This patch enables Opmask, ZMM_Hi256, and Hi16_ZMM AVX-512 states for
xstate context switch.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1392931491-33237-2-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # hw enabling
Pull DMA-mapping fixes from Marek Szyprowski:
"This contains fixes for incorrect atomic test in dma-mapping subsystem
for ARM and x86 architecture"
* 'fixes-for-v3.14' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
x86: dma-mapping: fix GFP_ATOMIC macro usage
ARM: dma-mapping: fix GFP_ATOMIC macro usage
Linux uses CPUID.MWAIT.EDX to validate the C-states
reported by ACPI, silently discarding states which
are not supported by the HW.
This test is too restrictive, as some HW now uses
sparse sub-state numbering, so the sub-state number
may be higher than the number of sub-states...
Also, rather than silently ignoring an invalid state,
we should complain about a firmware bug.
In practice...
Bay Trail systems originally supported C6-no-shrink as
MWAIT sub-state 0x58, and in CPUID.MWAIT.EDX 0x03000000
indicated that there were 3 MWAIT-C6 sub-states.
So acpi_idle would discard that C-state because 8 >= 3.
Upon discovering this issue, the ucode was updated so that
C6-no-shrink was also exported as 0x51, and the BIOS was
updated to match. However, systems shipped with 0x58,
will never get a BIOS update, and this patch allows
Linux to see C6-no-shrink on early Bay Trail.
Signed-off-by: Len Brown <len.brown@intel.com>
Intel Baytrail is based on Silvermont core so MSR_FSB_FREQ[2:0] == 0 means
that the CPU reference clock runs at 83.3MHz. Add this missing frequency to
the table.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Bin Gao <bin.gao@linux.intel.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1392810750-18660-2-git-send-email-mika.westerberg@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If we cannot calibrate TSC via MSR based calibration
try_msr_calibrate_tsc() stores zero to fast_calibrate and returns that
to the caller. This value gets then propagated further to clockevents
code resulting division by zero oops like the one below:
divide error: 0000 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 3.13.0+ #47
task: ffff880075508000 ti: ffff880075506000 task.ti: ffff880075506000
RIP: 0010:[<ffffffff810aec14>] [<ffffffff810aec14>] clockevents_config.part.3+0x24/0xa0
RSP: 0000:ffff880075507e58 EFLAGS: 00010246
RAX: ffffffffffffffff RBX: ffff880079c0cd80 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffffffffff
RBP: ffff880075507e70 R08: 0000000000000001 R09: 00000000000000be
R10: 00000000000000bd R11: 0000000000000003 R12: 000000000000b008
R13: 0000000000000008 R14: 000000000000b010 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff880079c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff880079fff000 CR3: 0000000001c0b000 CR4: 00000000001006f0
Stack:
ffff880079c0cd80 000000000000b008 0000000000000008 ffff880075507e88
ffffffff810aecb0 ffff880079c0cd80 ffff880075507e98 ffffffff81030168
ffff880075507ed8 ffffffff81d1104f 00000000000000c3 0000000000000000
Call Trace:
[<ffffffff810aecb0>] clockevents_config_and_register+0x20/0x30
[<ffffffff81030168>] setup_APIC_timer+0xc8/0xd0
[<ffffffff81d1104f>] setup_boot_APIC_clock+0x4cc/0x4d8
[<ffffffff81d0f5de>] native_smp_prepare_cpus+0x3dd/0x3f0
[<ffffffff81d02ee9>] kernel_init_freeable+0xc3/0x205
[<ffffffff8177c910>] ? rest_init+0x90/0x90
[<ffffffff8177c91e>] kernel_init+0xe/0x120
[<ffffffff8178deec>] ret_from_fork+0x7c/0xb0
[<ffffffff8177c910>] ? rest_init+0x90/0x90
Prevent this from happening by:
1) Modifying try_msr_calibrate_tsc() to return calibration value or zero
if it fails.
2) Check this return value in native_calibrate_tsc() and in case of zero
fallback to use normal non-MSR based calibration.
