[PATCH 3/8] staging/mei: MEI "Link" layer code - MEI Hardware communications.

[Oren Weil]

functions that handle the communication between clients.
e.g. connect/disconnect to/from a client, send MEI message,
read MEI message, flow control handling.

Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Signed-off-by: Itzhak Tzeel-Krupp <itzhak.tzeel-krupp@xxxxxxxxx>
Signed-off-by: Oren Weil <oren.jer.weil@xxxxxxxxx>
---
 drivers/staging/mei/interface.c |  440 +++++++++++++++++++++++++++++++++++++++
 drivers/staging/mei/interface.h |  124 +++++++++++
 2 files changed, 564 insertions(+), 0 deletions(-)
 create mode 100644 drivers/staging/mei/interface.c
 create mode 100644 drivers/staging/mei/interface.h

diff --git a/drivers/staging/mei/interface.c b/drivers/staging/mei/interface.c
new file mode 100644
index 0000000..620770b
--- /dev/null
+++ b/drivers/staging/mei/interface.c
@@ -0,0 +1,440 @@
+/*
+ *
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2003-2011, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/pci.h>
+#include "mei.h"
+#include "interface.h"
+
+
+
+/**
+ * mei_set_csr_register - writes H_CSR register to the mei device,
+ * and ignores the H_IS bit for it is write-one-to-zero.
+ *
+ * @dev: the device structure
+ */
+void mei_hcsr_set(struct mei_device *dev)
+{
+	if ((dev->host_hw_state & H_IS) == H_IS)
+		dev->host_hw_state &= ~H_IS;
+	mei_reg_write(dev, H_CSR, dev->host_hw_state);
+	dev->host_hw_state = mei_hcsr_read(dev);
+}
+
+/**
+ * mei_csr_enable_interrupts - enables mei device interrupts
+ *
+ * @dev: the device structure
+ */
+void mei_enable_interrupts(struct mei_device *dev)
+{
+	dev->host_hw_state |= H_IE;
+	mei_hcsr_set(dev);
+}
+
+/**
+ * mei_csr_disable_interrupts - disables mei device interrupts
+ *
+ * @dev: the device structure
+ */
+void mei_disable_interrupts(struct mei_device *dev)
+{
+	dev->host_hw_state &= ~H_IE;
+	mei_hcsr_set(dev);
+}
+
+/**
+ * _host_get_filled_slots - gets number of device filled buffer slots
+ *
+ * @device: the device structure
+ *
+ * returns number of filled slots
+ */
+static unsigned char _host_get_filled_slots(const struct mei_device *dev)
+{
+	char read_ptr, write_ptr;
+
+	read_ptr = (char) ((dev->host_hw_state & H_CBRP) >> 8);
+	write_ptr = (char) ((dev->host_hw_state & H_CBWP) >> 16);
+
+	return (unsigned char) (write_ptr - read_ptr);
+}
+
+/**
+ * mei_host_buffer_is_empty - checks if host buffer is empty.
+ *
+ * @dev: the device structure
+ *
+ * returns 1 if empty, 0 - otherwise.
+ */
+int mei_host_buffer_is_empty(struct mei_device *dev)
+{
+	unsigned char filled_slots;
+
+	dev->host_hw_state = mei_hcsr_read(dev);
+	filled_slots = _host_get_filled_slots(dev);
+
+	if (filled_slots == 0)
+		return 1;
+
+	return 0;
+}
+
+/**
+ * mei_count_empty_write_slots - counts write empty slots.
+ *
+ * @dev: the device structure
+ *
+ * returns -1(ESLOTS_OVERFLOW) if overflow, otherwise empty slots count
+ */
+int mei_count_empty_write_slots(struct mei_device *dev)
+{
+	unsigned char buffer_depth, filled_slots, empty_slots;
+
+	dev->host_hw_state = mei_hcsr_read(dev);
+	buffer_depth = (unsigned char) ((dev->host_hw_state & H_CBD) >> 24);
+	filled_slots = _host_get_filled_slots(dev);
+	empty_slots = buffer_depth - filled_slots;
+
+	/* check for overflow */
+	if (filled_slots > buffer_depth)
+		return -EOVERFLOW;
+
+	return empty_slots;
+}
+
+/**
+ * mei_write_message - writes a message to mei device.
+ *
+ * @dev: the device structure
+ * @header: header of message
+ * @write_buffer: message buffer will be written
+ * @write_length: message size will be written
+ *
+ * returns 1 if success, 0 - otherwise.
+ */
+int mei_write_message(struct mei_device *dev,
+			     struct mei_msg_hdr *header,
+			     unsigned char *write_buffer,
+			     unsigned long write_length)
+{
+	u32 temp_msg = 0;
+	unsigned long bytes_written = 0;
+	unsigned char buffer_depth, filled_slots, empty_slots;
+	unsigned long dw_to_write;
+
+	dev->host_hw_state = mei_hcsr_read(dev);
+
+	dev_dbg(&dev->pdev->dev,
+			"host_hw_state = 0x%08x.\n",
+			dev->host_hw_state);
+
+	dev_dbg(&dev->pdev->dev,
+			"mei_write_message header=%08x.\n",
+			*((u32 *) header));
+
+	buffer_depth = (unsigned char) ((dev->host_hw_state & H_CBD) >> 24);
+	filled_slots = _host_get_filled_slots(dev);
+	empty_slots = buffer_depth - filled_slots;
+	dev_dbg(&dev->pdev->dev,
+			"filled = %hu, empty = %hu.\n",
+			filled_slots, empty_slots);
+
+	dw_to_write = ((write_length + 3) / 4);
+
+	if (dw_to_write > empty_slots)
+		return 0;
+
+	mei_reg_write(dev, H_CB_WW, *((u32 *) header));
+
+	while (write_length >= 4) {
+		mei_reg_write(dev, H_CB_WW,
+				*(u32 *) (write_buffer + bytes_written));
+		bytes_written += 4;
+		write_length -= 4;
+	}
+
+	if (write_length > 0) {
+		memcpy(&temp_msg, &write_buffer[bytes_written], write_length);
+		mei_reg_write(dev, H_CB_WW, temp_msg);
+	}
+
+	dev->host_hw_state |= H_IG;
+	mei_hcsr_set(dev);
+	dev->me_hw_state = mei_mecsr_read(dev);
+	if ((dev->me_hw_state & ME_RDY_HRA) != ME_RDY_HRA)
+		return 0;
+
+	dev->write_hang = 0;
+	return 1;
+}
+
+/**
+ * mei_count_full_read_slots - counts read full slots.
+ *
+ * @dev: the device structure
+ *
+ * returns -1(ESLOTS_OVERFLOW) if overflow, otherwise filled slots count
+ */
+int mei_count_full_read_slots(struct mei_device *dev)
+{
+	char read_ptr, write_ptr;
+	unsigned char buffer_depth, filled_slots;
+
+	dev->me_hw_state = mei_mecsr_read(dev);
+	buffer_depth = (unsigned char)((dev->me_hw_state & ME_CBD_HRA) >> 24);
+	read_ptr = (char) ((dev->me_hw_state & ME_CBRP_HRA) >> 8);
+	write_ptr = (char) ((dev->me_hw_state & ME_CBWP_HRA) >> 16);
+	filled_slots = (unsigned char) (write_ptr - read_ptr);
+
+	/* check for overflow */
+	if (filled_slots > buffer_depth)
+		return -EOVERFLOW;
+
+	dev_dbg(&dev->pdev->dev, "filled_slots =%08x\n", filled_slots);
+	return (int)filled_slots;
+}
+
+/**
+ * mei_read_slots - reads a message from mei device.
