Merge tag 'please-pull-apei' into x86/ras

APEI is currently implemented so that it depends on x86 hardware.
The primary dependency is that GHES uses the x86 NMI for hardware
error notification and MCE for memory error handling. These patches
remove that dependency.

Other APEI features such as error reporting via external IRQ, error
serialization, or error injection, do not require changes to use them
on non-x86 architectures.

The following patch set eliminates the APEI Kconfig x86 dependency
by making these changes:
- treat NMI notification as GHES architecture - HAVE_ACPI_APEI_NMI
- group and wrap around #ifdef CONFIG_HAVE_ACPI_APEI_NMI code which
  is used only for NMI path
- identify architectural boxes and abstract it accordingly (tlb flush and MCE)
- rework ioremap for both IRQ and NMI context

NMI code is kept in ghes.c file since NMI and IRQ context are tightly coupled.

Note, these patches introduce no functional changes for x86. The NMI notification
feature is hard selected for x86. Architectures that want to use this
feature should also provide NMI code infrastructure.

21 files changed, 132 insertions, 91 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 5a645769f020..d2633ee099d9 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -186,6 +186,15 @@ static inline void *bio_data(struct bio *bio)
 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
 	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
 
+/*
+ * Check if adding a bio_vec after bprv with offset would create a gap in
+ * the SG list. Most drivers don't care about this, but some do.
+ */
+static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset)
+{
+	return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1));
+}
+
 #define bio_io_error(bio) bio_endio((bio), -EIO)
 
 /*
@@ -644,10 +653,6 @@ struct biovec_slab {
 
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 
-
-
-#define bip_vec_idx(bip, idx)	(&(bip->bip_vec[(idx)]))
-
 #define bip_for_each_vec(bvl, bip, iter)				\
 	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 713f8b62b435..8699bcf5f099 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -512,6 +512,7 @@ struct request_queue {
 #define QUEUE_FLAG_DEAD        19	/* queue tear-down finished */
 #define QUEUE_FLAG_INIT_DONE   20	/* queue is initialized */
 #define QUEUE_FLAG_NO_SG_MERGE 21	/* don't attempt to merge SG segments*/
+#define QUEUE_FLAG_SG_GAPS     22	/* queue doesn't support SG gaps */
 
 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
 				 (1 << QUEUE_FLAG_STACKABLE)	|	\
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index ec4112d257bc..8f8ae95c6e27 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -482,8 +482,8 @@ extern struct cpufreq_governor cpufreq_gov_conservative;
  *********************************************************************/
 
 /* Special Values of .frequency field */
-#define CPUFREQ_ENTRY_INVALID	~0
-#define CPUFREQ_TABLE_END	~1
+#define CPUFREQ_ENTRY_INVALID	~0u
+#define CPUFREQ_TABLE_END	~1u
 /* Special Values of .flags field */
 #define CPUFREQ_BOOST_FREQ	(1 << 0)
 
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index e2a6bd7fb133..45a91474487d 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -143,7 +143,7 @@ extern void elv_drain_elevator(struct request_queue *);
  * io scheduler registration
  */
 extern void __init load_default_elevator_module(void);
-extern int __init elv_register(struct elevator_type *);
+extern int elv_register(struct elevator_type *);
 extern void elv_unregister(struct elevator_type *);
 
 /*
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 17aa1cce6f8e..30faf797c2c3 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -91,6 +91,7 @@ struct kernfs_elem_attr {
 	const struct kernfs_ops	*ops;
 	struct kernfs_open_node	*open;
 	loff_t			size;
+	struct kernfs_node	*notify_next;	/* for kernfs_notify() */
 };
 
 /*
@@ -304,6 +305,7 @@ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
 			       struct kernfs_root *root, unsigned long magic,
 			       bool *new_sb_created, const void *ns);
 void kernfs_kill_sb(struct super_block *sb);
+struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns);
 
 void kernfs_init(void);
 
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index b12f4bbd064c..35b51e7af886 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -578,8 +578,6 @@ struct mlx4_cq {
 	u32			cons_index;
 
 	u16                     irq;
-	bool                    irq_affinity_change;
-
 	__be32		       *set_ci_db;
 	__be32		       *arm_db;
 	int			arm_sn;
@@ -1167,6 +1165,8 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap,
 		   int *vector);
 void mlx4_release_eq(struct mlx4_dev *dev, int vec);
 
