[RFC PATCH 06/13] Intel(R) MEI Driver

[Oren Weil <oren.jer.weil@intel.com>]

diff --git a/drivers/char/mei/interface.c b/drivers/char/mei/interface.c
new file mode 100644
index 0000000..23bcd7e
--- /dev/null
+++ b/drivers/char/mei/interface.c
@@ -0,0 +1,478 @@
+/*
+ *
+ * Intel(R) Management Engine Interface (Intel(R) 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#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_set_csr_register(struct iamt_mei_device *dev)
+{
+	if ((dev->host_hw_state & H_IS) == H_IS)
+		dev->host_hw_state &= ~H_IS;
+	write_mei_register(dev, H_CSR, dev->host_hw_state);
+	dev->host_hw_state = get_host_hw_state(dev);
+}
+
+/**
+ * mei_csr_enable_interrupts - enables mei device interrupts
+ *
+ * @dev: the device structure
+ */
+void mei_csr_enable_interrupts(struct iamt_mei_device *dev)
+{
+	dev->host_hw_state |= H_IE;
+	mei_set_csr_register(dev);
+}
+
+/**
+ * mei_csr_disable_interrupts - disables mei device interrupts
+ *
+ * @dev: the device structure
+ */
+void mei_csr_disable_interrupts(struct iamt_mei_device *dev)
+{
+	dev->host_hw_state &= ~H_IE;
+	mei_set_csr_register(dev);
+}
+
+/**
+ * mei_csr_clear_his - clears H_IS bit in H_CSR
+ *
+ * @dev: the device structure
+ */
+void mei_csr_clear_his(struct iamt_mei_device *dev)
+{
+	write_mei_register(dev, H_CSR, dev->host_hw_state);
+	dev->host_hw_state = get_host_hw_state(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 iamt_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);
+}
+
+/**
+ * host_buffer_is_empty - checks if host buffer is empty.
+ *
+ * @dev: the device structure
+ *
+ * returns 1 if empty, 0 - otherwise.
+ */
+int host_buffer_is_empty(struct iamt_mei_device *dev)
+{
+	unsigned char filled_slots;
+
+	dev->host_hw_state = get_host_hw_state(dev);
+	filled_slots = _host_get_filled_slots(dev);
+
+	if (filled_slots == 0)
+		return 1;
+
+	return 0;
+}
+
+/**
+ * count_empty_write_slots - counts write empty slots.
+ *
+ * @dev: the device structure
+ *
+ * returns -1(ESLOTS_OVERFLOW) if overflow, otherwise empty slots count
+ */
+s32 count_empty_write_slots(struct iamt_mei_device *dev)
+{
+	unsigned char buffer_depth, filled_slots, empty_slots;
+
+	dev->host_hw_state = get_host_hw_state(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;
+
+	if (filled_slots > buffer_depth) {
+		/* overflow */
+		return -ESLOTS_OVERFLOW;
+	}
+
+	return (s32) empty_slots;
+}
+
+/**
+ * mei_write_message - writes a message to mei device.
+ *
+ * @dev: the device structure
+ * @mei_hdr: 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 iamt_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 = get_host_hw_state(dev);
+	DBG("host_hw_state = 0x%08x.\n", dev->host_hw_state);
+	DBG("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;
+	DBG("filled = %hu, empty = %hu.\n", filled_slots, empty_slots);
+
+	dw_to_write = ((write_length + 3) / 4);
+
+	if (dw_to_write > empty_slots)
+		return 0;
+
+	write_mei_register(dev, H_CB_WW, *((u32 *) header));
+
+	while (write_length >= 4) {
+		write_mei_register(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);
+		write_mei_register(dev, H_CB_WW, temp_msg);
+	}
+
+	dev->host_hw_state |= H_IG;
+	mei_set_csr_register(dev);
+	dev->me_hw_state = get_me_hw_state(dev);
+	if ((dev->me_hw_state & ME_RDY_HRA) != ME_RDY_HRA)
+		return 0;
+
+	dev->write_hang = 0;
+	return 1;
+}
+
+/**
+ * count_full_read_slots - counts read full slots.
+ *
+ * @dev: the device structure
+ *
+ * returns -1(ESLOTS_OVERFLOW) if overflow, otherwise filled slots count
