v4.19.13 snapshot.
diff --git a/arch/powerpc/boot/opal.c b/arch/powerpc/boot/opal.c
new file mode 100644
index 0000000..0272570
--- /dev/null
+++ b/arch/powerpc/boot/opal.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2016 IBM Corporation.
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include "ops.h"
+#include "stdio.h"
+#include "io.h"
+#include <libfdt.h>
+#include "../include/asm/opal-api.h"
+
+#ifdef CONFIG_PPC64_BOOT_WRAPPER
+
+/* Global OPAL struct used by opal-call.S */
+struct opal {
+ u64 base;
+ u64 entry;
+} opal;
+
+static u32 opal_con_id;
+
+/* see opal-wrappers.S */
+int64_t opal_console_write(int64_t term_number, u64 *length, const u8 *buffer);
+int64_t opal_console_read(int64_t term_number, uint64_t *length, u8 *buffer);
+int64_t opal_console_write_buffer_space(uint64_t term_number, uint64_t *length);
+int64_t opal_console_flush(uint64_t term_number);
+int64_t opal_poll_events(uint64_t *outstanding_event_mask);
+
+void opal_kentry(unsigned long fdt_addr, void *vmlinux_addr);
+
+static int opal_con_open(void)
+{
+ /*
+ * When OPAL loads the boot kernel it stashes the OPAL base and entry
+ * address in r8 and r9 so the kernel can use the OPAL console
+ * before unflattening the devicetree. While executing the wrapper will
+ * probably trash r8 and r9 so this kentry hook restores them before
+ * entering the decompressed kernel.
+ */
+ platform_ops.kentry = opal_kentry;
+ return 0;
+}
+
+static void opal_con_putc(unsigned char c)
+{
+ int64_t rc;
+ uint64_t olen, len;
+
+ do {
+ rc = opal_console_write_buffer_space(opal_con_id, &olen);
+ len = be64_to_cpu(olen);
+ if (rc)
+ return;
+ opal_poll_events(NULL);
+ } while (len < 1);
+
+
+ olen = cpu_to_be64(1);
+ opal_console_write(opal_con_id, &olen, &c);
+}
+
+static void opal_con_close(void)
+{
+ opal_console_flush(opal_con_id);
+}
+
+static void opal_init(void)
+{
+ void *opal_node;
+
+ opal_node = finddevice("/ibm,opal");
+ if (!opal_node)
+ return;
+ if (getprop(opal_node, "opal-base-address", &opal.base, sizeof(u64)) < 0)
+ return;
+ opal.base = be64_to_cpu(opal.base);
+ if (getprop(opal_node, "opal-entry-address", &opal.entry, sizeof(u64)) < 0)
+ return;
+ opal.entry = be64_to_cpu(opal.entry);
+}
+
+int opal_console_init(void *devp, struct serial_console_data *scdp)
+{
+ opal_init();
+
+ if (devp) {
+ int n = getprop(devp, "reg", &opal_con_id, sizeof(u32));
+ if (n != sizeof(u32))
+ return -1;
+ opal_con_id = be32_to_cpu(opal_con_id);
+ } else
+ opal_con_id = 0;
+
+ scdp->open = opal_con_open;
+ scdp->putc = opal_con_putc;
+ scdp->close = opal_con_close;
+
+ return 0;
+}
+#else
+int opal_console_init(void *devp, struct serial_console_data *scdp)
+{
+ return -1;
+}
+#endif /* __powerpc64__ */