Merge tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO updates from Greg KH:
 "Here is the big staging and IIO driver pull request for 4.9-rc1.

  There are a lot of patches in here, the majority due to the
  drivers/staging/greybus/ subsystem being merged in with full
  development history that went back a few years, in order to preserve
  the work that those developers did over time.

  Lots and lots of tiny cleanups happened in the tree as well, due to
  the Outreachy application process and lots of other developers showing
  up for the first time to clean code up.  Along with those changes, we
  deleted a wireless driver, and added a raspberrypi driver (currently
  marked broken), and lots of new iio drivers.

  Overall the tree still shrunk with more lines removed than added,
  about 10 thousand lines removed in total. Full details are in the very
  long shortlog below.

  All of this has been in the linux-next tree with no issues. There will
  be some merge problems with other subsystem trees, but those are all
  minor problems and shouldn't be hard to work out when they happen
  (MAINTAINERS and some lustre build problems with the IB tree)"

And furter from me asking for clarification about greybus:
 "Right now there is a phone from Motorola shipping with this code (a
  slightly older version, but the same tree), so even though Ara is not
  alive in the same form, the functionality is happening. We are working
  with the developers of that phone to merge the newer stuff in with
  their fork so they can use the upstream version in future versions of
  their phone product line.

  Toshiba has at least one chip shipping in their catalog that
  needs/uses this protocol over a Unipro link, and rumor has it that
  there might be more in the future.

  There are also other users of the greybus protocols, there is a talk
  next week at ELC that shows how it is being used across a network
  connection to control a device, and previous ELC talks have showed the
  protocol stack being used over USB to drive embedded Linux boards.
  I've also talked to some people who are starting to work to add a host
  controller driver to control arduinos as the greybus PHY protocols are
  very useful to control a serial/i2c/spio/whatever device across a
  random physical link, as it is a way to have a self-describing device
  be attached to a host without needing manual configuration.

  So yes, people are using it, and there is still the chance that it
  will show up in a phone/laptop/tablet/whatever from Google in the
  future as well, the tech isn't dead, even if the original large phone
  project happens to be"

* tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (3703 commits)
  Staging: fbtft: Fix bug in fbtft-core
  staging: rtl8188eu: fix double unlock error in rtw_resume_process()
  staging:r8188eu: remove GEN_MLME_EXT_HANDLER macro
  staging:r8188eu: remove GEN_DRV_CMD_HANDLER macro
  staging:r8188eu: remove GEN_EVT_CODE macro
  staging:r8188eu: remove GEN_CMD_CODE macro
  staging:r8188eu: remove pkt_newalloc member of the recv_buf structure
  staging:r8188eu: remove rtw_handle_dualmac declaration
  staging:r8188eu: remove (RGTRY|BSSID)_(OFT|SZ) macros
  staging:r8188eu: change rtl8188e_process_phy_info function argument type
  Staging: fsl-mc: Remove blank lines
  Staging: fsl-mc: Fix unaligned * in block comments
  Staging: comedi: Align the * in block comments
  Staging : ks7010 : Fix block comments warninig
  Staging: vt6655: Remove explicit NULL comparison using Coccinelle
  staging: rtl8188eu: core: rtw_xmit: Use macros instead of constants
  staging: rtl8188eu: core: rtw_xmit: Move constant of the right side
  staging: dgnc: Fix lines longer than 80 characters
  Staging: dgnc: constify attribute_group structures
  Staging: most: hdm-dim2: constify attribute_group structures
  ...

1 files changed, 226 insertions, 347 deletions

diff --git a/drivers/staging/unisys/visorbus/visorchannel.c b/drivers/staging/unisys/visorbus/visorchannel.c
index 4337358..300a65d 100644
--- a/drivers/staging/unisys/visorbus/visorchannel.c
+++ b/drivers/staging/unisys/visorbus/visorchannel.c
@@ -15,14 +15,13 @@
  */
 
 /*
- *  This provides Supervisor channel communication primitives, which are
+ *  This provides s-Par channel communication primitives, which are
  *  independent of the mechanism used to access the channel data.
  */
 
