Merge branch 'core/mutexes' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into drm-next

Merge in the tip core/mutexes branch for future GPU driver use.

Ingo will send this branch to Linus prior to drm-next.

* 'core/mutexes' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  locking-selftests: Handle unexpected failures more strictly
  mutex: Add more w/w tests to test EDEADLK path handling
  mutex: Add more tests to lib/locking-selftest.c
  mutex: Add w/w tests to lib/locking-selftest.c
  mutex: Add w/w mutex slowpath debugging
  mutex: Add support for wound/wait style locks
  arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
  powerpc/pci: Fix boot panic on mpc83xx (regression)
  s390/ipl: Fix FCP WWPN and LUN format strings for read
  fs: fix new splice.c kernel-doc warning
  spi/pxa2xx: fix memory corruption due to wrong size used in devm_kzalloc()
  s390/mem_detect: fix memory hole handling
  s390/dma: support debug_dma_mapping_error
  s390/dma: fix mapping_error detection
  s390/irq: Only define synchronize_irq() on SMP
  Input: xpad - fix for "Mad Catz Street Fighter IV FightPad" controllers
  Input: wacom - add a new stylus (0x100802) for Intuos5 and Cintiqs
  spi/pxa2xx: use GFP_ATOMIC in sg table allocation
  fuse: hold i_mutex in fuse_file_fallocate()
  Input: add missing dependencies on CONFIG_HAS_IOMEM
  ...

