linux-stable.git/arch/powerpc/kernel/traps.c, branch linux-4.7.y

Merge tag 'powerpc-4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2016-03-19T22:38:41+00:00

Pull powerpc updates from Michael Ellerman:
 "This was delayed a day or two by some build-breakage on old toolchains
  which we've now fixed.

  There's two PCI commits both acked by Bjorn.

  There's one commit to mm/hugepage.c which is (co)authored by Kirill.

  Highlights:
   - Restructure Linux PTE on Book3S/64 to Radix format from Paul
     Mackerras
   - Book3s 64 MMU cleanup in preparation for Radix MMU from Aneesh
     Kumar K.V
   - Add POWER9 cputable entry from Michael Neuling
   - FPU/Altivec/VSX save/restore optimisations from Cyril Bur
   - Add support for new ftrace ABI on ppc64le from Torsten Duwe

  Various cleanups & minor fixes from:
   - Adam Buchbinder, Andrew Donnellan, Balbir Singh, Christophe Leroy,
     Cyril Bur, Luis Henriques, Madhavan Srinivasan, Pan Xinhui, Russell
     Currey, Sukadev Bhattiprolu, Suraj Jitindar Singh.

  General:
   - atomics: Allow architectures to define their own __atomic_op_*
     helpers from Boqun Feng
   - Implement atomic{, 64}_*_return_* variants and acquire/release/
     relaxed variants for (cmp)xchg from Boqun Feng
   - Add powernv_defconfig from Jeremy Kerr
   - Fix BUG_ON() reporting in real mode from Balbir Singh
   - Add xmon command to dump OPAL msglog from Andrew Donnellan
   - Add xmon command to dump process/task similar to ps(1) from Douglas
     Miller
   - Clean up memory hotplug failure paths from David Gibson

  pci/eeh:
   - Redesign SR-IOV on PowerNV to give absolute isolation between VFs
     from Wei Yang.
   - EEH Support for SRIOV VFs from Wei Yang and Gavin Shan.
   - PCI/IOV: Rename and export virtfn_{add, remove} from Wei Yang
   - PCI: Add pcibios_bus_add_device() weak function from Wei Yang
   - MAINTAINERS: Update EEH details and maintainership from Russell
     Currey

  cxl:
   - Support added to the CXL driver for running on both bare-metal and
     hypervisor systems, from Christophe Lombard and Frederic Barrat.
   - Ignore probes for virtual afu pci devices from Vaibhav Jain

  perf:
   - Export Power8 generic and cache events to sysfs from Sukadev
     Bhattiprolu
   - hv-24x7: Fix usage with chip events, display change in counter
     values, display domain indices in sysfs, eliminate domain suffix in
     event names, from Sukadev Bhattiprolu

  Freescale:
   - Updates from Scott: "Highlights include 8xx optimizations, 32-bit
     checksum optimizations, 86xx consolidation, e5500/e6500 cpu
     hotplug, more fman and other dt bits, and minor fixes/cleanup"

* tag 'powerpc-4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (179 commits)
  powerpc: Fix unrecoverable SLB miss during restore_math()
  powerpc/8xx: Fix do_mtspr_cpu6() build on older compilers
  powerpc/rcpm: Fix build break when SMP=n
  powerpc/book3e-64: Use hardcoded mttmr opcode
  powerpc/fsl/dts: Add "jedec,spi-nor" flash compatible
  powerpc/T104xRDB: add tdm riser card node to device tree
  powerpc32: PAGE_EXEC required for inittext
  powerpc/mpc85xx: Add pcsphy nodes to FManV3 device tree
  powerpc/mpc85xx: Add MDIO bus muxing support to the board device tree(s)
  powerpc/86xx: Introduce and use common dtsi
  powerpc/86xx: Update device tree
  powerpc/86xx: Move dts files to fsl directory
  powerpc/86xx: Switch to kconfig fragments approach
  powerpc/86xx: Update defconfigs
  powerpc/86xx: Consolidate common platform code
  powerpc32: Remove one insn in mulhdu
  powerpc32: small optimisation in flush_icache_range()
  powerpc: Simplify test in __dma_sync()
  powerpc32: move xxxxx_dcache_range() functions inline
  powerpc32: Remove clear_pages() and define clear_page() inline
  ...

powerpc: query dynamic DEBUG_PAGEALLOC setting

2016-03-17T22:09:34+00:00

We can disable debug_pagealloc processing even if the code is compiled
with CONFIG_DEBUG_PAGEALLOC.  This patch changes the code to query
whether it is enabled or not in runtime.

Signed-off-by: Joonsoo Kim 
Acked-by: David Rientjes 
Cc: Christian Borntraeger 
Cc: Benjamin Herrenschmidt 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc: Fix misspellings in comments.