[mw: Added subject and changelog]
Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bin Gao <bin.gao@linux.intel.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1392810750-18660-1-git-send-email-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* pci/misc:
PCI: Enable INTx if BIOS left them disabled
ia64/PCI: Set IORESOURCE_ROM_SHADOW only for the default VGA device
x86/PCI: Set IORESOURCE_ROM_SHADOW only for the default VGA device
PCI: Update outdated comment for pcibios_bus_report_status()
PCI: Cleanup per-arch list of object files
PCI: cpqphp: Fix hex vs decimal typo in cpqhpc_probe()
x86/PCI: Fix function definition whitespace
x86/PCI: Reword comments
x86/PCI: Remove unnecessary local variable initialization
PCI: Remove unnecessary list_empty(&pci_pme_list) check
BAD_MADT_ENTRY() is arch independent and will be used for all
architectures which parse MADT, so move it to linux/acpi.h to
reduce code duplication.
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Nothing cares about ACPI_PROCFS. This has been the case since v2.6.38.
This Kconfig symbol serves no purpose and its help text is now
misleading. It can safely be removed. If this symbol would be needed
again in the future it can be readded in a commit that adds code that
actually uses it.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The x86 CPU feature modalias handling existed before it was reimplemented
generically. This patch aligns the x86 handling so that it
(a) reuses some more code that is now generic;
(b) uses the generic format for the modalias module metadata entry, i.e., it
now uses 'cpu:type:x86,venVVVVfamFFFFmodMMMM:feature:,XXXX,YYYY' instead of
the 'x86cpu:vendor:VVVV👪FFFF:model:MMMM:feature:,XXXX,YYYY' that was
used before.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should open NMI window right after an iret, but SVM exits before it.
We wanted to single step using the trap flag and then open it.
(or we could emulate the iret instead)
We don't do it since commit 3842d135ff (likely), because the iret exit
handler does not request an event, so NMI window remains closed until
the next exit.
Fix this by making KVM_REQ_EVENT request in the iret handler.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When this was introduced, kvm_flush_remote_tlbs() could be called
without holding mmu_lock. It is now acknowledged that the function
must be called before releasing mmu_lock, and all callers have already
been changed to do so.
There is no need to use smp_mb() and cmpxchg() any more.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The first is a fix for the way the ring buffer stores timestamps.
After a restructure of the code was done, the ring buffer timestamp
logic missed the fact that the first event on a sub buffer is to have
a zero delta, as the full timestamp is stored on the sub buffer itself.
But because the delta was not cleared to zero, the timestamp for that
event will be calculated as the real timestamp + the delta from the
last timestamp. This can skew the timestamps of the events and
have them say they happened when they didn't really happen. That's bad.
The second fix is for modifying the function graph caller site.
When the stop machine was removed from updating the function tracing
code, it missed updating the function graph call site location.
It is still modified as if it is being done via stop machine. But it's not.
This can lead to a GPF and kernel crash if the function graph call site
happens to lie between cache lines and one CPU is executing it while
another CPU is doing the update. It would be a very hard condition to
hit, but the result is sever enough to have it fixed ASAP.
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Merge tag 'trace-fixes-v3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull twi tracing fixes from Steven Rostedt:
"Two urgent fixes in the tracing utility.
The first is a fix for the way the ring buffer stores timestamps.
After a restructure of the code was done, the ring buffer timestamp
logic missed the fact that the first event on a sub buffer is to have
a zero delta, as the full timestamp is stored on the sub buffer
itself. But because the delta was not cleared to zero, the timestamp
for that event will be calculated as the real timestamp + the delta
from the last timestamp. This can skew the timestamps of the events
and have them say they happened when they didn't really happen.
That's bad.
The second fix is for modifying the function graph caller site. When
the stop machine was removed from updating the function tracing code,
it missed updating the function graph call site location. It is still
modified as if it is being done via stop machine. But it's not. This
can lead to a GPF and kernel crash if the function graph call site
happens to lie between cache lines and one CPU is executing it while
another CPU is doing the update. It would be a very hard condition to
hit, but the result is severe enough to have it fixed ASAP"
* tag 'trace-fixes-v3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/x86: Use breakpoints for converting function graph caller
ring-buffer: Fix first commit on sub-buffer having non-zero delta
Pull x86 EFI fixes from Peter Anvin:
"A few more EFI-related fixes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/efi: Check status field to validate BGRT header
x86/efi: Fix 32-bit fallout
Setting the IORESOURCE_ROM_SHADOW flag on a VGA card other than the primary
prevents it from reading its own ROM. It will get the content of the
shadow ROM at C000 instead, which is of the primary VGA card and the driver
of the secondary card will bail out.
