add initial smp bringup

1 files changed, 43 insertions, 0 deletions

diff --git a/arch/riscv64/kernel/arch.c b/arch/riscv64/kernel/arch.c
new file mode 100644
index 0000000..c4009e7
--- /dev/null
+++ b/arch/riscv64/kernel/arch.c
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: copyleft-next-0.3.1 */
+/* Copyright 2023, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
+
+/**
+ * @file arch.c
+ * Misc riscv specific stuff implementations.
+ */
+
+#include <kmi/assert.h>
+#include <kmi/debug.h>
+#include "csr.h"
+#include "arch.h"
+
+id_t __cpuid_to_hartid[MAX_CPUS];
+
+id_t hartid_to_cpuid(id_t hart)
+{
+	for (size_t i = 0; i < MAX_CPUS; ++i)
+		if (cpuid_to_hartid(i) == hart)
+			return i;
+
+	error("failed to match hart id %d to cpu id\n", hart);
+	/* default to zero, though this should maybe be a panic? */
+	return 0;
+}
+
+pm_t branch_to_satp(struct vmem *branch, enum mm_mode mode)
+{
+	/* Sv57 && Sv64 in the future? */
+	branch = (struct vmem *)__pa(branch);
+	pm_t pn = (pm_t)(branch) >> page_shift();
+
+	pm_t m = DEFAULT_Sv_MODE;
+
+	switch (mode) {
+	case Sv32: m = SATP_MODE_Sv32; break;
+	case Sv39: m = SATP_MODE_Sv39; break;
+	case Sv48: m = SATP_MODE_Sv48; break;
+	default: bug("unknown satp mode\n"); break;
+	}
+
+	return m | pn;
+}