Remove the wp_works_ok member of struct cpuinfo_x86. It's an
optimization back from Linux v0.99 times where we had no fixup support
yet and did the CR0.WP test via special code in the page fault handler.
The < 0 test was an optimization to not do the special casing for each
NULL ptr access violation but just for the first one doing the WP test.
Today it serves no real purpose as the test no longer needs special code
in the page fault handler and the only call side -- mem_init() -- calls
it just once, anyway. However, Xen pre-initializes it to 1, to skip the
test.
Doing the test again for Xen should be no issue at all, as even the
commit introducing skipping the test (commit d560bc6157 ("x86, xen:
Suppress WP test on Xen")) mentioned it being ban aid only. And, in
fact, testing the patch on Xen showed nothing breaks.
The pre-fixup times are long gone and with the removal of the fallback
handling code in commit a5c2a893db ("x86, 386 removal: Remove
CONFIG_X86_WP_WORKS_OK") the kernel requires a working CR0.WP anyway.
So just get rid of the "optimization" and do the test unconditionally.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Arnd Hannemann <hannemann@nets.rwth-aachen.de>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/1486933932-585-3-git-send-email-minipli@googlemail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull x86 fixes from Ingo Molnar:
"Misc fixes and minor updates all over the place:
- an SGI/UV fix
- a defconfig update
- a build warning fix
- move the boot_params file to the arch location in debugfs
- a pkeys fix
- selftests fix
- boot message fixes
- sparse fixes
- a resume warning fix
- ioapic hotplug fixes
- reboot quirks
... plus various minor cleanups"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/build/x86_64_defconfig: Enable CONFIG_R8169
x86/reboot/quirks: Add ASUS EeeBook X205TA/W reboot quirk
x86/hpet: Prevent might sleep splat on resume
x86/boot: Correct setup_header.start_sys name
x86/purgatory: Fix sparse warning, symbol not declared
x86/purgatory: Make functions and variables static
x86/events: Remove last remnants of old filenames
x86/pkeys: Check against max pkey to avoid overflows
x86/ioapic: Split IOAPIC hot-removal into two steps
x86/PCI: Implement pcibios_release_device to release IRQ from IOAPIC
x86/intel_rdt: Remove duplicate inclusion of linux/cpu.h
x86/vmware: Remove duplicate inclusion of asm/timer.h
x86/hyperv: Hide unused label
x86/reboot/quirks: Add ASUS EeeBook X205TA reboot quirk
x86/platform/uv/BAU: Fix HUB errors by remove initial write to sw-ack register
x86/selftests: Add clobbers for int80 on x86_64
x86/apic: Simplify enable_IR_x2apic(), remove try_to_enable_IR()
x86/apic: Fix a warning message in logical CPU IDs allocation
x86/kdebugfs: Move boot params hierarchy under (debugfs)/x86/
Pull scheduler fixes from Ingo Molnar:
"A fix for KVM's scheduler clock which (erroneously) was always marked
unstable, a fix for RT/DL load balancing, plus latency fixes"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface
sched/core: Fix pick_next_task() for RT,DL
sched/fair: Make select_idle_cpu() more aggressive
Wanpeng Li reported that since the following commit:
acb04058de ("sched/clock: Fix hotplug crash")
... KVM always runs with unstable sched-clock even though KVM's
kvm_clock _is_ stable.
The problem is that we've tied clear_sched_clock_stable() to the TSC
state, and overlooked that sched_clock() is a paravirt function.
Solve this by doing two things:
- tie the sched_clock() stable state more clearly to the TSC stable
state for the normal (!paravirt) case.
- only call clear_sched_clock_stable() when we mark TSC unstable
when we use native_sched_clock().
The first means we can actually run with stable sched_clock in more
situations then before, which is good. And since commit:
12907fbb1a ("sched/clock, clocksource: Add optional cs::mark_unstable() method")
... this should be reliable. Since any detection of TSC fail now results
in marking the TSC unstable.
Reported-by: Wanpeng Li <kernellwp@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: acb04058de ("sched/clock: Fix hotplug crash")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add #include <linux/cred.h> dependencies to all .c files rely on sched.h
doing that for them.
Note that even if the count where we need to add extra headers seems high,
it's still a net win, because <linux/sched.h> is included in over
2,200 files ...
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.
