1 files changed, 75 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/hvconsole.c b/arch/powerpc/platforms/pseries/hvconsole.c
new file mode 100644
index 000000000..1ac52963e
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/hvconsole.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * hvconsole.c
+ * Copyright (C) 2004 Hollis Blanchard, IBM Corporation
+ * Copyright (C) 2004 IBM Corporation
+ *
+ * Additional Author(s):
+ *  Ryan S. Arnold <rsa@us.ibm.com>
+ *
+ * LPAR console support.
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <asm/hvcall.h>
+#include <asm/hvconsole.h>
+#include <asm/plpar_wrappers.h>
+
+/**
+ * hvc_get_chars - retrieve characters from firmware for denoted vterm adapter
+ * @vtermno: The vtermno or unit_address of the adapter from which to fetch the
+ *	data.
+ * @buf: The character buffer into which to put the character data fetched from
+ *	firmware.
+ * @count: not used?
+ */
+int hvc_get_chars(uint32_t vtermno, char *buf, int count)
+{
+	long ret;
+	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+	unsigned long *lbuf = (unsigned long *)buf;
+
+	ret = plpar_hcall(H_GET_TERM_CHAR, retbuf, vtermno);
+	lbuf[0] = be64_to_cpu(retbuf[1]);
+	lbuf[1] = be64_to_cpu(retbuf[2]);
+
+	if (ret == H_SUCCESS)
+		return retbuf[0];
+
+	return 0;
+}
+
+EXPORT_SYMBOL(hvc_get_chars);
+
+
+/**
+ * hvc_put_chars: send characters to firmware for denoted vterm adapter
+ * @vtermno: The vtermno or unit_address of the adapter from which the data
+ *	originated.
+ * @buf: The character buffer that contains the character data to send to
+ *	firmware. Must be at least 16 bytes, even if count is less than 16.
+ * @count: Send this number of characters.
+ */
+int hvc_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+	unsigned long *lbuf = (unsigned long *) buf;
+	long ret;
+
+
+	/* hcall will ret H_PARAMETER if 'count' exceeds firmware max.*/
+	if (count > MAX_VIO_PUT_CHARS)
+		count = MAX_VIO_PUT_CHARS;
+
+	ret = plpar_hcall_norets(H_PUT_TERM_CHAR, vtermno, count,
+				 cpu_to_be64(lbuf[0]),
+				 cpu_to_be64(lbuf[1]));
+	if (ret == H_SUCCESS)
+		return count;
+	if (ret == H_BUSY)
+		return -EAGAIN;
+	return -EIO;
+}
+
+EXPORT_SYMBOL(hvc_put_chars);