Fix this by checking if the arch code or vga-arbitration has already
determined the vga_default_device, if so only apply the fix to this primary
video device and let the comment reflect this.
[bhelgaas: add subject, split x86 & ia64 into separate patches]
Signed-off-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
There have been reports of EFI crashes since -rc1. The following two
commits fix known issues.
* Fix boot failure on 32-bit EFI due to the recent EFI memmap changes
merged during the merge window - Borislav Petkov
* Avoid a crash during efi_bgrt_init() by detecting invalid BGRT
headers based on the 'status' field.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86 fixes from Peter Anvin:
"A collection of small fixes:
- There still seem to be problems with asm goto which requires the
empty asm hack.
- If SMAP is disabled at compile time, don't enable it nor try to
interpret a page fault as an SMAP violation.
- Fix a case of unbounded recursion while tracing"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, smap: smap_violation() is bogus if CONFIG_X86_SMAP is off
x86, smap: Don't enable SMAP if CONFIG_X86_SMAP is disabled
compiler/gcc4: Make quirk for asm_volatile_goto() unconditional
x86: Use preempt_disable_notrace() in cycles_2_ns()
Madper reported seeing the following crash,
BUG: unable to handle kernel paging request at ffffffffff340003
IP: [<ffffffff81d85ba4>] efi_bgrt_init+0x9d/0x133
Call Trace:
[<ffffffff81d8525d>] efi_late_init+0x9/0xb
[<ffffffff81d68f59>] start_kernel+0x436/0x450
[<ffffffff81d6892c>] ? repair_env_string+0x5c/0x5c
[<ffffffff81d68120>] ? early_idt_handlers+0x120/0x120
[<ffffffff81d685de>] x86_64_start_reservations+0x2a/0x2c
[<ffffffff81d6871e>] x86_64_start_kernel+0x13e/0x14d
This is caused because the layout of the ACPI BGRT header on this system
doesn't match the definition from the ACPI spec, and so we get a bogus
physical address when dereferencing ->image_address in efi_bgrt_init().
Luckily the status field in the BGRT header clearly marks it as invalid,
so we can check that field and skip BGRT initialisation.
Reported-by: Madper Xie <cxie@redhat.com>
Suggested-by: Toshi Kani <toshi.kani@hp.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
We do not enable the new efi memmap on 32-bit and thus we need to run
runtime_code_page_mkexec() unconditionally there. Fix that.
Reported-and-tested-by: Lejun Zhu <lejun.zhu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
The VDSO does not play well with LTO, so just disable LTO for it.
Also pass a 32bit linker flag for the 32bit version.
[ hpa: change braces to parens to match kernel Makefile style ]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391846481-31491-1-git-send-email-ak@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
If CONFIG_X86_SMAP is disabled, smap_violation() tests for conditions
which are incorrect (as the AC flag doesn't matter), causing spurious
faults.
The dynamic disabling of SMAP (nosmap on the command line) is fine
because it disables X86_FEATURE_SMAP, therefore causing the
static_cpu_has() to return false.
Found by Fengguang Wu's test system.
[ v3: move all predicates into smap_violation() ]
[ v2: use IS_ENABLED() instead of #ifdef ]
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.7+
If SMAP support is not compiled into the kernel, don't enable SMAP in
CR4 -- in fact, we should clear it, because the kernel doesn't contain
the proper STAC/CLAC instructions for SMAP support.
Found by Fengguang Wu's test system.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.7+
There should no longer be any IBM x440 systems or those using the
Summit/EXA chipset out in the wild, so remove support for it.
We've done our due diligence in reaching out to any contact information
listed for this chipset and no indication was given that it should be
kept around.
Signed-off-by: David Rientjes <rientjes@google.com>
There should no longer be any ia32-based Unisys ES7000 systems out in
the wild, so remove support for it.
We've done our due diligence in reaching out to any contact information
listed for this system and no indication was given that it should be
kept around.
Signed-off-by: David Rientjes <rientjes@google.com>
When the conversion was made to remove stop machine and use the breakpoint
logic instead, the modification of the function graph caller is still
done directly as though it was being done under stop machine.
As it is not converted via stop machine anymore, there is a possibility
that the code could be layed across cache lines and if another CPU is
accessing that function graph call when it is being updated, it could
cause a General Protection Fault.
Convert the update of the function graph caller to use the breakpoint
method as well.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@vger.kernel.org # 3.5+
Fixes: 08d636b6d4 "ftrace/x86: Have arch x86_64 use breakpoints instead of stop machine"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
GFP_ATOMIC is not a single gfp flag, but a macro which expands to the other
flags, where meaningful is the LACK of __GFP_WAIT flag. To check if caller
wants to perform an atomic allocation, the code must test for a lack of the
__GFP_WAIT flag. This patch fixes the issue introduced in v3.5-rc1.
CC: stable@vger.kernel.org
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Steven Noonan forwarded a users report where they had a problem starting
vsftpd on a Xen paravirtualized guest, with this in dmesg:
BUG: Bad page map in process vsftpd pte:8000000493b88165 pmd:e9cc01067
page:ffffea00124ee200 count:0 mapcount:-1 mapping: (null) index:0x0
page flags: 0x2ffc0000000014(referenced|dirty)
addr:00007f97eea74000 vm_flags:00100071 anon_vma:ffff880e98f80380 mapping: (null) index:7f97eea74
CPU: 4 PID: 587 Comm: vsftpd Not tainted 3.12.7-1-ec2 #1
Call Trace:
dump_stack+0x45/0x56
print_bad_pte+0x22e/0x250
unmap_single_vma+0x583/0x890
unmap_vmas+0x65/0x90
exit_mmap+0xc5/0x170
mmput+0x65/0x100
do_exit+0x393/0x9e0
do_group_exit+0xcc/0x140
SyS_exit_group+0x14/0x20
system_call_fastpath+0x1a/0x1f
Disabling lock debugging due to kernel taint
BUG: Bad rss-counter state mm:ffff880e9ca60580 idx:0 val:-1
BUG: Bad rss-counter state mm:ffff880e9ca60580 idx:1 val:1
The issue could not be reproduced under an HVM instance with the same
kernel, so it appears to be exclusive to paravirtual Xen guests. He
bisected the problem to commit 1667918b64 ("mm: numa: clear numa
hinting information on mprotect") that was also included in 3.12-stable.
The problem was related to how xen translates ptes because it was not
accounting for the _PAGE_NUMA bit. This patch splits pte_present to add
a pteval_present helper for use by xen so both bare metal and xen use
the same code when checking if a PTE is present.
[mgorman@suse.de: wrote changelog, proposed minor modifications]
[akpm@linux-foundation.org: fix typo in comment]
Reported-by: Steven Noonan <steven@uplinklabs.net>
Tested-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Elena Ufimtseva <ufimtseva@gmail.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org> [3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch allows each architecture to add its specific assembly optimized
arch_mcs_spin_lock_contended and arch_mcs_spinlock_uncontended for
MCS lock and unlock functions.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: AswinChandramouleeswaran <aswin@hp.com>
Cc: George Spelvin <linux@horizon.com>
Cc: Rik vanRiel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: MichelLespinasse <walken@google.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Figo.zhang" <figo1802@gmail.com>
Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew R Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1390347382.3138.67.camel@schen9-DESK
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In slit init code, too many pxm_to_node() function calls are done.
We can store from_node/to_node instead of keep calling
pxm_to_node().
- Before this patch: pxm_to_node() is called n*(1+n*3) times.
- After this patch: pxm_to_node() is called n*(1+n) times.
for 8 sockets, it will be 72 instead of 200.
for 32 sockets, it will be 1056 instead of 3104.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/1390770102-4007-1-git-send-email-yinghai@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The "nox2apic" variable can be defined as __initdata since it is
only used for bootstrap. It can now unconditionally be defined
since it will later be freed.
At the same time, it is also better off as a bool.