Create a trivial placeholder <linux/sched/clock.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Ingo Molnar:
"Two documentation updates, plus a debugging annotation fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/crash: Update the stale comment in reserve_crashkernel()
x86/irq, trace: Add __irq_entry annotation to x86's platform IRQ handlers
Documentation, x86, resctrl: Recommend locking for resctrlfs
Apart from adding the helper function itself, the rest of the kernel is
converted mechanically using:
git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_count);/mmgrab\(\1\);/'
git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_count);/mmgrab\(\&\1\);/'
This is needed for a later patch that hooks into the helper, but might
be a worthwhile cleanup on its own.
(Michal Hocko provided most of the kerneldoc comment.)
Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull char/misc driver updates from Greg KH:
"Here is the big char/misc driver patchset for 4.11-rc1.
Lots of different driver subsystems updated here: rework for the
hyperv subsystem to handle new platforms better, mei and w1 and extcon
driver updates, as well as a number of other "minor" driver updates.
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (169 commits)
goldfish: Sanitize the broken interrupt handler
x86/platform/goldfish: Prevent unconditional loading
vmbus: replace modulus operation with subtraction
vmbus: constify parameters where possible
vmbus: expose hv_begin/end_read
vmbus: remove conditional locking of vmbus_write
vmbus: add direct isr callback mode
vmbus: change to per channel tasklet
vmbus: put related per-cpu variable together
vmbus: callback is in softirq not workqueue
binder: Add support for file-descriptor arrays
binder: Add support for scatter-gather
binder: Add extra size to allocator
binder: Refactor binder_transact()
binder: Support multiple /dev instances
binder: Deal with contexts in debugfs
binder: Support multiple context managers
binder: Split flat_binder_object
auxdisplay: ht16k33: remove private workqueue
auxdisplay: ht16k33: rework input device initialization
...
Pull x86 microcode updates from Ingo Molnar:
"The main changes are further simplification and unification of the
code between the AMD and Intel microcode loaders, plus other
simplifications - by Borislav Petkov"
* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode/AMD: Remove struct cont_desc.eq_id
x86/microcode/AMD: Remove AP scanning optimization
x86/microcode/AMD: Simplify saving from initrd
x86/microcode/AMD: Unify load_ucode_amd_ap()
x86/microcode/AMD: Check patch level only on the BSP
x86/microcode: Remove local vendor variable
x86/microcode/AMD: Use find_microcode_in_initrd()
x86/microcode/AMD: Get rid of global this_equiv_id
x86/microcode: Decrease CPUID use
x86/microcode/AMD: Rework container parsing
x86/microcode/AMD: Extend the container struct
x86/microcode/AMD: Shorten function parameter's name
x86/microcode/AMD: Clean up find_equiv_id()
x86/microcode: Convert to bare minimum MSR accessors
x86/MSR: Carve out bare minimum accessors
Pull x86 fpu updates from Ingo Molnar:
"The main changes relate to fixes between (lack of) CPUID and FPU
detection that should only affect old or weird CPUs, by Andy
Lutomirski"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Fix the "Giving up, no FPU found" test
x86/fpu: Fix CPUID-less FPU detection
x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message
x86/cpu: Re-apply forced caps every time CPU caps are re-read
x86/cpu: Factor out application of forced CPU caps
x86/cpu: Add X86_FEATURE_CPUID
x86/fpu/xstate: Move XSAVES state init to a function
Pull x86 cpufeature updates from Ingo Molnar:
"The main changes in this cycle were related to enable ring-3
MONITOR/MWAIT instructions support on supported CPUs, by Grzegorz
Andrejczuk and Piotr Luc"
* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpufeature: Move RING3MWAIT feature to avoid conflicts
x86/cpufeature: Enable RING3MWAIT for Knights Mill
x86/cpufeature: Enable RING3MWAIT for Knights Landing
x86/cpufeature: Add RING3MWAIT to CPU features
x86/elf: Add HWCAP2 to expose ring 3 MONITOR/MWAIT
x86/msr: Add MSR_MISC_FEATURE_ENABLES and RING3MWAIT bit
x86/cpufeature: Add AVX512_VPOPCNTDQ feature
Pull scheduler updates from Ingo Molnar:
"The main changes in this (fairly busy) cycle were:
- There was a class of scheduler bugs related to forgetting to update
the rq-clock timestamp which can cause weird and hard to debug
problems, so there's a new debug facility for this: which uncovered
a whole lot of bugs which convinced us that we want to keep the
debug facility.