2016-03-01T08:27:20+00:00

Signed-off-by: Adam Buchbinder 
Signed-off-by: Michael Ellerman

powerpc: Fix BUG_ON() reporting in real mode

2016-02-24T09:09:04+00:00

I ran into this issue while debugging an early boot problem. The system
hit a BUG_ON() but report bug failed to print the line number and file
name. The reason being that the system was running in real mode and
report_bug() searches for addresses in the PAGE_OFFSET+ region.

Suggested-by: Paul Mackerras 
Signed-off-by: Balbir Singh 
Signed-off-by: Michael Ellerman

powerpc: Remove unused function trace_syscall()

2015-11-26T11:11:16+00:00

This function has been unused since commit 14cf11af6cf6 ("powerpc: Merge enough
to start building in arch/powerpc."), so remove it.

Signed-off-by: Rashmica Gupta 
Reviewed-by: Andrew Donnellan 
Reviewed-by: Anshuman Khandual 
Signed-off-by: Michael Ellerman

powerpc: Set the correct kernel taint on machine check errors.

2015-07-06T10:24:35+00:00

This means the 'M' flag will work properly when the kernel prints a backtrace.

Signed-off-by: Daniel Axtens 
Signed-off-by: Michael Ellerman

powerpc: Fix handling of DSCR related facility unavailable exception

2015-06-07T09:19:57+00:00

Currently DSCR (Data Stream Control Register) can be accessed with
mfspr or mtspr instructions inside a thread via two different SPR
numbers. One being the user accessible problem state SPR number 0x03
and the other being the privilege state SPR number 0x11. All access
through the privilege state SPR number get emulated through illegal
instruction exception. Any access through the problem state SPR number
raises one facility unavailable exception which sets the thread based
dscr_inherit bit and enables DSCR facility through FSCR register thus
allowing direct access to DSCR without going through this exception in
the future. We set the thread.dscr_inherit bit whether the access was
with mfspr or mtspr instruction which is neither correct nor does it
match the behaviour through the instruction emulation code path driven
from privilege state SPR number. User currently observes two different
kind of behaviour when accessing the DSCR through these two SPR numbers.
This problem can be observed through these two test cases by replacing
the privilege state SPR number with the problem state SPR number.

	(1) http://ozlabs.org/~anton/junkcode/dscr_default_test.c
	(2) http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c

This patch fixes the problem by making sure that the behaviour visible
to the user remains the same irrespective of which SPR number is being
used. Inside facility unavailable exception, we check whether it was
cuased by a mfspr or a mtspr isntrucction. In case of mfspr instruction,
just emulate the instruction. In case of mtspr instruction, set the
thread based dscr_inherit bit and also enable the facility through FSCR.
All user SPR based mfspr instruction will be emulated till one user SPR
based mtspr has been executed.

Signed-off-by: Anshuman Khandual 
Signed-off-by: Michael Ellerman

powerpc: Remove some unused functions

2015-01-28T04:00:24+00:00

Remove slice_set_psize() which is not used.

It was added in 3a8247cc2c85 "powerpc: Only demote individual slices
rather than whole process" but was never used.

Remove vsx_assist_exception() which is not used.

It was added in ce48b2100785 "powerpc: Add VSX context save/restore,
ptrace and signal support" but was never used.

Remove generic_mach_cpu_die() which is not used.

Its last caller was removed in 375f561a4131 "powerpc/powernv: Always go
into nap mode when CPU is offline".

Remove mpc7448_hpc2_power_off() and mpc7448_hpc2_halt() which are
unused.

These were introduced in c5d56332fd6c "[POWERPC] Add general support for
mpc7448hpc2 (Taiga) platform" but were never used.

This was partially found by using a static code analysis program called
cppcheck.

Signed-off-by: Rickard Strandqvist 
[mpe: Update changelog with details on when/why they are unused]
Signed-off-by: Michael Ellerman

powerpc: Replace __get_cpu_var uses

2014-11-03T01:12:32+00:00

This still has not been merged and now powerpc is the only arch that does
not have this change. Sorry about missing linuxppc-dev before.

V2->V2
  - Fix up to work against 3.18-rc1

__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Cc: Benjamin Herrenschmidt 
CC: Paul Mackerras 
Signed-off-by: Christoph Lameter 
[mpe: Fix build errors caused by set/or_softirq_pending(), and rework
      assignment in __set_breakpoint() to use memcpy().]
Signed-off-by: Michael Ellerman

powerpc/book3s: Add basic infrastructure to handle HMI in Linux.

2014-08-05T06:33:48+00:00

Handle Hypervisor Maintenance Interrupt (HMI) in Linux. This patch implements
basic infrastructure to handle HMI in Linux host. The design is to invoke
opal handle hmi in real mode for recovery and set irq_pending when we hit HMI.
During check_irq_replay pull opal hmi event and print hmi info on console.

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt