Commit Graph

574194 Commits

Author SHA1 Message Date
Michael Ellerman
2527083cb8 powerpc fixes for 4.5 #3
- eeh: Fix partial hotplug criterion from Gavin Shan
  - mm: Clear the invalid slot information correctly from Aneesh Kumar K.V
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJWzXquAAoJEFHr6jzI4aWADHsP/2lbwqz/vS3Ep4zlySHNvStL
 /DrRN2TN35THZ59FPRxgEfeqPxTCXtbpD6zEXwD0gf6m39I2zArhaQMOHXMtVPvV
 p0nAtwR0PX/PxlQTJDpHlg074vVAD7s3iuvad6oNQObLcXhoZ7wYtbStZ9Ithm4R
 YfqZTelzsw+GfMuTYnvAQf5aoRYztUpy7OheaJbbDmSZgMFwF896ZPJnaG9rAOPE
 xcSsRaSfHiUR2NE2ua1K5yya+1ilZqrZhib7QxXgzGuxoVa2AAiPR7Hpx2kX1Wm+
 z0DqPXISzRbVf9zyLgWD3TpJ4OMHI/CYVW+t/Gx/yWCMfNcfavUrh0vPdHRVEPZu
 zxmIUoI6yv7jQ6bcfdzR5s0Mr5pYWlUj5MZg2r8aGqloYcLPk5DiENg+c0QmKI05
 kQPCBoQz2ezzJWAt1BYshkc+mlimv3ODaNWFP34Nc6kcDaSO6a0rhVOecvKuR6dv
 UBNpeh5np1rKq1wX0ri0yAmnm//yXqe+bK0I8Ctipi0++e73sVJGzfFdVvXwEhhW
 h+v1BkdgW8WK/xlH+JCPiXd5dfXrUeFI0D65Kgpb7IbFc9hcXDmp2Dv7+8zx/Wcl
 L2NpuucSDxi+LHkE10QiypgLWSKjn9OSi8PLocqABNXG8uHxIp54jRfyViBNALXF
 XlPveqTgpt7On3aa0qVh
 =bk3U
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-4.5-4' into next

Pull in our current fixes from 4.5, in particular the "Fix Multi hit
ERAT" bug is causing folks some grief when testing next.
2016-02-25 21:52:58 +11:00
Balbir Singh
a4c3f909b4 powerpc: Fix BUG_ON() reporting in real mode
I ran into this issue while debugging an early boot problem. The system
hit a BUG_ON() but report bug failed to print the line number and file
name. The reason being that the system was running in real mode and
report_bug() searches for addresses in the PAGE_OFFSET+ region.

Suggested-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-24 20:09:04 +11:00
pan xinhui
10d8b1480e powerpc: Use BUILD_BUG_ON_MSG() for unsupported {cmp}xchg sizes
__xchg_called_with_bad_pointer() can't tell us which code uses {cmp}xchg
with an unsupported size, and no error is reported until the link stage.

To make such problems easier to debug, use BUILD_BUG_ON_MSG() instead.

Signed-off-by: pan xinhui <xinhui.pan@linux.vnet.ibm.com>
[mpe: Tweak change log wording & add relaxed/acquire]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

fixup
2016-02-24 20:08:48 +11:00
Jeremy Kerr
289543a5c2 powerpc/powernv: Add AST graphics driver to powernv_defconfig
Most current OpenPOWER platforms have an AST BMC, so add graphics
support via the AST DRM driver.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-24 17:14:53 +11:00
Jeremy Kerr
78a31c764b powerpc/powernv: Add powernv firmware interface drivers to powernv_defconfig
There are a few firmware-provided interfaces for OpenPOWER platforms:
the PRD infrastructure, IPMI support, and MTD access to the PNOR flash.

This change adds these to powernv_defconfig

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-24 17:14:52 +11:00
Jeremy Kerr
31b1108bcf powerpc/powernv: Add powernv_defconfig
This change adds a defconfig for the non-virtualised power platforms,
based on pseries_defconfig, but without pseries, and little-endian,
and no OF trampoline.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-24 17:14:52 +11:00
Michael Neuling
c3ab300ea5 powerpc: Add POWER9 cputable entry
Add a cputable entry for POWER9.  More code is required to actually
boot and run on a POWER9 but this gets the base piece in which we can
start building on.

Copies over from POWER8 except for:
- Adds a new CPU_FTR_ARCH_300 bit to start hanging new architecture
   features from (in subsequent patches).
- Advertises new user features bits PPC_FEATURE2_ARCH_3_00 &
  HAS_IEEE128 when on POWER9.
- Drops CPU_FTR_SUBCORE.
- Drops PMU code and machine check.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-22 20:47:48 +11:00
Michael Neuling
15b1624b78 powerpc: Use defines for __init_tlb_power[78]
Use defines for literals __init_tlb_power[78] rather than hand coding
them.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-22 20:47:47 +11:00
Michael Neuling
ce5732a28d powerpc/powernv: Create separate subcores CPU feature bit
Subcores isn't really part of the 2.07 architecture but currently we
turn it on using the 2.07 feature bit.  Subcores is really a POWER8
specific feature.

This adds a new CPU_FTR bit just for subcores and moves the subcore
init code over to use this.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-22 20:47:46 +11:00
Andrew Donnellan
88409d0c86 powerpc/powernv: don't create OPAL msglog sysfs entry if memcons init fails
When initialising OPAL interfaces, there is a possibility that
opal_msglog_init() may fail to initialise the msglog/memory console.

Fix opal_msglog_sysfs_init() so it doesn't try to create sysfs entry for
the msglog if this occurs.

Suggested-by: Joel Stanley <joel@jms.id.au>
Fixes: 9b4fffa149 ("powerpc/powernv: new function to access OPAL msglog")
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-22 20:31:55 +11:00
Aneesh Kumar K.V
9ab3ac233a powerpc/mm/hash: Clear the invalid slot information correctly
We can get a hash pte fault with 4k base page size and find the pte
already inserted with 64K base page size. In that case we need to clear
the existing slot information from the old pte. Fix this correctly

With THP, we also clear the slot information with respect to all
the 64K hash pte mapping that 16MB page. They are all invalid
now. This make sure we don't find the slot valid when we fault with
4k base page size. Finding the slot valid should not result in any wrong
behavior because we do check again in hash page table for the validity.
But we can avoid that check completely.

Fixes: a43c0eb836 ("powerpc/mm: Convert 4k hash insert to C")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-22 19:27:39 +11:00
Gavin Shan
f6bf0fa14c powerpc/eeh: Fix partial hotplug criterion
During error recovery, the device could be removed as part of the
partial hotplug. The criterion used to come with partial hotplug
is: if the device driver provides error_detected(), slot_reset()
and resume() callbacks, it's immune from hotplug. Otherwise,
it's going to experience partial hotplug during EEH recovery. But
the criterion isn't correct enough: mlx4_core driver for Mellanox
adapters provides error_detected(), slot_reset() callbacks, but
resume() isn't there. Those Mellanox adapters won't be to involved
in the partial hotplug.

This fixes the criterion to a practical one: adpater with driver
that provides error_detected(), slot_reset() will be immune from
partial hotplug. resume() isn't mandatory.

Fixes: f2da4ccf ("powerpc/eeh: More relaxed hotplug criterion")
Cc: stable@vger.kernel.org #v4.4+
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-22 19:25:55 +11:00
Boqun Feng
56c08e6d22 powerpc: atomic: Implement acquire/release/relaxed variants for cmpxchg
Implement cmpxchg{,64}_relaxed and atomic{,64}_cmpxchg_relaxed, based on
which _release variants can be built.

To avoid superfluous barriers in _acquire variants, we implement these
operations with assembly code rather use __atomic_op_acquire() to build
them automatically.

For the same reason, we keep the assembly implementation of fully
ordered cmpxchg operations.

However, we don't do the similar for _release, because that will require
putting barriers in the middle of ll/sc loops, which is probably a bad
idea.

Note cmpxchg{,64}_relaxed and atomic{,64}_cmpxchg_relaxed are not
compiler barriers.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-18 00:11:39 +11:00
Boqun Feng
26760fc19a powerpc: atomic: Implement acquire/release/relaxed variants for xchg
Implement xchg{,64}_relaxed and atomic{,64}_xchg_relaxed, based on these
_relaxed variants, release/acquire variants and fully ordered versions
can be built.

Note that xchg{,64}_relaxed and atomic_{,64}_xchg_relaxed are not
compiler barriers.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-18 00:11:31 +11:00
Boqun Feng
dc53617c4a powerpc: atomic: Implement atomic{, 64}_*_return_* variants
On powerpc, acquire and release semantics can be achieved with
lightweight barriers("lwsync" and "ctrl+isync"), which can be used to
implement __atomic_op_{acquire,release}.

For release semantics, since we only need to ensure all memory accesses
that issue before must take effects before the -store- part of the
atomics, "lwsync" is what we only need. On the platform without
"lwsync", "sync" should be used. Therefore in __atomic_op_release() we
use PPC_RELEASE_BARRIER.

For acquire semantics, "lwsync" is what we only need for the similar
reason.  However on the platform without "lwsync", we can use "isync"
rather than "sync" as an acquire barrier. Therefore in
__atomic_op_acquire() we use PPC_ACQUIRE_BARRIER, which is barrier() on
UP, "lwsync" if available and "isync" otherwise.

Implement atomic{,64}_{add,sub,inc,dec}_return_relaxed, and build other
variants with these helpers.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-18 00:11:21 +11:00
Boqun Feng
e1ab7f39d7 atomics: Allow architectures to define their own __atomic_op_* helpers
Some architectures may have their special barriers for acquire, release
and fence semantics, so that general memory barriers(smp_mb__*_atomic())
in the default __atomic_op_*() may be too strong, so allow architectures
to define their own helpers which can overwrite the default helpers.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-18 00:11:02 +11:00
Russell Currey
78c1cffdab MAINTAINERS: Update EEH details and maintainership
Enhanced Error Handling could mean anything in the context of the entire
kernel, so change the name to reference that it is both for PCI and
powerpc.

EEH covers a bit more than the previously listed files, so add the headers
and platform-specific code to the EEH maintained section.

In addition, I am taking over the maintainership.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-18 00:05:28 +11:00
Balbir Singh
94e3d92359 powerpc: Fix kgdb on little endian ppc64le
I spent some time trying to use kgdb and debugged my inability to
resume from kgdb_handle_breakpoint(). NIP is not incremented
and that leads to a loop in the debugger.

I've tested this lightly on a virtual instance with KDB enabled.
After the patch, I am able to get the "go" command to work as
expected.

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-18 00:03:26 +11:00
Alexey Kardashevskiy
6ecad912a0 powerpc/ioda: Set "read" permission when "write" is set
Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty of
platforms. However IODA2 is strict about this and produces an EEH when
"read" permission is not set and reading happens.

This adds a workaround in the IODA code to always add the "read" bit
when the "write" bit is set.

Fixes: 10b35b2b74 ("powerpc/powernv: Do not set "read" flag if direction==DMA_NONE")
Cc: stable@vger.kernel.org # 4.2+
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-17 23:52:17 +11:00
Aneesh Kumar K.V
c777e2a8b6 powerpc/mm: Fix Multi hit ERAT cause by recent THP update
With ppc64 we use the deposited pgtable_t to store the hash pte slot
information. We should not withdraw the deposited pgtable_t without
marking the pmd none. This ensure that low level hash fault handling
will skip this huge pte and we will handle them at upper levels.

Recent change to pmd splitting changed the above in order to handle the
race between pmd split and exit_mmap. The race is explained below.

Consider following race:

		CPU0				CPU1
shrink_page_list()
  add_to_swap()
    split_huge_page_to_list()
      __split_huge_pmd_locked()
        pmdp_huge_clear_flush_notify()
	// pmd_none() == true
					exit_mmap()
					  unmap_vmas()
					    zap_pmd_range()
					      // no action on pmd since pmd_none() == true
	pmd_populate()

As result the THP will not be freed. The leak is detected by check_mm():

	BUG: Bad rss-counter state mm:ffff880058d2e580 idx:1 val:512

The above required us to not mark pmd none during a pmd split.

The fix for ppc is to clear the huge pte of _PAGE_USER, so that low
level fault handling code skip this pte. At higher level we do take ptl
lock. That should serialze us against the pmd split. Once the lock is
acquired we do check the pmd again using pmd_same. That should always
return false for us and hence we should retry the access. We do the
pmd_same check in all case after taking plt with
THP (do_huge_pmd_wp_page, do_huge_pmd_numa_page and
huge_pmd_set_accessed)

Also make sure we wait for irq disable section in other cpus to finish
before flipping a huge pte entry with a regular pmd entry. Code paths
like find_linux_pte_or_hugepte depend on irq disable to get
a stable pte_t pointer. A parallel thp split need to make sure we
don't convert a pmd pte to a regular pmd entry without waiting for the
irq disable section to finish.

Fixes: eef1b3ba05 ("thp: implement split_huge_pmd()")
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-15 21:10:04 +11:00
Gavin Shan
1bc74f1ccd powerpc/powernv: Fix stale PE primary bus
When PCI bus is unplugged during full hotplug for EEH recovery,
the platform PE instance (struct pnv_ioda_pe) isn't released and
it dereferences the stale PCI bus that has been released. It leads
to kernel crash when referring to the stale PCI bus.

This fixes the issue by correcting the PE's primary bus when it's
oneline at plugging time, in pnv_pci_dma_bus_setup() which is to
be called by pcibios_fixup_bus().

Cc: stable@vger.kernel.org # v4.1+
Reported-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reported-by: Pradipta Ghosh <pradghos@in.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-15 21:10:04 +11:00
Gavin Shan
05ba75f848 powerpc/eeh: Fix stale cached primary bus
When PE is created, its primary bus is cached to pe->bus. At later
point, the cached primary bus is returned from eeh_pe_bus_get().
However, we could get stale cached primary bus and run into kernel
crash in one case: full hotplug as part of fenced PHB error recovery
releases all PCI busses under the PHB at unplugging time and recreate
them at plugging time. pe->bus is still dereferencing the PCI bus
that was released.

This adds another PE flag (EEH_PE_PRI_BUS) to represent the validity
of pe->bus. pe->bus is updated when its first child EEH device is
online and the flag is set. Before unplugging in full hotplug for
error recovery, the flag is cleared.

Fixes: 8cdb2833 ("powerpc/eeh: Trace PCI bus from PE")
Cc: stable@vger.kernel.org #v3.11+
Reported-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reported-by: Pradipta Ghosh <pradghos@in.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-15 21:10:04 +11:00
Denis Kirjanov
126df08c52 powerpc/pseries: Don't trace hcalls on offline CPUs
If a cpu is hotplugged while the hcall trace points are active, it's
possible to hit a warning from RCU due to the trace points calling into
RCU from an offline cpu, eg:

  RCU used illegally from offline CPU!
  rcu_scheduler_active = 1, debug_locks = 1

Make the hypervisor tracepoints conditional by using
TRACE_EVENT_FN_COND.

Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-15 21:10:03 +11:00
Sukadev Bhattiprolu
e4f226b158 powerpc/perf/hv-gpci: Increase request buffer size
The GPCI hcall allows for a 4K buffer but we limit the buffer to 1K.
The problem with a 1K buffer is if a request results in returning
more values than can be accomodated in the 1K buffer the request will
fail.

The buffer we are using is currently allocated on the stack and hence
limited in size. Instead use a per-CPU 4K buffer like we do with 24x7
counters (hv-24x7.c).

While here, rename the macro GPCI_MAX_DATA_BYTES to HGPCI_MAX_DATA_BYTES
for consistency with 24x7 counters.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 14:30:56 +11:00
Wei Yang
be283eeb7f powerpc/powernv: allocate sparse PE# when using M64 BAR in Single PE mode
When M64 BAR is set to Single PE mode, the PE# assigned to VF could be
sparse.

This patch restructures the code to allocate sparse PE# for VFs when M64
BAR is set to Single PE mode. Also it rename the offset to pe_num_map to
reflect the content is the PE number.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 12:04:58 +11:00
Wei Yang
dfcc8d45c3 powerpc/powernv: boundary the total VF BAR size instead of the individual one
Each VF could have 6 BARs at most. When the total BAR size exceeds the
gate, after expanding it will also exhaust the M64 Window.

This patch limits the boundary by checking the total VF BAR size instead of
the individual BAR.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 12:04:57 +11:00
Wei Yang
f2dd0afeea powerpc/powernv: replace the hard coded boundary with gate
At the moment 64bit-prefetchable window can be maximum 64GB, which is
currently got from device tree. This means that in shared mode the maximum
supported VF BAR size is 64GB/256=256MB. While this size could exhaust the
whole 64bit-prefetchable window. This is a design decision to set a
boundary to 64MB of the VF BAR size. Since VF BAR size with 64MB would
occupy a quarter of the 64bit-prefetchable window, this is affordable.

This patch replaces magic limit of 64MB with "gate", which is 1/4 of the
M64 Segment Size(m64_segsize >> 2) and adds comment to explain the reason
for it.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vent.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 12:04:57 +11:00
Wei Yang
ee8222fe95 powerpc/powernv: use one M64 BAR in Single PE mode for one VF BAR
In current implementation, when VF BAR is bigger than 64MB, it uses 4 M64
BARs in Single PE mode to cover the number of VFs required to be enabled.
By doing so, several VFs would be in one VF Group and leads to interference
between VFs in the same group.

And in this patch, m64_wins is renamed to m64_map, which means index number
of the M64 BAR used to map the VF BAR. Based on Gavin's comments. Also
makes sure the VF BAR size is bigger than 32MB when M64 BAR is used in
Single PE mode.

This patch changes the design by using one M64 BAR in Single PE mode for
one VF BAR. This gives absolute isolation for VFs.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 12:04:56 +11:00
Wei Yang
7fbe7a9374 powerpc/powernv: simplify the calculation of iov resource alignment
The alignment of IOV BAR on PowerNV platform is the total size of the IOV
BAR. No matter whether the IOV BAR is extended with number of
roundup_pow_of_two(total_vfs) or number of max PE number (256), the total
size could be calculated by (vfs_expanded * VF_BAR_size).

This patch simplifies the pnv_pci_iov_resource_alignment() by removing the
first case.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 12:04:55 +11:00
Wei Yang
b033185419 powerpc/powernv: don't enable SRIOV when VF BAR has non 64bit-prefetchable BAR
On PHB3, we enable SRIOV devices by mapping IOV BAR with M64 BARs. If a
SRIOV device's IOV BAR is not 64bit-prefetchable, this is not assigned from
64bit prefetchable window, which means M64 BAR can't work on it.

The reason is PCI bridges support only 2 memory windows and the kernel code
programs bridges in the way that one window is 32bit-nonprefetchable and
the other one is 64bit-prefetchable. So if devices' IOV BAR is 64bit and
non-prefetchable, it will be mapped into 32bit space and therefore M64
cannot be used for it.

This patch makes this explicit and truncate IOV resource in this case to
save MMIO space.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 12:04:54 +11:00
Gavin Shan
ccc9662da5 powerpc/powernv: Simplify definitions of EEH debugfs handlers
The EEH debugfs handlers have same prototype. This introduces
a macro to define them, then to simplify the code. No logical
changes.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 12:04:46 +11:00
Douglas Miller
6dfb54049f powerpc/xmon: Add xmon command to dump process/task similar to ps(1)
Add 'P' command with optional task_struct address to dump all/one task's
information: task pointer, kernel stack pointer, PID, PPID, state
(interpreted), CPU where (last) running, and command.

Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-10 10:22:04 +11:00
Andrew Donnellan
fde93a0f77 powerpc/xmon: add command to dump OPAL msglog
Add the 'do' command to dump the OPAL msglog in xmon.

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
[mpe: Reduce the amount of ifdefery required]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-09 21:03:39 +11:00
Andrew Donnellan
9b4fffa149 powerpc/powernv: new function to access OPAL msglog
Currently, the OPAL msglog/console buffer is exposed as a sysfs file, with
the sysfs read handler responsible for retrieving the log from the OPAL
buffer. We'd like to be able to use it in xmon as well.

Refactor the OPAL msglog code to create a new function, opal_msglog_copy(),
that copies to an arbitrary buffer. Separate the initialisation code into
generic memcons init and sysfs file creation.

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-09 20:27:04 +11:00
Andrew Donnellan
31f6a4ada1 powerpc/eeh: fix incorrect function name in comment
The comment block above pcibios_set_pcie_reset_state() incorrectly refers
to pcibios_set_pcie_slot_reset(). Fix the comment accordingly.

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-08 22:34:59 +11:00
Andrew Donnellan
2e34057929 powerpc/xmon: fix typo in usage message
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-08 22:34:52 +11:00
Russell Currey
2de50e9674 powerpc/powernv: Remove support for p5ioc2
"p5ioc2 is used by approximately 2 machines in the world, and has never
ever been a supported configuration."

The code for p5ioc2 is essentially unused and complicates what is already
a very complicated codebase.  Its removal is essentially a "free win" in
the effort to simplify the powernv PCI code.

In addition, support for p5ioc2 has been dropped from skiboot.  There's no
reason to keep it around in the kernel.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-08 22:03:37 +11:00
Andreas Schwab
f15838e9ca powerpc: Fix dedotify for binutils >= 2.26
Since binutils 2.26 BFD is doing suffix merging on STRTAB sections.  But
dedotify modifies the symbol names in place, which can also modify
unrelated symbols with a name that matches a suffix of a dotted name.  To
remove the leading dot of a symbol name we can just increment the pointer
into the STRTAB section instead.

Backport to all stables to avoid breakage when people update their
binutils - mpe.

Cc: stable@vger.kernel.org
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-08 22:01:46 +11:00
Linus Torvalds
388f7b1d6e Linux 4.5-rc3 2016-02-07 15:38:30 -08:00
Linus Torvalds
c17dfb019d ARM: SoC fixes for v4.5-rc
The first real batch of fixes for this release cycle, so there are a few more
 than usual.
 
 Most of these are fixes and tweaks to board support (DT bugfixes, etc). I've
 also picked up a couple of small cleanups that seemed innocent enough that
 there was little reason to wait (const/__initconst and Kconfig deps).
 
 Quite a bit of the changes on OMAP were due to fixes to no longer write to
 rodata from assembly when ARM_KERNMEM_PERMS was enabled, but there were also
 other fixes.
 
 Kirkwood had a bunch of gpio fixes for some boards. OMAP had RTC fixes
 on OMAP5, and Nomadik had changes to MMC parameters in DT.
 
 All in all, mostly the usual mix of various fixes.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJWt8K0AAoJEIwa5zzehBx3HxsQAJMqKkTCr/2hzHTw5V8sTgDf
 zrVYEi5WF5IGLR4eON31rF31tbEmQd0bqVlsTLy/yK3hu1gTQwDyqBJqoEQBMQUW
 lBShtVERP3mNUm0yICeupaWIhoRqaymlwFKKfq93f+YTn27pEDQ1ImEHuARlbAKa
 3zCd91ClRRm3WxrBXj9srt/NyMX7BlcHLjcN1BurpVkR0aciW1B692Lb8LotEP4k
 D1CLNZeQEwV+uOHcJsvjEdB/Uh42+dpsxbIAaBW2cFB0iuX3BsnmferoFe0cXmpC
 wO5ffvzr0LCMsrUzUsbvn0RgRtMDi2RxrS1n0cXrAVPP6OEeOaMLwGdPUGvQ2EVI
 cvCHpw3qXRz7CTERpy7bv0YugIY3vZPukJrne2ZEH7cpA/JLsuqlKm/cOmPRB7gJ
 tC2mXlP5jHbbGRiq/Kk3QB7QsKIxHfIalCZMMiRe0ldWSDW6jDpvrv4Nsfzs3etN
 LaB0iIm3f5DqOFjjZi+LVUJUGE3M8/3Fs2f70rCdPKDGq9fTqD3+2mK7l80ZaYXG
 J3wPKM+9WXGISakS/biQzvYA9iDnbDZCTUxBIM6VlvcHmARJEH3TS5ZjR0eaIb7w
 Sqx7e2ufm/2wpGINDoT1qms14cI8ayj7iq+8fDnI3R9XSXxeKk5J5jo9fKnbnDWP
 4A4Ai+NYBv/rDWjkg19s
 =1iBu
 -----END PGP SIGNATURE-----

Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC fixes from Olof Johansson:
 "The first real batch of fixes for this release cycle, so there are a
  few more than usual.

  Most of these are fixes and tweaks to board support (DT bugfixes,
  etc).  I've also picked up a couple of small cleanups that seemed
  innocent enough that there was little reason to wait (const/
  __initconst and Kconfig deps).

  Quite a bit of the changes on OMAP were due to fixes to no longer
  write to rodata from assembly when ARM_KERNMEM_PERMS was enabled, but
  there were also other fixes.

  Kirkwood had a bunch of gpio fixes for some boards.  OMAP had RTC
  fixes on OMAP5, and Nomadik had changes to MMC parameters in DT.

  All in all, mostly the usual mix of various fixes"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (46 commits)
  ARM: multi_v7_defconfig: enable DW_WATCHDOG
  ARM: nomadik: fix up SD/MMC DT settings
  ARM64: tegra: Add chosen node for tegra132 norrin
  ARM: realview: use "depends on" instead of "if" after prompt
  ARM: tango: use "depends on" instead of "if" after prompt
  ARM: tango: use const and __initconst for smp_operations
  ARM: realview: use const and __initconst for smp_operations
  bus: uniphier-system-bus: revive tristate prompt
  arm64: dts: Add missing DMA Abort interrupt to Juno
  bus: vexpress-config: Add missing of_node_put
  ARM: dts: am57xx: sbc-am57x: correct Eth PHY settings
  ARM: dts: am57xx: cl-som-am57x: fix CPSW EMAC pinmux
  ARM: dts: am57xx: sbc-am57x: fix UART3 pinmux
  ARM: dts: am57xx: cl-som-am57x: update SPI Flash frequency
  ARM: dts: am57xx: cl-som-am57x: set HOST mode for USB2
  ARM: dts: am57xx: sbc-am57x: fix SB-SOM EEPROM I2C address
  ARM: dts: LogicPD Torpedo: Revert Duplicative Entries
  ARM: dts: am437x: pixcir_tangoc: use correct flags for irq types
  ARM: dts: am4372: fix irq type for arm twd and global timer
  ARM: dts: at91: sama5d4 xplained: fix phy0 IRQ type
  ...
2016-02-07 15:23:20 -08:00
Linus Torvalds
63fee123da Merge branch 'mailbox-devel' of git://git.linaro.org/landing-teams/working/fujitsu/integration
Pull mailbox fixes from Jassi Brar:

 - fix getting element from the pcc-channels array by simply indexing
   into it

 - prevent building mailbox-test driver for archs that don't have IOMEM

* 'mailbox-devel' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  mailbox: Fix dependencies for !HAS_IOMEM archs
  mailbox: pcc: fix channel calculation in get_pcc_channel()
2016-02-07 15:17:47 -08:00
Linus Torvalds
46df55ceea USB fixes for 4.5-rc3
Here are some USB fixes for 4.5-rc3.
 