+int mlx4_eq_get_irq(struct mlx4_dev *dev, int vec);
+
 int mlx4_get_phys_port_id(struct mlx4_dev *dev);
 int mlx4_wol_read(struct mlx4_dev *dev, u64 *config, int port);
 int mlx4_wol_write(struct mlx4_dev *dev, u64 config, int port);
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index 11692dea18aa..42aa9b9ecd5f 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -17,6 +17,7 @@
 #include <linux/lockdep.h>
 #include <linux/atomic.h>
 #include <asm/processor.h>
+#include <linux/osq_lock.h>
 
 /*
  * Simple, straightforward mutexes with strict semantics:
@@ -46,7 +47,6 @@
  * - detects multi-task circular deadlocks and prints out all affected
  *   locks and tasks (and only those tasks)
  */
-struct optimistic_spin_queue;
 struct mutex {
 	/* 1: unlocked, 0: locked, negative: locked, possible waiters */
 	atomic_t		count;
@@ -56,7 +56,7 @@ struct mutex {
 	struct task_struct	*owner;
 #endif
 #ifdef CONFIG_MUTEX_SPIN_ON_OWNER
-	struct optimistic_spin_queue	*osq;	/* Spinner MCS lock */
+	struct optimistic_spin_queue osq; /* Spinner MCS lock */
 #endif
 #ifdef CONFIG_DEBUG_MUTEXES
 	const char 		*name;
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index 6a45fb583ff1..1d2a6ab6b8bb 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -32,15 +32,24 @@ static inline void touch_nmi_watchdog(void)
 #ifdef arch_trigger_all_cpu_backtrace
 static inline bool trigger_all_cpu_backtrace(void)
 {
-	arch_trigger_all_cpu_backtrace();
+	arch_trigger_all_cpu_backtrace(true);
 
 	return true;
 }
+static inline bool trigger_allbutself_cpu_backtrace(void)
+{
+	arch_trigger_all_cpu_backtrace(false);
+	return true;
+}
 #else
 static inline bool trigger_all_cpu_backtrace(void)
 {
 	return false;
 }
+static inline bool trigger_allbutself_cpu_backtrace(void)
+{
+	return false;
+}
 #endif
 
 #ifdef CONFIG_LOCKUP_DETECTOR
@@ -48,9 +57,14 @@ int hw_nmi_is_cpu_stuck(struct pt_regs *);
 u64 hw_nmi_get_sample_period(int watchdog_thresh);
 extern int watchdog_user_enabled;
 extern int watchdog_thresh;
+extern int sysctl_softlockup_all_cpu_backtrace;
 struct ctl_table;
 extern int proc_dowatchdog(struct ctl_table *, int ,
 			   void __user *, size_t *, loff_t *);
 #endif
 
+#ifdef CONFIG_HAVE_ACPI_APEI_NMI
+#include <asm/nmi.h>
+#endif
+
 #endif
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index a70c9493d55a..d449018d0726 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -25,9 +25,6 @@ struct phy_device *of_phy_attach(struct net_device *dev,
 
 extern struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np);
 
-extern void of_mdiobus_link_phydev(struct mii_bus *mdio,
-				   struct phy_device *phydev);
-
 #else /* CONFIG_OF */
 static inline int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 {
@@ -63,11 +60,6 @@ static inline struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np)
 {
 	return NULL;
 }
-
-static inline void of_mdiobus_link_phydev(struct mii_bus *mdio,
-					  struct phy_device *phydev)
-{
-}
 #endif /* CONFIG_OF */
 
