litmus-rt-edfsc.git/arch/powerpc/sysdev, branch wip-joshua

powerpc/xics: Work around limitations of OPAL XICS priority handling

2017-03-18T11:14:30+00:00

commit a69e2fb70350a66f91175cd2625f1e8215c5b6e9 upstream.

The CPPR (Current Processor Priority Register) of a XICS interrupt
presentation controller contains a value N, such that only interrupts
with a priority "more favoured" than N will be received by the CPU,
where "more favoured" means "less than". So if the CPPR has the value 5
then only interrupts with a priority of 0-4 inclusive will be received.

In theory the CPPR can support a value of 0 to 255 inclusive.
In practice Linux only uses values of 0, 4, 5 and 0xff. Setting the CPPR
to 0 rejects all interrupts, setting it to 0xff allows all interrupts.
The values 4 and 5 are used to differentiate IPIs from external
interrupts. Setting the CPPR to 5 allows IPIs to be received but not
external interrupts.

The CPPR emulation in the OPAL XICS implementation only directly
supports priorities 0 and 0xff. All other priorities are considered
equivalent, and mapped to a single priority value internally. This means
when using icp-opal we can not allow IPIs but not externals.

This breaks Linux's use of priority values when a CPU is hot unplugged.
After migrating IRQs away from the CPU that is being offlined, we set
the priority to 5, meaning we still want the offline CPU to receive
IPIs. But the effect of the OPAL XICS emulation's use of a single
priority value is that all interrupts are rejected by the CPU. With the
CPU offline, and not receiving IPIs, we may not be able to wake it up to
bring it back online.

The first part of the fix is in icp_opal_set_cpu_priority(). CPPR values
of 0 to 4 inclusive will correctly cause all interrupts to be rejected,
so we pass those CPPR values through to OPAL. However if we are called
with a CPPR of 5 or greater, the caller is expecting to be able to allow
IPIs but not external interrupts. We know this doesn't work, so instead
of rejecting all interrupts we choose the opposite which is to allow all
interrupts. This is still not correct behaviour, but we know for the
only existing caller (xics_migrate_irqs_away()), that it is the better
option.

The other part of the fix is in xics_migrate_irqs_away(). Instead of
setting priority (CPPR) to 0, and then back to 5 before migrating IRQs,
we migrate the IRQs before setting the priority back to 5. This should
have no effect on an ICP backend with a working set_priority(), and on
icp-opal it means we will keep all interrupts blocked until after we've
finished doing the IRQ migration. Additionally we wait for 5ms after
doing the migration to make sure there are no IRQs in flight.

Fixes: d74361881f0d ("powerpc/xics: Add ICP OPAL backend")
Suggested-by: Michael Ellerman 
Reported-by: Vaidyanathan Srinivasan 
Tested-by: Vaidyanathan Srinivasan 
Signed-off-by: Balbir Singh 
[mpe: Rewrote comments and change log, change delay to 5ms]
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/powernv: Fix CPU hotplug to handle waking on HVI

2017-02-14T23:25:40+00:00

commit 9b256714979fad61ae11d90b53cf67dd5e6484eb upstream.

The IPIs come in as HVI not EE, so we need to test the appropriate
SRR1 bits. The encoding is such that it won't have false positives
on P7 and P8 so we can just test it like that. We also need to handle
the icp-opal variant of the flush.

Fixes: d74361881f0d ("powerpc/xics: Add ICP OPAL backend")
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/icp-opal: Fix missing KVM case and harden replay

2017-01-26T07:24:39+00:00

commit 9728a7c8ab2f7a1c8d5c95278d2e4f4ac1285385 upstream.

The icp-opal call is missing the code from icp-native to recover
interrupts snatched by KVM. Without that, when running KVM, we can
get into a situation where an interrupt is lost and the CPU stuck
with an elevated CPPR.

Also harden replay by always checking the return from opal_int_eoi().

Fixes: d74361881f0d ("powerpc/xics: Add ICP OPAL backend")
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2016-10-14T21:26:58+00:00

Pull kbuild updates from Michal Marek:

 - EXPORT_SYMBOL for asm source by Al Viro.

