cdx: add MCDI protocol interface for firmware interaction

The MCDI (Management CPU Driver Interface) is used as a
protocol to communicate with the RPU firmware. It has
pre-defined set of messages for different message exchanges
between APU and RPU.

Signed-off-by: Puneet Gupta <puneet.gupta@amd.com>
Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
Signed-off-by: Tarak Reddy <tarak.reddy@amd.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Tested-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Link: https://lore.kernel.org/r/20230313132636.31850-5-nipun.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 90 insertions, 0 deletions

diff --git a/drivers/cdx/controller/bitfield.h b/drivers/cdx/controller/bitfield.h
new file mode 100644
index 000000000000..567f8ec47582
--- /dev/null
+++ b/drivers/cdx/controller/bitfield.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright 2005-2006 Fen Systems Ltd.
+ * Copyright 2006-2013 Solarflare Communications Inc.
+ * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
+ */
+
+#ifndef CDX_BITFIELD_H
+#define CDX_BITFIELD_H
+
+#include <linux/bitfield.h>
+
+/* Lowest bit numbers and widths */
+#define CDX_DWORD_LBN 0
+#define CDX_DWORD_WIDTH 32
+
+/* Specified attribute (e.g. LBN) of the specified field */
+#define CDX_VAL(field, attribute) field ## _ ## attribute
+/* Low bit number of the specified field */
+#define CDX_LOW_BIT(field) CDX_VAL(field, LBN)
+/* Bit width of the specified field */
+#define CDX_WIDTH(field) CDX_VAL(field, WIDTH)
+/* High bit number of the specified field */
+#define CDX_HIGH_BIT(field) (CDX_LOW_BIT(field) + CDX_WIDTH(field) - 1)
+
+/* A doubleword (i.e. 4 byte) datatype - little-endian in HW */
+struct cdx_dword {
+	__le32 cdx_u32;
+};
+
+/* Value expanders for printk */
+#define CDX_DWORD_VAL(dword)				\
+	((unsigned int)le32_to_cpu((dword).cdx_u32))
+
+/*
+ * Extract bit field portion [low,high) from the 32-bit little-endian
+ * element which contains bits [min,max)
+ */
+#define CDX_DWORD_FIELD(dword, field)					\
+	(FIELD_GET(GENMASK(CDX_HIGH_BIT(field), CDX_LOW_BIT(field)),	\
+		   le32_to_cpu((dword).cdx_u32)))
+
+/*
+ * Creates the portion of the named bit field that lies within the
+ * range [min,max).
+ */
+#define CDX_INSERT_FIELD(field, value)				\
+	(FIELD_PREP(GENMASK(CDX_HIGH_BIT(field),		\
+			    CDX_LOW_BIT(field)), value))
+
+/*
+ * Creates the portion of the named bit fields that lie within the
+ * range [min,max).
+ */
+#define CDX_INSERT_FIELDS(field1, value1,		\
+			  field2, value2,		\
+			  field3, value3,		\
+			  field4, value4,		\
+			  field5, value5,		\
+			  field6, value6,		\
+			  field7, value7)		\
+	(CDX_INSERT_FIELD(field1, (value1)) |		\
+	 CDX_INSERT_FIELD(field2, (value2)) |		\
+	 CDX_INSERT_FIELD(field3, (value3)) |		\
+	 CDX_INSERT_FIELD(field4, (value4)) |		\
+	 CDX_INSERT_FIELD(field5, (value5)) |		\
+	 CDX_INSERT_FIELD(field6, (value6)) |		\
+	 CDX_INSERT_FIELD(field7, (value7)))
+
+#define CDX_POPULATE_DWORD(dword, ...)					\
+	(dword).cdx_u32 = cpu_to_le32(CDX_INSERT_FIELDS(__VA_ARGS__))
+
+/* Populate a dword field with various numbers of arguments */
+#define CDX_POPULATE_DWORD_7 CDX_POPULATE_DWORD
+#define CDX_POPULATE_DWORD_6(dword, ...) \
+	CDX_POPULATE_DWORD_7(dword, CDX_DWORD, 0, __VA_ARGS__)
+#define CDX_POPULATE_DWORD_5(dword, ...) \
+	CDX_POPULATE_DWORD_6(dword, CDX_DWORD, 0, __VA_ARGS__)
+#define CDX_POPULATE_DWORD_4(dword, ...) \
+	CDX_POPULATE_DWORD_5(dword, CDX_DWORD, 0, __VA_ARGS__)
+#define CDX_POPULATE_DWORD_3(dword, ...) \
+	CDX_POPULATE_DWORD_4(dword, CDX_DWORD, 0, __VA_ARGS__)
+#define CDX_POPULATE_DWORD_2(dword, ...) \
+	CDX_POPULATE_DWORD_3(dword, CDX_DWORD, 0, __VA_ARGS__)
+#define CDX_POPULATE_DWORD_1(dword, ...) \
+	CDX_POPULATE_DWORD_2(dword, CDX_DWORD, 0, __VA_ARGS__)
+#define CDX_SET_DWORD(dword) \
+	CDX_POPULATE_DWORD_1(dword, CDX_DWORD, 0xffffffff)
+
+#endif /* CDX_BITFIELD_H */