg0 = arg0;
+	ipi.arg1 = arg1;
+
+	ret = send_ipi_many(&ipi);
+
+	return ret;
+}