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Commit 5e2d059b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - A fix for a bug in our page table fragment allocator, where a page
     table page could be freed and reallocated for something else while
     still in use, leading to memory corruption etc. The fix reuses
     pt_mm in struct page (x86 only) for a powerpc only refcount.

   - Fixes to our pkey support. Several are user-visible changes, but
     bring us in to line with x86 behaviour and/or fix outright bugs.
     Thanks to Florian Weimer for reporting many of these.

   - A series to improve the hvc driver & related OPAL console code,
     which have been seen to cause hardlockups at times. The hvc driver
     changes in particular have been in linux-next for ~month.

   - Increase our MAX_PHYSMEM_BITS to 128TB when SPARSEMEM_VMEMMAP=y.

   - Remove Power8 DD1 and Power9 DD1 support, neither chip should be in
     use anywhere other than as a paper weight.

   - An optimised memcmp implementation using Power7-or-later VMX
     instructions

   - Support for barrier_nospec on some NXP CPUs.

   - Support for flushing the count cache on context switch on some IBM
     CPUs (controlled by firmware), as a Spectre v2 mitigation.

   - A series to enhance the information we print on unhandled signals
     to bring it into line with other arches, including showing the
     offending VMA and dumping the instructions around the fault.

  Thanks to: Aaro Koskinen, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Alexey Spirkov, Alistair Popple, Andrew Donnellan,
  Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Bartosz Golaszewski,
  Benjamin Herrenschmidt, Bharat Bhushan, Bjoern Noetel, Boqun Feng,
  Breno Leitao, Bryant G. Ly, Camelia Groza, Christophe Leroy, Christoph
  Hellwig, Cyril Bur, Dan Carpenter, Daniel Klamt, Darren Stevens, Dave
  Young, David Gibson, Diana Craciun, Finn Thain, Florian Weimer,
  Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geoff Levand,
  Guenter Roeck, Gustavo Romero, Haren Myneni, Hari Bathini, Joel
  Stanley, Jonathan Neuschäfer, Kees Cook, Madhavan Srinivasan, Mahesh
  Salgaonkar, Markus Elfring, Mathieu Malaterre, Mauro S. M. Rodrigues,
  Michael Hanselmann, Michael Neuling, Michael Schmitz, Mukesh Ojha,
  Murilo Opsfelder Araujo, Nicholas Piggin, Parth Y Shah, Paul
  Mackerras, Paul Menzel, Ram Pai, Randy Dunlap, Rashmica Gupta, Reza
  Arbab, Rodrigo R. Galvao, Russell Currey, Sam Bobroff, Scott Wood,
  Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stan Johnson, Thiago
  Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vasant Hegde, Venkat
  Rao, zhong jiang"

* tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (234 commits)
  powerpc/mm/book3s/radix: Add mapping statistics
  powerpc/uaccess: Enable get_user(u64, *p) on 32-bit
  powerpc/mm/hash: Remove unnecessary do { } while(0) loop
  powerpc/64s: move machine check SLB flushing to mm/slb.c
  powerpc/powernv/idle: Fix build error
  powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range
  powerpc/mm: remove warning about ‘type’ being set
  powerpc/32: Include setup.h header file to fix warnings
  powerpc: Move `path` variable inside DEBUG_PROM
  powerpc/powermac: Make some functions static
  powerpc/powermac: Remove variable x that's never read
  cxl: remove a dead branch
  powerpc/powermac: Add missing include of header pmac.h
  powerpc/kexec: Use common error handling code in setup_new_fdt()
  powerpc/xmon: Add address lookup for percpu symbols
  powerpc/mm: remove huge_pte_offset_and_shift() prototype
  powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled
  powerpc/pseries: Fix endianness while restoring of r3 in MCE handler.
  powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements
  powerpc/fadump: handle crash memory ranges array index overflow
  ...
parents d1907752 a2dc009a

