Merge branch 'x86-olpc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-olpc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, olpc: XO-1 uses/depends on PCI
  x86, olpc: Register XO-1 platform devices
  x86, olpc: Add XO-1 poweroff support
  x86, olpc: Don't retry EC commands forever
  x86, olpc: Rework BIOS signature check
  x86, olpc: Only enable PCI configuration type override on XO-1

Merge branch 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, mtrr: Support mtrr lookup for range spanning across MTRR range
  x86, mtrr: Refactor MTRR type overlap check code

Merge branch 'x86-mrst-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-mrst-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: sfi: Make local functions static
  x86, earlyprintk: Add hsu early console for Intel Medfield platform
  x86, earlyprintk: Add earlyprintk for Intel Moorestown platform
  x86: Add two helper macros for fixed address mapping
  x86, mrst: A function in a header file needs to be marked "inline"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-32, percpu: Correct the ordering of the percpu readmostly section
  x86, mm: Enable ARCH_DMA_ADDR_T_64BIT with X86_64 || HIGHMEM64G
  x86: Spread tlb flush vector between nodes
  percpu: Introduce a read-mostly percpu API
  x86, mm: Fix incorrect data type in vmalloc_sync_all()
  x86, mm: Hold mm->page_table_lock while doing vmalloc_sync
  x86, mm: Fix bogus whitespace in sync_global_pgds()
  x86-32: Fix sparse warning for the __PHYSICAL_MASK calculation
  x86, mm: Add RESERVE_BRK_ARRAY() helper
  mm, x86: Saving vmcore with non-lazy freeing of vmas
  x86, kdump: Change copy_oldmem_page() to use cached addressing
  x86, mm: fix uninitialized addr in kernel_physical_mapping_init()
  x86, kmemcheck: Remove double test
  x86, mm: Make spurious_fault check explicitly check the PRESENT bit
  x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes
  x86, mm: Separate x86_64 vmalloc_sync_all() into separate functions
  x86, mm: Avoid unnecessary TLB flush

* 'x86-mem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, mem: Optimize memmove for small size and unaligned cases
  x86, mem: Optimize memcpy by avoiding memory false dependece
  x86, mem: Don't implement forward memmove() as memcpy()

Merge branch 'x86-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, hotplug: In the MWAIT case of play_dead, CLFLUSH the cache line
  x86, hotplug: Move WBINVD back outside the play_dead loop
  x86, hotplug: Use mwait to offline a processor, fix the legacy case
  x86, mwait: Move mwait constants to a common header file

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, fpu: Merge fpu_save_init()
  x86-32, fpu: Rewrite fpu_save_init()
  x86, fpu: Remove PSHUFB_XMM5_* macros
  x86, fpu: Remove unnecessary ifdefs from i387 code.
  x86-32, fpu: Remove math_emulate stub
  x86-64, fpu: Simplify constraints for fxsave/fxtstor
  x86-64, fpu: Fix %cs value in convert_from_fxsr()
  x86-64, fpu: Disable preemption when using TS_USEDFPU
  x86, fpu: Merge __save_init_fpu()
  x86, fpu: Merge tolerant_fwait()
  x86, fpu: Merge fpu_init()
  x86: Use correct type for %cr4
  x86, xsave: Disable xsave in i387 emulation mode

Fixed up fxsaveq-induced conflict in arch/x86/include/asm/i387.h

Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Remove pr_<level> uses of KERN_<level>
  therm_throt.c: Trivial printk message fix for a unsuitable abbreviation of 'thermal'
  x86: Use {push,pop}{l,q}_cfi in more places
  i386: Add unwind directives to syscall ptregs stubs
  x86-64: Use symbolics instead of raw numbers in entry_64.S
  x86-64: Adjust frame type at paranoid_exit:
  x86-64: Fix unwind annotations in syscall stubs

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, cpu: Fix X86_FEATURE_NOPL
  x86, cpu: Re-run get_cpu_cap() after adjusting the CPUID level

Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Remove stale pmtimer_64.c
  x86, cleanups: Use clear_page/copy_page rather than memset/memcpy
  x86: Remove unnecessary #ifdef ACPI/X86_IO_ACPI
  x86, cleanup: Remove obsolete boot_cpu_id variable

Merge branch 'x86-bios-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-bios-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, bios: Make the x86 early memory reservation a kernel option
  x86, bios: By default, reserve the low 64K for all BIOSes

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-64, asm: If the assembler supports fxsave64, use it
  i386: Make kernel_execve() suitable for stack unwinding

