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-rw-r--r--src/arch/riscv/smp.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/src/arch/riscv/smp.c b/src/arch/riscv/smp.c
new file mode 100644
index 0000000000..8d07d39ded
--- /dev/null
+++ b/src/arch/riscv/smp.c
@@ -0,0 +1,85 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2018 HardenedLinux.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <stddef.h>
+#include <arch/encoding.h>
+#include <arch/smp/smp.h>
+#include <arch/smp/spinlock.h>
+#include <mcall.h>
+#include <commonlib/compiler.h>
+#include <console/console.h>
+
+void smp_pause(int working_hartid)
+{
+#define SYNCA (OTHER_HLS(working_hartid)->entry.sync_a)
+#define SYNCB (OTHER_HLS(working_hartid)->entry.sync_b)
+
+ int hartid = read_csr(mhartid);
+
+ if (hartid != working_hartid) {
+ /* waiting for work hart */
+ do {
+ barrier();
+ } while (SYNCA != 0x01234567);
+
+ clear_csr(mstatus, MSTATUS_MIE);
+ write_csr(mie, MIP_MSIP);
+
+ /* count how many cores enter the halt */
+ __sync_fetch_and_add(&SYNCB, 1);
+
+ do {
+ barrier();
+ __asm__ volatile ("wfi");
+ } while ((read_csr(mip) & MIP_MSIP) == 0);
+ set_msip(hartid, 0);
+ HLS()->entry.fn(HLS()->entry.arg);
+ } else {
+ /* Initialize the counter and
+ * mark the work hart into smp_pause */
+ SYNCB = 0;
+ SYNCA = 0x01234567;
+
+ /* waiting for other Hart to enter the halt */
+ do {
+ barrier();
+ } while (SYNCB + 1 < CONFIG_RISCV_HART_NUM);
+
+ /* initialize for the next call */
+ SYNCA = 0;
+ SYNCB = 0;
+ }
+#undef SYNCA
+#undef SYNCB
+}
+
+void smp_resume(void (*fn)(void *), void *arg)
+{
+ int hartid = read_csr(mhartid);
+
+ if (fn == NULL)
+ die("must pass a non-null function pointer\n");
+
+ for (int i = 0; i < CONFIG_RISCV_HART_NUM; i++) {
+ OTHER_HLS(i)->entry.fn = fn;
+ OTHER_HLS(i)->entry.arg = arg;
+ }
+
+ for (int i = 0; i < CONFIG_RISCV_HART_NUM; i++)
+ if (i != hartid)
+ set_msip(i, 1);
+
+ HLS()->entry.fn(HLS()->entry.arg);
+}