   This does bring a regression, because genksyms no longer generates
   checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
   working on a patch to fix this.

   Plus, we are talking about functions like strcpy(), which rarely
   change prototypes.

 - Fixes for PPC fallout of the above by Stephen Rothwell and Nick
   Piggin

 - fixdep speedup by Alexey Dobriyan.

 - preparatory work by Nick Piggin to allow architectures to build with
   -ffunction-sections, -fdata-sections and --gc-sections

 - CONFIG_THIN_ARCHIVES support by Stephen Rothwell

 - fix for filenames with colons in the initramfs source by me.

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
  initramfs: Escape colons in depfile
  ppc: there is no clear_pages to export
  powerpc/64: whitelist unresolved modversions CRCs
  kbuild: -ffunction-sections fix for archs with conflicting sections
  kbuild: add arch specific post-link Makefile
  kbuild: allow archs to select link dead code/data elimination
  kbuild: allow architectures to use thin archives instead of ld -r
  kbuild: Regenerate genksyms lexer
  kbuild: genksyms fix for typeof handling
  fixdep: faster CONFIG_ search
  ia64: move exports to definitions
  sparc32: debride memcpy.S a bit
  [sparc] unify 32bit and 64bit string.h
  sparc: move exports to definitions
  ppc: move exports to definitions
  arm: move exports to definitions
  s390: move exports to definitions
  m68k: move exports to definitions
  alpha: move exports to actual definitions
  x86: move exports to actual definitions
  ...

Merge tag 'powerpc-4.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2016-10-14T18:07:42+00:00

Pull more powerpc updates from Michael Ellerman:
 "Some more powerpc updates for 4.9:

  Freescale updates from Scott Wood:
   - qbman support (a prerequisite for datapath drivers such as ethernet)
   - a PCI DMA fix+improvement
   - reset handler changes
   - more 8xx optimizations
   - some cleanups and fixes.'

  Fixes:
   - selftests/powerpc: Add missing binaries to .gitignores (Michael Ellerman)
   - selftests/powerpc: Fix build break caused by EXPORT_SYMBOL changes (Michael Ellerman)
   - powerpc/pseries: Fix stack corruption in htpe code (Laurent Dufour)
   - powerpc/64s: Fix power4_fixup_nap placement (Nicholas Piggin)
   - powerpc/64: Fix incorrect return value from __copy_tofrom_user (Paul Mackerras)
   - powerpc/mm/hash64: Fix might_have_hea() check (Michael Ellerman)

  Other:
   - MAINTAINERS: Remove myself from PA Semi entries (Olof Johansson)
   - MAINTAINERS: Drop separate pseries entry (Michael Ellerman)
   - MAINTAINERS: Update powerpc website & add selftests (Michael Ellerman):

* tag 'powerpc-4.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (35 commits)
  powerpc/mm/hash64: Fix might_have_hea() check
  powerpc/64: Fix incorrect return value from __copy_tofrom_user
  powerpc/64s: Fix power4_fixup_nap placement
  powerpc/pseries: Fix stack corruption in htpe code
  selftests/powerpc: Fix build break caused by EXPORT_SYMBOL changes
  MAINTAINERS: Update powerpc website & add selftests
  MAINTAINERS: Drop separate pseries entry
  MAINTAINERS: Remove myself from PA Semi entries
  selftests/powerpc: Add missing binaries to .gitignores
  arch/powerpc: Add CONFIG_FSL_DPAA to corenetXX_smp_defconfig
  soc/qman: Add self-test for QMan driver
  soc/bman: Add self-test for BMan driver
  soc/fsl: Introduce DPAA 1.x QMan device driver
  soc/fsl: Introduce DPAA 1.x BMan device driver
  powerpc/8xx: make user addr DTLB miss the short path
  powerpc/8xx: Move additional DTLBMiss handlers out of exception area
  powerpc/8xx: use r3 to scratch CR in ITLBmiss
  soc/fsl/qe: fix gpio save_regs functions
  powerpc/8xx: add dedicated machine check handler
  powerpc/8xx: add system_reset_exception
  ...

Merge tag 'powerpc-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2016-10-08T03:19:31+00:00

Pull powerpc updates from Michael Ellerman:
 "Highlights:
   - Major rework of Book3S 64-bit exception vectors (Nicholas Piggin)
   - Use gas sections for arranging exception vectors et. al.
   - Large set of TM cleanups and selftests (Cyril Bur)
   - Enable transactional memory (TM) lazily for userspace (Cyril Bur)
   - Support for XZ compression in the zImage wrapper (Oliver
     O'Halloran)
   - Add support for bpf constant blinding (Naveen N. Rao)
   - Beginnings of upstream support for PA Semi Nemo motherboards
     (Darren Stevens)

  Fixes:
   - Ensure .mem(init|exit).text are within _stext/_etext (Michael
     Ellerman)
   - xmon: Don't use ld on 32-bit (Michael Ellerman)
   - vdso64: Use double word compare on pointers (Anton Blanchard)
   - powerpc/nvram: Fix an incorrect partition merge (Pan Xinhui)
   - powerpc: Fix usage of _PAGE_RO in hugepage (Christophe Leroy)
   - powerpc/mm: Update FORCE_MAX_ZONEORDER range to allow hugetlb w/4K
     (Aneesh Kumar K.V)
   - Fix memory leak in queue_hotplug_event() error path (Andrew
     Donnellan)
   - Replay hypervisor maintenance interrupt first (Nicholas Piggin)

  Various performance optimisations (Anton Blanchard):
   - Align hot loops of memset() and backwards_memcpy()
   - During context switch, check before setting mm_cpumask
   - Remove static branch prediction in atomic{, 64}_add_unless
   - Only disable HAVE_EFFICIENT_UNALIGNED_ACCESS on POWER7 little
     endian
   - Set default CPU type to POWER8 for little endian builds

  Cleanups & features:
   - Sparse fixes/cleanups (Daniel Axtens)
   - Preserve CFAR value on SLB miss caused by access to bogus address
     (Paul Mackerras)
   - Radix MMU fixups for POWER9 (Aneesh Kumar K.V)
   - Support for setting used_(vsr|vr|spe) in sigreturn path (for CRIU)
     (Simon Guo)
   - Optimise syscall entry for virtual, relocatable case (Nicholas
     Piggin)
   - Optimise MSR handling in exception handling (Nicholas Piggin)
   - Support for kexec with Radix MMU (Benjamin Herrenschmidt)
   - powernv EEH fixes (Russell Currey)
   - Suprise PCI hotplug support for powernv (Gavin Shan)
   - Endian/sparse fixes for powernv PCI (Gavin Shan)
   - Defconfig updates (Anton Blanchard)
   - KVM: PPC: Book3S HV: Migrate pinned pages out of CMA (Balbir Singh)
   - cxl: Flush PSL cache before resetting the adapter (Frederic Barrat)
   - cxl: replace loop with for_each_child_of_node(), remove unneeded
     of_node_put() (Andrew Donnellan)
   - Fix HV facility unavailable to use correct handler (Nicholas
     Piggin)
   - Remove unnecessary syscall trampoline (Nicholas Piggin)
   - fadump: Fix build break when CONFIG_PROC_VMCORE=n (Michael
     Ellerman)
   - Quieten EEH message when no adapters are found (Anton Blanchard)
   - powernv: Add PHB register dump debugfs handle (Russell Currey)
   - Use kprobe blacklist for exception handlers & asm functions
     (Nicholas Piggin)
   - Document the syscall ABI (Nicholas Piggin)
   - MAINTAINERS: Update cxl maintainers (Michael Neuling)
   - powerpc: Remove all usages of NO_IRQ (Michael Ellerman)

  Minor cleanups:
   - Andrew Donnellan, Christophe Leroy, Colin Ian King, Cyril Bur,
     Frederic Barrat, Pan Xinhui, PrasannaKumar Muralidharan, Rui Teng,
     Simon Guo"

