Document what's going on in asm/backoff.h with a large and descriptive
comment. Refer to it above the cpu_relax() definition in
asm/processor_64.h
Rename the pause patching section to have "3insn" in it's name like
the other patching sections do.
Based upon feedback from Sam Ravnborg.
Signed-off-by: David S. Miller <davem@davemloft.net>
In atomic backoff and cpu_relax(), use the pause instruction
found on SPARC-T4 and later.
It makes the cpu strand unselectable for the given number of
cycles, unless an intervening disrupting trap occurs.
Signed-off-by: David S. Miller <davem@davemloft.net>
For atomic backoff, we just loop over an exponentially backed off
counter. This is extremely ineffective as it doesn't actually yield
the cpu strand so that other competing strands can use the cpu core.
In cpus previous to SPARC-T4 we have to do this in a slightly hackish
way, by doing an operation with no side effects that also happens to
mark the strand as unavailable.
The mechanism we choose for this is three reads of the %ccr
(condition-code) register into %g0 (the zero register).
SPARC-T4 has an explicit "pause" instruction, and we'll make use of
that in a subsequent commit.
Yield strands also in cpu_relax(). We really should have done this a
very long time ago.
Signed-off-by: David S. Miller <davem@davemloft.net>
The Montgomery Multiply, Montgomery Square, and Multiple-Precision
Multiply instructions work by loading a combination of the floating
point and multiple register windows worth of integer registers
with the inputs.
These values are 64-bit. But for 32-bit userland processes we only
save the low 32-bits of each integer register during a register spill.
This is because the register window save area is in the user stack and
has a fixed layout.
Therefore, the only way to use these instruction in 32-bit mode is to
perform the following sequence:
1) Load the top-32bits of a choosen integer register with a sentinel,
say "-1". This will be in the outer-most register window.
The idea is that we're trying to see if the outer-most register
window gets spilled, and thus the 64-bit values were truncated.
2) Load all the inputs for the montmul/montsqr/mpmul instruction,
down to the inner-most register window.
3) Execute the opcode.
4) Traverse back up to the outer-most register window.
5) Check the sentinel, if it's still "-1" store the results.
Otherwise retry the entire sequence.
This retry is extremely troublesome. If you're just unlucky and an
interrupt or other trap happens, it'll push that outer-most window to
the stack and clear the sentinel when we restore it.
We could retry forever and never make forward progress if interrupts
arrive at a fast enough rate (consider perf events as one example).
So we have do limited retries and fallback to software which is
extremely non-deterministic.
Luckily it's very straightforward to provide a mechanism to let
32-bit applications use a 64-bit stack. Stacks in 64-bit mode are
biased by 2047 bytes, which means that the lowest bit is set in the
actual %sp register value.
So if we see bit zero set in a 32-bit application's stack we treat
it like a 64-bit stack.
Runtime detection of such a facility is tricky, and cumbersome at
best. For example, just trying to use a biased stack and seeing if it
works is hard to recover from (the signal handler will need to use an
alt stack, plus something along the lines of longjmp). Therefore, we
add a system call to report a bitmask of arch specific features like
this in a cheap and less hairy way.
With help from Andy Polyakov.
Signed-off-by: David S. Miller <davem@davemloft.net>
Here is one patch, a revert of a omap serial driver patch that was causing
problems, for your 3.7-rc tree.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull serial fix from Greg Kroah-Hartman:
"Here is one patch, a revert of a omap serial driver patch that was
causing problems, for your 3.7-rc tree.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'tty-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
Revert "serial: omap: fix software flow control"
Pull DMA-mapping revert from Marek Szyprowski:
"Due to my mistake, my previous pull request (merged as commit
cff7b8ba60: "Merge branch 'fixes_for_linus' ..") contained a patch
which is aimed for v3.8 and lacks its dependences. This pull request
reverts it and fixes build break of ARM architecture."
* 'fixes_for_linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
Revert "ARM: dma-mapping: support debug_dma_mapping_error"
Pull x86 fixes from Ingo Molnar:
"This fixes a couple of nasty page table initialization bugs which were
causing kdump regressions. A clean rearchitecturing of the code is in
the works - meanwhile these are reverts that restore the
best-known-working state of the kernel.
There's also EFI fixes and other small fixes."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, mm: Undo incorrect revert in arch/x86/mm/init.c
x86: efi: Turn off efi_enabled after setup on mixed fw/kernel
x86, mm: Find_early_table_space based on ranges that are actually being mapped
x86, mm: Use memblock memory loop instead of e820_RAM
x86, mm: Trim memory in memblock to be page aligned
x86/irq/ioapic: Check for valid irq_cfg pointer in smp_irq_move_cleanup_interrupt
x86/efi: Fix oops caused by incorrect set_memory_uc() usage
x86-64: Fix page table accounting
Revert "x86/mm: Fix the size calculation of mapping tables"
MAINTAINERS: Add EFI git repository location
Pull perf fixes from Ingo Molnar:
"Most of the kernel diffstat relates to a group of Intel P6 and KNC
(Xeon-Phi Knights Corner) PMU driver fixes, neither of which is in
heavy use, so we took the fixes.
The rest is diverse smallish fixes to the tooling and kernel side."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Remove unused variable in nhmex_rbox_alter_er()
perf/x86: Enable overflow on Intel KNC with a custom knc_pmu_handle_irq()
perf/x86: Remove cpuc->enable check on Intl KNC event enable/disable
perf/x86: Make Intel KNC use full 40-bit width of counters
perf/x86/uncore: Handle pci_read_config_dword() errors
perf/x86: Remove P6 cpuc->enabled check
perf/x86: Update/fix generic events on P6 PMU
perf/x86: Fix P6 FP_ASSIST event constraint
perf, cpu hotplug: Use cached value of smp_processor_id()
perf, cpu hotplug: Run CPU_STARTING notifiers with irqs disabled
x86/perf: Fix virtualization sanity check
perf test: Fix exclude_guest parse events tests
perf tools: do not flush maps on COMM for perf report
perf help: Fix --help for builtins
perf trace: Check if sample raw_data field is set
perf trace: Validate syscall id before growing syscall table
This reverts commit 871ae57adc, which is
scheduled for v3.8 and accidently got into v3.7-rc series.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Pull ARM fixes from Russell King:
"A random collection of various fixes, mainly from Arnd and a few other
people. Not thing really stands out here."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: drop experimental status for hotplug and Thumb2
ARM: 7560/1: SMP_TWD: use DIV_ROUND_CLOSEST() for periodic mode
ARM: 7559/1: smp: switch away from the idmap before updating init_mm.mm_count
ARM: 7556/1: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD
ARM: 7555/1: kexec: fix segment memory addresses check
ARM: warnings in arch/arm/include/asm/uaccess.h
ARM: binfmt_flat: unused variable 'persistent'
ARM: be really quiet when building with 'make -s'
ARM: pass -marm to gcc by default for both C and assembler
ARM: Xen: fix initial build problems
ARM: export default read_current_timer
ARM: Fix another build warning in arch/arm/mm/alignment.c
ARM: export set_irq_flags
ARM: kprobes: make more tests conditional
Pull CMA and DMA-mapping fixes from Marek Szyprowski:
"This consists mainly of a set of one-liner fixes and cleanups for a
few minor issues identified in both Contiguous Memory Allocator code
and ARM DMA-mapping subsystem."
* 'fixes_for_linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
ARM: mm: Remove unused arm_vmregion priv field
ARM: dma-mapping: fix build warning in __dma_alloc()
ARM: dma-mapping: support debug_dma_mapping_error
mm: cma: alloc_contig_range: return early for err path
drivers: cma: Fix wrong CMA selected region size default value
drivers: dma-coherent: Fix typo in dma_mmap_from_coherent documentation
drivers: dma-contiguous: Don't redefine SZ_1M
Commit
844ab6f9 x86, mm: Find_early_table_space based on ranges that are actually being mapped
added back some lines back wrongly that has been removed in commit
7b16bbf97 Revert "x86/mm: Fix the size calculation of mapping tables"
remove them again.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQW_vuaYQbmagVnxT2DGsYc=9tNeAbdBq53sYkitPOwxSQ@mail.gmail.com
Acked-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
When 32-bit EFI is used with 64-bit kernel (or vice versa), turn off
efi_enabled once setup is done. Beyond setup, it is normally used to
determine if runtime services are available and we will have none.
This will resolve issues stemming from efivars modprobe panicking on a
32/64-bit setup, as well as some reboot issues on similar setups.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=45991
Reported-by: Marko Kohtala <marko.kohtala@gmail.com>
Reported-by: Maxim Kammerer <mk@dee.su>
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: stable@kernel.org # 3.4 - 3.6
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Current logic finds enough space for direct mapping page tables from 0
to end. Instead, we only need to find enough space to cover mr[0].start
to mr[nr_range].end -- the range that is actually being mapped by
init_memory_mapping()
This is needed after 1bbbbe779a, to address
the panic reported here:
https://lkml.org/lkml/2012/10/20/160https://lkml.org/lkml/2012/10/21/157
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/20121024195311.GB11779@jshin-Toonie
Tested-by: Tom Rini <trini@ti.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This reverts commit 957ee7270d
(serial: omap: fix software flow control).
As Russell has pointed out, that commit isn't fixing
Software Flow Control at all, and it actually makes
it even more broken.
It was agreed to revert this commit and use Russell's
latest UART patches instead.
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We need to handle E820_RAM and E820_RESERVED_KERNEL at the same time.
Also memblock has page aligned range for ram, so we could avoid mapping
partial pages.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQVZirvaBMFYRfXMmWEcHbKSicQEHz4VAwUv0xFCk51ZNw@mail.gmail.com
Acked-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
We will not map partial pages, so need to make sure memblock
allocation will not allocate those bytes out.
Also we will use for_each_mem_pfn_range() to loop to map memory
range to keep them consistent.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQVZirvaBMFYRfXMmWEcHbKSicQEHz4VAwUv0xFCk51ZNw@mail.gmail.com
Acked-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
Posting this patch to fix an issue concerning sparse irq's that
I raised a while back. There was discussion about adding
refcounting to sparse irqs (to fix other potential race
conditions), but that does not appear to have been addressed
yet. This covers the only issue of this type that I've
encountered in this area.
A NULL pointer dereference can occur in
smp_irq_move_cleanup_interrupt() if we haven't yet setup the
irq_cfg pointer in the irq_desc.irq_data.chip_data.
In create_irq_nr() there is a window where we have set
vector_irq in __assign_irq_vector(), but not yet called
irq_set_chip_data() to set the irq_cfg pointer.
Should an IRQ_MOVE_CLEANUP_VECTOR hit the cpu in question during
this time, smp_irq_move_cleanup_interrupt() will attempt to
process the aforementioned irq, but panic when accessing
irq_cfg.
Only continue processing the irq if irq_cfg is non-NULL.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20121016125021.GA22935@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Calling __pa() with an ioremap'd address is invalid. If we
encounter an efi_memory_desc_t without EFI_MEMORY_WB set in
->attribute we currently call set_memory_uc(), which in turn
calls __pa() on a potentially ioremap'd address.