 #if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY)
diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
new file mode 100644
index 000000000000..90230d5811c5
--- /dev/null
+++ b/include/linux/osq_lock.h
@@ -0,0 +1,27 @@
+#ifndef __LINUX_OSQ_LOCK_H
+#define __LINUX_OSQ_LOCK_H
+
+/*
+ * An MCS like lock especially tailored for optimistic spinning for sleeping
+ * lock implementations (mutex, rwsem, etc).
+ */
+
+#define OSQ_UNLOCKED_VAL (0)
+
+struct optimistic_spin_queue {
+	/*
+	 * Stores an encoded value of the CPU # of the tail node in the queue.
+	 * If the queue is empty, then it's set to OSQ_UNLOCKED_VAL.
+	 */
+	atomic_t tail;
+};
+
+/* Init macro and function. */
+#define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
+
+static inline void osq_lock_init(struct optimistic_spin_queue *lock)
+{
+	atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
+}
+
+#endif
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 3c545b48aeab..8304959ad336 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -360,6 +360,9 @@ static inline void ClearPageCompound(struct page *page)
 	ClearPageHead(page);
 }
 #endif
+
+#define PG_head_mask ((1L << PG_head))
+
 #else
 /*
  * Reduce page flag use as much as possible by overlapping
diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index a5fc7d01aad6..dec01d6c3f80 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -146,10 +146,10 @@
  * Declaration/definition used for per-CPU variables that must be read mostly.
  */
 #define DECLARE_PER_CPU_READ_MOSTLY(type, name)			\
-	DECLARE_PER_CPU_SECTION(type, name, "..readmostly")
+	DECLARE_PER_CPU_SECTION(type, name, "..read_mostly")
 
 #define DEFINE_PER_CPU_READ_MOSTLY(type, name)				\
-	DEFINE_PER_CPU_SECTION(type, name, "..readmostly")
+	DEFINE_PER_CPU_SECTION(type, name, "..read_mostly")
 
 /*
  * Intermodule exports for per-CPU variables.  sparse forgets about
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 864ddafad8cc..68041446c450 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -536,6 +536,15 @@ struct phy_driver {
 	/* See set_wol, but for checking whether Wake on LAN is enabled. */
 	void (*get_wol)(struct phy_device *dev, struct ethtool_wolinfo *wol);
 
+	/*
+	 * Called to inform a PHY device driver when the core is about to
+	 * change the link state. This callback is supposed to be used as
+	 * fixup hook for drivers that need to take action when the link
+	 * state changes. Drivers are by no means allowed to mess with the
+	 * PHY device structure in their implementations.
+	 */
+	void (*link_change_notify)(struct phy_device *dev);
+
 	struct device_driver driver;
 };
 #define to_phy_driver(d) container_of(d, struct phy_driver, driver)
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 077904c8b70d..cc79eff4a1ad 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -334,6 +334,9 @@ static inline void user_single_step_siginfo(struct task_struct *tsk,
  * calling arch_ptrace_stop() when it would be superfluous.  For example,
  * if the thread has not been back to user mode since the last stop, the
  * thread state might indicate that nothing needs to be done.
+ *
+ * This is guaranteed to be invoked once before a task stops for ptrace and
+ * may include arch-specific operations necessary prior to a ptrace stop.
  */
 #define arch_ptrace_stop_needed(code, info)	(0)
 #endif
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 5a75d19aa661..6a94cc8b1ca0 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -44,7 +44,6 @@
 #include <linux/debugobjects.h>
 #include <linux/bug.h>
 #include <linux/compiler.h>
-#include <linux/percpu.h>
 #include <asm/barrier.h>
 
 extern int rcu_expedited; /* for sysctl */
@@ -300,41 +299,6 @@ bool __rcu_is_watching(void);
 #endif /* #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) || defined(CONFIG_SMP) */
 
