Merge branch 'iosm-driver'

M Chetan Kumar says:

====================
net: iosm: PCIe Driver for Intel M.2 Modem

The IOSM (IPC over Shared Memory) driver is a PCIe host driver implemented
for linux or chrome platform for data exchange over PCIe interface between
Host platform & Intel M.2 Modem. The driver exposes interface conforming to
the MBIM protocol. Any front end application ( eg: Modem Manager) could
easily manage the MBIM interface to enable data communication towards WWAN.

Intel M.2 modem uses 2 BAR regions. The first region is dedicated to Doorbell
register for IRQs and the second region is used as scratchpad area for book
keeping modem execution stage details along with host system shared memory
region context details. The upper edge of the driver exposes the control and
data channels for user space application interaction. At lower edge these data
and control channels are associated to pipes. The pipes are lowest level
interfaces used over PCIe as a logical channel for message exchange. A single
channel maps to UL and DL pipe and are initialized on device open.

On UL path, driver copies application sent data to SKBs associate it with
transfer descriptor and puts it on to ring buffer for DMA transfer. Once
information has been updated in shared memory region, host gives a Doorbell
to modem to perform DMA and modem uses MSI to communicate back to host.
For receiving data in DL path, SKBs are pre-allocated during pipe open and
transfer descriptors are given to modem for DMA transfer.

The driver exposes two types of ports, namely "wwan0mbim0", a char device node
which is used for MBIM control operation and "wwan0-x",(x = 0,1,2..7) network
interfaces for IP data communication.
1) MBIM Control Interface:
This node exposes an interface between modem and application using char device
exposed by "IOSM" driver to establish and manage the MBIM data communication
with PCIe based Intel M.2 Modems.

2) MBIM Data Interface:
The IOSM driver exposes IP link interface "wwan0-x" of type "wwan" for IP traffic.
Iproute network utility is used for creating "wwan0-x" network interface and for
associating it with MBIM IP session. The Driver supports upto 8 IP sessions for
simultaneous IP communication.

This applies on top of WWAN core rtnetlink series posted here:
https://lore.kernel.org/netdev/1623486057-13075-1-git-send-email-loic.poulain@linaro.org/

Also driver has been compiled and tested on top of netdev net-next tree.
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 444 insertions, 0 deletions