 #include <linux/uuid.h>
 #include <linux/io.h>
 
-#include "version.h"
 #include "visorbus.h"
 #include "controlvmchannel.h"
 
@@ -55,110 +54,6 @@ struct visorchannel {
 	uuid_le inst;
 };
 
-/* Creates the struct visorchannel abstraction for a data area in memory,
- * but does NOT modify this data area.
- */
-static struct visorchannel *
-visorchannel_create_guts(u64 physaddr, unsigned long channel_bytes,
-			 gfp_t gfp, unsigned long off,
-			 uuid_le guid, bool needs_lock)
-{
-	struct visorchannel *channel;
-	int err;
-	size_t size = sizeof(struct channel_header);
-
-	if (physaddr == 0)
-		return NULL;
-
-	channel = kzalloc(sizeof(*channel), gfp);
-	if (!channel)
-		return NULL;
-
-	channel->needs_lock = needs_lock;
-	spin_lock_init(&channel->insert_lock);
-	spin_lock_init(&channel->remove_lock);
-
-	/* Video driver constains the efi framebuffer so it will get a
-	 * conflict resource when requesting its full mem region. Since
-	 * we are only using the efi framebuffer for video we can ignore
-	 * this. Remember that we haven't requested it so we don't try to
-	 * release later on.
-	 */
-	channel->requested = request_mem_region(physaddr, size, MYDRVNAME);
-	if (!channel->requested) {
-		if (uuid_le_cmp(guid, spar_video_guid)) {
-			/* Not the video channel we care about this */
-			goto err_destroy_channel;
-		}
-	}
-
-	channel->mapped = memremap(physaddr, size, MEMREMAP_WB);
-	if (!channel->mapped) {
-		release_mem_region(physaddr, size);
-		goto err_destroy_channel;
-	}
-
-	channel->physaddr = physaddr;
-	channel->nbytes = size;
-
-	err = visorchannel_read(channel, 0, &channel->chan_hdr,
-				sizeof(struct channel_header));
-	if (err)
-		goto err_destroy_channel;
-
-	/* we had better be a CLIENT of this channel */
-	if (channel_bytes == 0)
-		channel_bytes = (ulong)channel->chan_hdr.size;
-	if (uuid_le_cmp(guid, NULL_UUID_LE) == 0)
-		guid = channel->chan_hdr.chtype;
-
-	memunmap(channel->mapped);
-	if (channel->requested)
-		release_mem_region(channel->physaddr, channel->nbytes);
-	channel->mapped = NULL;
-	channel->requested = request_mem_region(channel->physaddr,
-						channel_bytes, MYDRVNAME);
-	if (!channel->requested) {
-		if (uuid_le_cmp(guid, spar_video_guid)) {
-			/* Different we care about this */
-			goto err_destroy_channel;
-		}
-	}
-
-	channel->mapped = memremap(channel->physaddr, channel_bytes,
-			MEMREMAP_WB);
-	if (!channel->mapped) {
-		release_mem_region(channel->physaddr, channel_bytes);
-		goto err_destroy_channel;
-	}
-
-	channel->nbytes = channel_bytes;
-	channel->guid = guid;
-	return channel;
-
-err_destroy_channel:
-	visorchannel_destroy(channel);
-	return NULL;
-}
-
-struct visorchannel *
-visorchannel_create(u64 physaddr, unsigned long channel_bytes,
-		    gfp_t gfp, uuid_le guid)
-{
-	return visorchannel_create_guts(physaddr, channel_bytes, gfp, 0, guid,
-					false);
-}
-EXPORT_SYMBOL_GPL(visorchannel_create);
-
-struct visorchannel *
-visorchannel_create_with_lock(u64 physaddr, unsigned long channel_bytes,
-			      gfp_t gfp, uuid_le guid)
-{
-	return visorchannel_create_guts(physaddr, channel_bytes, gfp, 0, guid,
-					true);
-}
-EXPORT_SYMBOL_GPL(visorchannel_create_with_lock);
-
 void
 visorchannel_destroy(struct visorchannel *channel)
 {
@@ -171,21 +66,18 @@ visorchannel_destroy(struct visorchannel *channel)
 	}
 	kfree(channel);
 }
-EXPORT_SYMBOL_GPL(visorchannel_destroy);
 