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042354380.7839@chino.kir.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that there is only a single wait_for_init_deassert()
function, just convert the member of struct apic to a bool to
determine whether we need to wait for init_deassert to become
non-zero.
There are no more callers of default_wait_for_init_deassert(),
so fold it into the caller.
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042354010.7839@chino.kir.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
es7000_wait_for_init_deassert() is functionally equivalent to
default_wait_for_init_deassert(), so remove the duplicate code
and use only a single function.
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042353030.7839@chino.kir.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There isn't an explicit stolen memory base register on gen2.
Some old comment in the i915 code suggests we should get it via
max_low_pfn_mapped, but that's clearly a bad idea on my MGM.
The e820 map in said machine looks like this:
BIOS-e820: [mem 0x0000000000000000-0x000000000009f7ff] usable
BIOS-e820: [mem 0x000000000009f800-0x000000000009ffff] reserved
BIOS-e820: [mem 0x00000000000ce000-0x00000000000cffff] reserved
BIOS-e820: [mem 0x00000000000dc000-0x00000000000fffff] reserved
BIOS-e820: [mem 0x0000000000100000-0x000000001f6effff] usable
BIOS-e820: [mem 0x000000001f6f0000-0x000000001f6f7fff] ACPI data
BIOS-e820: [mem 0x000000001f6f8000-0x000000001f6fffff] ACPI NVS
BIOS-e820: [mem 0x000000001f700000-0x000000001fffffff] reserved
BIOS-e820: [mem 0x00000000fec10000-0x00000000fec1ffff] reserved
BIOS-e820: [mem 0x00000000ffb00000-0x00000000ffbfffff] reserved
BIOS-e820: [mem 0x00000000fff00000-0x00000000ffffffff] reserved
That makes max_low_pfn_mapped = 1f6f0000, so assuming our stolen
memory would start there would place it on top of some ACPI
memory regions. So not a good idea as already stated.
The 9MB region after the ACPI regions at 0x1f700000 however
looks promising given that the macine reports the stolen memory
size to be 8MB. Looking at the PGTBL_CTL register, the GTT
entries are at offset 0x1fee00000, and given that the GTT
entries occupy 128KB, it looks like the stolen memory could
start at 0x1f700000 and the GTT entries would occupy the last
128KB of the stolen memory.
After some more digging through chipset documentation, I've
determined the BIOS first allocates space for something called
TSEG (something to do with SMM) from the top of memory, and then
it allocates the graphics stolen memory below that. Accordind to
the chipset documentation TSEG has a fixed size of 1MB on 855.
So that explains the top 1MB in the e820 region. And it also
confirms that the GTT entries are in fact at the end of the the
stolen memory region.
Derive the stolen memory base address on gen2 the same as the
BIOS does (TOM-TSEG_SIZE-stolen_size). There are a few
differences between the registers on various gen2 chipsets, so a
few different codepaths are required.
865G is again bit more special since it seems to support enough
memory to hit 4GB address space issues. This means the PCI
allocations will also affect the location of the stolen memory.
Fortunately there appears to be the TOUD register which may give
us the correct answer directly. But the chipset docs are a bit
unclear, so I'm not 100% sure that the graphics stolen memory is
always the last thing the BIOS steals. Someone would need to
verify it on a real system.
I tested this on the my 830 and 855 machines, and so far
everything looks peachy.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1391628540-23072-3-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For gen2 devices we're going to need another way to determine
the stolen memory base address. Make that into a vfunc as well.
Also drop the bogus inline keyword from gen8_stolen_size().
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1391628540-23072-2-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A bunch of unknown NMIs have popped up on a Pentium4 recently when booting
into a kdump kernel. This was exposed because the watchdog timer went
from 60 seconds down to 10 seconds (increasing the ability to reproduce
this problem).
What is happening is on boot up of the second kernel (the kdump one),
the previous nmi_watchdogs were enabled on thread 0 and thread 1. The
second kernel only initializes one cpu but the perf counter on thread 1
still counts.
Normally in a kdump scenario, the other cpus are blocking in an NMI loop,
but more importantly their local apics have the performance counters disabled
(iow LVTPC is masked). So any counters that fire are masked and never get
through to the second kernel.