Merge branch 'x86-amd-nb-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-amd-nb-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, amd_nb: Enable GART support for AMD family 0x15 CPUs
  x86, amd: Use compute unit information to determine thread siblings
  x86, amd: Extract compute unit information for AMD CPUs
  x86, amd: Add support for CPUID topology extension of AMD CPUs
  x86, nmi: Support NMI watchdog on newer AMD CPU families
  x86, mtrr: Assume SYS_CFG[Tom2ForceMemTypeWB] exists on all future AMD CPUs
  x86, k8: Rename k8.[ch] to amd_nb.[ch] and CONFIG_K8_NB to CONFIG_AMD_NB
  x86, k8-gart: Decouple handling of garts and northbridges
  x86, cacheinfo: Fix dependency of AMD L3 CID
  x86, kvm: add new AMD SVM feature bits
  x86, cpu: Fix allowed CPUID bits for KVM guests
  x86, cpu: Update AMD CPUID feature bits
  x86, cpu: Fix renamed, not-yet-shipping AMD CPUID feature bit
  x86, AMD: Remove needless CPU family check (for L3 cache info)
  x86, tsc: Remove CPU frequency calibration on AMD

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (29 commits)
  sched: Export account_system_vtime()
  sched: Call tick_check_idle before __irq_enter
  sched: Remove irq time from available CPU power
  sched: Do not account irq time to current task
  x86: Add IRQ_TIME_ACCOUNTING
  sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time
  sched: Add a PF flag for ksoftirqd identification
  sched: Consolidate account_system_vtime extern declaration
  sched: Fix softirq time accounting
  sched: Drop group_capacity to 1 only if local group has extra capacity
  sched: Force balancing on newidle balance if local group has capacity
  sched: Set group_imb only a task can be pulled from the busiest cpu
  sched: Do not consider SCHED_IDLE tasks to be cache hot
  sched: Drop all load weight manipulation for RT tasks
  sched: Create special class for stop/migrate work
  sched: Unindent labels
  sched: Comment updates: fix default latency and granularity numbers
  tracing/sched: Add sched_pi_setprio tracepoint
  sched: Give CPU bound RT tasks preference
  sched: Try not to migrate higher priority RT tasks
  ...

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (163 commits)
  tracing: Fix compile issue for trace_sched_wakeup.c
  [S390] hardirq: remove pointless header file includes
  [IA64] Move local_softirq_pending() definition
  perf, powerpc: Fix power_pmu_event_init to not use event->ctx
  ftrace: Remove recursion between recordmcount and scripts/mod/empty
  jump_label: Add COND_STMT(), reducer wrappery
  perf: Optimize sw events
  perf: Use jump_labels to optimize the scheduler hooks
  jump_label: Add atomic_t interface
  jump_label: Use more consistent naming
  perf, hw_breakpoint: Fix crash in hw_breakpoint creation
  perf: Find task before event alloc
  perf: Fix task refcount bugs
  perf: Fix group moving
  irq_work: Add generic hardirq context callbacks
  perf_events: Fix transaction recovery in group_sched_in()
  perf_events: Fix bogus AMD64 generic TLB events
  perf_events: Fix bogus context time tracking
  tracing: Remove parent recording in latency tracer graph options
  tracing: Use one prologue for the preempt irqs off tracer function tracers
  ...

Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (52 commits)
  sched: fix RCU lockdep splat from task_group()
  rcu: using ACCESS_ONCE() to observe the jiffies_stall/rnp->qsmask value
  sched: suppress RCU lockdep splat in task_fork_fair
  net: suppress RCU lockdep false positive in sock_update_classid
  rcu: move check from rcu_dereference_bh to rcu_read_lock_bh_held
  rcu: Add advice to PROVE_RCU_REPEATEDLY kernel config parameter
  rcu: Add tracing data to support queueing models
  rcu: fix sparse errors in rcutorture.c
  rcu: only one evaluation of arg in rcu_dereference_check() unless sparse
  kernel: Remove undead ifdef CONFIG_DEBUG_LOCK_ALLOC
  rcu: fix _oddness handling of verbose stall warnings
  rcu: performance fixes to TINY_PREEMPT_RCU callback checking
  rcu: upgrade stallwarn.txt documentation for CPU-bound RT processes
  vhost: add __rcu annotations
  rcu: add comment stating that list_empty() applies to RCU-protected lists
  rcu: apply TINY_PREEMPT_RCU read-side speedup to TREE_PREEMPT_RCU
  rcu: combine duplicate code, courtesy of CONFIG_PREEMPT_RCU
  rcu: Upgrade srcu_read_lock() docbook about SRCU grace periods
  rcu: document ways of stalling updates in low-memory situations
  rcu: repair code-duplication FIXMEs
  ...

Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Check the depth of subclass
  lockdep: Add improved subclass caching
  affs: Use sema_init instead of init_MUTEX
  hfs: Convert tree_lock to mutex
  arm: Bcmring: semaphore cleanup
  printk: Make console_sem a semaphore not a pseudo mutex
  drivers/macintosh/adb: Do not claim that the semaphore is a mutex
  parport: Semaphore cleanup
  irda: Semaphore cleanup
  net: Wan/cosa.c: Convert "mutex" to semaphore
  net: Ppp_async: semaphore cleanup
  hamradio: Mkiss: semaphore cleanup
  hamradio: 6pack: semaphore cleanup
  net: 3c527: semaphore cleanup
  input: Serio/hp_sdc: semaphore cleanup
  input: Serio/hil_mlc: semaphore cleanup
  input: Misc/hp_sdc_rtc: semaphore cleanup
  lockup_detector: Make callback function static
  lockup detector: Fix grammar by adding a missing "to" in the comments
  lockdep: Remove __debug_show_held_locks

Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86/amd-iommu: Update copyright headers
  x86/amd-iommu: Reenable AMD IOMMU if it's mysteriously vanished over suspend
  AGP: Warn when GATT memory cannot be set to UC
  x86, GART: Disable GART table walk probes
  x86, GART: Remove superfluous AMD64_GARTEN

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (26 commits)
  selinux: include vmalloc.h for vmalloc_user
  secmark: fix config problem when CONFIG_NF_CONNTRACK_SECMARK is not set
  selinux: implement mmap on /selinux/policy
  SELinux: allow userspace to read policy back out of the kernel
  SELinux: drop useless (and incorrect) AVTAB_MAX_SIZE
  SELinux: deterministic ordering of range transition rules
  kernel: roundup should only reference arguments once
  kernel: rounddown helper function
  secmark: export secctx, drop secmark in procfs
  conntrack: export lsm context rather than internal secid via netlink
  security: secid_to_secctx returns len when data is NULL
  secmark: make secmark object handling generic
  secmark: do not return early if there was no error
  AppArmor: Ensure the size of the copy is < the buffer allocated to hold it
  TOMOYO: Print URL information before panic().
  security: remove unused parameter from security_task_setscheduler()
  tpm: change 'tpm_suspend_pcr' to be module parameter
  selinux: fix up style problem on /selinux/status
  selinux: change to new flag variable
  selinux: really fix dependency causing parallel compile failure.
  ...

* 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  virtio_blk: remove BKL leftovers
  virtio: console: Disable lseek(2) for port file operations
  virtio: console: Send SIGIO in case of port unplug
  virtio: console: Send SIGIO on new data arrival on ports
  virtio: console: Send SIGIO to processes that request it for host events
  virtio: console: Reference counting portdev structs is not needed
  virtio: console: Add reference counting for port struct
  virtio: console: Use cdev_alloc() instead of cdev_init()
  virtio: console: Add a find_port_by_devt() function
  virtio: console: Add a list of portdevs that are active
  virtio: console: open: Use a common path for error handling
  virtio: console: remove_port() should return void
  virtio: console: Make write() return -ENODEV on hot-unplug
  virtio: console: Make read() return -ENODEV on hot-unplug
  virtio: console: Unblock poll on port hot-unplug
  virtio: console: Un-block reads on chardev close
  virtio: console: Check if portdev is valid in send_control_msg()
  virtio: console: Remove control vq data only if using multiport support
  virtio: console: Reset vdev before removing device

* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw: (22 commits)
  GFS2: fixed typo
  GFS2: Fix type mapping for demote_rq interface
  GFS2 fatal: filesystem consistency error on rename
  GFS2: Improve journal allocation via sysfs
  GFS2: Add "norecovery" mount option as a synonym for "spectator"
  GFS2: Fix spectator umount issue
  GFS2: Fix compiler warning from previous patch
  GFS2: reserve more blocks for transactions
  GFS2: Fix journal check for spectator mounts
  GFS2: Remove upgrade mount option
  GFS2: Remove localcaching mount option
  GFS2: Remove ignore_local_fs mount argument
  GFS2: Make . and .. qstrs constant
  GFS2: Use new workqueue scheme
  GFS2: Update handling of DLM return codes to match reality
  GFS2: Don't enforce min hold time when two demotes occur in rapid succession
  GFS2: Fix whitespace in previous patch
  GFS2: fallocate support
  GFS2: Add a bug trap in allocation code
  GFS2: No longer experimental
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (22 commits)
  ceph: do not carry i_lock for readdir from dcache
  fs/ceph/xattr.c: Use kmemdup
  rbd: passing wrong variable to bvec_kunmap_irq()
  rbd: null vs ERR_PTR
  ceph: fix num_pages_free accounting in pagelist
  ceph: add CEPH_MDS_OP_SETDIRLAYOUT and associated ioctl.
  ceph: don't crash when passed bad mount options
  ceph: fix debugfs warnings
  block: rbd: removing unnecessary test
  block: rbd: fixed may leaks
  ceph: switch from BKL to lock_flocks()
  ceph: preallocate flock state without locks held
  ceph: add pagelist_reserve, pagelist_truncate, pagelist_set_cursor
  ceph: use mapping->nrpages to determine if mapping is empty
  ceph: only invalidate on check_caps if we actually have pages
  ceph: do not hide .snap in root directory
  rbd: introduce rados block device (rbd), based on libceph
  ceph: factor out libceph from Ceph file system
  ceph-rbd: osdc support for osd call and rollback operations
  ceph: messenger and osdc changes for rbd
  ...