Documentation/ABI/testing/ppc-memtrace

+5 −4
Original line number Diff line number Diff line
@@ -13,10 +13,11 @@ Contact: linuxppc-dev@lists.ozlabs.org 
Description:	Write an integer containing the size in bytes of the memory

		you want removed from each NUMA node to this file - it must be

		aligned to the memblock size. This amount of RAM will be removed

		from the kernel mappings and the following debugfs files will be

		created. This can only be successfully done once per boot. Once

		memory is successfully removed from each node, the following

		files are created.

		from each NUMA node in the kernel mappings and the following

		debugfs files will be created. Once memory is successfully

		removed from each node, the following files are created. To

		re-add memory to the kernel, echo 0 into this file (it will be

		automatically onlined).



What:		/sys/kernel/debug/powerpc/memtrace/<node-id>

Date:		Aug 2017

Documentation/admin-guide/kernel-parameters.txt

+4 −0
Original line number Diff line number Diff line
@@ -2784,6 +2784,10 @@ 
			nosmt=force: Force disable SMT, cannot be undone

				     via the sysfs control file.



	nospectre_v1	[PPC] Disable mitigations for Spectre Variant 1 (bounds

			check bypass). With this option data leaks are possible

			in the system.



	nospectre_v2	[X86] Disable all mitigations for the Spectre variant 2

			(indirect branch prediction) vulnerability. System may

			allow data leaks with this option, which is equivalent

Documentation/hwmon/ibmpowernv

+41 −2
Original line number Diff line number Diff line
@@ -33,9 +33,48 @@ fanX_input Measured RPM value. 
fanX_min		Threshold RPM for alert generation.

fanX_fault		0: No fail condition

			1: Failing fan



tempX_input		Measured ambient temperature.

tempX_max		Threshold ambient temperature for alert generation.

inX_input		Measured power supply voltage

tempX_highest		Historical maximum temperature

tempX_lowest		Historical minimum temperature

tempX_enable		Enable/disable all temperature sensors belonging to the

			sub-group. In POWER9, this attribute corresponds to

			each OCC. Using this attribute each OCC can be asked to

			disable/enable all of its temperature sensors.

			1: Enable

			0: Disable



inX_input		Measured power supply voltage (millivolt)

inX_fault		0: No fail condition.

			1: Failing power supply.

power1_input		System power consumption (microWatt)
 
inX_highest		Historical maximum voltage

inX_lowest		Historical minimum voltage

inX_enable		Enable/disable all voltage sensors belonging to the

			sub-group. In POWER9, this attribute corresponds to

			each OCC. Using this attribute each OCC can be asked to

			disable/enable all of its voltage sensors.

			1: Enable

			0: Disable



powerX_input		Power consumption (microWatt)

powerX_input_highest	Historical maximum power

powerX_input_lowest	Historical minimum power

powerX_enable		Enable/disable all power sensors belonging to the

			sub-group. In POWER9, this attribute corresponds to

			each OCC. Using this attribute each OCC can be asked to

			disable/enable all of its power sensors.

			1: Enable

			0: Disable



currX_input		Measured current (milliampere)

currX_highest		Historical maximum current

currX_lowest		Historical minimum current

currX_enable		Enable/disable all current sensors belonging to the

			sub-group. In POWER9, this attribute corresponds to

			each OCC. Using this attribute each OCC can be asked to

			disable/enable all of its current sensors.

			1: Enable

			0: Disable



energyX_input		Cumulative energy (microJoule)

Documentation/powerpc/DAWR-POWER9.txt

0 → 100644
+58 −0
Original line number Diff line number Diff line 
DAWR issues on POWER9

============================



On POWER9 the DAWR can cause a checkstop if it points to cache

inhibited (CI) memory. Currently Linux has no way to disinguish CI

memory when configuring the DAWR, so (for now) the DAWR is disabled by

this commit:



    commit 9654153158d3e0684a1bdb76dbababdb7111d5a0

    Author: Michael Neuling <mikey@neuling.org>

    Date:   Tue Mar 27 15:37:24 2018 +1100

    powerpc: Disable DAWR in the base POWER9 CPU features



Technical Details:

============================



DAWR has 6 different ways of being set.