 The usual, xhci fixes for reported issues, combined with some small
 gadget driver fixes, and a MAINTAINERS file update.  All have been in
 linux-next with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAla205wACgkQMUfUDdst+ymVcACgksg9fcSsphvjo4ruxN79QrjW
 GaEAn3VmLc2WyLf13on9cXmBi8KrS+WY
 =sFPR
 -----END PGP SIGNATURE-----

Merge tag 'usb-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
 "Here are some USB fixes for 4.5-rc3.

  The usual, xhci fixes for reported issues, combined with some small
  gadget driver fixes, and a MAINTAINERS file update.  All have been in
  linux-next with no reported issues"

* tag 'usb-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  xhci: harden xhci_find_next_ext_cap against device removal
  xhci: Fix list corruption in urb dequeue at host removal
  usb: host: xhci-plat: fix NULL pointer in probe for device tree case
  usb: xhci-mtk: fix AHB bus hang up caused by roothubs polling
  usb: xhci-mtk: fix bpkts value of LS/HS periodic eps not behind TT
  usb: xhci: apply XHCI_PME_STUCK_QUIRK to Intel Broxton-M platforms
  usb: xhci: set SSIC port unused only if xhci_suspend succeeds
  usb: xhci: add a quirk bit for ssic port unused
  usb: xhci: handle both SSIC ports in PME stuck quirk
  usb: dwc3: gadget: set the OTG flag in dwc3 gadget driver.
  Revert "xhci: don't finish a TD if we get a short-transfer event mid TD"
  MAINTAINERS: fix my email address
  usb: dwc2: Fix probe problem on bcm2835
  Revert "usb: dwc2: Move reset into dwc2_get_hwparams()"
  usb: musb: ux500: Fix NULL pointer dereference at system PM
  usb: phy: mxs: declare variable with initialized value
  usb: phy: msm: fix error handling in probe.
2016-02-06 22:14:46 -08:00
Linus Torvalds
dacd53c805 Staging / IIO driver fixes for 4.5-rc3
Here are some IIO and staging driver fixes for 4.5-rc3.  All of them,
 except one, are for IIO drivers, and one is for a speakup driver fix
 caused by some earlier patches, to resolve a reported build failure.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAla21D8ACgkQMUfUDdst+ykHiQCgqYizz86HYi3ZR0LRgGwm3Gws
 4sEAn2x230E41WXDhLTLT3N6fAaetYl9
 =wa/Y
 -----END PGP SIGNATURE-----

Merge tag 'staging-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO driver fixes from Greg KH:
 "Here are some IIO and staging driver fixes for 4.5-rc3.

  All of them, except one, are for IIO drivers, and one is for a speakup
  driver fix caused by some earlier patches, to resolve a reported build
  failure"

* tag 'staging-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  Staging: speakup: Fix allyesconfig build on mn10300
  iio: dht11: Use boottime
  iio: ade7753: avoid uninitialized data
  iio: pressure: mpl115: fix temperature offset sign
  iio: imu: Fix dependencies for !HAS_IOMEM archs
  staging: iio: Fix dependencies for !HAS_IOMEM archs
  iio: adc: Fix dependencies for !HAS_IOMEM archs
  iio: inkern: fix a NULL dereference on error
  iio:adc:ti_am335x_adc Fix buffered mode by identifying as software buffer.
  iio: light: acpi-als: Report data as processed
  iio: dac: mcp4725: set iio name property in sysfs
  iio: add HAS_IOMEM dependency to VF610_ADC
  iio: add IIO_TRIGGER dependency to STK8BA50
  iio: proximity: lidar: correct return value
  iio-light: Use a signed return type for ltr501_match_samp_freq()
2016-02-06 22:13:16 -08:00
Linus Torvalds
5af9c2e19d Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
 "22 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits)
  epoll: restrict EPOLLEXCLUSIVE to POLLIN and POLLOUT
  radix-tree: fix oops after radix_tree_iter_retry
  MAINTAINERS: trim the file triggers for ABI/API
  dax: dirty inode only if required
  thp: make deferred_split_scan() work again
  mm: replace vma_lock_anon_vma with anon_vma_lock_read/write
  ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup
  um: asm/page.h: remove the pte_high member from struct pte_t
  mm, hugetlb: don't require CMA for runtime gigantic pages
  mm/hugetlb: fix gigantic page initialization/allocation
  mm: downgrade VM_BUG in isolate_lru_page() to warning
  mempolicy: do not try to queue pages from !vma_migratable()
  mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress
  vmstat: make vmstat_update deferrable
  mm, vmstat: make quiet_vmstat lighter
  mm/Kconfig: correct description of DEFERRED_STRUCT_PAGE_INIT
  memblock: don't mark memblock_phys_mem_size() as __init
  dump_stack: avoid potential deadlocks
  mm: validate_mm browse_rb SMP race condition
  m32r: fix build failure due to SMP and MMU
  ...
2016-02-05 20:20:07 -08:00
Linus Torvalds
5d6a6a75e0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph fixes from Sage Weil:
 "We have a few wire protocol compatibility fixes, ports of a few recent
  CRUSH mapping changes, and a couple error path fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  libceph: MOSDOpReply v7 encoding
  libceph: advertise support for TUNABLES5
  crush: decode and initialize chooseleaf_stable
  crush: add chooseleaf_stable tunable
  crush: ensure take bucket value is valid
  crush: ensure bucket id is valid before indexing buckets array
  ceph: fix snap context leak in error path
  ceph: checking for IS_ERR instead of NULL
2016-02-05 19:52:57 -08:00
Linus Torvalds
9b108828ed Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
 "Fixes all over the place:

   - amdkfd: two static checker fixes
   - mst: a bunch of static checker and spec/hw interaction fixes
   - amdgpu: fix Iceland hw properly, and some fiji bugs, along with
     some write-combining fixes.
   - exynos: some regression fixes
   - adv7511: fix some EDID reading issues"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (38 commits)
  drm/dp/mst: deallocate payload on port destruction
  drm/dp/mst: Reverse order of MST enable and clearing VC payload table.
  drm/dp/mst: move GUID storage from mgr, port to only mst branch
  drm/dp/mst: change MST detection scheme
  drm/dp/mst: Calculate MST PBN with 31.32 fixed point
  drm: Add drm_fixp_from_fraction and drm_fixp2int_ceil
  drm/mst: Add range check for max_payloads during init
  drm/mst: Don't ignore the MST PBN self-test result
  drm: fix missing reference counting decrease
  drm/amdgpu: disable uvd and vce clockgating on Fiji
  drm/amdgpu: remove exp hardware support from iceland
  drm/amdgpu: load MEC ucode manually on iceland
  drm/amdgpu: don't load MEC2 on topaz
  drm/amdgpu: drop topaz support from gmc8 module
  drm/amdgpu: pull topaz gmc bits into gmc_v7
  drm/amdgpu: The VI specific EXE bit should only apply to GMC v8.0 above
  drm/amdgpu: iceland use CI based MC IP
  drm/amdgpu: move gmc7 support out of CIK dependency
  drm/amdgpu/gfx7: enable cp inst/reg error interrupts
  drm/amdgpu/gfx8: enable cp inst/reg error interrupts
  ...
2016-02-05 19:38:15 -08:00
Linus Torvalds
22f60701d5 Power management and ACPI fixes for v4.5-rc3
- PM core fix to avoid false-positive warnings generated when
    the pm_domain field is cleared for a device that appears to
    be bound to a driver (Rafael Wysocki).
 
  - New MCH size workaround quirk for Intel Haswell-ULT (Josh Boyer).
 
  - Fix for an "unused function" compiler warning in the generic
    power domains framework (Ulf Hansson).
 
  - Fixup for the ACPI driver for Intel SoCs (acpi-lpss) to set
    the PM domain pointer of a device properly in one place that
    was overlooked by a recent PM core update (Andy Shevchenko).
 
  - Removal of a redundant function declaration in the ACPI CPPC
    core code (Timur Tabi).
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABCAAGBQJWtTQKAAoJEILEb/54YlRxQboP+gOgld+AZxMTe/88umM92utO
 M9PqzJhFGQ1kCUQliJhcgB2eggwXQwb8dKo+THv8Ql8DEzPLERcRMD/jffdRj2vQ
 3LQBVkD48nGwu6HOMZ0+e/61AkSkORhq9W7W3wkLcNdUhmetHpoG9+By/5ekf9WR
 BEDdvdEOyWHx044GWIgennaJC7wrmzrzxbjiVW1+aD0p/yRd2eFqNGSFcc2U4hoG
 gylay5sGJ/XU7v6kYg3mr04w+UXOkR/TrbsKheg0BTw/RJzgO69rZnrpZkjymHb0
 98XMNwGu+W2E1lRaKXBqctpuGD5NDOvuZIlqow5JBQXVLZbHE8gkGXJDET72cwRB
 wBPwiiYmdMxZrFU7pwP8FeeX39EDlWCQw4ji4DPqk8VAFjKu6HnHRd0K9vgJ46Gh
 YEGIQVvnuPB7DC3dPpa+FBaL1uIysZSri6/hTJQ9i7oz+WSoW1oNfatBtMtBFKvs
 BZ31QUq2rOf+fjjRiggHmSu/gzHd0ydOKaI3awm1aNJ9wP/J4xj1wBmhrIx9Tbxw
 NXu3wyf1LpRA4Z3s8TUIygWMAPhdoBW9TzgrIlzf26SB42CY+1ftub1xkLqTqTmU
 G1lQcc9wFdYvwUQVAy1Gq1iuwUM/V/UEKZVcttG8yEe5w0qKDdjARNqPFTGcEF0G
 LqLTypyGztWfPOxHs74m
 =DFSF
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are: a fix for a recently introduced false-positive warnings
  about PM domain pointers being changed inappropriately (harmless but
  annoying), an MCH size workaround quirk for one more platform, a
  compiler warning fix (generic power domains framework), an ACPI LPSS
  (Intel SoCs) driver fixup and a cleanup of the ACPI CPPC core code.

  Specifics:

   - PM core fix to avoid false-positive warnings generated when the
     pm_domain field is cleared for a device that appears to be bound to
     a driver (Rafael Wysocki).

   - New MCH size workaround quirk for Intel Haswell-ULT (Josh Boyer).

   - Fix for an "unused function" compiler warning in the generic power
     domains framework (Ulf Hansson).

   - Fixup for the ACPI driver for Intel SoCs (acpi-lpss) to set the PM
     domain pointer of a device properly in one place that was
     overlooked by a recent PM core update (Andy Shevchenko).

   - Removal of a redundant function declaration in the ACPI CPPC core
     code (Timur Tabi)"

* tag 'pm+acpi-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: Avoid false-positive warnings in dev_pm_domain_set()
  PM / Domains: Silence compiler warning for an unused function
  ACPI / CPPC: remove redundant mbox_send_message() declaration
  ACPI / LPSS: set PM domain via helper setter
  PNP: Add Haswell-ULT to Intel MCH size workaround
2016-02-05 18:11:23 -08:00
Jason Baron
b6a515c8a0 epoll: restrict EPOLLEXCLUSIVE to POLLIN and POLLOUT
In the current implementation of the EPOLLEXCLUSIVE flag (added for
4.5-rc1), if epoll waiters create different POLL* sets and register them
as exclusive against the same target fd, the current implementation will
stop waking any further waiters once it finds the first idle waiter.
This means that waiters could miss wakeups in certain cases.

For example, when we wake up a pipe for reading we do:
wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); So if
one epoll set or epfd is added to pipe p with POLLIN and a second set
epfd2 is added to pipe p with POLLRDNORM, only epfd may receive the
wakeup since the current implementation will stop after it finds any
intersection of events with a waiter that is blocked in epoll_wait().

We could potentially address this by requiring all epoll waiters that
are added to p be required to pass the same set of POLL* events.  IE the
first EPOLL_CTL_ADD that passes EPOLLEXCLUSIVE establishes the set POLL*
flags to be used by any other epfds that are added as EPOLLEXCLUSIVE.
However, I think it might be somewhat confusing interface as we would
have to reference count the number of users for that set, and so
userspace would have to keep track of that count, or we would need a
more involved interface.  It also adds some shared state that we'd have
store somewhere.  I don't think anybody will want to bloat
__wait_queue_head for this.

I think what we could do instead, is to simply restrict EPOLLEXCLUSIVE
such that it can only be specified with EPOLLIN and/or EPOLLOUT.  So
that way if the wakeup includes 'POLLIN' and not 'POLLOUT', we can stop
once we hit the first idle waiter that specifies the EPOLLIN bit, since
any remaining waiters that only have 'POLLOUT' set wouldn't need to be
woken.  Likewise, we can do the same thing if 'POLLOUT' is in the wakeup
bit set and not 'POLLIN'.  If both 'POLLOUT' and 'POLLIN' are set in the
wake bit set (there is at least one example of this I saw in fs/pipe.c),
then we just wake the entire exclusive list.  Having both 'POLLOUT' and
'POLLIN' both set should not be on any performance critical path, so I
think that's ok (in fs/pipe.c its in pipe_release()).  We also continue
to include EPOLLERR and EPOLLHUP by default in any exclusive set.  Thus,
the user can specify EPOLLERR and/or EPOLLHUP but is not required to do
so.

Since epoll waiters may be interested in other events as well besides
EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP, these can still be added by
doing a 'dup' call on the target fd and adding that as one normally
would with EPOLL_CTL_ADD.  Since I think that the POLLIN and POLLOUT
events are what we are interest in balancing, I think that the 'dup'
thing could perhaps be added to only one of the waiter threads.
However, I think that EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP should be
sufficient for the majority of use-cases.

Since EPOLLEXCLUSIVE is intended to be used with a target fd shared
among multiple epfds, where between 1 and n of the epfds may receive an
event, it does not satisfy the semantics of EPOLLONESHOT where only 1
epfd would get an event.  Thus, it is not allowed to be specified in
conjunction with EPOLLEXCLUSIVE.

EPOLL_CTL_MOD is also not allowed if the fd was previously added as
EPOLLEXCLUSIVE.  It seems with the limited number of flags to not be as
interesting, but this could be relaxed at some further point.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Tested-by: Madars Vitolins <m@silodev.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Eric Wong <normalperson@yhbt.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05 18:10:40 -08:00
Konstantin Khlebnikov
732042821c radix-tree: fix oops after radix_tree_iter_retry
Helper radix_tree_iter_retry() resets next_index to the current index.
In following radix_tree_next_slot current chunk size becomes zero.  This
isn't checked and it tries to dereference null pointer in slot.

Tagged iterator is fine because retry happens only at slot 0 where tag
bitmask in iter->tags is filled with single bit.

Fixes: 46437f9a55 ("radix-tree: fix race in gang lookup")
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Jeremiah Mahler <jmmahler@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05 18:10:40 -08:00
Michael Kerrisk (man-pages)
b14fd334ff MAINTAINERS: trim the file triggers for ABI/API
Commit ea8f8fc863 ("MAINTAINERS: add linux-api for review of API/ABI
changes") added file triggers for various paths that likely indicated
API/ABI changes.  However, catching all changes in Documentation/ABI/
and include/uapi/ produces a large volume of mail to linux-api, rather
than only API/ABI changes.  Drop those two entries, but leave
include/linux/syscalls.h and kernel/sys_ni.c to catch syscall-related
changes.

[josh@joshtriplett.org: redid changelog]
Signed-off-by: Michael Kerrisk <mtk.man-pages@gmail.com>
Acked-by: Shuah khan <shuahkh@osg.samsung.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05 18:10:40 -08:00