diff --git a/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.h b/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.h
new file mode 100644
index 000000000000..35aa1387306e
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.h
@@ -0,0 +1,444 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#ifndef IOSM_IPC_PROTOCOL_OPS_H
+#define IOSM_IPC_PROTOCOL_OPS_H
+
+#define SIZE_MASK 0x00FFFFFF
+#define COMPLETION_STATUS 24
+#define RESET_BIT 7
+
+/**
+ * enum ipc_mem_td_cs - Completion status of a TD
+ * @IPC_MEM_TD_CS_INVALID:	      Initial status - td not yet used.
+ * @IPC_MEM_TD_CS_PARTIAL_TRANSFER:   More data pending -> next TD used for this
+ * @IPC_MEM_TD_CS_END_TRANSFER:	      IO transfer is complete.
+ * @IPC_MEM_TD_CS_OVERFLOW:	      IO transfer to small for the buff to write
+ * @IPC_MEM_TD_CS_ABORT:	      TD marked as abort and shall be discarded
+ *				      by AP.
+ * @IPC_MEM_TD_CS_ERROR:	      General error.
+ */
+enum ipc_mem_td_cs {
+	IPC_MEM_TD_CS_INVALID,
+	IPC_MEM_TD_CS_PARTIAL_TRANSFER,
+	IPC_MEM_TD_CS_END_TRANSFER,
+	IPC_MEM_TD_CS_OVERFLOW,
+	IPC_MEM_TD_CS_ABORT,
+	IPC_MEM_TD_CS_ERROR,
+};
+
+/**
+ * enum ipc_mem_msg_cs - Completion status of IPC Message
+ * @IPC_MEM_MSG_CS_INVALID:	Initial status.
+ * @IPC_MEM_MSG_CS_SUCCESS:	IPC Message completion success.
+ * @IPC_MEM_MSG_CS_ERROR:	Message send error.
+ */
+enum ipc_mem_msg_cs {
+	IPC_MEM_MSG_CS_INVALID,
+	IPC_MEM_MSG_CS_SUCCESS,
+	IPC_MEM_MSG_CS_ERROR,
+};
+
+/**
+ * struct ipc_msg_prep_args_pipe - struct for pipe args for message preparation
+ * @pipe:	Pipe to open/close
+ */
+struct ipc_msg_prep_args_pipe {
+	struct ipc_pipe *pipe;
+};
+
+/**
+ * struct ipc_msg_prep_args_sleep - struct for sleep args for message
+ *				    preparation
+ * @target:	0=host, 1=device
+ * @state:	0=enter sleep, 1=exit sleep
+ */
+struct ipc_msg_prep_args_sleep {
+	unsigned int target;
+	unsigned int state;
+};
+
+/**
+ * struct ipc_msg_prep_feature_set - struct for feature set argument for
+ *				     message preparation
+ * @reset_enable:	0=out-of-band, 1=in-band-crash notification
+ */
+struct ipc_msg_prep_feature_set {
+	u8 reset_enable;
+};
+
+/**
+ * struct ipc_msg_prep_map - struct for map argument for message preparation
+ * @region_id:	Region to map
+ * @addr:	Pcie addr of region to map
+ * @size:	Size of the region to map
+ */
+struct ipc_msg_prep_map {
+	unsigned int region_id;
+	unsigned long addr;
+	size_t size;
+};
+
+/**
+ * struct ipc_msg_prep_unmap - struct for unmap argument for message preparation
+ * @region_id:	Region to unmap
+ */
+struct ipc_msg_prep_unmap {
+	unsigned int region_id;
+};
+
+/**
+ * struct ipc_msg_prep_args - Union to handle different message types
+ * @pipe_open:		Pipe open message preparation struct
+ * @pipe_close:		Pipe close message preparation struct
+ * @sleep:		Sleep message preparation struct
+ * @feature_set:	Feature set message preparation struct
+ * @map:		Memory map message preparation struct
+ * @unmap:		Memory unmap message preparation struct
+ */
+union ipc_msg_prep_args {
+	struct ipc_msg_prep_args_pipe pipe_open;
+	struct ipc_msg_prep_args_pipe pipe_close;
+	struct ipc_msg_prep_args_sleep sleep;
+	struct ipc_msg_prep_feature_set feature_set;
+	struct ipc_msg_prep_map map;