 u64
 visorchannel_get_physaddr(struct visorchannel *channel)
 {
 	return channel->physaddr;
 }
-EXPORT_SYMBOL_GPL(visorchannel_get_physaddr);
 
 ulong
 visorchannel_get_nbytes(struct visorchannel *channel)
 {
 	return channel->nbytes;
 }
-EXPORT_SYMBOL_GPL(visorchannel_get_nbytes);
 
 char *
 visorchannel_uuid_id(uuid_le *guid, char *s)
@@ -193,28 +85,24 @@ visorchannel_uuid_id(uuid_le *guid, char *s)
 	sprintf(s, "%pUL", guid);
 	return s;
 }
-EXPORT_SYMBOL_GPL(visorchannel_uuid_id);
 
 char *
 visorchannel_id(struct visorchannel *channel, char *s)
 {
 	return visorchannel_uuid_id(&channel->guid, s);
 }
-EXPORT_SYMBOL_GPL(visorchannel_id);
 
 char *
 visorchannel_zoneid(struct visorchannel *channel, char *s)
 {
 	return visorchannel_uuid_id(&channel->chan_hdr.zone_uuid, s);
 }
-EXPORT_SYMBOL_GPL(visorchannel_zoneid);
 
 u64
 visorchannel_get_clientpartition(struct visorchannel *channel)
 {
 	return channel->chan_hdr.partition_handle;
 }
-EXPORT_SYMBOL_GPL(visorchannel_get_clientpartition);
 
 int
 visorchannel_set_clientpartition(struct visorchannel *channel,
@@ -223,8 +111,13 @@ visorchannel_set_clientpartition(struct visorchannel *channel,
 	channel->chan_hdr.partition_handle = partition_handle;
 	return 0;
 }
-EXPORT_SYMBOL_GPL(visorchannel_set_clientpartition);
 
+/**
+ * visorchannel_get_uuid() - queries the UUID of the designated channel
+ * @channel: the channel to query
+ *
+ * Return: the UUID of the provided channel
+ */
 uuid_le
 visorchannel_get_uuid(struct visorchannel *channel)
 {
@@ -243,7 +136,6 @@ visorchannel_read(struct visorchannel *channel, ulong offset,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(visorchannel_read);
 
 int
 visorchannel_write(struct visorchannel *channel, ulong offset,
@@ -265,156 +157,125 @@ visorchannel_write(struct visorchannel *channel, ulong offset,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(visorchannel_write);
-
-int
-visorchannel_clear(struct visorchannel *channel, ulong offset, u8 ch,
-		   ulong nbytes)
-{
-	int err;
-	int bufsize = PAGE_SIZE;
-	int written = 0;
-	u8 *buf;
-
-	buf = (u8 *)__get_free_page(GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	memset(buf, ch, bufsize);
-
-	while (nbytes > 0) {
-		int thisbytes = bufsize;
-
-		if (nbytes < thisbytes)
-			thisbytes = nbytes;
-		err = visorchannel_write(channel, offset + written,
-					 buf, thisbytes);
-		if (err)
-			goto out_free_page;
-
-		written += thisbytes;
-		nbytes -= thisbytes;
-	}
-	err = 0;
-
-out_free_page:
-	free_page((unsigned long)buf);
-	return err;
-}
-EXPORT_SYMBOL_GPL(visorchannel_clear);
 
 void __iomem  *
 visorchannel_get_header(struct visorchannel *channel)
 {
 	return (void __iomem *)&channel->chan_hdr;
 }
-EXPORT_SYMBOL_GPL(visorchannel_get_header);
 
-/** Return offset of a specific SIGNAL_QUEUE_HEADER from the beginning of a
- *  channel header
+/*
+ * Return offset of a specific SIGNAL_QUEUE_HEADER from the beginning of a
+ * channel header
  */
 #define SIG_QUEUE_OFFSET(chan_hdr, q) \
 	((chan_hdr)->ch_space_offset + \
 	 ((q) * sizeof(struct signal_queue_header)))
 