However, on a P4 the local apic is shared by both threads and thread1's PMI
(despite being configured to only interrupt thread1) will generate an NMI on
thread0. Because thread0 knows nothing about this NMI, it is seen as an
unknown NMI.
This would be fine because it is a kdump kernel, strange things happen
what is the big deal about a single unknown NMI.
Unfortunately, the P4 comes with another quirk: clearing the overflow bit
to prevent a stream of NMIs. This is the problem.
The kdump kernel can not execute because of the endless NMIs that happen.
To solve this, I instrumented the p4 perf init code, to walk all the counters
and zero them out (just like a normal reset would).
Now when the counters go off, they do not generate anything and no unknown
NMIs are seen.
I tested this on a P4 we have in our lab. After two or three crashes, I could
normally reproduce the problem. Now after 10 crashes, everything continues
to boot correctly.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140120154115.GZ25953@redhat.com
[ Fixed a stylistic detail. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On a P4 box stressing perf with:
./perf record -o perf.data ./perf stat -v ./perf bench all
it was noticed that a slew of unknown NMIs would pop out rather quickly.
Painfully debugging this ancient platform, led me to notice cross cpu counter
corruption.
The P4 machine is special in that it has 18 counters, half are used for cpu0
and the other half is for cpu1 (or all 18 if hyperthreading is disabled). But
the splitting of the counters has to be actively managed by the software.
In this particular bug, one of the cpu0 specific counters was being used by
cpu1 and caused all sorts of random unknown nmis.
I am not entirely sure on the corruption path, but what happens is:
o perf schedules a group with p4_pmu_schedule_events()
o inside p4_pmu_schedule_events(), it notices an hwc pointer is being reused
but for a different cpu, so it 'swaps' the config bits and returns the
updated 'assign' array with a _new_ index.
o perf schedules another group with p4_pmu_schedule_events()
o inside p4_pmu_schedule_events(), it notices an hwc pointer is being reused
(the same one as above) but for the _same_ cpu [BUG!!], so it updates the
'assign' array to use the _old_ (wrong cpu) index because the _new_ index is in
an earlier part of the 'assign' array (and hasn't been committed yet).
o perf commits the transaction using the wrong index and corrupts the other cpu
The [BUG!!] is because the 'hwc->config' is updated but not the 'hwc->idx'. So
the check for 'p4_should_swap_ts()' is correct the first time around but
incorrect the second time around (because hwc->config was updated in between).
I think the spirit of perf was to not modify anything until all the
transactions had a chance to 'test' if they would succeed, and if so, commit
atomically. However, P4 breaks this spirit by touching the hwc->config
element.
So my fix is to continue the un-perf like breakage, by assigning hwc->idx to -1
on swap to tell follow up group scheduling to find a new index.
Of course if the transaction fails rolling this back will be difficult, but
that is not different than how the current code works. :-) And I wasn't sure
how much effort to cleanup the code I should do for a platform that is almost
10 years old by now.
Hence the lazy fix.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1391024270-19469-1-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Calling printk() from NMI context is bad (TM), so move it to IRQ
context.
In doing so we slightly change (probably wreck) the debugfs
nmi_longest_ns thingy, in that it doesn't update to reflect the
longest, nor does writing to it reset the count.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-rdw0au56a5ymis1u8p48c12d@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When debug preempt is enabled, preempt_disable() can be traced by
function and function graph tracing.
There's a place in the function graph tracer that calls trace_clock()
which eventually calls cycles_2_ns() outside of the recursion
protection. When cycles_2_ns() calls preempt_disable() it gets traced
and the graph tracer will go into a recursive loop causing a crash or
worse, a triple fault.
Simple fix is to use preempt_disable_notrace() in cycles_2_ns, which
makes sense because the preempt_disable() tracing may use that code
too, and it tracing it, even with recursion protection is rather
pointless.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140204141315.2a968a72@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current code forgets to change the CR4 state on the current CPU.
Use on_each_cpu() instead of smp_call_function().
Reported-by: Mark Davies <junk@eslaf.co.uk>
Suggested-by: Mark Davies <junk@eslaf.co.uk>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: fweisbec@gmail.com
Link: http://lkml.kernel.org/n/tip-69efsat90ibhnd577zy3z9gh@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