+ *
+ * @dev: the device structure
+ * @buffer: message buffer will be written
+ * @buffer_length: message size will be read
+ */
+void mei_read_slots(struct mei_device *dev,
+		     unsigned char *buffer, unsigned long buffer_length)
+{
+	u32 i = 0;
+	unsigned char temp_buf[sizeof(u32)];
+
+	while (buffer_length >= sizeof(u32)) {
+		((u32 *) buffer)[i] = mei_mecbrw_read(dev);
+
+		dev_dbg(&dev->pdev->dev,
+				"buffer[%d]= %d\n",
+				i, ((u32 *) buffer)[i]);
+
+		i++;
+		buffer_length -= sizeof(u32);
+	}
+
+	if (buffer_length > 0) {
+		*((u32 *) &temp_buf) = mei_mecbrw_read(dev);
+		memcpy(&buffer[i * 4], temp_buf, buffer_length);
+	}
+
+	dev->host_hw_state |= H_IG;
+	mei_hcsr_set(dev);
+}
+
+/**
+ * mei_flow_ctrl_creds - checks flow_control credentials.
+ *
+ * @dev: the device structure
+ * @file_ext: private data of the file object
+ *
+ * returns 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
+ */
+int mei_flow_ctrl_creds(struct mei_device *dev, struct mei_cl *file_ext)
+{
+	int i;
+
+	if (!dev->num_mei_me_clients)
+		return 0;
+
+	if (file_ext == NULL)
+		return 0;
+
+	if (file_ext->mei_flow_ctrl_creds > 0)
+		return 1;
+
+	for (i = 0; i < dev->num_mei_me_clients; i++) {
+		if (dev->me_clients[i].client_id == file_ext->me_client_id) {
+			if (dev->me_clients[i].mei_flow_ctrl_creds > 0) {
+				BUG_ON(dev->me_clients[i].props.single_recv_buf
+					 == 0);
+				return 1;
+			}
+			return 0;
+		}
+	}
+	BUG();
+	return 0;
+}
+
+/**
+ * mei_flow_ctrl_reduce - reduces flow_control.
+ *
+ * @dev: the device structure
+ * @file_ext: private data of the file object
+ */
+void mei_flow_ctrl_reduce(struct mei_device *dev, struct mei_cl *file_ext)
+{
+	int i;
+
+	if (!dev->num_mei_me_clients)
+		return;
+
+	for (i = 0; i < dev->num_mei_me_clients; i++) {
+		if (dev->me_clients[i].client_id == file_ext->me_client_id) {
+			if (dev->me_clients[i].props.single_recv_buf != 0) {
+				BUG_ON(dev->me_clients[i].mei_flow_ctrl_creds
+						<= 0);
+				dev->me_clients[i].mei_flow_ctrl_creds--;
+			} else {
+				BUG_ON(file_ext->mei_flow_ctrl_creds <= 0);
+				file_ext->mei_flow_ctrl_creds--;
+			}
+			return;
+		}
+	}
+	BUG();
+}
+
+/**
+ * mei_send_flow_control - sends flow control to fw.
+ *
+ * @dev: the device structure
+ * @file_ext: private data of the file object
+ *
+ * returns 1 if success, 0 - otherwise.
+ */
+int mei_send_flow_control(struct mei_device *dev, struct mei_cl *file_ext)
+{
+	struct mei_msg_hdr *mei_hdr;
+	struct hbm_flow_control *mei_flow_control;
+
+	mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
+	mei_hdr->host_addr = 0;
+	mei_hdr->me_addr = 0;
+	mei_hdr->length = sizeof(struct hbm_flow_control);
+	mei_hdr->msg_complete = 1;
+	mei_hdr->reserved = 0;
+
+	mei_flow_control = (struct hbm_flow_control *) &dev->wr_msg_buf[1];
+	memset(mei_flow_control, 0, sizeof(mei_flow_control));
+	mei_flow_control->host_addr = file_ext->host_client_id;
+	mei_flow_control->me_addr = file_ext->me_client_id;
+	mei_flow_control->cmd.cmd = MEI_FLOW_CONTROL_CMD;
+	memset(mei_flow_control->reserved, 0,
+			sizeof(mei_flow_control->reserved));
+	dev_dbg(&dev->pdev->dev, "sending flow control host client = %d, ME client = %d\n",
+	    file_ext->host_client_id, file_ext->me_client_id);
+	if (!mei_write_message(dev, mei_hdr,
+				(unsigned char *) mei_flow_control,
+				sizeof(struct hbm_flow_control)))
+		return 0;
+
+	return 1;
+
+}
+
+/**
+ * mei_other_client_is_connecting - checks if other
+ *    client with the same client id is connected.