+ */
+s32 count_full_read_slots(struct iamt_mei_device *dev)
+{
+	char read_ptr, write_ptr;
+	unsigned char buffer_depth, filled_slots;
+
+	dev->me_hw_state = get_me_hw_state(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);
+
+	if (filled_slots > buffer_depth) {
+		/* overflow */
+		return -ESLOTS_OVERFLOW;
+	}
+
+	DBG("filled_slots =%08x\n", filled_slots);
+	return (s32) 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 iamt_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] = get_me_cb_rw(dev);
+		DBG("buffer[%d]= %d\n", i, ((u32 *) buffer)[i]);
+		i++;
+		buffer_length -= sizeof(u32);
+	}
+
+	if (buffer_length > 0) {
+		*((u32 *) &temp_buf) = get_me_cb_rw(dev);
+		memcpy(&buffer[i * 4], temp_buf, buffer_length);
+	}
+
+	dev->host_hw_state |= H_IG;
+	mei_set_csr_register(dev);
+}
+
+/**
+ * flow_ctrl_creds - checks flow_control credentials.
+ *
+ * @dev: the device structure
+ * @file_ext: private data of the file object
+ *
+ * returns 1 if flow_ctrl_creds >0, 0 - otherwise.
+ */
+int flow_ctrl_creds(struct iamt_mei_device *dev,
+				   struct mei_file_private *file_ext)
+{
+	u8 i;
+
+	if (!dev->num_mei_me_clients)
+		return 0;
+
+	if (file_ext == NULL)
+		return 0;
+
+	if (file_ext->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].flow_ctrl_creds > 0) {
+				BUG_ON(dev->me_clients[i].props.single_recv_buf
+					 == 0);
+				return 1;
+			}
+			return 0;
+		}
+	}
+	BUG();
+	return 0;
+}
+
+/**
+ * flow_ctrl_reduce - reduces flow_control.
+ *
+ * @dev: the device structure
+ * @file_ext: private data of the file object
+ */
+void flow_ctrl_reduce(struct iamt_mei_device *dev,
+			 struct mei_file_private *file_ext)
+{
+	u8 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].flow_ctrl_creds <= 0);
+				dev->me_clients[i].flow_ctrl_creds--;
+			} else {
+				BUG_ON(file_ext->flow_ctrl_creds <= 0);
+				file_ext->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 iamt_mei_device *dev,
+				 struct mei_file_private *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));
+	DBG("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;
+
+}
+
+/**
+ * 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 other_client_is_connecting(struct iamt_mei_device *dev,
+		struct mei_file_private *file_ext)
+{
+	struct mei_file_private *file_pos = NULL;
+	struct mei_file_private *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_send_wd - sends watch dog message to fw.
+ *
+ * @dev: the device structure
+ *
+ * returns 1 if success, 0 - otherwise.
+ */
+int mei_send_wd(struct iamt_mei_device *dev)
+{
+	struct mei_msg_hdr *mei_hdr;
+
+	mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
+	mei_hdr->host_addr = dev->wd_file_ext.host_client_id;
+	mei_hdr->me_addr = dev->wd_file_ext.me_client_id;
+	mei_hdr->msg_complete = 1;
+	mei_hdr->reserved = 0;
+
+	if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE)) {
+		mei_hdr->length = MEI_START_WD_DATA_SIZE;
+	} else {
+		BUG_ON(memcmp(dev->wd_data, mei_stop_wd_params,
+			MEI_WD_PARAMS_SIZE));
+		mei_hdr->length = MEI_WD_PARAMS_SIZE;
+	}
+
+	if (!mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length))
+		return 0;
+
+	return 1;
+}
+
+/**
+ * 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 iamt_mei_device *dev,
+			  struct mei_file_private *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 iamt_mei_device *dev,
+		       struct mei_file_private *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;
+}


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