-/** Return offset of a specific queue entry (data) from the beginning of a
- *  channel header
+/*
+ * Return offset of a specific queue entry (data) from the beginning of a
+ * channel header
  */
 #define SIG_DATA_OFFSET(chan_hdr, q, sig_hdr, slot) \
 	(SIG_QUEUE_OFFSET(chan_hdr, q) + (sig_hdr)->sig_base_offset + \
 	    ((slot) * (sig_hdr)->signal_size))
 
-/** Write the contents of a specific field within a SIGNAL_QUEUE_HEADER back
- *  into host memory
+/*
+ * Write the contents of a specific field within a SIGNAL_QUEUE_HEADER back
+ * into host memory
  */
 #define SIG_WRITE_FIELD(channel, queue, sig_hdr, FIELD)			 \
-	(visorchannel_write(channel,					 \
-			    SIG_QUEUE_OFFSET(&channel->chan_hdr, queue) +\
-			    offsetof(struct signal_queue_header, FIELD), \
-			    &((sig_hdr)->FIELD),			 \
-			    sizeof((sig_hdr)->FIELD)) >= 0)
+	visorchannel_write(channel,					 \
+			   SIG_QUEUE_OFFSET(&channel->chan_hdr, queue) +\
+			   offsetof(struct signal_queue_header, FIELD), \
+			   &((sig_hdr)->FIELD),			 \
+			   sizeof((sig_hdr)->FIELD))
 
-static bool
+static int
 sig_read_header(struct visorchannel *channel, u32 queue,
 		struct signal_queue_header *sig_hdr)
 {
-	int err;
-
 	if (channel->chan_hdr.ch_space_offset < sizeof(struct channel_header))
-		return false;
+		return -EINVAL;
 
 	/* Read the appropriate SIGNAL_QUEUE_HEADER into local memory. */
-	err = visorchannel_read(channel,
-				SIG_QUEUE_OFFSET(&channel->chan_hdr, queue),
-				sig_hdr, sizeof(struct signal_queue_header));
-	if (err)
-		return false;
-
-	return true;
+	return visorchannel_read(channel,
+				 SIG_QUEUE_OFFSET(&channel->chan_hdr, queue),
+				 sig_hdr, sizeof(struct signal_queue_header));
 }
 
-static inline bool
+static inline int
 sig_read_data(struct visorchannel *channel, u32 queue,
 	      struct signal_queue_header *sig_hdr, u32 slot, void *data)
 {
-	int err;
 	int signal_data_offset = SIG_DATA_OFFSET(&channel->chan_hdr, queue,
 						 sig_hdr, slot);
 
-	err = visorchannel_read(channel, signal_data_offset,
-				data, sig_hdr->signal_size);
-	if (err)
-		return false;
-
-	return true;
+	return visorchannel_read(channel, signal_data_offset,
+				 data, sig_hdr->signal_size);
 }
 
-static inline bool
+static inline int
 sig_write_data(struct visorchannel *channel, u32 queue,
 	       struct signal_queue_header *sig_hdr, u32 slot, void *data)
 {
-	int err;
 	int signal_data_offset = SIG_DATA_OFFSET(&channel->chan_hdr, queue,
 						 sig_hdr, slot);
 
-	err = visorchannel_write(channel, signal_data_offset,
-				 data, sig_hdr->signal_size);
-	if (err)
-		return false;
-
-	return true;
+	return visorchannel_write(channel, signal_data_offset,
+				  data, sig_hdr->signal_size);
 }
 
-static bool
+static int
 signalremove_inner(struct visorchannel *channel, u32 queue, void *msg)
 {
 	struct signal_queue_header sig_hdr;
+	int error;
+
+	error = sig_read_header(channel, queue, &sig_hdr);
+	if (error)
+		return error;
 
-	if (!sig_read_header(channel, queue, &sig_hdr))
-		return false;
 	if (sig_hdr.head == sig_hdr.tail)
-		return false;	/* no signals to remove */
+		return -EIO;	/* no signals to remove */
 
 	sig_hdr.tail = (sig_hdr.tail + 1) % sig_hdr.max_slots;
-	if (!sig_read_data(channel, queue, &sig_hdr, sig_hdr.tail, msg))
-		return false;
+
+	error = sig_read_data(channel, queue, &sig_hdr, sig_hdr.tail, msg);
+	if (error)
+		return error;
+
 	sig_hdr.num_received++;
 
-	/* For each data field in SIGNAL_QUEUE_HEADER that was modified,
+	/*
+	 * For each data field in SIGNAL_QUEUE_HEADER that was modified,
 	 * update host memory.
 	 */
 	mb(); /* required for channel synch */
-	if (!SIG_WRITE_FIELD(channel, queue, &sig_hdr, tail))
-		return false;
-	if (!SIG_WRITE_FIELD(channel, queue, &sig_hdr, num_received))
-		return false;
-	return true;
+
+	error = SIG_WRITE_FIELD(channel, queue, &sig_hdr, tail);
+	if (error)
+		return error;
+	error = SIG_WRITE_FIELD(channel, queue, &sig_hdr, num_received);
+	if (error)
+		return error;
+
+	return 0;
 }
 
-bool
+/**
+ * visorchannel_signalremove() - removes a message from the designated
+ *                               channel/queue
+ * @channel: the channel the message will be removed from
+ * @queue:   the queue the message will be removed from
+ * @msg:     the message to remove
+ *
+ * Return: integer error code indicating the status of the removal
+ */
+int
 visorchannel_signalremove(struct visorchannel *channel, u32 queue, void *msg)
 {
-	bool rc;
+	int rc;
 	unsigned long flags;
 
 	if (channel->needs_lock) {
@@ -429,6 +290,15 @@ visorchannel_signalremove(struct visorchannel *channel, u32 queue, void *msg)
 }
 EXPORT_SYMBOL_GPL(visorchannel_signalremove);
 
+/**
+ * visorchannel_signalempty() - checks if the designated channel/queue
+ *                              contains any messages
+ * @channel: the channel to query
+ * @queue:   the queue in the channel to query
+ *
+ * Return: boolean indicating whether any messages in the designated
+ *         channel/queue are present
+ */
 bool
 visorchannel_signalempty(struct visorchannel *channel, u32 queue)
 {
@@ -439,7 +309,7 @@ visorchannel_signalempty(struct visorchannel *channel, u32 queue)
 	if (channel->needs_lock)
 		spin_lock_irqsave(&channel->remove_lock, flags);
 
-	if (!sig_read_header(channel, queue, &sig_hdr))
+	if (sig_read_header(channel, queue, &sig_hdr))
 		rc = true;
 	if (sig_hdr.head == sig_hdr.tail)
 		rc = true;
@@ -450,13 +320,15 @@ visorchannel_signalempty(struct visorchannel *channel, u32 queue)
 }
 EXPORT_SYMBOL_GPL(visorchannel_signalempty);
 
-static bool
+static int
 signalinsert_inner(struct visorchannel *channel, u32 queue, void *msg)
 {
 	struct signal_queue_header sig_hdr;
+	int error;
 
-	if (!sig_read_header(channel, queue, &sig_hdr))
-		return false;
+	error = sig_read_header(channel, queue, &sig_hdr);
+	if (error)
+		return error;
 
 	sig_hdr.head = (sig_hdr.head + 1) % sig_hdr.max_slots;
 	if (sig_hdr.head == sig_hdr.tail) {
@@ -467,169 +339,176 @@ signalinsert_inner(struct visorchannel *channel, u32 queue, void *msg)
 					    num_overflows),
 				   &sig_hdr.num_overflows,
 				   sizeof(sig_hdr.num_overflows));
-		return false;
+		return -EIO;
 	}
 
-	if (!sig_write_data(channel, queue, &sig_hdr, sig_hdr.head, msg))
-		return false;
+	error = sig_write_data(channel, queue, &sig_hdr, sig_hdr.head, msg);
+	if (error)
+		return error;
 
 	sig_hdr.num_sent++;
 
-	/* For each data field in SIGNAL_QUEUE_HEADER that was modified,
+	/*
+	 * For each data field in SIGNAL_QUEUE_HEADER that was modified,
 	 * update host memory.
 	 */
 	mb(); /* required for channel synch */
-	if (!SIG_WRITE_FIELD(channel, queue, &sig_hdr, head))
-		return false;
-	if (!SIG_WRITE_FIELD(channel, queue, &sig_hdr, num_sent))
-		return false;
 