+ *
+ * @dev: the device structure
+ * @file_ext: private data of the file object
+ *
+ * returns 1 if other client is connected, 0 - otherwise.
+ */
+int mei_other_client_is_connecting(struct mei_device *dev,
+				struct mei_cl *file_ext)
+{
+	struct mei_cl *file_pos = NULL;
+	struct mei_cl *file_next = NULL;
+
+	list_for_each_entry_safe(file_pos, file_next, &dev->file_list, link) {
+		if ((file_pos->state == MEI_FILE_CONNECTING) &&
+			(file_pos != file_ext) &&
+			file_ext->me_client_id == file_pos->me_client_id)
+			return 1;
+
+	}
+	return 0;
+}
+
+/**
+ * mei_disconnect - sends disconnect message to fw.
+ *
+ * @dev: the device structure
+ * @file_ext: private data of the file object
+ *
+ * returns 1 if success, 0 - otherwise.
+ */
+int mei_disconnect(struct mei_device *dev, struct mei_cl *file_ext)
+{
+	struct mei_msg_hdr *mei_hdr;
+	struct hbm_client_disconnect_request *mei_cli_disconnect;
+
+	mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
+	mei_hdr->host_addr = 0;
+	mei_hdr->me_addr = 0;
+	mei_hdr->length = sizeof(struct hbm_client_disconnect_request);
+	mei_hdr->msg_complete = 1;
+	mei_hdr->reserved = 0;
+
+	mei_cli_disconnect =
+	    (struct hbm_client_disconnect_request *) &dev->wr_msg_buf[1];
+	memset(mei_cli_disconnect, 0, sizeof(mei_cli_disconnect));
+	mei_cli_disconnect->host_addr = file_ext->host_client_id;
+	mei_cli_disconnect->me_addr = file_ext->me_client_id;
+	mei_cli_disconnect->cmd.cmd = CLIENT_DISCONNECT_REQ_CMD;
+	mei_cli_disconnect->reserved[0] = 0;
+
+	if (!mei_write_message(dev, mei_hdr,
+				(unsigned char *) mei_cli_disconnect,
+				sizeof(struct hbm_client_disconnect_request)))
+		return 0;
+
+	return 1;
+}
+
+/**
+ * mei_connect - sends connect message to fw.
+ *
+ * @dev: the device structure
+ * @file_ext: private data of the file object
+ *
+ * returns 1 if success, 0 - otherwise.
+ */
+int mei_connect(struct mei_device *dev, struct mei_cl *file_ext)
+{
+	struct mei_msg_hdr *mei_hdr;
+	struct hbm_client_connect_request *mei_cli_connect;
+
+	mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
+	mei_hdr->host_addr = 0;
+	mei_hdr->me_addr = 0;
+	mei_hdr->length = sizeof(struct hbm_client_connect_request);
+	mei_hdr->msg_complete = 1;
+	mei_hdr->reserved = 0;
+
+	mei_cli_connect =
+	    (struct hbm_client_connect_request *) &dev->wr_msg_buf[1];
+	mei_cli_connect->host_addr = file_ext->host_client_id;
+	mei_cli_connect->me_addr = file_ext->me_client_id;
+	mei_cli_connect->cmd.cmd = CLIENT_CONNECT_REQ_CMD;
+	mei_cli_connect->reserved = 0;
+
+	if (!mei_write_message(dev, mei_hdr,
+				(unsigned char *) mei_cli_connect,
+				sizeof(struct hbm_client_connect_request)))
+		return 0;
+
+	return 1;
+}
diff --git a/drivers/staging/mei/interface.h b/drivers/staging/mei/interface.h
new file mode 100644
index 0000000..1bac32a
--- /dev/null
+++ b/drivers/staging/mei/interface.h
@@ -0,0 +1,124 @@
+/*
+ *
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2003-2011, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+