Documentation/ww-mutex-design.txt

@@ -0,0 +1,344 @@
+Wait/Wound Deadlock-Proof Mutex Design
+======================================
+
+Please read mutex-design.txt first, as it applies to wait/wound mutexes too.
+
+Motivation for WW-Mutexes
+-------------------------
+
+GPU's do operations that commonly involve many buffers.  Those buffers
+can be shared across contexts/processes, exist in different memory
+domains (for example VRAM vs system memory), and so on.  And with
+PRIME / dmabuf, they can even be shared across devices.  So there are
+a handful of situations where the driver needs to wait for buffers to
+become ready.  If you think about this in terms of waiting on a buffer
+mutex for it to become available, this presents a problem because
+there is no way to guarantee that buffers appear in a execbuf/batch in
+the same order in all contexts.  That is directly under control of
+userspace, and a result of the sequence of GL calls that an application
+makes.	Which results in the potential for deadlock.  The problem gets
+more complex when you consider that the kernel may need to migrate the
+buffer(s) into VRAM before the GPU operates on the buffer(s), which
+may in turn require evicting some other buffers (and you don't want to
+evict other buffers which are already queued up to the GPU), but for a
+simplified understanding of the problem you can ignore this.
+
+The algorithm that the TTM graphics subsystem came up with for dealing with
+this problem is quite simple.  For each group of buffers (execbuf) that need
+to be locked, the caller would be assigned a unique reservation id/ticket,
+from a global counter.  In case of deadlock while locking all the buffers
+associated with a execbuf, the one with the lowest reservation ticket (i.e.
+the oldest task) wins, and the one with the higher reservation id (i.e. the
+younger task) unlocks all of the buffers that it has already locked, and then
+tries again.
+
+In the RDBMS literature this deadlock handling approach is called wait/wound:
+The older tasks waits until it can acquire the contended lock. The younger tasks
+needs to back off and drop all the locks it is currently holding, i.e. the
+younger task is wounded.
+
+Concepts
+--------
+
+Compared to normal mutexes two additional concepts/objects show up in the lock
+interface for w/w mutexes:
+
+Acquire context: To ensure eventual forward progress it is important the a task
+trying to acquire locks doesn't grab a new reservation id, but keeps the one it
+acquired when starting the lock acquisition. This ticket is stored in the
+acquire context. Furthermore the acquire context keeps track of debugging state
+to catch w/w mutex interface abuse.
+
+W/w class: In contrast to normal mutexes the lock class needs to be explicit for
+w/w mutexes, since it is required to initialize the acquire context.
+
+Furthermore there are three different class of w/w lock acquire functions:
+
+* Normal lock acquisition with a context, using ww_mutex_lock.
+
+* Slowpath lock acquisition on the contending lock, used by the wounded task
+  after having dropped all already acquired locks. These functions have the
+  _slow postfix.
+
+  From a simple semantics point-of-view the _slow functions are not strictly
+  required, since simply calling the normal ww_mutex_lock functions on the
+  contending lock (after having dropped all other already acquired locks) will
+  work correctly. After all if no other ww mutex has been acquired yet there's
+  no deadlock potential and hence the ww_mutex_lock call will block and not
+  prematurely return -EDEADLK. The advantage of the _slow functions is in
+  interface safety:
+  - ww_mutex_lock has a __must_check int return type, whereas ww_mutex_lock_slow
+    has a void return type. Note that since ww mutex code needs loops/retries
+    anyway the __must_check doesn't result in spurious warnings, even though the
+    very first lock operation can never fail.
+  - When full debugging is enabled ww_mutex_lock_slow checks that all acquired
+    ww mutex have been released (preventing deadlocks) and makes sure that we
+    block on the contending lock (preventing spinning through the -EDEADLK
+    slowpath until the contended lock can be acquired).
+
+* Functions to only acquire a single w/w mutex, which results in the exact same
+  semantics as a normal mutex. This is done by calling ww_mutex_lock with a NULL
+  context.
+
+  Again this is not strictly required. But often you only want to acquire a
+  single lock in which case it's pointless to set up an acquire context (and so
+  better to avoid grabbing a deadlock avoidance ticket).
+
+Of course, all the usual variants for handling wake-ups due to signals are also
+provided.
+
+Usage
+-----
+
+Three different ways to acquire locks within the same w/w class. Common
+definitions for methods #1 and #2:
+
+static DEFINE_WW_CLASS(ww_class);
+
+struct obj {
+	struct ww_mutex lock;
+	/* obj data */
+};
+
+struct obj_entry {
+	struct list_head head;
+	struct obj *obj;
+};
+
+Method 1, using a list in execbuf->buffers that's not allowed to be reordered.
+This is useful if a list of required objects is already tracked somewhere.
+Furthermore the lock helper can use propagate the -EALREADY return code back to
+the caller as a signal that an object is twice on the list. This is useful if
+the list is constructed from userspace input and the ABI requires userspace to
+not have duplicate entries (e.g. for a gpu commandbuffer submission ioctl).
+
+int lock_objs(struct list_head *list, struct ww_acquire_ctx *ctx)
+{
+	struct obj *res_obj = NULL;
+	struct obj_entry *contended_entry = NULL;
+	struct obj_entry *entry;
+
+	ww_acquire_init(ctx, &ww_class);
+
+retry:
+	list_for_each_entry (entry, list, head) {
+		if (entry->obj == res_obj) {
+			res_obj = NULL;
+			continue;
+		}
+		ret = ww_mutex_lock(&entry->obj->lock, ctx);
+		if (ret < 0) {
+			contended_entry = entry;
+			goto err;
+		}
+	}
+
+	ww_acquire_done(ctx);
+	return 0;
+
+err:
+	list_for_each_entry_continue_reverse (entry, list, head)
+		ww_mutex_unlock(&entry->obj->lock);
+
+	if (res_obj)
+		ww_mutex_unlock(&res_obj->lock);
+
+	if (ret == -EDEADLK) {
+		/* we lost out in a seqno race, lock and retry.. */
+		ww_mutex_lock_slow(&contended_entry->obj->lock, ctx);
+		res_obj = contended_entry->obj;
+		goto retry;
+	}
+	ww_acquire_fini(ctx);
+
+	return ret;
+}
+
+Method 2, using a list in execbuf->buffers that can be reordered. Same semantics
+of duplicate entry detection using -EALREADY as method 1 above. But the
