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, 233 insertions, 0 deletions

diff --git a/drivers/staging/lustre/lustre/llite/range_lock.c b/drivers/staging/lustre/lustre/llite/range_lock.c
new file mode 100644
index 000000000000..94c818f1478b
--- /dev/null
+++ b/drivers/staging/lustre/lustre/llite/range_lock.c
@@ -0,0 +1,233 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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 version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * GPL HEADER END
+ */
+/*
+ * Range lock is used to allow multiple threads writing a single shared
+ * file given each thread is writing to a non-overlapping portion of the
+ * file.
+ *
+ * Refer to the possible upstream kernel version of range lock by
+ * Jan Kara <jack@suse.cz>: https://lkml.org/lkml/2013/1/31/480
+ *
+ * This file could later replaced by the upstream kernel version.
+ */
+/*
+ * Author: Prakash Surya <surya1@llnl.gov>
+ * Author: Bobi Jam <bobijam.xu@intel.com>
+ */
+#include "range_lock.h"
+#include "../include/lustre/lustre_user.h"
+
+/**
+ * Initialize a range lock tree
+ *
+ * \param tree [in]	an empty range lock tree
+ *
+ * Pre:  Caller should have allocated the range lock tree.
+ * Post: The range lock tree is ready to function.
+ */
+void range_lock_tree_init(struct range_lock_tree *tree)
+{
+	tree->rlt_root = NULL;
+	tree->rlt_sequence = 0;
+	spin_lock_init(&tree->rlt_lock);
+}
+
+/**
+ * Initialize a range lock node
+ *
+ * \param lock  [in]	an empty range lock node
+ * \param start [in]	start of the covering region
+ * \param end   [in]	end of the covering region
+ *
+ * Pre:  Caller should have allocated the range lock node.
+ * Post: The range lock node is meant to cover [start, end] region
+ */
+void range_lock_init(struct range_lock *lock, __u64 start, __u64 end)
+{
+	memset(&lock->rl_node, 0, sizeof(lock->rl_node));
+	if (end != LUSTRE_EOF)
+		end >>= PAGE_SHIFT;
+	interval_set(&lock->rl_node, start >> PAGE_SHIFT, end);
+	INIT_LIST_HEAD(&lock->rl_next_lock);
+	lock->rl_task = NULL;
+	lock->rl_lock_count = 0;
+	lock->rl_blocking_ranges = 0;
+	lock->rl_sequence = 0;
+}
+
+static inline struct range_lock *next_lock(struct range_lock *lock)
+{
+	return list_entry(lock->rl_next_lock.next, typeof(*lock), rl_next_lock);
+}
+
+/**
+ * Helper function of range_unlock()
+ *
+ * \param node [in]	a range lock found overlapped during interval node
+ *			search
+ * \param arg [in]	the range lock to be tested
+ *
+ * \retval INTERVAL_ITER_CONT	indicate to continue the search for next
+ *				overlapping range node
+ * \retval INTERVAL_ITER_STOP	indicate to stop the search
+ */
+static enum interval_iter range_unlock_cb(struct interval_node *node, void *arg)
+{
+	struct range_lock *lock = arg;
+	struct range_lock *overlap = node2rangelock(node);
+	struct range_lock *iter;
+
+	list_for_each_entry(iter, &overlap->rl_next_lock, rl_next_lock) {
+		if (iter->rl_sequence > lock->rl_sequence) {
+			--iter->rl_blocking_ranges;
+			LASSERT(iter->rl_blocking_ranges > 0);
+		}
+	}
+	if (overlap->rl_sequence > lock->rl_sequence) {
+		--overlap->rl_blocking_ranges;
+		if (overlap->rl_blocking_ranges == 0)
+			wake_up_process(overlap->rl_task);
+	}
+	return INTERVAL_ITER_CONT;
+}
+
+/**
+ * Unlock a range lock, wake up locks blocked by this lock.
+ *
+ * \param tree [in]	range lock tree
+ * \param lock [in]	range lock to be deleted
+ *
+ * If this lock has been granted, relase it; if not, just delete it from
+ * the tree or the same region lock list. Wake up those locks only blocked
+ * by this lock through range_unlock_cb().