+
+#ifndef _MEI_INTERFACE_H_
+#define _MEI_INTERFACE_H_
+
+#include <linux/mei.h>
+#include "hw.h"
+
+
+#define HBM_MINOR_VERSION                   0
+#define HBM_MAJOR_VERSION                   1
+#define HBM_TIMEOUT                         1	/* 1 second */
+
+
+#define HOST_START_REQ_CMD                  0x01
+#define HOST_START_RES_CMD                  0x81
+
+#define HOST_STOP_REQ_CMD                   0x02
+#define HOST_STOP_RES_CMD                   0x82
+
+#define ME_STOP_REQ_CMD                     0x03
+
+#define HOST_ENUM_REQ_CMD                   0x04
+#define HOST_ENUM_RES_CMD                   0x84
+
+#define HOST_CLIENT_PROPERTIES_REQ_CMD      0x05
+#define HOST_CLIENT_PROPERTIES_RES_CMD      0x85
+
+#define CLIENT_CONNECT_REQ_CMD              0x06
+#define CLIENT_CONNECT_RES_CMD              0x86
+
+#define CLIENT_DISCONNECT_REQ_CMD           0x07
+#define CLIENT_DISCONNECT_RES_CMD           0x87
+
+#define MEI_FLOW_CONTROL_CMD               0x08
+
+
+#define AMT_WD_VALUE 120	/* seconds */
+
+#define MEI_WATCHDOG_DATA_SIZE         16
+#define MEI_START_WD_DATA_SIZE         20
+#define MEI_WD_PARAMS_SIZE             4
+
+
+enum mei_stop_reason_types {
+	DRIVER_STOP_REQUEST = 0x00,
+	DEVICE_D1_ENTRY = 0x01,
+	DEVICE_D2_ENTRY = 0x02,
+	DEVICE_D3_ENTRY = 0x03,
+	SYSTEM_S1_ENTRY = 0x04,
+	SYSTEM_S2_ENTRY = 0x05,
+	SYSTEM_S3_ENTRY = 0x06,
+	SYSTEM_S4_ENTRY = 0x07,
+	SYSTEM_S5_ENTRY = 0x08
+};
+
+enum me_stop_reason_types {
+	FW_UPDATE = 0x00
+};
+
+enum client_connect_status_types {
+	CCS_SUCCESS = 0x00,
+	CCS_NOT_FOUND = 0x01,
+	CCS_ALREADY_STARTED = 0x02,
+	CCS_OUT_OF_RESOURCES = 0x03,
+	CCS_MESSAGE_SMALL = 0x04
+};
+
+enum client_disconnect_status_types {
+	CDS_SUCCESS = 0x00
+};
+
+
+void mei_read_slots(struct mei_device *dev,
+		     unsigned char *buffer, unsigned long buffer_length);
+
+int mei_write_message(struct mei_device *dev,
+			     struct mei_msg_hdr *header,
+			     unsigned char *write_buffer,
+			     unsigned long write_length);
+
+int mei_host_buffer_is_empty(struct mei_device *dev);
+
+int mei_count_full_read_slots(struct mei_device *dev);
+
+int mei_count_empty_write_slots(struct mei_device *dev);
+
+int mei_flow_ctrl_creds(struct mei_device *dev, struct mei_cl *file_ext);
+
+int mei_wd_send(struct mei_device *dev);
+int mei_wd_stop(struct mei_device *dev, bool preserve);
+void mei_wd_host_init(struct mei_device *dev);
+void mei_wd_start_setup(struct mei_device *dev);
+
+void mei_flow_ctrl_reduce(struct mei_device *dev,
+			 struct mei_cl *file_ext);
+
+int mei_send_flow_control(struct mei_device *dev,
+				 struct mei_cl *file_ext);
+
+int mei_disconnect(struct mei_device *dev,
+			  struct mei_cl *file_ext);
+int mei_other_client_is_connecting(struct mei_device *dev,
+				     struct mei_cl *file_ext);
+int mei_connect(struct mei_device *dev,
+		       struct mei_cl *file_ext);
+
+#endif /* _MEI_INTERFACE_H_ */
-- 
1.7.1

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