1 files changed, 535 insertions, 0 deletions

diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
new file mode 100644
index 000000000..66f4d12d0
--- /dev/null
+++ b/drivers/misc/mei/interrupt.c
@@ -0,0 +1,535 @@
+/*
+ *
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2003-2012, 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/export.h>
+#include <linux/kthread.h>
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/jiffies.h>
+#include <linux/slab.h>
+#include <linux/pm_runtime.h>
+
+#include <linux/mei.h>
+
+#include "mei_dev.h"
+#include "hbm.h"
+#include "client.h"
+
+
+/**
+ * mei_irq_compl_handler - dispatch complete handlers
+ *	for the completed callbacks
+ *
+ * @dev: mei device
+ * @cmpl_list: list of completed cbs
+ */
+void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list)
+{
+	struct mei_cl_cb *cb, *next;
+	struct mei_cl *cl;
+
+	list_for_each_entry_safe(cb, next, cmpl_list, list) {
+		cl = cb->cl;
+		list_del_init(&cb->list);
+
+		dev_dbg(dev->dev, "completing call back.\n");
+		mei_cl_complete(cl, cb);
+	}
+}
+EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
+
+/**
+ * mei_cl_hbm_equal - check if hbm is addressed to the client
+ *
+ * @cl: host client
+ * @mei_hdr: header of mei client message
+ *
+ * Return: true if matches, false otherwise
+ */
+static inline int mei_cl_hbm_equal(struct mei_cl *cl,
+			struct mei_msg_hdr *mei_hdr)
+{
+	return  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
+		mei_cl_me_id(cl) == mei_hdr->me_addr;
+}
+
+/**
+ * mei_irq_discard_msg  - discard received message
+ *
+ * @dev: mei device
+ * @hdr: message header
+ */
+static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
+{
+	/*
+	 * no need to check for size as it is guarantied
+	 * that length fits into rd_msg_buf
+	 */
+	mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
+	dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
+		MEI_HDR_PRM(hdr));
+}
+
+/**
+ * mei_cl_irq_read_msg - process client message
+ *
+ * @cl: reading client
+ * @mei_hdr: header of mei client message
+ * @cmpl_list: completion list
+ *
+ * Return: always 0
+ */
+static int mei_cl_irq_read_msg(struct mei_cl *cl,
+			       struct mei_msg_hdr *mei_hdr,
+			       struct list_head *cmpl_list)
+{
+	struct mei_device *dev = cl->dev;
+	struct mei_cl_cb *cb;
+	size_t buf_sz;
+
+	cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
+	if (!cb) {
+		if (!mei_cl_is_fixed_address(cl)) {
+			cl_err(dev, cl, "pending read cb not found\n");
+			goto discard;
+		}
+		cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
+		if (!cb)
+			goto discard;
+		list_add_tail(&cb->list, &cl->rd_pending);
+	}
+
+	if (!mei_cl_is_connected(cl)) {
+		cl_dbg(dev, cl, "not connected\n");
+		cb->status = -ENODEV;
+		goto discard;
+	}
+
+	buf_sz = mei_hdr->length + cb->buf_idx;
+	/* catch for integer overflow */
+	if (buf_sz < cb->buf_idx) {
+		cl_err(dev, cl, "message is too big len %d idx %zu\n",
+		       mei_hdr->length, cb->buf_idx);
+		cb->status = -EMSGSIZE;
+		goto discard;
+	}
+
+	if (cb->buf.size < buf_sz) {
+		cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
+			cb->buf.size, mei_hdr->length, cb->buf_idx);
+		cb->status = -EMSGSIZE;
+		goto discard;
+	}
+
+	mei_read_slots(dev, cb->buf.data + cb->buf_idx, mei_hdr->length);
+
+	cb->buf_idx += mei_hdr->length;
+
+	if (mei_hdr->msg_complete) {
+		cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
+		list_move_tail(&cb->list, cmpl_list);
+	} else {
+		pm_runtime_mark_last_busy(dev->dev);
+		pm_request_autosuspend(dev->dev);
+	}
+
+	return 0;
+
+discard:
+	if (cb)
+		list_move_tail(&cb->list, cmpl_list);
+	mei_irq_discard_msg(dev, mei_hdr);
+	return 0;
+}
+
+/**
+ * mei_cl_irq_disconnect_rsp - send disconnection response message
+ *
+ * @cl: client
+ * @cb: callback block.
+ * @cmpl_list: complete list.
+ *
+ * Return: 0, OK; otherwise, error.