(Peter Zijlstra, Matt Fleming)
- Various cputime related updates: eliminate cputime and use u64
nanoseconds directly, simplify and improve the arch interfaces,
implement delayed accounting more widely, etc. - (Frederic
Weisbecker)
- Move code around for better structure plus cleanups (Ingo Molnar)
- Move IO schedule accounting deeper into the scheduler plus related
changes to improve the situation (Tejun Heo)
- ... plus a round of sched/rt and sched/deadline fixes, plus other
fixes, updats and cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (85 commits)
sched/core: Remove unlikely() annotation from sched_move_task()
sched/autogroup: Rename auto_group.[ch] to autogroup.[ch]
sched/topology: Split out scheduler topology code from core.c into topology.c
sched/core: Remove unnecessary #include headers
sched/rq_clock: Consolidate the ordering of the rq_clock methods
delayacct: Include <uapi/linux/taskstats.h>
sched/core: Clean up comments
sched/rt: Show the 'sched_rr_timeslice' SCHED_RR timeslice tuning knob in milliseconds
sched/clock: Add dummy clear_sched_clock_stable() stub function
sched/cputime: Remove generic asm headers
sched/cputime: Remove unused nsec_to_cputime()
s390, sched/cputime: Remove unused cputime definitions
powerpc, sched/cputime: Remove unused cputime definitions
s390, sched/cputime: Make arch_cpu_idle_time() to return nsecs
ia64, sched/cputime: Remove unused cputime definitions
ia64: Convert vtime to use nsec units directly
ia64, sched/cputime: Move the nsecs based cputime headers to the last arch using it
sched/cputime: Remove jiffies based cputime
sched/cputime, vtime: Return nsecs instead of cputime_t to account
sched/cputime: Complete nsec conversion of tick based accounting
...
Pull RAS updates from Ingo Molnar:
"The main changes in this cycle were:
- Assign notifier chain priorities for all RAS related handlers to
make the ordering explicit (Borislav Petkov)
- Improve the AMD MCA banks sysfs output (Yazen Ghannam)
- Various cleanups and restructuring of the x86 RAS code (Borislav
Petkov)"
* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ras, EDAC, acpi: Assign MCE notifier handlers a priority
x86/ras: Get rid of mce_process_work()
EDAC/mce/amd: Dump TSC value
EDAC/mce/amd: Unexport amd_decode_mce()
x86/ras/amd/inj: Change dependency
x86/ras: Flip the TSC-adding logic
x86/ras/amd: Make sysfs names of banks more user-friendly
x86/ras/therm_throt: Do not log a fake MCE for thermal events
x86/ras/inject: Make it depend on X86_LOCAL_APIC=y
Commit:
a33d331761 ("x86/CPU/AMD: Fix Bulldozer topology")
restored the initial approach we had with the Fam15h topology of
enumerating CU (Compute Unit) threads as cores. And this is still
correct - they're beefier than HT threads but still have some
shared functionality.
Our current approach has a problem with the Mad Max Steam game, for
example. Yves Dionne reported a certain "choppiness" while playing on
v4.9.5.
That problem stems most likely from the fact that the CU threads share
resources within one CU and when we schedule to a thread of a different
compute unit, this incurs latency due to migrating the working set to a
different CU through the caches.
When the thread siblings mask mirrors that aspect of the CUs and
threads, the scheduler pays attention to it and tries to schedule within
one CU first. Which takes care of the latency, of course.
Reported-by: Yves Dionne <yves.dionne@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.9
Cc: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Link: http://lkml.kernel.org/r/20170205105022.8705-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Introduce ELF_HWCAP2 variable for x86 and reserve its bit 0 to expose the
ring 3 MONITOR/MWAIT.
HWCAP variables contain bitmasks which can be used by userspace
applications to detect which instruction sets are supported by CPU. On x86
architecture information about CPU capabilities can be checked via CPUID
instructions, unfortunately presence of ring 3 MONITOR/MWAIT feature cannot
be checked this way. ELF_HWCAP cannot be used as well, because on x86 it is
set to CPUID[1].EDX which means that all bits are reserved there.
HWCAP2 approach was chosen because it reuses existing solution present
in other architectures, so only minor modifications are required to the
kernel and userspace applications. When ELF_HWCAP2 is defined
kernel maps it to AT_HWCAP2 during the start of the application.
This way the ring 3 MONITOR/MWAIT feature can be detected using getauxval()
API in a simple and fast manner. ELF_HWCAP2 type is u32 to be consistent
with x86 ELF_HWCAP type.
Signed-off-by: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Piotr.Luc@intel.com
Cc: dave.hansen@linux.intel.com
Link: http://lkml.kernel.org/r/1484918557-15481-3-git-send-email-grzegorz.andrejczuk@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Erik reported that on a preproduction hardware a CMCI storm triggers the
BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is
started by the CMCI logic before the MCE CPU hotplug callback starts the
timer with add_timer_on(). So the timer is already queued which triggers
the BUG.
Using add_timer_on() is pretty pointless in this code because the timer is
strictlty per CPU, initialized as pinned and all operations which arm the
timer happen on the CPU to which the timer belongs.
Simplify the whole machinery by using mod_timer() instead of add_timer_on()
which avoids the problem because mod_timer() can handle already queued
timers. Use __start_timer() everywhere so the earliest armed expiry time is
preserved.
Reported-by: Erik Veijola <erik.veijola@intel.com>
Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We have these three related functions:
extern void e820_add_region(u64 start, u64 size, int type);
extern u64 e820_update_range(u64 start, u64 size, unsigned old_type, unsigned new_type);
extern u64 e820_remove_range(u64 start, u64 size, unsigned old_type, int checktype);
But it's not clear from the naming that they are 3 operations based around the
same 'memory range' concept. Rename them to better signal this, and move
the prototypes next to each other:
extern void e820__range_add (u64 start, u64 size, int type);
extern u64 e820__range_update(u64 start, u64 size, unsigned old_type, unsigned new_type);
extern u64 e820__range_remove(u64 start, u64 size, unsigned old_type, int checktype);
Note that this improved organization of the functions shows another problem that was easy
to miss before: sometimes the E820 entry type is 'int', sometimes 'unsigned int' - but this
will be fixed in a separate patch.
No change in functionality.
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add the TSC value to the MCE record only when the MCE being logged is
precise, i.e., it is logged as an exception or an MCE-related interrupt.
So it doesn't look particularly easy to do without touching/changing a
bunch of places. That's why I'm trying tricks first.
For example, the mce-apei.c case I'm addressing by setting ->tsc only
for errors of panic severity. The idea there is, that, panic errors will
have raised an #MC and not polled.
And then instead of propagating a flag to mce_setup(), it seems
easier/less code to set ->tsc depending on the call sites, i.e.,
are we polling or are we preparing an MCE record in an exception
handler/thresholding interrupt.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170123183514.13356-5-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The equivalence ID was needed outside of the container scanning logic
but now, after this has been cleaned up, not anymore. Now, cont_desc.mc
is used to denote whether the container we're looking at has the proper
microcode patch for this CPU or not.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-17-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The idea was to not scan the microcode blob on each AP (Application
Processor) during boot and thus save us some milliseconds. However, on
architectures where the microcode engine is shared between threads, this
doesn't work. Here's why:
The microcode on CPU0, i.e., the first thread, gets updated. The second
thread, i.e., CPU1, i.e., the first AP walks into load_ucode_amd_ap(),
sees that there's no container cached and goes and scans for the proper
blob.
It finds it and as a last step of apply_microcode_early_amd(), it tries
to apply the patch but that core has already the updated microcode
revision which it has received through CPU0's update. So it returns
false and we do desc->size = -1 to prevent other APs from scanning.
However, the next AP, CPU2, has a different microcode engine which
hasn't been updated yet. The desc->size == -1 test prevents it from
scanning the blob anew and we fail to update it.
The fix is much more straight-forward than it looks: the BSP
(BootStrapping Processor), i.e., CPU0, caches the microcode patch
in amd_ucode_patch. We use that on the AP and try to apply it.
In the 99.9999% of cases where we have homogeneous cores - *not*
mixed-steppings - the application will be successful and we're good to
go.
In the remaining small set of systems, we will simply rescan the blob
and find (or not, if none present) the proper patch and apply it then.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-16-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