On CONFIG_X86_32 this results in the following oops:
BUG: unable to handle kernel paging request at f7f22280
IP: [<c10257b9>] reserve_ram_pages_type+0x89/0x210
*pdpt = 0000000001978001 *pde = 0000000001ffb067 *pte = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in:
Pid: 0, comm: swapper Not tainted 3.0.0-acpi-efi-0805 #3
EIP: 0060:[<c10257b9>] EFLAGS: 00010202 CPU: 0
EIP is at reserve_ram_pages_type+0x89/0x210
EAX: 0070e280 EBX: 38714000 ECX: f7814000 EDX: 00000000
ESI: 00000000 EDI: 38715000 EBP: c189fef0 ESP: c189fea8
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process swapper (pid: 0, ti=c189e000 task=c18bbe60 task.ti=c189e000)
Stack:
80000200 ff108000 00000000 c189ff00 00038714 00000000 00000000 c189fed0
c104f8ca 00038714 00000000 00038715 00000000 00000000 00038715 00000000
00000010 38715000 c189ff48 c1025aff 38715000 00000000 00000010 00000000
Call Trace:
[<c104f8ca>] ? page_is_ram+0x1a/0x40
[<c1025aff>] reserve_memtype+0xdf/0x2f0
[<c1024dc9>] set_memory_uc+0x49/0xa0
[<c19334d0>] efi_enter_virtual_mode+0x1c2/0x3aa
[<c19216d4>] start_kernel+0x291/0x2f2
[<c19211c7>] ? loglevel+0x1b/0x1b
[<c19210bf>] i386_start_kernel+0xbf/0xc8
The only time we can call set_memory_uc() for a memory region is
when it is part of the direct kernel mapping. For the case where
we ioremap a memory region we must leave it alone.
This patch reimplements the fix from e8c7106280 ("x86, efi:
Calling __pa() with an ioremap()ed address is invalid") which
was reverted in e1ad783b12 because it caused a regression on
some MacBooks (they hung at boot). The regression was caused
because the commit only marked EFI_RUNTIME_SERVICES_DATA as
E820_RESERVED_EFI, when it should have marked all regions that
have the EFI_MEMORY_RUNTIME attribute.
Despite first impressions, it's not possible to use
ioremap_cache() to map all cached memory regions on
CONFIG_X86_64 because of the way that the memory map might be
configured as detailed in the following bug report,
https://bugzilla.redhat.com/show_bug.cgi?id=748516
e.g. some of the EFI memory regions *need* to be mapped as part
of the direct kernel mapping.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Huang Ying <huang.ying.caritas@gmail.com>
Cc: Keith Packard <keithp@keithp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1350649546-23541-1-git-send-email-matt@console-pimps.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Although based on the Intel P6 design, the interrupt mechnanism
for KNC more closely resembles the Intel architectural
perfmon one.
We can't just re-use that code though, because KNC has different
MSR numbers for the status and ack registers.
In this case we just cut-and paste from perf_event_intel.c
with some minor changes, as it looks like it would not be
worth the trouble to change that code to be MSR-configurable.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: eranian@gmail.com
Cc: Meadows Lawrence F <lawrence.f.meadows@intel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1210171304410.23243@vincent-weaver-1.um.maine.edu
[ Small stylistic edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86_pmu.enable() is called from x86_pmu_enable() with
cpuc->enabled set to 0. This means we weren't re-enabling the
counters after a context switch.
This patch just removes the check, as it should't be necessary
(and the equivelent x86_ generic code does not have the checks).
The origin of this problem is the KNC driver being based on the
P6 one. The P6 driver also has this issue, but works anyway
due to various lucky accidents.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: eranian@gmail.com
Cc: Meadows
Cc: Lawrence F <lawrence.f.meadows@intel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1210171303290.23243@vincent-weaver-1.um.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Early versions of Intel KNC chips have a bug where bits above 32
were not properly set. We worked around this by only using the
bottom 32 bits (out of 40 that should be available).
It turns out this workaround breaks overflow handling.
The buggy silicon will in theory never be used in production
systems, so remove this workaround so we get proper overflow
support.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: eranian@gmail.com
Cc: Meadows Lawrence F <lawrence.f.meadows@intel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1210171302140.23243@vincent-weaver-1.um.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This, beyond handling corner cases, also fixes some build warnings:
arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function ‘snbep_uncore_pci_disable_box’:
arch/x86/kernel/cpu/perf_event_intel_uncore.c:124:9: warning: ‘config’ is used uninitialized in this function [-Wuninitialized]
arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function ‘snbep_uncore_pci_enable_box’:
arch/x86/kernel/cpu/perf_event_intel_uncore.c:135:9: warning: ‘config’ is used uninitialized in this function [-Wuninitialized]
arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function ‘snbep_uncore_pci_read_counter’:
arch/x86/kernel/cpu/perf_event_intel_uncore.c:164:2: warning: ‘count’ is used uninitialized in this function [-Wuninitialized]
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Cc: a.p.zijlstra@chello.nl
Link: http://lkml.kernel.org/r/1351068140-13456-1-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 20167d3421 ("x86-64: Fix
accounting in kernel_physical_mapping_init()") went a little too
far by entirely removing the counting of pre-populated page
tables: this should be done at boot time (to cover the page
tables set up in early boot code), but shouldn't be done during
memory hot add.
Hence, re-add the removed increments of "pages", but make them
and the one in phys_pte_init() conditional upon !after_bootmem.
Reported-Acked-and-Tested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/506DAFBA020000780009FA8C@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Between 2.6.33 and 2.6.34 the PMU code was made modular.
The x86_pmu_enable() call was extended to disable cpuc->enabled
and iterate the counters, enabling one at a time, before calling
enable_all() at the end, followed by re-enabling cpuc->enabled.
Since cpuc->enabled was set to 0, that change effectively caused
the "val |= ARCH_PERFMON_EVENTSEL_ENABLE;" code in p6_pmu_enable_event()
and p6_pmu_disable_event() to be dead code that was never called.
This change removes this code (which was confusing) and adds some
extra commentary to make it more clear what is going on.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1210191732000.14552@vincent-weaver-1.um.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch updates the generic events on p6, including some new
extended cache events.
Values for these events were taken from the equivelant PAPI
predefined events.
Tested on a Pentium II.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1210191730080.14552@vincent-weaver-1.um.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
According to Intel SDM Volume 3B, FP_ASSIST is limited to Counter 1 only,
not Counter 0.
Tested on a Pentium II.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1210191728570.14552@vincent-weaver-1.um.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
722bc6b167 x86/mm: Fix the size calculation of mapping tables
Tried to address the issue that the first 2/4M should use 4k pages
if PSE enabled, but extra counts should only be valid for x86_32.
This commit caused a kdump regression: the kdump kernel hangs.
Work is in progress to fundamentally fix the various page table
initialization issues that we have, via the design suggested
by H. Peter Anvin, but it's not ready yet to be merged.
So, to get a working kdump revert to the last known working version,
which is the revert of this commit and of a followup fix (which was
incomplete):
bd2753b2dd x86/mm: Only add extra pages count for the first memory range during pre-allocation
Tested kdump on physical and virtual machines.
Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Flavio Leitner <fbl@redhat.com>
Tested-by: Flavio Leitner <fbl@redhat.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Flavio Leitner <fbl@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: ianfang.cn@gmail.com
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In check_hw_exists() we try to detect non-emulated MSR accesses
by writing an arbitrary value into one of the PMU registers
and check if it's value after a readout is still the same.
This algorithm silently assumes that the register does not contain
the magic value already, which is wrong in at least one situation.
Fix the algorithm to really do a read-modify-write cycle. This fixes
a warning under Xen under some circumstances on AMD family 10h CPUs.
The reasons in more details actually sound like a story from
Believe It or Not!:
First you need an AMD family 10h/12h CPU. These do not reset the
PERF_CTR registers on a reboot.
Now you boot bare metal Linux, which goes successfully through this
check, but leaves the magic value of 0xabcd in the register. You
don't use the performance counters, but do a reboot (warm reset).
