Message-ID: <20250529070017.7288-2-shubhrajyoti.datta@amd.com>
Date: Thu, 29 May 2025 12:30:13 +0530
From: Shubhrajyoti Datta <shubhrajyoti.datta@....com>
To: <linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>,
	<linux-edac@...r.kernel.org>
CC: <git@....com>, Krzysztof Kozlowski <krzk@...nel.org>, Rob Herring
	<robh@...nel.org>, Conor Dooley <conor+dt@...nel.org>, Borislav Petkov
	<bp@...en8.de>, Tony Luck <tony.luck@...el.com>, James Morse
	<james.morse@....com>, Mauro Carvalho Chehab <mchehab@...nel.org>, "Robert
 Richter" <rric@...nel.org>, Nipun Gupta <nipun.gupta@....com>, Nikhil Agarwal
	<nikhil.agarwal@....com>, Shubhrajyoti Datta <shubhrajyoti.datta@....com>
Subject: [PATCH v7 1/5] cdx: add the headers to include/linux

Add a the bitfield.h and mcdi.h headers.
This is in preparation for VersalNET EDAC
driver that relies on it.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@....com>
---

Changes in v7:
- add a minimal header instead moving them

Changes in v6:
 - Patch added

 include/linux/cdx/bitfield.h |  78 ++++++++++++++
 include/linux/cdx/mcdi.h     | 192 +++++++++++++++++++++++++++++++++++
 2 files changed, 270 insertions(+)
 create mode 100644 include/linux/cdx/bitfield.h
 create mode 100644 include/linux/cdx/mcdi.h