+	struct ipc_msg_prep_unmap unmap;
+};
+
+/**
+ * enum ipc_msg_prep_type - Enum for message prepare actions
+ * @IPC_MSG_PREP_SLEEP:		Sleep message preparation type
+ * @IPC_MSG_PREP_PIPE_OPEN:	Pipe open message preparation type
+ * @IPC_MSG_PREP_PIPE_CLOSE:	Pipe close message preparation type
+ * @IPC_MSG_PREP_FEATURE_SET:	Feature set message preparation type
+ * @IPC_MSG_PREP_MAP:		Memory map message preparation type
+ * @IPC_MSG_PREP_UNMAP:		Memory unmap message preparation type
+ */
+enum ipc_msg_prep_type {
+	IPC_MSG_PREP_SLEEP,
+	IPC_MSG_PREP_PIPE_OPEN,
+	IPC_MSG_PREP_PIPE_CLOSE,
+	IPC_MSG_PREP_FEATURE_SET,
+	IPC_MSG_PREP_MAP,
+	IPC_MSG_PREP_UNMAP,
+};
+
+/**
+ * struct ipc_rsp - Response to sent message
+ * @completion:	For waking up requestor
+ * @status:	Completion status
+ */
+struct ipc_rsp {
+	struct completion completion;
+	enum ipc_mem_msg_cs status;
+};
+
+/**
+ * enum ipc_mem_msg - Type-definition of the messages.
+ * @IPC_MEM_MSG_OPEN_PIPE:	AP ->CP: Open a pipe
+ * @IPC_MEM_MSG_CLOSE_PIPE:	AP ->CP: Close a pipe
+ * @IPC_MEM_MSG_ABORT_PIPE:	AP ->CP: wait for completion of the
+ *				running transfer and abort all pending
+ *				IO-transfers for the pipe
+ * @IPC_MEM_MSG_SLEEP:		AP ->CP: host enter or exit sleep
+ * @IPC_MEM_MSG_FEATURE_SET:	AP ->CP: Intel feature configuration
+ */
+enum ipc_mem_msg {
+	IPC_MEM_MSG_OPEN_PIPE = 0x01,
+	IPC_MEM_MSG_CLOSE_PIPE = 0x02,
+	IPC_MEM_MSG_ABORT_PIPE = 0x03,
+	IPC_MEM_MSG_SLEEP = 0x04,
+	IPC_MEM_MSG_FEATURE_SET = 0xF0,
+};
+
+/**
+ * struct ipc_mem_msg_open_pipe - Message structure for open pipe
+ * @tdr_addr:			Tdr address
+ * @tdr_entries:		Tdr entries
+ * @pipe_nr:			Pipe number
+ * @type_of_message:		Message type
+ * @irq_vector:			MSI vector number
+ * @accumulation_backoff:	Time in usec for data accumalation
+ * @completion_status:		Message Completion Status
+ */
+struct ipc_mem_msg_open_pipe {
+	__le64 tdr_addr;
+	__le16 tdr_entries;
+	u8 pipe_nr;
+	u8 type_of_message;
+	__le32 irq_vector;
+	__le32 accumulation_backoff;
+	__le32 completion_status;
+};
+
+/**
+ * struct ipc_mem_msg_close_pipe - Message structure for close pipe
+ * @reserved1:			Reserved
+ * @reserved2:			Reserved
+ * @pipe_nr:			Pipe number
+ * @type_of_message:		Message type
+ * @reserved3:			Reserved
+ * @reserved4:			Reserved
+ * @completion_status:		Message Completion Status
+ */
+struct ipc_mem_msg_close_pipe {
+	__le32 reserved1[2];
+	__le16 reserved2;
+	u8 pipe_nr;
+	u8 type_of_message;
+	__le32  reserved3;
+	__le32 reserved4;
+	__le32 completion_status;
+};
+
+/**
+ * struct ipc_mem_msg_abort_pipe - Message structure for abort pipe
+ * @reserved1:			Reserved
+ * @reserved2:			Reserved
+ * @pipe_nr:			Pipe number
+ * @type_of_message:		Message type
+ * @reserved3:			Reserved
+ * @reserved4:			Reserved
+ * @completion_status:		Message Completion Status
+ */
+struct ipc_mem_msg_abort_pipe {
+	__le32  reserved1[2];
+	__le16 reserved2;
+	u8 pipe_nr;
+	u8 type_of_message;
+	__le32 reserved3;
+	__le32 reserved4;
+	__le32 completion_status;
+};
+
+/**
+ * struct ipc_mem_msg_host_sleep - Message structure for sleep message.
+ * @reserved1:		Reserved
+ * @target:		0=host, 1=device, host or EP devie
+ *			is the message target
+ * @state:		0=enter sleep, 1=exit sleep,
+ *			2=enter sleep no protocol