Then you choose to boot Xen. The check will be triggered with a
recent Linux kernel as Dom0 again, trying to write 0xabcd into the
MSR. Xen silently drops the write (expected), but the subsequent read
will return the value in the register, which just happens to be the
expected magic value. Thus the test misleadingly succeeds, leaving
the kernel in the belief that the PMU is available. This will trigger
the following message:
[ 0.020294] ------------[ cut here ]------------
[ 0.020311] WARNING: at arch/x86/xen/enlighten.c:730 xen_apic_write+0x15/0x17()
[ 0.020318] Hardware name: empty
[ 0.020323] Modules linked in:
[ 0.020334] Pid: 1, comm: swapper/0 Not tainted 3.3.8 #7
[ 0.020340] Call Trace:
[ 0.020354] [<ffffffff81050379>] warn_slowpath_common+0x80/0x98
[ 0.020369] [<ffffffff810503a6>] warn_slowpath_null+0x15/0x17
[ 0.020378] [<ffffffff810034df>] xen_apic_write+0x15/0x17
[ 0.020392] [<ffffffff8101cb2b>] perf_events_lapic_init+0x2e/0x30
[ 0.020410] [<ffffffff81ee4dd0>] init_hw_perf_events+0x250/0x407
[ 0.020419] [<ffffffff81ee4b80>] ? check_bugs+0x2d/0x2d
[ 0.020430] [<ffffffff81002181>] do_one_initcall+0x7a/0x131
[ 0.020444] [<ffffffff81edbbf9>] kernel_init+0x91/0x15d
[ 0.020456] [<ffffffff817caaa4>] kernel_thread_helper+0x4/0x10
[ 0.020471] [<ffffffff817c347c>] ? retint_restore_args+0x5/0x6
[ 0.020481] [<ffffffff817caaa0>] ? gs_change+0x13/0x13
[ 0.020500] ---[ end trace a7919e7f17c0a725 ]---
The new code will change every of the 16 low bits read from the
register and tries to write and read-back that modified number
from the MSR.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Link: http://lkml.kernel.org/r/1349797115-28346-2-git-send-email-andre.przywara@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit e9da6e9905 ("ARM: dma-mapping:
remove custom consistent dma region") removed the last users of the
field. Remove it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fix build warning in __dma_alloc() as below:
arch/arm/mm/dma-mapping.c: In function '__dma_alloc':
arch/arm/mm/dma-mapping.c:653:29: warning: 'page' may be used uninitialized in this function [-Wuninitialized]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
* Fix mysterious SIGSEGV or SIGKILL in applications due to corrupting
of the %eip when returning from a signal handler.
* Fix various ARM compile issues after the merge fallout.
* Continue on making more of the Xen generic code usable by ARM platform.
* Fix SR-IOV passthrough to mirror multifunction PCI devices.
* Fix various compile warnings.
* Remove hypercalls that don't exist anymore.
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Merge tag 'stable/for-linus-3.7-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull xen bug-fixes from Konrad Rzeszutek Wilk:
- Fix mysterious SIGSEGV or SIGKILL in applications due to corrupting
of the %eip when returning from a signal handler.
- Fix various ARM compile issues after the merge fallout.
- Continue on making more of the Xen generic code usable by ARM
platform.
- Fix SR-IOV passthrough to mirror multifunction PCI devices.
- Fix various compile warnings.
- Remove hypercalls that don't exist anymore.
* tag 'stable/for-linus-3.7-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: dbgp: Fix warning when CONFIG_PCI is not enabled.
xen: arm: comment on why 64-bit xen_pfn_t is safe even on 32 bit
xen: balloon: use correct type for frame_list
xen/x86: don't corrupt %eip when returning from a signal handler
xen: arm: make p2m operations NOPs
xen: balloon: don't include e820.h
xen: grant: use xen_pfn_t type for frame_list.
xen: events: pirq_check_eoi_map is X86 specific
xen: XENMEM_translate_gpfn_list was remove ages ago and is unused.
xen: sysfs: fix build warning.
xen: sysfs: include err.h for PTR_ERR etc
xen: xenbus: quirk uses x86 specific cpuid
xen PV passthru: assign SR-IOV virtual functions to separate virtual slots
xen/xenbus: Fix compile warning.
xen/x86: remove duplicated include from enlighten.c
... and fix the race in updating unaligned control ones
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull perf fixes from Ingo Molnar:
"Most of these are uprobes race fixes from Oleg, and their preparatory
cleanups. (It's larger than what I'd normally send for an -rc kernel,
but they looked significant enough to not delay them.)
There's also an oprofile fix and an uncore PMU fix."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
perf/x86: Disable uncore on virtualized CPUs
oprofile, x86: Fix wrapping bug in op_x86_get_ctrl()
ring-buffer: Check for uninitialized cpu buffer before resizing
uprobes: Fix the racy uprobe->flags manipulation
uprobes: Fix prepare_uprobe() race with itself
uprobes: Introduce prepare_uprobe()
uprobes: Fix handle_swbp() vs unregister() + register() race
uprobes: Do not delete uprobe if uprobe_unregister() fails
uprobes: Don't return success if alloc_uprobe() fails
uprobes/x86: Only rep+nop can be emulated correctly
uprobes: Simplify is_swbp_at_addr(), remove stale comments
uprobes: Kill set_orig_insn()->is_swbp_at_addr()
uprobes: Introduce copy_opcode(), kill read_opcode()
uprobes: Kill set_swbp()->is_swbp_at_addr()
uprobes: Restrict valid_vma(false) to skip VM_SHARED vmas
uprobes: Change valid_vma() to demand VM_MAYEXEC rather than VM_EXEC
uprobes: Change write_opcode() to use FOLL_FORCE
uprobes: Move clear_thread_flag(TIF_UPROBE) to uprobe_notify_resume()
uprobes: Kill UTASK_BP_HIT state
uprobes: Fix UPROBE_SKIP_SSTEP checks in handle_swbp()
...
Pull s390 fixes from Martin Schwidefsky:
"Among the usual minor bug fixes the more interesting patches are the
perf counters for the latest machine, the missing select to enable
transparent huge pages and a build fix for the UAPI rework."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390,uapi: do not use uapi/asm-generic/kvm_para.h
s390/cache: fix data/instruction cache output
s390: fix linker script for 31 bit builds
s390/thp: select HAVE_ARCH_TRANSPARENT_HUGEPAGE
s390/kdump: Use 64 bit mode for 0x10000 entry point
perf_cpum_cf: Add support for counters available with IBM zEC12
s390/css: stop stsch loop after cc 3
s390/cio: use generic bitmap functions
s390/chpid: make headers usable (again)
Pull tile fixes from Chris Metcalf:
"This fixes one issue with compiler flags that can cause modules not to
load, and cleans up some warnings with ELF_R_xxx defines."
* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: avoid build warnings from duplicate ELF_R_xxx #defines
arch/tile: avoid generating .eh_frame information in modules
These are now provided in <asm-generic/module.h>, so clean up warnings
by not re-defining them in module.c.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
The tile tool chain uses the .eh_frame information for backtracing.
The vmlinux build drops any .eh_frame sections at link time, but when
present in kernel modules, it causes a module load failure due to the
presence of unsupported pc-relative relocations. When compiling to
use compiler feedback support, the compiler by default omits .eh_frame
information, so we don't see this problem. But when not using feedback,
we need to explicitly suppress the .eh_frame.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: stable@vger.kernel.org
Without the patch, kind of below warning will be dumped if DMA-API
debug is enabled:
[ 11.069763] ------------[ cut here ]------------
[ 11.074645] WARNING: at lib/dma-debug.c:948 check_unmap+0x770/0x860()
[ 11.081420] ehci-omap ehci-omap.0: DMA-API: device driver failed to
check map error[device address=0x0000000
0adb78e80] [size=8 bytes] [mapped as single]
[ 11.095611] Modules linked in:
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Both these features have been around for a long time now, and haven't
had any recent issues brought up. So lets drop their experimental
status.
In any case, hotplugis selected by other non-experimental options
which then cause a Kconfig warning.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We can not directly call kvm_release_pfn_clean to release the pfn
since we can meet noslot pfn which is used to cache mmio info into
spte
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
The periodic mode is currently calculated by a simple division
but we should pay more attention to our integer arithmetics.
Also delete a comment that does not make any sense.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