+ */
+static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
+				     struct list_head *cmpl_list)
+{
+	struct mei_device *dev = cl->dev;
+	u32 msg_slots;
+	int slots;
+	int ret;
+
+	msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
+	slots = mei_hbuf_empty_slots(dev);
+	if (slots < 0)
+		return -EOVERFLOW;
+
+	if ((u32)slots < msg_slots)
+		return -EMSGSIZE;
+
+	ret = mei_hbm_cl_disconnect_rsp(dev, cl);
+	list_move_tail(&cb->list, cmpl_list);
+
+	return ret;
+}
+
+/**
+ * mei_cl_irq_read - processes client read related operation from the
+ *	interrupt thread context - request for flow control credits
+ *
+ * @cl: client
+ * @cb: callback block.
+ * @cmpl_list: complete list.
+ *
+ * Return: 0, OK; otherwise, error.
+ */
+static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
+			   struct list_head *cmpl_list)
+{
+	struct mei_device *dev = cl->dev;
+	u32 msg_slots;
+	int slots;
+	int ret;
+
+	if (!list_empty(&cl->rd_pending))
+		return 0;
+
+	msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
+	slots = mei_hbuf_empty_slots(dev);
+	if (slots < 0)
+		return -EOVERFLOW;
+
+	if ((u32)slots < msg_slots)
+		return -EMSGSIZE;
+
+	ret = mei_hbm_cl_flow_control_req(dev, cl);
+	if (ret) {
+		cl->status = ret;
+		cb->buf_idx = 0;
+		list_move_tail(&cb->list, cmpl_list);
+		return ret;
+	}
+
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_request_autosuspend(dev->dev);
+
+	list_move_tail(&cb->list, &cl->rd_pending);
+
+	return 0;
+}
+
+static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
+{
+	return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
+}
+
+static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
+{
+	return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
+}
+
+static inline int hdr_is_valid(u32 msg_hdr)
+{
+	struct mei_msg_hdr *mei_hdr;
+
+	mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
+	if (!msg_hdr || mei_hdr->reserved)
+		return -EBADMSG;
+
+	return 0;
+}
+
+/**
+ * mei_irq_read_handler - bottom half read routine after ISR to
+ * handle the read processing.
+ *
+ * @dev: the device structure
+ * @cmpl_list: An instance of our list structure
+ * @slots: slots to read.
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+int mei_irq_read_handler(struct mei_device *dev,
+			 struct list_head *cmpl_list, s32 *slots)
+{
+	struct mei_msg_hdr *mei_hdr;
+	struct mei_cl *cl;
+	int ret;
+
+	if (!dev->rd_msg_hdr) {
+		dev->rd_msg_hdr = mei_read_hdr(dev);
+		(*slots)--;
+		dev_dbg(dev->dev, "slots =%08x.\n", *slots);
+
+		ret = hdr_is_valid(dev->rd_msg_hdr);
+		if (ret) {
+			dev_err(dev->dev, "corrupted message header 0x%08X\n",
+				dev->rd_msg_hdr);
+			goto end;
+		}
+	}
+
+	mei_hdr = (struct mei_msg_hdr *)&dev->rd_msg_hdr;
+	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
+
+	if (mei_slots2data(*slots) < mei_hdr->length) {
+		dev_err(dev->dev, "less data available than length=%08x.\n",
+				*slots);
+		/* we can't read the message */
+		ret = -ENODATA;
+		goto end;
+	}
+
+	/*  HBM message */
+	if (hdr_is_hbm(mei_hdr)) {
+		ret = mei_hbm_dispatch(dev, mei_hdr);
+		if (ret) {
+			dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
+					ret);
+			goto end;
+		}
+		goto reset_slots;
+	}
+
+	/* find recipient cl */
+	list_for_each_entry(cl, &dev->file_list, link) {
+		if (mei_cl_hbm_equal(cl, mei_hdr)) {
+			cl_dbg(dev, cl, "got a message\n");
+			break;
+		}
+	}
+
+	/* if no recipient cl was found we assume corrupted header */
+	if (&cl->link == &dev->file_list) {
+		/* A message for not connected fixed address clients
+		 * should be silently discarded
+		 * On power down client may be force cleaned,
+		 * silently discard such messages
+		 */
+		if (hdr_is_fixed(mei_hdr) ||
+		    dev->dev_state == MEI_DEV_POWER_DOWN) {
+			mei_irq_discard_msg(dev, mei_hdr);
+			ret = 0;
+			goto reset_slots;
+		}
+		dev_err(dev->dev, "no destination client found 0x%08X\n",
+				dev->rd_msg_hdr);
+		ret = -EBADMSG;
+		goto end;
+	}
+
+	ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
+
+
+reset_slots:
+	/* reset the number of slots and header */
+	*slots = mei_count_full_read_slots(dev);
+	dev->rd_msg_hdr = 0;
+
+	if (*slots == -EOVERFLOW) {
+		/* overflow - reset */
+		dev_err(dev->dev, "resetting due to slots overflow.\n");
+		/* set the event since message has been read */
+		ret = -ERANGE;
+		goto end;
+	}
+end:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(mei_irq_read_handler);
+
+
+/**
+ * mei_irq_write_handler -  dispatch write requests
+ *  after irq received
+ *
+ * @dev: the device structure
+ * @cmpl_list: An instance of our list structure
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
+{
+
+	struct mei_cl *cl;
+	struct mei_cl_cb *cb, *next;
+	s32 slots;
+	int ret;
+
+
+	if (!mei_hbuf_acquire(dev))
+		return 0;
+
+	slots = mei_hbuf_empty_slots(dev);
+	if (slots < 0)
+		return -EOVERFLOW;
+
+	if (slots == 0)
+		return -EMSGSIZE;
+
+	/* complete all waiting for write CB */
+	dev_dbg(dev->dev, "complete all waiting for write cb.\n");
+
+	list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
+		cl = cb->cl;
+
+		cl->status = 0;
+		cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
+		cl->writing_state = MEI_WRITE_COMPLETE;
+		list_move_tail(&cb->list, cmpl_list);
+	}
+
+	/* complete control write list CB */
+	dev_dbg(dev->dev, "complete control write list cb.\n");
+	list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
+		cl = cb->cl;
+		switch (cb->fop_type) {
+		case MEI_FOP_DISCONNECT:
+			/* send disconnect message */
+			ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
+			if (ret)
+				return ret;
+
+			break;
+		case MEI_FOP_READ:
+			/* send flow control message */
+			ret = mei_cl_irq_read(cl, cb, cmpl_list);
+			if (ret)
+				return ret;
+
+			break;
+		case MEI_FOP_CONNECT:
+			/* connect message */
+			ret = mei_cl_irq_connect(cl, cb, cmpl_list);
+			if (ret)
+				return ret;
+
+			break;
+		case MEI_FOP_DISCONNECT_RSP:
+			/* send disconnect resp */
+			ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
+			if (ret)
+				return ret;
+			break;
+
+		case MEI_FOP_NOTIFY_START:
+		case MEI_FOP_NOTIFY_STOP:
+			ret = mei_cl_irq_notify(cl, cb, cmpl_list);
+			if (ret)
+				return ret;
+			break;
+		default:
+			BUG();
+		}
+
+	}
+	/* complete  write list CB */
+	dev_dbg(dev->dev, "complete write list cb.\n");
+	list_for_each_entry_safe(cb, next, &dev->write_list, list) {
+		cl = cb->cl;
+		ret = mei_cl_irq_write(cl, cb, cmpl_list);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mei_irq_write_handler);
+
+
+/**
+ * mei_connect_timeout  - connect/disconnect timeouts
+ *
+ * @cl: host client
+ */
+static void mei_connect_timeout(struct mei_cl *cl)
+{
+	struct mei_device *dev = cl->dev;
+
+	if (cl->state == MEI_FILE_CONNECTING) {
+		if (dev->hbm_f_dot_supported) {
+			cl->state = MEI_FILE_DISCONNECT_REQUIRED;
+			wake_up(&cl->wait);
+			return;
+		}
+	}
+	mei_reset(dev);
+}
+
+#define MEI_STALL_TIMER_FREQ (2 * HZ)
+/**
+ * mei_schedule_stall_timer - re-arm stall_timer work
+ *
+ * Schedule stall timer
+ *
+ * @dev: the device structure
+ */
+void mei_schedule_stall_timer(struct mei_device *dev)
+{
+	schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
+}
+
+/**
+ * mei_timer - timer function.
+ *
+ * @work: pointer to the work_struct structure
+ *
+ */
+void mei_timer(struct work_struct *work)
+{
+	struct mei_cl *cl;
+	struct mei_device *dev = container_of(work,
+					struct mei_device, timer_work.work);
+	bool reschedule_timer = false;
+
+	mutex_lock(&dev->device_lock);
+
+	/* Catch interrupt stalls during HBM init handshake */
+	if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
+	    dev->hbm_state != MEI_HBM_IDLE) {
+
+		if (dev->init_clients_timer) {
+			if (--dev->init_clients_timer == 0) {
+				dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
+					dev->hbm_state);
+				mei_reset(dev);
+				goto out;
+			}
+			reschedule_timer = true;
+		}
+	}
+
+	if (dev->dev_state != MEI_DEV_ENABLED)
+		goto out;
+
+	/*** connect/disconnect timeouts ***/
+	list_for_each_entry(cl, &dev->file_list, link) {
+		if (cl->timer_count) {
+			if (--cl->timer_count == 0) {
+				dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
+				mei_connect_timeout(cl);
+				goto out;
+			}
+			reschedule_timer = true;
+		}
+	}
+
+out:
+	if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
+		mei_schedule_stall_timer(dev);
+
+	mutex_unlock(&dev->device_lock);
+}