diff --git a/include/linux/cdx/bitfield.h b/include/linux/cdx/bitfield.h
new file mode 100644
index 000000000000..3f0bf2dbb2c7
--- /dev/null
+++ b/include/linux/cdx/bitfield.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright 2005-2006 Fen Systems Ltd.
+ * Copyright 2006-2013 Solarflare Communications Inc.
+ * Copyright (C) 2022-2025, 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;
+};
+
+/*
+ * 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 */
diff --git a/include/linux/cdx/mcdi.h b/include/linux/cdx/mcdi.h
new file mode 100644
index 000000000000..46e3f63b062a
--- /dev/null
+++ b/include/linux/cdx/mcdi.h
@@ -0,0 +1,192 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright 2008-2013 Solarflare Communications Inc.
+ * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
+ */
+
+#ifndef CDX_MCDI_H
+#define CDX_MCDI_H
+
+#include <linux/mutex.h>
+#include <linux/kref.h>
+#include <linux/rpmsg.h>
+
+#include "linux/cdx/bitfield.h"
+
+/**
+ * enum cdx_mcdi_mode - MCDI transaction mode
+ * @MCDI_MODE_EVENTS: wait for an mcdi response callback.
+ * @MCDI_MODE_FAIL: we think MCDI is dead, so fail-fast all calls
+ */
+enum cdx_mcdi_mode {
+	MCDI_MODE_EVENTS,
+	MCDI_MODE_FAIL,
+};
+
+#define MCDI_RPC_TIMEOUT	(10 * HZ)
+#define MCDI_RPC_LONG_TIMEOU	(60 * HZ)
+#define MCDI_RPC_POST_RST_TIME	(10 * HZ)
+
+/**
+ * enum cdx_mcdi_cmd_state - State for an individual MCDI command
+ * @MCDI_STATE_QUEUED: Command not started and is waiting to run.
+ * @MCDI_STATE_RETRY: Command was submitted and MC rejected with no resources,
+ *	as MC have too many outstanding commands. Command will be retried once
+ *	another command returns.
+ * @MCDI_STATE_RUNNING: Command was accepted and is running.
+ * @MCDI_STATE_RUNNING_CANCELLED: Command is running but the issuer cancelled
+ *	the command.
+ * @MCDI_STATE_FINISHED: Processing of this command has completed.
+ */
+
+enum cdx_mcdi_cmd_state {
+	MCDI_STATE_QUEUED,
+	MCDI_STATE_RETRY,
+	MCDI_STATE_RUNNING,
+	MCDI_STATE_RUNNING_CANCELLED,
+	MCDI_STATE_FINISHED,
+};
+
+/**
+ * struct cdx_mcdi - CDX MCDI Firmware interface, to interact
+ *	with CDX controller.
+ * @mcdi: MCDI interface
+ * @mcdi_ops: MCDI operations
+ * @r5_rproc : R5 Remoteproc device handle
+ * @rpdev: RPMsg device
+ * @ept: RPMsg endpoint
+ * @work: Post probe work
+ */
+struct cdx_mcdi {
+	/* MCDI interface */
+	struct cdx_mcdi_data *mcdi;
+	const struct cdx_mcdi_ops *mcdi_ops;
+
+	struct rproc *r5_rproc;
+	struct rpmsg_device *rpdev;
+	struct rpmsg_endpoint *ept;
+	struct work_struct work;
+};
+
+struct cdx_mcdi_ops {
+	void (*mcdi_request)(struct cdx_mcdi *cdx,
+			     const struct cdx_dword *hdr, size_t hdr_len,
+			     const struct cdx_dword *sdu, size_t sdu_len);
+	unsigned int (*mcdi_rpc_timeout)(struct cdx_mcdi *cdx, unsigned int cmd);
+};
+
+typedef void cdx_mcdi_async_completer(struct cdx_mcdi *cdx,
+				      unsigned long cookie, int rc,
+				      struct cdx_dword *outbuf,
+				      size_t outlen_actual);
+
+/**
+ * struct cdx_mcdi_cmd - An outstanding MCDI command
+ * @ref: Reference count. There will be one reference if the command is
+ *	in the mcdi_iface cmd_list, another if it's on a cleanup list,
+ *	and a third if it's queued in the work queue.
+ * @list: The data for this entry in mcdi->cmd_list
+ * @cleanup_list: The data for this entry in a cleanup list
+ * @work: The work item for this command, queued in mcdi->workqueue
+ * @mcdi: The mcdi_iface for this command
+ * @state: The state of this command
+ * @inlen: inbuf length
+ * @inbuf: Input buffer
+ * @quiet: Whether to silence errors
+ * @reboot_seen: Whether a reboot has been seen during this command,
+ *	to prevent duplicates
+ * @seq: Sequence number
+ * @started: Jiffies this command was started at
+ * @cookie: Context for completion function
+ * @completer: Completion function
+ * @handle: Command handle
+ * @cmd: Command number
+ * @rc: Return code
+ * @outlen: Length of output buffer
+ * @outbuf: Output buffer
+ */
+struct cdx_mcdi_cmd {
+	struct kref ref;
+	struct list_head list;
+	struct list_head cleanup_list;
+	struct work_struct work;
+	struct cdx_mcdi_iface *mcdi;
+	enum cdx_mcdi_cmd_state state;
+	size_t inlen;
+	const struct cdx_dword *inbuf;
+	bool quiet;
+	bool reboot_seen;
+	u8 seq;
+	unsigned long started;
+	unsigned long cookie;
+	cdx_mcdi_async_completer *completer;
+	unsigned int handle;
+	unsigned int cmd;
+	int rc;
+	size_t outlen;
+	struct cdx_dword *outbuf;
+	/* followed by inbuf data if necessary */
+};
+
+/**
+ * struct cdx_mcdi_iface - MCDI protocol context
+ * @cdx: The associated NIC
+ * @iface_lock: Serialise access to this structure
+ * @outstanding_cleanups: Count of cleanups
+ * @cmd_list: List of outstanding and running commands
+ * @workqueue: Workqueue used for delayed processing
+ * @cmd_complete_wq: Waitqueue for command completion
+ * @db_held_by: Command the MC doorbell is in use by
+ * @seq_held_by: Command each sequence number is in use by
+ * @prev_handle: The last used command handle
+ * @mode: Poll for mcdi completion, or wait for an mcdi_event
+ * @prev_seq: The last used sequence number
+ * @new_epoch: Indicates start of day or start of MC reboot recovery
+ */
+struct cdx_mcdi_iface {
+	struct cdx_mcdi *cdx;
+	/* Serialise access */
+	struct mutex iface_lock;
+	unsigned int outstanding_cleanups;
+	struct list_head cmd_list;
+	struct workqueue_struct *workqueue;
+	wait_queue_head_t cmd_complete_wq;
+	struct cdx_mcdi_cmd *db_held_by;
+	struct cdx_mcdi_cmd *seq_held_by[16];
+	unsigned int prev_handle;
+	enum cdx_mcdi_mode mode;
+	u8 prev_seq;
+	bool new_epoch;
+};
+
+/**
+ * struct cdx_mcdi_data - extra state for NICs that implement MCDI
+ * @iface: Interface/protocol state
+ * @fn_flags: Flags for this function, as returned by %MC_CMD_DRV_ATTACH.
+ */
+struct cdx_mcdi_data {
+	struct cdx_mcdi_iface iface;
+	u32 fn_flags;
+};
+
+/*
+ * We expect that 16- and 32-bit fields in MCDI requests and responses
+ * are appropriately aligned, but 64-bit fields are only
+ * 32-bit-aligned.
+ */
+#define MCDI_DECLARE_BUF(_name, _len) struct cdx_dword _name[DIV_ROUND_UP(_len, 4)] = {{0}}
+#define _MCDI_PTR(_buf, _offset)					\
+	((u8 *)(_buf) + (_offset))
+#define MCDI_PTR(_buf, _field)						\
+	_MCDI_PTR(_buf, MC_CMD_ ## _field ## _OFST)
+#define _MCDI_CHECK_ALIGN(_ofst, _align)				\
+	((void)BUILD_BUG_ON_ZERO((_ofst) & ((_align) - 1)),		\
+	 (_ofst))
+#define _MCDI_DWORD(_buf, _field)					\
+	((_buf) + (_MCDI_CHECK_ALIGN(MC_CMD_ ## _field ## _OFST, 4) >> 2))
+
+#define MCDI_SET_DWORD(_buf, _field, _value)				\
+	CDX_POPULATE_DWORD_1(*_MCDI_DWORD(_buf, _field), CDX_DWORD, _value)
+#define MCDI_DWORD(_buf, _field)					\
+	CDX_DWORD_FIELD(*_MCDI_DWORD(_buf, _field), CDX_DWORD)
+#endif /* CDX_MCDI_H */
-- 
2.34.1

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