+ * @reserved2:		Reserved
+ * @type_of_message:	Message type
+ * @reserved3:		Reserved
+ * @reserved4:		Reserved
+ * @completion_status:	Message Completion Status
+ */
+struct ipc_mem_msg_host_sleep {
+	__le32 reserved1[2];
+	u8 target;
+	u8 state;
+	u8 reserved2;
+	u8 type_of_message;
+	__le32 reserved3;
+	__le32 reserved4;
+	__le32 completion_status;
+};
+
+/**
+ * struct ipc_mem_msg_feature_set - Message structure for feature_set message
+ * @reserved1:			Reserved
+ * @reserved2:			Reserved
+ * @reset_enable:		0=out-of-band, 1=in-band-crash notification
+ * @type_of_message:		Message type
+ * @reserved3:			Reserved
+ * @reserved4:			Reserved
+ * @completion_status:		Message Completion Status
+ */
+struct ipc_mem_msg_feature_set {
+	__le32 reserved1[2];
+	__le16 reserved2;
+	u8 reset_enable;
+	u8 type_of_message;
+	__le32 reserved3;
+	__le32 reserved4;
+	__le32 completion_status;
+};
+
+/**
+ * struct ipc_mem_msg_common - Message structure for completion status update.
+ * @reserved1:			Reserved
+ * @reserved2:			Reserved
+ * @type_of_message:		Message type
+ * @reserved3:			Reserved
+ * @reserved4:			Reserved
+ * @completion_status:		Message Completion Status
+ */
+struct ipc_mem_msg_common {
+	__le32 reserved1[2];
+	u8 reserved2[3];
+	u8 type_of_message;
+	__le32 reserved3;
+	__le32 reserved4;
+	__le32 completion_status;
+};
+
+/**
+ * union ipc_mem_msg_entry - Union with all possible messages.
+ * @open_pipe:		Open pipe message struct
+ * @close_pipe:		Close pipe message struct
+ * @abort_pipe:		Abort pipe message struct
+ * @host_sleep:		Host sleep message struct
+ * @feature_set:	Featuer set message struct
+ * @common:		Used to access msg_type and to set the completion status
+ */
+union ipc_mem_msg_entry {
+	struct ipc_mem_msg_open_pipe open_pipe;
+	struct ipc_mem_msg_close_pipe close_pipe;
+	struct ipc_mem_msg_abort_pipe abort_pipe;
+	struct ipc_mem_msg_host_sleep host_sleep;
+	struct ipc_mem_msg_feature_set feature_set;
+	struct ipc_mem_msg_common common;
+};
+
+/* Transfer descriptor definition. */
+struct ipc_protocol_td {
+	union {
+		/*   0 :  63 - 64-bit address of a buffer in host memory. */
+		dma_addr_t address;
+		struct {
+			/*   0 :  31 - 32 bit address */
+			__le32 address;
+			/*  32 :  63 - corresponding descriptor */
+			__le32 desc;
+		} __packed shm;
+	} buffer;
+
+	/*	0 - 2nd byte - Size of the buffer.
+	 *	The host provides the size of the buffer queued.
+	 *	The EP device reads this value and shall update
+	 *	it for downlink transfers to indicate the
+	 *	amount of data written in buffer.
+	 *	3rd byte - This field provides the completion status
+	 *	of the TD. When queuing the TD, the host sets
+	 *	the status to 0. The EP device updates this
+	 *	field when completing the TD.
+	 */
+	__le32 scs;
+
+	/*	0th - nr of following descriptors
+	 *	1 - 3rd byte - reserved
+	 */
+	__le32 next;
+} __packed;
+
+/**
+ * ipc_protocol_msg_prep - Prepare message based upon message type
+ * @ipc_imem:	iosm_protocol instance
+ * @msg_type:	message prepare type
+ * @args:	message arguments
+ *
+ * Return: 0 on success and failure value on error
+ */
+int ipc_protocol_msg_prep(struct iosm_imem *ipc_imem,
+			  enum ipc_msg_prep_type msg_type,
+			  union ipc_msg_prep_args *args);
+