+ */
+void range_unlock(struct range_lock_tree *tree, struct range_lock *lock)
+{
+	spin_lock(&tree->rlt_lock);
+	if (!list_empty(&lock->rl_next_lock)) {
+		struct range_lock *next;
+
+		if (interval_is_intree(&lock->rl_node)) { /* first lock */
+			/* Insert the next same range lock into the tree */
+			next = next_lock(lock);
+			next->rl_lock_count = lock->rl_lock_count - 1;
+			interval_erase(&lock->rl_node, &tree->rlt_root);
+			interval_insert(&next->rl_node, &tree->rlt_root);
+		} else {
+			/* find the first lock in tree */
+			list_for_each_entry(next, &lock->rl_next_lock,
+					    rl_next_lock) {
+				if (!interval_is_intree(&next->rl_node))
+					continue;
+
+				LASSERT(next->rl_lock_count > 0);
+				next->rl_lock_count--;
+				break;
+			}
+		}
+		list_del_init(&lock->rl_next_lock);
+	} else {
+		LASSERT(interval_is_intree(&lock->rl_node));
+		interval_erase(&lock->rl_node, &tree->rlt_root);
+	}
+
+	interval_search(tree->rlt_root, &lock->rl_node.in_extent,
+			range_unlock_cb, lock);
+	spin_unlock(&tree->rlt_lock);
+}
+
+/**
+ * Helper function of range_lock()
+ *
+ * \param node [in]	a range lock found overlapped during interval node
+ *			search
+ * \param arg [in]	the range lock to be tested
+ *
+ * \retval INTERVAL_ITER_CONT	indicate to continue the search for next
+ *				overlapping range node
+ * \retval INTERVAL_ITER_STOP	indicate to stop the search
+ */
+static enum interval_iter range_lock_cb(struct interval_node *node, void *arg)
+{
+	struct range_lock *lock = (struct range_lock *)arg;
+	struct range_lock *overlap = node2rangelock(node);
+
+	lock->rl_blocking_ranges += overlap->rl_lock_count + 1;
+	return INTERVAL_ITER_CONT;
+}
+
+/**
+ * Lock a region
+ *
+ * \param tree [in]	range lock tree
+ * \param lock [in]	range lock node containing the region span
+ *
+ * \retval 0	get the range lock
+ * \retval <0	error code while not getting the range lock
+ *
+ * If there exists overlapping range lock, the new lock will wait and
+ * retry, if later it find that it is not the chosen one to wake up,
+ * it wait again.
+ */
+int range_lock(struct range_lock_tree *tree, struct range_lock *lock)
+{
+	struct interval_node *node;
+	int rc = 0;
+
+	spin_lock(&tree->rlt_lock);
+	/*
+	 * We need to check for all conflicting intervals
+	 * already in the tree.
+	 */
+	interval_search(tree->rlt_root, &lock->rl_node.in_extent,
+			range_lock_cb, lock);
+	/*
+	 * Insert to the tree if I am unique, otherwise I've been linked to
+	 * the rl_next_lock of another lock which has the same range as mine
+	 * in range_lock_cb().
+	 */
+	node = interval_insert(&lock->rl_node, &tree->rlt_root);
+	if (node) {
+		struct range_lock *tmp = node2rangelock(node);
+
+		list_add_tail(&lock->rl_next_lock, &tmp->rl_next_lock);
+		tmp->rl_lock_count++;
+	}
+	lock->rl_sequence = ++tree->rlt_sequence;
+
+	while (lock->rl_blocking_ranges > 0) {
+		lock->rl_task = current;
+		__set_current_state(TASK_INTERRUPTIBLE);
+		spin_unlock(&tree->rlt_lock);
+		schedule();
+
+		if (signal_pending(current)) {
+			range_unlock(tree, lock);
+			rc = -EINTR;
+			goto out;
+		}
+		spin_lock(&tree->rlt_lock);
+	}
+	spin_unlock(&tree->rlt_lock);
+out:
+	return rc;
+}