 /*
- * Hooks for cond_resched() and friends to avoid RCU CPU stall warnings.
- */
-
-#define RCU_COND_RESCHED_LIM 256	/* ms vs. 100s of ms. */
-DECLARE_PER_CPU(int, rcu_cond_resched_count);
-void rcu_resched(void);
-
-/*
- * Is it time to report RCU quiescent states?
- *
- * Note unsynchronized access to rcu_cond_resched_count.  Yes, we might
- * increment some random CPU's count, and possibly also load the result from
- * yet another CPU's count.  We might even clobber some other CPU's attempt
- * to zero its counter.  This is all OK because the goal is not precision,
- * but rather reasonable amortization of rcu_note_context_switch() overhead
- * and extremely high probability of avoiding RCU CPU stall warnings.
- * Note that this function has to be preempted in just the wrong place,
- * many thousands of times in a row, for anything bad to happen.
- */
-static inline bool rcu_should_resched(void)
-{
-	return raw_cpu_inc_return(rcu_cond_resched_count) >=
-	       RCU_COND_RESCHED_LIM;
-}
-
-/*
- * Report quiscent states to RCU if it is time to do so.
- */
-static inline void rcu_cond_resched(void)
-{
-	if (unlikely(rcu_should_resched()))
-		rcu_resched();
-}
-
-/*
  * Infrastructure to implement the synchronize_() primitives in
  * TREE_RCU and rcu_barrier_() primitives in TINY_RCU.
  */
@@ -358,9 +322,19 @@ void wait_rcu_gp(call_rcu_func_t crf);
  * initialization.
  */
 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+void init_rcu_head(struct rcu_head *head);
+void destroy_rcu_head(struct rcu_head *head);
 void init_rcu_head_on_stack(struct rcu_head *head);
 void destroy_rcu_head_on_stack(struct rcu_head *head);
 #else /* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+static inline void init_rcu_head(struct rcu_head *head)
+{
+}
+
+static inline void destroy_rcu_head(struct rcu_head *head)
+{
+}
+
 static inline void init_rcu_head_on_stack(struct rcu_head *head)
 {
 }
diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h
index d5b13bc07a0b..561e8615528d 100644
--- a/include/linux/rwsem-spinlock.h
+++ b/include/linux/rwsem-spinlock.h
@@ -15,13 +15,13 @@
 #ifdef __KERNEL__
 /*
  * the rw-semaphore definition
- * - if activity is 0 then there are no active readers or writers
- * - if activity is +ve then that is the number of active readers
- * - if activity is -1 then there is one active writer
+ * - if count is 0 then there are no active readers or writers
+ * - if count is +ve then that is the number of active readers
+ * - if count is -1 then there is one active writer
  * - if wait_list is not empty, then there are processes waiting for the semaphore
  */
 struct rw_semaphore {
-	__s32			activity;
+	__s32			count;
 	raw_spinlock_t		wait_lock;
 	struct list_head	wait_list;
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 8d79708146aa..035d3c57fc8a 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -13,10 +13,11 @@
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
-
 #include <linux/atomic.h>
+#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
+#include <linux/osq_lock.h>
+#endif
 
-struct optimistic_spin_queue;
 struct rw_semaphore;
 
 #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
@@ -25,15 +26,15 @@ struct rw_semaphore;
 /* All arch specific implementations share the same struct */
 struct rw_semaphore {
 	long count;
-	raw_spinlock_t wait_lock;
 	struct list_head wait_list;
-#ifdef CONFIG_SMP
+	raw_spinlock_t wait_lock;
+#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
+	struct optimistic_spin_queue osq; /* spinner MCS lock */
 	/*
 	 * Write owner. Used as a speculative check to see
 	 * if the owner is running on the cpu.
 	 */
 	struct task_struct *owner;
-	struct optimistic_spin_queue *osq; /* spinner MCS lock */
 #endif
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	struct lockdep_map	dep_map;
@@ -64,22 +65,19 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
 # define __RWSEM_DEP_MAP_INIT(lockname)
 #endif
 
-#if defined(CONFIG_SMP) && !defined(CONFIG_RWSEM_GENERIC_SPINLOCK)
-#define __RWSEM_INITIALIZER(name)			\
-	{ RWSEM_UNLOCKED_VALUE,				\
-	  __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock),	\
-	  LIST_HEAD_INIT((name).wait_list),		\
-	  NULL, /* owner */				\
-	  NULL /* mcs lock */                           \
-	  __RWSEM_DEP_MAP_INIT(name) }
+#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
+#define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL
 #else
-#define __RWSEM_INITIALIZER(name)			\
-	{ RWSEM_UNLOCKED_VALUE,				\
-	  __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock),	\
-	  LIST_HEAD_INIT((name).wait_list)		\
-	  __RWSEM_DEP_MAP_INIT(name) }
+#define __RWSEM_OPT_INIT(lockname)
 #endif
 
+#define __RWSEM_INITIALIZER(name)				\
+	{ .count = RWSEM_UNLOCKED_VALUE,			\
+	  .wait_list = LIST_HEAD_INIT((name).wait_list),	\
+	  .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock)	\
+	  __RWSEM_OPT_INIT(name)				\
+	  __RWSEM_DEP_MAP_INIT(name) }
+
 #define DECLARE_RWSEM(name) \
 	struct rw_semaphore name = __RWSEM_INITIALIZER(name)
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 306f4f0c987a..0376b054a0d0 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -872,21 +872,21 @@ enum cpu_idle_type {
 #define SD_NUMA			0x4000	/* cross-node balancing */
 
 #ifdef CONFIG_SCHED_SMT
-static inline const int cpu_smt_flags(void)
+static inline int cpu_smt_flags(void)
 {
 	return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
 }
 #endif
 
 #ifdef CONFIG_SCHED_MC
-static inline const int cpu_core_flags(void)
+static inline int cpu_core_flags(void)
 {
 	return SD_SHARE_PKG_RESOURCES;
 }
 #endif
 
 #ifdef CONFIG_NUMA
-static inline const int cpu_numa_flags(void)
+static inline int cpu_numa_flags(void)
 {
 	return SD_NUMA;
 }
@@ -999,7 +999,7 @@ void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
 bool cpus_share_cache(int this_cpu, int that_cpu);
 
 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
-typedef const int (*sched_domain_flags_f)(void);
+typedef int (*sched_domain_flags_f)(void);
 
 #define SDTL_OVERLAP	0x01
 
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 8e98297f1388..ec538fc287a6 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -305,8 +305,6 @@ struct ucred {
 /* IPX options */
 #define IPX_TYPE	1
 
-extern int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
-			       int offset, int len);
 extern int csum_partial_copy_fromiovecend(unsigned char *kdata, 
 					  struct iovec *iov, 
 					  int offset, 
@@ -315,8 +313,6 @@ extern unsigned long iov_pages(const struct iovec *iov, int offset,
 			       unsigned long nr_segs);
 
 extern int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr_storage *address, int mode);
-extern int memcpy_toiovecend(const struct iovec *v, unsigned char *kdata,
-			     int offset, int len);
 extern int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr);
 extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data);
 
diff --git a/include/linux/uio.h b/include/linux/uio.h
index e2231e47cec1..09a7cffc224e 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -94,8 +94,20 @@ static inline size_t iov_iter_count(struct iov_iter *i)
 	return i->count;
 }
 
-static inline void iov_iter_truncate(struct iov_iter *i, size_t count)
+/*
+ * Cap the iov_iter by given limit; note that the second argument is
+ * *not* the new size - it's upper limit for such.  Passing it a value
+ * greater than the amount of data in iov_iter is fine - it'll just do
+ * nothing in that case.
+ */
+static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
 {
+	/*
+	 * count doesn't have to fit in size_t - comparison extends both
+	 * operands to u64 here and any value that would be truncated by
+	 * conversion in assignement is by definition greater than all
+	 * values of size_t, including old i->count.
+	 */
 	if (i->count > count)
 		i->count = count;
 }
@@ -111,6 +123,9 @@ static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
 
 int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
 int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len);
-
+int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
+			int offset, int len);
+int memcpy_toiovecend(const struct iovec *v, unsigned char *kdata,
+		      int offset, int len);
 
 #endif
diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 1a64b26046ed..9b7de1b46437 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -70,7 +70,9 @@
 	US_FLAG(NEEDS_CAP16,	0x00400000)			\
 		/* cannot handle READ_CAPACITY_10 */		\
 	US_FLAG(IGNORE_UAS,	0x00800000)			\
-		/* Device advertises UAS but it is broken */
+		/* Device advertises UAS but it is broken */	\
+	US_FLAG(BROKEN_FUA,	0x01000000)			\
+		/* Cannot handle FUA in WRITE or READ CDBs */	\
 
 #define US_FLAG(name, value)	US_FL_##name = value ,
 enum { US_DO_ALL_FLAGS };