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/hfsplus: (29 commits)
  hfsplus: fix getxattr return value
  hfsplus: remove the unused hfsplus_kmap/hfsplus_kunmap helpers
  hfsplus: create correct initial catalog entries for device files
  hfsplus: remove superflous rootflags field in hfsplus_inode_info
  hfsplus: fix link corruption
  hfsplus: validate btree flags
  hfsplus: handle more on-disk corruptions without oopsing
  hfsplus: hfs_bnode_find() can fail, resulting in hfs_bnode_split() breakage
  hfsplus: fix oops on mount with corrupted btree extent records
  hfsplus: fix rename over directories
  hfsplus: convert tree_lock to mutex
  hfsplus: add missing extent locking in hfsplus_write_inode
  hfsplus: protect readdir against removals from open_dir_list
  hfsplus: use atomic bitops for the superblock flags
  hfsplus: add per-superblock lock for volume header updates
  hfsplus: remove the rsrc_inodes list
  hfsplus: do not cache and write next_alloc
  hfsplus: fix error handling in hfsplus_symlink
  hfsplus: merge mknod/mkdir/creat
  hfsplus: clean up hfsplus_write_inode
  ...

Checkin c957ef2c had inconsistent
ordering of .data..percpu..page_aligned and .data..percpu..readmostly;
the still-broken version affected x86-32 at least.

The page aligned version really must be page aligned...
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
LKML-Reference: <1287544022.4571.7.camel@sli10-conroe.sh.intel.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>

Remove the BKL usage added in "block: push down BKL into .locked_ioctl".
Virtio-blk doesn't use the BKL for anything, and doesn't implement any
ioctl command by itself, but only uses the generic scsi_cmd_ioctl
which is fine without the BKL.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The ports are char devices; do not have seeking capabilities.  Calling
nonseekable_open() from the fops_open() call and setting the llseek fops
pointer to no_llseek ensures an lseek() call from userspace returns
-ESPIPE.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

If a port has registered for SIGIO signals, let the application
know that the port is getting unplugged.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Send a SIGIO signal when new data arrives on a port. This is sent only
when the process has requested for the signal to be sent using fcntl().
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

A process can request for SIGIO on host connect / disconnect events
using the O_ASYNC file flag using fcntl().

If that's requested, and if the guest-side connection for the port is
open, any host-side open/close events for that port will raise a SIGIO.
The process can then use poll() within the signal handler to find out
which port triggered the signal.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Explain in a comment why there's no need to reference-count the portdev
struct: when a device is yanked out, we can't do anything more with it
anyway so just give up doing anything more with the data or the vqs and
exit cleanly.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

When a port got hot-unplugged, when a port was open, any file operation
after the unplugging resulted in a crash. This is fixed by ref-counting
the port structure, and releasing it only when the file is closed.

This splits the unplug operation in two parts: first marks the port
as unavailable, removes all the buffers in the vqs and removes the port
from the per-device list of ports. The second stage, invoked when all
references drop to zero, releases the chardev and frees all other memory.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This moves to using cdev on the heap instead of it being embedded in the
ports struct. This helps individual refcounting and will allow us to
properly remove cdev structs after hot-unplugs and close operations.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

To convert to using cdev as a pointer to avoid kref troubles, we have to
use a different method to get to a port from an inode than the current
container_of method.

Add find_port_by_devt() that looks up all portdevs and ports with those
portdevs to find the right port.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The virtio_console.c driver is capable of handling multiple devices at a
time. Maintain a list of devices for future traversal.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Just re-arrange code for future patches.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

When a port is removed, we have to assume the port is gone. So a
success/failure return value doesn't make sense.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

When a port is hot-unplugged while an app was blocked on a write() call,
the call was unblocked but would not get an error returned.

Return -ENODEV to ensure the app knows the port has gone away.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

When a port is hot-unplugged while an app was blocked on a read() call,
the call was unblocked but would not get an error returned.

Return -ENODEV to ensure the app knows the port has gone away.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

When a port is hot-unplugged while an app is blocked on poll(), unblock
the poll() and return.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

If a chardev is closed, any blocked read / poll calls should just return
and not attempt to use other state.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>