+/**
+ * ipc_protocol_msg_hp_update - Function for head pointer update
+ *				of message ring
+ * @ipc_imem:	iosm_protocol instance
+ */
+void ipc_protocol_msg_hp_update(struct iosm_imem *ipc_imem);
+
+/**
+ * ipc_protocol_msg_process - Function for processing responses
+ *			      to IPC messages
+ * @ipc_imem:	iosm_protocol instance
+ * @irq:	IRQ vector
+ *
+ * Return:	True on success, false if error
+ */
+bool ipc_protocol_msg_process(struct iosm_imem *ipc_imem, int irq);
+
+/**
+ * ipc_protocol_ul_td_send - Function for sending the data to CP
+ * @ipc_protocol:	iosm_protocol instance
+ * @pipe:		Pipe instance
+ * @p_ul_list:		uplink sk_buff list
+ *
+ * Return: true in success, false in case of error
+ */
+bool ipc_protocol_ul_td_send(struct iosm_protocol *ipc_protocol,
+			     struct ipc_pipe *pipe,
+			     struct sk_buff_head *p_ul_list);
+
+/**
+ * ipc_protocol_ul_td_process - Function for processing the sent data
+ * @ipc_protocol:	iosm_protocol instance
+ * @pipe:		Pipe instance
+ *
+ * Return: sk_buff instance
+ */
+struct sk_buff *ipc_protocol_ul_td_process(struct iosm_protocol *ipc_protocol,
+					   struct ipc_pipe *pipe);
+
+/**
+ * ipc_protocol_dl_td_prepare - Function for providing DL TDs to CP
+ * @ipc_protocol:	iosm_protocol instance
+ * @pipe:		Pipe instance
+ *
+ * Return: true in success, false in case of error
+ */
+bool ipc_protocol_dl_td_prepare(struct iosm_protocol *ipc_protocol,
+				struct ipc_pipe *pipe);
+
+/**
+ * ipc_protocol_dl_td_process - Function for processing the DL data
+ * @ipc_protocol:	iosm_protocol instance
+ * @pipe:		Pipe instance
+ *
+ * Return: sk_buff instance
+ */
+struct sk_buff *ipc_protocol_dl_td_process(struct iosm_protocol *ipc_protocol,
+					   struct ipc_pipe *pipe);
+
+/**
+ * ipc_protocol_get_head_tail_index - Function for getting Head and Tail
+ *				      pointer index of given pipe
+ * @ipc_protocol:	iosm_protocol instance
+ * @pipe:		Pipe Instance
+ * @head:		head pointer index of the given pipe
+ * @tail:		tail pointer index of the given pipe
+ */
+void ipc_protocol_get_head_tail_index(struct iosm_protocol *ipc_protocol,
+				      struct ipc_pipe *pipe, u32 *head,
+				      u32 *tail);
+/**
+ * ipc_protocol_get_ipc_status - Function for getting the IPC Status
+ * @ipc_protocol:	iosm_protocol instance
+ *
+ * Return: Returns IPC State
+ */
+enum ipc_mem_device_ipc_state ipc_protocol_get_ipc_status(struct iosm_protocol
+							  *ipc_protocol);
+
+/**
+ * ipc_protocol_pipe_cleanup - Function to cleanup pipe resources
+ * @ipc_protocol:	iosm_protocol instance
+ * @pipe:		Pipe instance
+ */
+void ipc_protocol_pipe_cleanup(struct iosm_protocol *ipc_protocol,
+			       struct ipc_pipe *pipe);
+
+/**
+ * ipc_protocol_get_ap_exec_stage - Function for getting AP Exec Stage
+ * @ipc_protocol:	pointer to struct iosm protocol
+ *
+ * Return: returns BOOT Stages
+ */
+enum ipc_mem_exec_stage
+ipc_protocol_get_ap_exec_stage(struct iosm_protocol *ipc_protocol);
+
+/**
+ * ipc_protocol_pm_dev_get_sleep_notification - Function for getting Dev Sleep
+ *						notification
+ * @ipc_protocol:	iosm_protocol instance
+ *
+ * Return: Returns dev PM State
+ */
+u32 ipc_protocol_pm_dev_get_sleep_notification(struct iosm_protocol
+					       *ipc_protocol);
+#endif