-	return true;
+	error = SIG_WRITE_FIELD(channel, queue, &sig_hdr, head);
+	if (error)
+		return error;
+	error = SIG_WRITE_FIELD(channel, queue, &sig_hdr, num_sent);
+	if (error)
+		return error;
+
+	return 0;
 }
 
-bool
-visorchannel_signalinsert(struct visorchannel *channel, u32 queue, void *msg)
+/**
+ * visorchannel_create_guts() - creates the struct visorchannel abstraction
+ *                              for a data area in memory, but does NOT modify
+ *                              this data area
+ * @physaddr:      physical address of start of channel
+ * @channel_bytes: size of the channel in bytes; this may 0 if the channel has
+ *                 already been initialized in memory (which is true for all
+ *                 channels provided to guest environments by the s-Par
+ *                 back-end), in which case the actual channel size will be
+ *                 read from the channel header in memory
+ * @gfp:           gfp_t to use when allocating memory for the data struct
+ * @guid:          uuid that identifies channel type; this may 0 if the channel
+ *                 has already been initialized in memory (which is true for all
+ *                 channels provided to guest environments by the s-Par
+ *                 back-end), in which case the actual channel guid will be
+ *                 read from the channel header in memory
+ * @needs_lock:    must specify true if you have multiple threads of execution
+ *                 that will be calling visorchannel methods of this
+ *                 visorchannel at the same time
+ *
+ * Return: pointer to visorchannel that was created if successful,
+ *         otherwise NULL
+ */
+static struct visorchannel *
+visorchannel_create_guts(u64 physaddr, unsigned long channel_bytes,
+			 gfp_t gfp, uuid_le guid, bool needs_lock)
 {
-	bool rc;
-	unsigned long flags;
+	struct visorchannel *channel;
+	int err;
+	size_t size = sizeof(struct channel_header);
 
-	if (channel->needs_lock) {
-		spin_lock_irqsave(&channel->insert_lock, flags);
-		rc = signalinsert_inner(channel, queue, msg);
-		spin_unlock_irqrestore(&channel->insert_lock, flags);
-	} else {
-		rc = signalinsert_inner(channel, queue, msg);
+	if (physaddr == 0)
+		return NULL;
+
+	channel = kzalloc(sizeof(*channel), gfp);
+	if (!channel)
+		return NULL;
+
+	channel->needs_lock = needs_lock;
+	spin_lock_init(&channel->insert_lock);
+	spin_lock_init(&channel->remove_lock);
+
+	/*
+	 * Video driver constains the efi framebuffer so it will get a
+	 * conflict resource when requesting its full mem region. Since
+	 * we are only using the efi framebuffer for video we can ignore
+	 * this. Remember that we haven't requested it so we don't try to
+	 * release later on.
+	 */
+	channel->requested = request_mem_region(physaddr, size, MYDRVNAME);
+	if (!channel->requested) {
+		if (uuid_le_cmp(guid, spar_video_guid)) {
+			/* Not the video channel we care about this */
+			goto err_destroy_channel;
+		}
 	}
 
-	return rc;
-}
-EXPORT_SYMBOL_GPL(visorchannel_signalinsert);
+	channel->mapped = memremap(physaddr, size, MEMREMAP_WB);
+	if (!channel->mapped) {
+		release_mem_region(physaddr, size);
+		goto err_destroy_channel;
+	}
 
-int
-visorchannel_signalqueue_slots_avail(struct visorchannel *channel, u32 queue)
-{
-	struct signal_queue_header sig_hdr;
-	u32 slots_avail, slots_used;
-	u32 head, tail;
-
-	if (!sig_read_header(channel, queue, &sig_hdr))
-		return 0;
-	head = sig_hdr.head;
-	tail = sig_hdr.tail;
-	if (head < tail)
-		head = head + sig_hdr.max_slots;
-	slots_used = head - tail;
-	slots_avail = sig_hdr.max_signals - slots_used;
-	return (int)slots_avail;
-}
-EXPORT_SYMBOL_GPL(visorchannel_signalqueue_slots_avail);
+	channel->physaddr = physaddr;
+	channel->nbytes = size;
 