+list-reordering allows for a bit more idiomatic code.
+
+int lock_objs(struct list_head *list, struct ww_acquire_ctx *ctx)
+{
+	struct obj_entry *entry, *entry2;
+
+	ww_acquire_init(ctx, &ww_class);
+
+	list_for_each_entry (entry, list, head) {
+		ret = ww_mutex_lock(&entry->obj->lock, ctx);
+		if (ret < 0) {
+			entry2 = entry;
+
+			list_for_each_entry_continue_reverse (entry2, list, head)
+				ww_mutex_unlock(&entry2->obj->lock);
+
+			if (ret != -EDEADLK) {
+				ww_acquire_fini(ctx);
+				return ret;
+			}
+
+			/* we lost out in a seqno race, lock and retry.. */
+			ww_mutex_lock_slow(&entry->obj->lock, ctx);
+
+			/*
+			 * Move buf to head of the list, this will point
+			 * buf->next to the first unlocked entry,
+			 * restarting the for loop.
+			 */
+			list_del(&entry->head);
+			list_add(&entry->head, list);
+		}
+	}
+
+	ww_acquire_done(ctx);
+	return 0;
+}
+
+Unlocking works the same way for both methods #1 and #2:
+
+void unlock_objs(struct list_head *list, struct ww_acquire_ctx *ctx)
+{
+	struct obj_entry *entry;
+
+	list_for_each_entry (entry, list, head)
+		ww_mutex_unlock(&entry->obj->lock);
+
+	ww_acquire_fini(ctx);
+}
+
+Method 3 is useful if the list of objects is constructed ad-hoc and not upfront,
+e.g. when adjusting edges in a graph where each node has its own ww_mutex lock,
+and edges can only be changed when holding the locks of all involved nodes. w/w
+mutexes are a natural fit for such a case for two reasons:
+- They can handle lock-acquisition in any order which allows us to start walking
+  a graph from a starting point and then iteratively discovering new edges and
+  locking down the nodes those edges connect to.
+- Due to the -EALREADY return code signalling that a given objects is already
+  held there's no need for additional book-keeping to break cycles in the graph
+  or keep track off which looks are already held (when using more than one node
+  as a starting point).
+
+Note that this approach differs in two important ways from the above methods:
+- Since the list of objects is dynamically constructed (and might very well be
+  different when retrying due to hitting the -EDEADLK wound condition) there's
+  no need to keep any object on a persistent list when it's not locked. We can
+  therefore move the list_head into the object itself.
+- On the other hand the dynamic object list construction also means that the -EALREADY return
+  code can't be propagated.
+
+Note also that methods #1 and #2 and method #3 can be combined, e.g. to first lock a
+list of starting nodes (passed in from userspace) using one of the above
+methods. And then lock any additional objects affected by the operations using
+method #3 below. The backoff/retry procedure will be a bit more involved, since
+when the dynamic locking step hits -EDEADLK we also need to unlock all the
+objects acquired with the fixed list. But the w/w mutex debug checks will catch
+any interface misuse for these cases.
+
+Also, method 3 can't fail the lock acquisition step since it doesn't return
+-EALREADY. Of course this would be different when using the _interruptible
+variants, but that's outside of the scope of these examples here.
+
+struct obj {
+	struct ww_mutex ww_mutex;
+	struct list_head locked_list;
+};
+
+static DEFINE_WW_CLASS(ww_class);
+
+void __unlock_objs(struct list_head *list)
+{
+	struct obj *entry, *temp;
+
+	list_for_each_entry_safe (entry, temp, list, locked_list) {
+		/* need to do that before unlocking, since only the current lock holder is
+		allowed to use object */
+		list_del(&entry->locked_list);
+		ww_mutex_unlock(entry->ww_mutex)
+	}
+}
+
+void lock_objs(struct list_head *list, struct ww_acquire_ctx *ctx)
+{
+	struct obj *obj;
+
+	ww_acquire_init(ctx, &ww_class);
+
+retry:
+	/* re-init loop start state */
+	loop {
+		/* magic code which walks over a graph and decides which objects
+		 * to lock */
+
+		ret = ww_mutex_lock(obj->ww_mutex, ctx);
+		if (ret == -EALREADY) {
+			/* we have that one already, get to the next object */
+			continue;
+		}
+		if (ret == -EDEADLK) {
+			__unlock_objs(list);
+
+			ww_mutex_lock_slow(obj, ctx);
+			list_add(&entry->locked_list, list);
+			goto retry;
+		}
+
+		/* locked a new object, add it to the list */
+		list_add_tail(&entry->locked_list, list);
+	}
+
+	ww_acquire_done(ctx);
+	return 0;
+}
+
+void unlock_objs(struct list_head *list, struct ww_acquire_ctx *ctx)
+{
+	__unlock_objs(list);
+	ww_acquire_fini(ctx);
+}
+
+Method 4: Only lock one single objects. In that case deadlock detection and
+prevention is obviously overkill, since with grabbing just one lock you can't
+produce a deadlock within just one class. To simplify this case the w/w mutex
+api can be used with a NULL context.
+
+Implementation Details
+----------------------
+
+Design:
+  ww_mutex currently encapsulates a struct mutex, this means no extra overhead for
+  normal mutex locks, which are far more common. As such there is only a small
+  increase in code size if wait/wound mutexes are not used.
+
+  In general, not much contention is expected. The locks are typically used to
+  serialize access to resources for devices. The only way to make wakeups
+  smarter would be at the cost of adding a field to struct mutex_waiter. This
+  would add overhead to all cases where normal mutexes are used, and
+  ww_mutexes are generally less performance sensitive.
+
+Lockdep:
+  Special care has been taken to warn for as many cases of api abuse
+  as possible. Some common api abuses will be caught with
+  CONFIG_DEBUG_MUTEXES, but CONFIG_PROVE_LOCKING is recommended.
+
+  Some of the errors which will be warned about:
+   - Forgetting to call ww_acquire_fini or ww_acquire_init.
+   - Attempting to lock more mutexes after ww_acquire_done.
+   - Attempting to lock the wrong mutex after -EDEADLK and
+     unlocking all mutexes.
+   - Attempting to lock the right mutex after -EDEADLK,
+     before unlocking all mutexes.
+
+   - Calling ww_mutex_lock_slow before -EDEADLK was returned.
+
+   - Unlocking mutexes with the wrong unlock function.
+   - Calling one of the ww_acquire_* twice on the same context.
+   - Using a different ww_class for the mutex than for the ww_acquire_ctx.
+   - Normal lockdep errors that can result in deadlocks.
+
+  Some of the lockdep errors that can result in deadlocks:
+   - Calling ww_acquire_init to initialize a second ww_acquire_ctx before
+     having called ww_acquire_fini on the first.
+   - 'normal' deadlocks that can occur.
+
+FIXME: Update this section once we have the TASK_DEADLOCK task state flag magic
+implemented.

arch/ia64/include/asm/mutex.h

@@ -29,17 +29,15 @@ __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
  *  __mutex_fastpath_lock_retval - try to take the lock by moving the count
  *                                 from 1 to a 0 value
  *  @count: pointer of type atomic_t
- *  @fail_fn: function to call if the original value was not 1
  *
- * Change the count from 1 to a value lower than 1, and call <fail_fn> if
- * it wasn't 1 originally. This function returns 0 if the fastpath succeeds,
- * or anything the slow path function returns.
+ * Change the count from 1 to a value lower than 1. This function returns 0
+ * if the fastpath succeeds, or -1 otherwise.
  */
 static inline int
-__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
+__mutex_fastpath_lock_retval(atomic_t *count)
 {
 	if (unlikely(ia64_fetchadd4_acq(count, -1) != 1))
-		return fail_fn(count);
+		return -1;
 	return 0;
 }
 

arch/powerpc/include/asm/mutex.h

@@ -82,17 +82,15 @@ __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
  *  __mutex_fastpath_lock_retval - try to take the lock by moving the count
  *                                 from 1 to a 0 value
  *  @count: pointer of type atomic_t
- *  @fail_fn: function to call if the original value was not 1
  *
- * Change the count from 1 to a value lower than 1, and call <fail_fn> if
- * it wasn't 1 originally. This function returns 0 if the fastpath succeeds,
- * or anything the slow path function returns.
+ * Change the count from 1 to a value lower than 1. This function returns 0
+ * if the fastpath succeeds, or -1 otherwise.
  */
 static inline int
-__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
+__mutex_fastpath_lock_retval(atomic_t *count)
 {
 	if (unlikely(__mutex_dec_return_lock(count) < 0))
-		return fail_fn(count);
+		return -1;
 	return 0;
 }
 

arch/powerpc/sysdev/fsl_pci.c

@@ -97,22 +97,14 @@ static int fsl_indirect_read_config(struct pci_bus *bus, unsigned int devfn,
 	return indirect_read_config(bus, devfn, offset, len, val);
 }
 
-static struct pci_ops fsl_indirect_pci_ops =
+#if defined(CONFIG_FSL_SOC_BOOKE) || defined(CONFIG_PPC_86xx)
+
+static struct pci_ops fsl_indirect_pcie_ops =
 {
 	.read = fsl_indirect_read_config,
 	.write = indirect_write_config,
 };
 
-static void __init fsl_setup_indirect_pci(struct pci_controller* hose,
-					  resource_size_t cfg_addr,
-					  resource_size_t cfg_data, u32 flags)
-{
-	setup_indirect_pci(hose, cfg_addr, cfg_data, flags);
-	hose->ops = &fsl_indirect_pci_ops;
-}
-
-#if defined(CONFIG_FSL_SOC_BOOKE) || defined(CONFIG_PPC_86xx)
-
 #define MAX_PHYS_ADDR_BITS	40
 static u64 pci64_dma_offset = 1ull << MAX_PHYS_ADDR_BITS;
 
@@ -504,13 +496,15 @@ int __init fsl_add_bridge(struct platform_device *pdev, int is_primary)
 	if (!hose->private_data)
 		goto no_bridge;
 
-	fsl_setup_indirect_pci(hose, rsrc.start, rsrc.start + 0x4,
+	setup_indirect_pci(hose, rsrc.start, rsrc.start + 0x4,
 			   PPC_INDIRECT_TYPE_BIG_ENDIAN);
 
 	if (in_be32(&pci->block_rev1) < PCIE_IP_REV_3_0)
 		hose->indirect_type |= PPC_INDIRECT_TYPE_FSL_CFG_REG_LINK;
 
 	if (early_find_capability(hose, 0, 0, PCI_CAP_ID_EXP)) {
+		/* use fsl_indirect_read_config for PCIe */
+		hose->ops = &fsl_indirect_pcie_ops;
 		/* For PCIE read HEADER_TYPE to identify controler mode */
 		early_read_config_byte(hose, 0, 0, PCI_HEADER_TYPE, &hdr_type);
 		if ((hdr_type & 0x7f) != PCI_HEADER_TYPE_BRIDGE)
@@ -814,7 +808,7 @@ int __init mpc83xx_add_bridge(struct device_node *dev)
 		if (ret)
 			goto err0;
 	} else {
-		fsl_setup_indirect_pci(hose, rsrc_cfg.start,
+		setup_indirect_pci(hose, rsrc_cfg.start,
 				   rsrc_cfg.start + 4, 0);
 	}
 

arch/s390/include/asm/dma-mapping.h

@@ -50,9 +50,10 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	struct dma_map_ops *dma_ops = get_dma_ops(dev);
 
+	debug_dma_mapping_error(dev, dma_addr);
 	if (dma_ops->mapping_error)
 		return dma_ops->mapping_error(dev, dma_addr);
-	return (dma_addr == 0UL);
+	return (dma_addr == DMA_ERROR_CODE);
 }
 
 static inline void *dma_alloc_coherent(struct device *dev, size_t size,

arch/s390/kernel/ipl.c

@@ -754,9 +754,9 @@ static struct bin_attribute sys_reipl_fcp_scp_data_attr = {
 	.write = reipl_fcp_scpdata_write,
 };
 
-DEFINE_IPL_ATTR_RW(reipl_fcp, wwpn, "0x%016llx\n", "%016llx\n",
+DEFINE_IPL_ATTR_RW(reipl_fcp, wwpn, "0x%016llx\n", "%llx\n",
 		   reipl_block_fcp->ipl_info.fcp.wwpn);
-DEFINE_IPL_ATTR_RW(reipl_fcp, lun, "0x%016llx\n", "%016llx\n",
+DEFINE_IPL_ATTR_RW(reipl_fcp, lun, "0x%016llx\n", "%llx\n",
 		   reipl_block_fcp->ipl_info.fcp.lun);
 DEFINE_IPL_ATTR_RW(reipl_fcp, bootprog, "%lld\n", "%lld\n",
 		   reipl_block_fcp->ipl_info.fcp.bootprog);
@@ -1323,9 +1323,9 @@ static struct shutdown_action __refdata reipl_action = {
 
 /* FCP dump device attributes */
 
-DEFINE_IPL_ATTR_RW(dump_fcp, wwpn, "0x%016llx\n", "%016llx\n",
+DEFINE_IPL_ATTR_RW(dump_fcp, wwpn, "0x%016llx\n", "%llx\n",
 		   dump_block_fcp->ipl_info.fcp.wwpn);
-DEFINE_IPL_ATTR_RW(dump_fcp, lun, "0x%016llx\n", "%016llx\n",
+DEFINE_IPL_ATTR_RW(dump_fcp, lun, "0x%016llx\n", "%llx\n",
 		   dump_block_fcp->ipl_info.fcp.lun);
 DEFINE_IPL_ATTR_RW(dump_fcp, bootprog, "%lld\n", "%lld\n",
 		   dump_block_fcp->ipl_info.fcp.bootprog);

arch/s390/kernel/irq.c

@@ -312,6 +312,7 @@ void measurement_alert_subclass_unregister(void)
 }
 EXPORT_SYMBOL(measurement_alert_subclass_unregister);
 
+#ifdef CONFIG_SMP
 void synchronize_irq(unsigned int irq)
 {
 	/*
@@ -320,6 +321,7 @@ void synchronize_irq(unsigned int irq)
 	 */
 }
 EXPORT_SYMBOL_GPL(synchronize_irq);
+#endif
 
 #ifndef CONFIG_PCI
 

arch/s390/mm/mem_detect.c

@@ -123,7 +123,8 @@ void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr,
 			continue;
 		} else if ((addr <= chunk->addr) &&
 			   (addr + size >= chunk->addr + chunk->size)) {
-			memset(chunk, 0 , sizeof(*chunk));
+			memmove(chunk, chunk + 1, (MEMORY_CHUNKS-i-1) * sizeof(*chunk));
+			memset(&mem_chunk[MEMORY_CHUNKS-1], 0, sizeof(*chunk));
 		} else if (addr + size < chunk->addr + chunk->size) {
 			chunk->size =  chunk->addr + chunk->size - addr - size;
 			chunk->addr = addr + size;

arch/sh/include/asm/mutex-llsc.h

@@ -37,7 +37,7 @@ __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
 }
 
 static inline int
-__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
+__mutex_fastpath_lock_retval(atomic_t *count)
 {
 	int __done, __res;
 
@@ -51,7 +51,7 @@ __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
 		: "t");
 
 	if (unlikely(!__done || __res != 0))
-		__res = fail_fn(count);
+		__res = -1;
 
 	return __res;
 }

arch/x86/include/asm/mutex_32.h

@@ -42,17 +42,14 @@ do {								\
  *  __mutex_fastpath_lock_retval - try to take the lock by moving the count
  *                                 from 1 to a 0 value
  *  @count: pointer of type atomic_t
- *  @fail_fn: function to call if the original value was not 1
  *
- * Change the count from 1 to a value lower than 1, and call <fail_fn> if it
- * wasn't 1 originally. This function returns 0 if the fastpath succeeds,
- * or anything the slow path function returns
+ * Change the count from 1 to a value lower than 1. This function returns 0
+ * if the fastpath succeeds, or -1 otherwise.
  */
-static inline int __mutex_fastpath_lock_retval(atomic_t *count,
-					       int (*fail_fn)(atomic_t *))
+static inline int __mutex_fastpath_lock_retval(atomic_t *count)
 {
 	if (unlikely(atomic_dec_return(count) < 0))
-		return fail_fn(count);
+		return -1;
 	else
 		return 0;
 }

arch/x86/include/asm/mutex_64.h

@@ -37,17 +37,14 @@ do {								\
  *  __mutex_fastpath_lock_retval - try to take the lock by moving the count
  *                                 from 1 to a 0 value
  *  @count: pointer of type atomic_t
- *  @fail_fn: function to call if the original value was not 1
  *
- * Change the count from 1 to a value lower than 1, and call <fail_fn> if
- * it wasn't 1 originally. This function returns 0 if the fastpath succeeds,
- * or anything the slow path function returns
+ * Change the count from 1 to a value lower than 1. This function returns 0
+ * if the fastpath succeeds, or -1 otherwise.
  */
-static inline int __mutex_fastpath_lock_retval(atomic_t *count,
-					       int (*fail_fn)(atomic_t *))
+static inline int __mutex_fastpath_lock_retval(atomic_t *count)
 {
 	if (unlikely(atomic_dec_return(count) < 0))
-		return fail_fn(count);
+		return -1;
 	else
 		return 0;
 }

drivers/input/joystick/xpad.c

@@ -137,7 +137,7 @@ static const struct xpad_device {
 	{ 0x0738, 0x4540, "Mad Catz Beat Pad", MAP_DPAD_TO_BUTTONS, XTYPE_XBOX },
 	{ 0x0738, 0x4556, "Mad Catz Lynx Wireless Controller", 0, XTYPE_XBOX },
 	{ 0x0738, 0x4716, "Mad Catz Wired Xbox 360 Controller", 0, XTYPE_XBOX360 },
-	{ 0x0738, 0x4728, "Mad Catz Street Fighter IV FightPad", XTYPE_XBOX360 },
+	{ 0x0738, 0x4728, "Mad Catz Street Fighter IV FightPad", MAP_TRIGGERS_TO_BUTTONS, XTYPE_XBOX360 },
 	{ 0x0738, 0x4738, "Mad Catz Wired Xbox 360 Controller (SFIV)", MAP_TRIGGERS_TO_BUTTONS, XTYPE_XBOX360 },
 	{ 0x0738, 0x6040, "Mad Catz Beat Pad Pro", MAP_DPAD_TO_BUTTONS, XTYPE_XBOX },
 	{ 0x0738, 0xbeef, "Mad Catz JOYTECH NEO SE Advanced GamePad", XTYPE_XBOX360 },

drivers/input/keyboard/Kconfig

@@ -431,6 +431,7 @@ config KEYBOARD_TEGRA
 
 config KEYBOARD_OPENCORES
 	tristate "OpenCores Keyboard Controller"
+	depends on HAS_IOMEM
 	help
 	  Say Y here if you want to use the OpenCores Keyboard Controller
 	  http://www.opencores.org/project,keyboardcontroller

drivers/input/serio/Kconfig

@@ -205,6 +205,7 @@ config SERIO_XILINX_XPS_PS2
 
 config SERIO_ALTERA_PS2
 	tristate "Altera UP PS/2 controller"
+	depends on HAS_IOMEM
 	help
 	  Say Y here if you have Altera University Program PS/2 ports.
 

drivers/input/tablet/wacom_wac.c

@@ -363,6 +363,7 @@ static int wacom_intuos_inout(struct wacom_wac *wacom)
 		case 0x140802: /* Intuos4/5 13HD/24HD Classic Pen */
 		case 0x160802: /* Cintiq 13HD Pro Pen */
 		case 0x180802: /* DTH2242 Pen */
+		case 0x100802: /* Intuos4/5 13HD/24HD General Pen */
 			wacom->tool[idx] = BTN_TOOL_PEN;
 			break;
 
@@ -401,6 +402,7 @@ static int wacom_intuos_inout(struct wacom_wac *wacom)
 		case 0x10080c: /* Intuos4/5 13HD/24HD Art Pen Eraser */
 		case 0x16080a: /* Cintiq 13HD Pro Pen Eraser */
 		case 0x18080a: /* DTH2242 Eraser */
+		case 0x10080a: /* Intuos4/5 13HD/24HD General Pen Eraser */
 			wacom->tool[idx] = BTN_TOOL_RUBBER;
 			break;
 

drivers/input/touchscreen/cyttsp_core.c

@@ -116,6 +116,15 @@ static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
 	return ttsp_write_block_data(ts, CY_REG_BASE, sizeof(cmd), &cmd);
 }
 
+static int cyttsp_handshake(struct cyttsp *ts)
+{
+	if (ts->pdata->use_hndshk)
+		return ttsp_send_command(ts,
+				ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
+
+	return 0;
+}
+
 static int cyttsp_load_bl_regs(struct cyttsp *ts)
 {
 	memset(&ts->bl_data, 0, sizeof(ts->bl_data));
@@ -133,7 +142,7 @@ static int cyttsp_exit_bl_mode(struct cyttsp *ts)
 	memcpy(bl_cmd, bl_command, sizeof(bl_command));
 	if (ts->pdata->bl_keys)
 		memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
-			ts->pdata->bl_keys, sizeof(bl_command));
+			ts->pdata->bl_keys, CY_NUM_BL_KEYS);
 
 	error = ttsp_write_block_data(ts, CY_REG_BASE,
 				      sizeof(bl_cmd), bl_cmd);
@@ -167,6 +176,10 @@ static int cyttsp_set_operational_mode(struct cyttsp *ts)
 	if (error)
 		return error;
 
+	error = cyttsp_handshake(ts);
+	if (error)
+		return error;
+
 	return ts->xy_data.act_dist == CY_ACT_DIST_DFLT ? -EIO : 0;
 }
 
@@ -188,6 +201,10 @@ static int cyttsp_set_sysinfo_mode(struct cyttsp *ts)
 	if (error)
 		return error;
 
+	error = cyttsp_handshake(ts);
+	if (error)
+		return error;
+
 	if (!ts->sysinfo_data.tts_verh && !ts->sysinfo_data.tts_verl)
 		return -EIO;
 
@@ -344,12 +361,9 @@ static irqreturn_t cyttsp_irq(int irq, void *handle)
 		goto out;
 
 	/* provide flow control handshake */
-	if (ts->pdata->use_hndshk) {
-		error = ttsp_send_command(ts,
-				ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
+	error = cyttsp_handshake(ts);
 	if (error)
 		goto out;
-	}
 
 	if (unlikely(ts->state == CY_IDLE_STATE))
 		goto out;

drivers/input/touchscreen/cyttsp_core.h

@@ -67,8 +67,8 @@ struct cyttsp_xydata {
 /* TTSP System Information interface definition */
 struct cyttsp_sysinfo_data {
 	u8 hst_mode;
-	u8 mfg_cmd;
 	u8 mfg_stat;
+	u8 mfg_cmd;
 	u8 cid[3];
 	u8 tt_undef1;
 	u8 uid[8];

drivers/spi/spi-pxa2xx-dma.c

@@ -59,7 +59,7 @@ static int pxa2xx_spi_map_dma_buffer(struct driver_data *drv_data,
 		int ret;
 
 		sg_free_table(sgt);
-		ret = sg_alloc_table(sgt, nents, GFP_KERNEL);
+		ret = sg_alloc_table(sgt, nents, GFP_ATOMIC);
 		if (ret)
 			return ret;
 	}

drivers/spi/spi-pxa2xx.c

@@ -1075,7 +1075,7 @@ pxa2xx_spi_acpi_get_pdata(struct platform_device *pdev)
 	    acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
 		return NULL;
 
-	pdata = devm_kzalloc(&pdev->dev, sizeof(*ssp), GFP_KERNEL);
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata) {
 		dev_err(&pdev->dev,
 			"failed to allocate memory for platform data\n");

drivers/spi/spi-s3c64xx.c

@@ -444,7 +444,7 @@ static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
 	}
 
 	ret = pm_runtime_get_sync(&sdd->pdev->dev);
-	if (ret != 0) {
+	if (ret < 0) {
 		dev_err(dev, "Failed to enable device: %d\n", ret);
 		goto out_tx;
 	}