1) ptrace

2) h_set_mode(DAWR)

3) h_set_dabr()

4) kvmppc_set_one_reg()

5) xmon



For ptrace, we now advertise zero breakpoints on POWER9 via the

PPC_PTRACE_GETHWDBGINFO call. This results in GDB falling back to

software emulation of the watchpoint (which is slow).



h_set_mode(DAWR) and h_set_dabr() will now return an error to the

guest on a POWER9 host. Current Linux guests ignore this error, so

they will silently not get the DAWR.



kvmppc_set_one_reg() will store the value in the vcpu but won't

actually set it on POWER9 hardware. This is done so we don't break

migration from POWER8 to POWER9, at the cost of silently losing the

DAWR on the migration.



For xmon, the 'bd' command will return an error on P9.



Consequences for users

============================



For GDB watchpoints (ie 'watch' command) on POWER9 bare metal , GDB

will accept the command. Unfortunately since there is no hardware

support for the watchpoint, GDB will software emulate the watchpoint

making it run very slowly.



The same will also be true for any guests started on a POWER9

host. The watchpoint will fail and GDB will fall back to software

emulation.



If a guest is started on a POWER8 host, GDB will accept the watchpoint

and configure the hardware to use the DAWR. This will run at full

speed since it can use the hardware emulation. Unfortunately if this

guest is migrated to a POWER9 host, the watchpoint will be lost on the

POWER9. Loads and stores to the watchpoint locations will not be

trapped in GDB. The watchpoint is remembered, so if the guest is

migrated back to the POWER8 host, it will start working again.

Documentation/powerpc/transactional_memory.txt

+44 −0
Original line number Diff line number Diff line
@@ -198,3 +198,47 @@ presented). The transaction cannot then be continued and will take the failure 
handler route.  Furthermore, the transactional 2nd register state will be

inaccessible.  GDB can currently be used on programs using TM, but not sensibly

in parts within transactions.



POWER9

======



TM on POWER9 has issues with storing the complete register state. This

is described in this commit:



    commit 4bb3c7a0208fc13ca70598efd109901a7cd45ae7

    Author: Paul Mackerras <paulus@ozlabs.org>

    Date:   Wed Mar 21 21:32:01 2018 +1100

    KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9



To account for this different POWER9 chips have TM enabled in

different ways.



On POWER9N DD2.01 and below, TM is disabled. ie

HWCAP2[PPC_FEATURE2_HTM] is not set.



On POWER9N DD2.1 TM is configured by firmware to always abort a

transaction when tm suspend occurs. So tsuspend will cause a

transaction to be aborted and rolled back. Kernel exceptions will also

cause the transaction to be aborted and rolled back and the exception

will not occur. If userspace constructs a sigcontext that enables TM

suspend, the sigcontext will be rejected by the kernel. This mode is

advertised to users with HWCAP2[PPC_FEATURE2_HTM_NO_SUSPEND] set.

HWCAP2[PPC_FEATURE2_HTM] is not set in this mode.



On POWER9N DD2.2 and above, KVM and POWERVM emulate TM for guests (as

described in commit 4bb3c7a0208f), hence TM is enabled for guests

ie. HWCAP2[PPC_FEATURE2_HTM] is set for guest userspace. Guests that

makes heavy use of TM suspend (tsuspend or kernel suspend) will result

in traps into the hypervisor and hence will suffer a performance

degradation. Host userspace has TM disabled

ie. HWCAP2[PPC_FEATURE2_HTM] is not set. (although we make enable it

at some point in the future if we bring the emulation into host

userspace context switching).



POWER9C DD1.2 and above are only available with POWERVM and hence

Linux only runs as a guest. On these systems TM is emulated like on

POWER9N DD2.2.



Guest migration from POWER8 to POWER9 will work with POWER9N DD2.2 and

POWER9C DD1.2. Since earlier POWER9 processors don't support TM

emulation, migration from POWER8 to POWER9 is not supported there.