-int
-visorchannel_signalqueue_max_slots(struct visorchannel *channel, u32 queue)
-{
-	struct signal_queue_header sig_hdr;
+	err = visorchannel_read(channel, 0, &channel->chan_hdr,
+				sizeof(struct channel_header));
+	if (err)
+		goto err_destroy_channel;
+
+	/* we had better be a CLIENT of this channel */
+	if (channel_bytes == 0)
+		channel_bytes = (ulong)channel->chan_hdr.size;
+	if (uuid_le_cmp(guid, NULL_UUID_LE) == 0)
+		guid = channel->chan_hdr.chtype;
+
+	memunmap(channel->mapped);
+	if (channel->requested)
+		release_mem_region(channel->physaddr, channel->nbytes);
+	channel->mapped = NULL;
+	channel->requested = request_mem_region(channel->physaddr,
+						channel_bytes, MYDRVNAME);
+	if (!channel->requested) {
+		if (uuid_le_cmp(guid, spar_video_guid)) {
+			/* Different we care about this */
+			goto err_destroy_channel;
+		}
+	}
+
+	channel->mapped = memremap(channel->physaddr, channel_bytes,
+			MEMREMAP_WB);
+	if (!channel->mapped) {
+		release_mem_region(channel->physaddr, channel_bytes);
+		goto err_destroy_channel;
+	}
+
+	channel->nbytes = channel_bytes;
+	channel->guid = guid;
+	return channel;
 
-	if (!sig_read_header(channel, queue, &sig_hdr))
-		return 0;
-	return (int)sig_hdr.max_signals;
+err_destroy_channel:
+	visorchannel_destroy(channel);
+	return NULL;
 }
-EXPORT_SYMBOL_GPL(visorchannel_signalqueue_max_slots);
 
-static void
-sigqueue_debug(struct signal_queue_header *q, int which, struct seq_file *seq)
+struct visorchannel *
+visorchannel_create(u64 physaddr, unsigned long channel_bytes,
+		    gfp_t gfp, uuid_le guid)
 {
-	seq_printf(seq, "Signal Queue #%d\n", which);
-	seq_printf(seq, "   VersionId          = %lu\n", (ulong)q->version);
-	seq_printf(seq, "   Type               = %lu\n", (ulong)q->chtype);
-	seq_printf(seq, "   oSignalBase        = %llu\n",
-		   (long long)q->sig_base_offset);
-	seq_printf(seq, "   SignalSize         = %lu\n", (ulong)q->signal_size);
-	seq_printf(seq, "   MaxSignalSlots     = %lu\n",
-		   (ulong)q->max_slots);
-	seq_printf(seq, "   MaxSignals         = %lu\n", (ulong)q->max_signals);
-	seq_printf(seq, "   FeatureFlags       = %-16.16Lx\n",
-		   (long long)q->features);
-	seq_printf(seq, "   NumSignalsSent     = %llu\n",
-		   (long long)q->num_sent);
-	seq_printf(seq, "   NumSignalsReceived = %llu\n",
-		   (long long)q->num_received);
-	seq_printf(seq, "   NumOverflows       = %llu\n",
-		   (long long)q->num_overflows);
-	seq_printf(seq, "   Head               = %lu\n", (ulong)q->head);
-	seq_printf(seq, "   Tail               = %lu\n", (ulong)q->tail);
+	return visorchannel_create_guts(physaddr, channel_bytes, gfp, guid,
+					false);
 }
 
-void
-visorchannel_debug(struct visorchannel *channel, int num_queues,
-		   struct seq_file *seq, u32 off)
+struct visorchannel *
+visorchannel_create_with_lock(u64 physaddr, unsigned long channel_bytes,
+			      gfp_t gfp, uuid_le guid)
 {
-	u64 addr = 0;
-	ulong nbytes = 0, nbytes_region = 0;
-	struct channel_header hdr;
-	struct channel_header *phdr = &hdr;
-	int i = 0;
-	int errcode = 0;
+	return visorchannel_create_guts(physaddr, channel_bytes, gfp, guid,
+					true);
+}
 
-	if (!channel)
-		return;
+/**
+ * visorchannel_signalinsert() - inserts a message into the designated
+ *                               channel/queue
+ * @channel: the channel the message will be added to
+ * @queue:   the queue the message will be added to
+ * @msg:     the message to insert
+ *
+ * Return: integer error code indicating the status of the insertion
+ */
+int
+visorchannel_signalinsert(struct visorchannel *channel, u32 queue, void *msg)
+{
+	int rc;
+	unsigned long flags;
 
-	addr = visorchannel_get_physaddr(channel);
-	nbytes_region = visorchannel_get_nbytes(channel);
-	errcode = visorchannel_read(channel, off,
-				    phdr, sizeof(struct channel_header));
-	if (errcode < 0) {
-		seq_printf(seq,
-			   "Read of channel header failed with errcode=%d)\n",
-			   errcode);
-		if (off == 0) {
-			phdr = &channel->chan_hdr;
-			seq_puts(seq, "(following data may be stale)\n");
-		} else {
-			return;
-		}
+	if (channel->needs_lock) {
+		spin_lock_irqsave(&channel->insert_lock, flags);
+		rc = signalinsert_inner(channel, queue, msg);
+		spin_unlock_irqrestore(&channel->insert_lock, flags);
+	} else {
+		rc = signalinsert_inner(channel, queue, msg);
 	}
-	nbytes = (ulong)(phdr->size);
-	seq_printf(seq, "--- Begin channel @0x%-16.16Lx for 0x%lx bytes (region=0x%lx bytes) ---\n",
-		   addr + off, nbytes, nbytes_region);
-	seq_printf(seq, "Type            = %pUL\n", &phdr->chtype);
-	seq_printf(seq, "ZoneGuid        = %pUL\n", &phdr->zone_uuid);
-	seq_printf(seq, "Signature       = 0x%-16.16Lx\n",
-		   (long long)phdr->signature);
-	seq_printf(seq, "LegacyState     = %lu\n", (ulong)phdr->legacy_state);
-	seq_printf(seq, "SrvState        = %lu\n", (ulong)phdr->srv_state);
-	seq_printf(seq, "CliStateBoot    = %lu\n", (ulong)phdr->cli_state_boot);
-	seq_printf(seq, "CliStateOS      = %lu\n", (ulong)phdr->cli_state_os);
-	seq_printf(seq, "HeaderSize      = %lu\n", (ulong)phdr->header_size);
-	seq_printf(seq, "Size            = %llu\n", (long long)phdr->size);
-	seq_printf(seq, "Features        = 0x%-16.16llx\n",
-		   (long long)phdr->features);
-	seq_printf(seq, "PartitionHandle = 0x%-16.16llx\n",
-		   (long long)phdr->partition_handle);
-	seq_printf(seq, "Handle          = 0x%-16.16llx\n",
-		   (long long)phdr->handle);
-	seq_printf(seq, "VersionId       = %lu\n", (ulong)phdr->version_id);
-	seq_printf(seq, "oChannelSpace   = %llu\n",
-		   (long long)phdr->ch_space_offset);
-	if ((phdr->ch_space_offset == 0) || (errcode < 0))
-		;
-	else
-		for (i = 0; i < num_queues; i++) {
-			struct signal_queue_header q;
-
-			errcode = visorchannel_read(channel,
-						    off +
-						    phdr->ch_space_offset +
-						    (i * sizeof(q)),
-						    &q, sizeof(q));
-			if (errcode < 0) {
-				seq_printf(seq,
-					   "failed to read signal queue #%d from channel @0x%-16.16Lx errcode=%d\n",
-					   i, addr, errcode);
-				continue;
-			}
-			sigqueue_debug(&q, i, seq);
-		}
-	seq_printf(seq, "--- End   channel @0x%-16.16Lx for 0x%lx bytes ---\n",
-		   addr + off, nbytes);
+
+	return rc;
 }
-EXPORT_SYMBOL_GPL(visorchannel_debug);
+EXPORT_SYMBOL_GPL(visorchannel_signalinsert);