* tag 'powerpc-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (156 commits)
  powerpc/bpf: Add support for bpf constant blinding
  powerpc/bpf: Implement support for tail calls
  powerpc/bpf: Introduce accessors for using the tmp local stack space
  powerpc/fadump: Fix build break when CONFIG_PROC_VMCORE=n
  powerpc: tm: Enable transactional memory (TM) lazily for userspace
  powerpc/tm: Add TM Unavailable Exception
  powerpc: Remove do_load_up_transact_{fpu,altivec}
  powerpc: tm: Rename transct_(*) to ck(\1)_state
  powerpc: tm: Always use fp_state and vr_state to store live registers
  selftests/powerpc: Add checks for transactional VSXs in signal contexts
  selftests/powerpc: Add checks for transactional VMXs in signal contexts
  selftests/powerpc: Add checks for transactional FPUs in signal contexts
  selftests/powerpc: Add checks for transactional GPRs in signal contexts
  selftests/powerpc: Check that signals always get delivered
  selftests/powerpc: Add TM tcheck helpers in C
  selftests/powerpc: Allow tests to extend their kill timeout
  selftests/powerpc: Introduce GPR asm helper header file
  selftests/powerpc: Move VMX stack frame macros to header file
  selftests/powerpc: Rework FPU stack placement macros and move to header file
  selftests/powerpc: Check for VSX preservation across userspace preemption
  ...

powerpc/fsl_pci: Size upper inbound window based on RAM size

2016-09-25T07:38:54+00:00

This allows PCI devices that can only address (e.g.) 36 or 40 bit DMA to
use direct DMA, at the cost of not being able to DMA to non-RAM addresses
(this doesn't affect MSIs as there is a separate dedicated window for
that) which we wouldn't have been able to do anyway if the RAM size didn't
trigger the creation of the second inbound window.

It also fixes an off-by-one error that set dma_direct_ops on PCI devices
whose dma mask could address all the space below the DMA offset
(previously 40 bits), but not the window that starts at the DMA offset.

Signed-off-by: Scott Wood 
Cc: Tillmann Heidsieck 
Tested-by: Tillmann Heidsieck

soc/fsl/qe: fix Oops on CPM1 (and likely CPM2)

2016-09-25T07:38:52+00:00

Commit 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram")
has changed the way muram is managed.
genalloc uses kmalloc(), hence requires the SLAB to be up and running.

On powerpc 8xx, cpm_reset() is called early during startup.
cpm_reset() then calls cpm_muram_init() before SLAB is available,
hence the following Oops.

cpm_reset() cannot be called during initcalls because the CPM is
needed for console.

This patch removes the call to cpm_muram_init() from cpm_reset().
cpm_muram_init() will be called from a new function called cpm_init()
which is declared as subsys_initcall, unless cpm_muram_alloc() is
called earlier for the serial console in which case cpm_muram_init()
will be called from there.

The reason for calling it from two places is that some drivers
(e.g. i2c-cpm) need some of the initialisations done by
cpm_muram_init() but don't call cpm_muram_alloc(). The console
driver calls cpm_muram_alloc() but some platforms might not use
the CPM serial ports for console.

[    0.000000] Unable to handle kernel paging request for data at address 0x00000008
[    0.000000] Faulting instruction address: 0xc01acce0
[    0.000000] Oops: Kernel access of bad area, sig: 11 [#1]
[    0.000000] PREEMPT CMPC885
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.14-g0886ed8 #5
[    0.000000] task: c05183e0 ti: c0536000 task.ti: c0536000
[    0.000000] NIP: c01acce0 LR: c0011068 CTR: 00000000
[    0.000000] REGS: c0537e50 TRAP: 0300   Not tainted (4.4.14-s3k-dev-g0886ed8-svn)
[    0.000000] MSR: 00001032   CR: 28044428  XER: 00000000
[    0.000000] DAR: 00000008 DSISR: c0000000
GPR00: c0011068 c0537f00 c05183e0 00000000 00009000 ffffffff 00000bc0 ffffffff
GPR08: ff003000 ff00b000 ff003bbf 00000000 22044422 100d43a8 00000000 07ff94e8
GPR16: 00000000 07bb5d70 00000000 07ff81f4 07ff81f4 07ff81f4 00000000 00000000
GPR24: 07ffb3a0 07fe7628 c0550000 c7ffa190 c0540000 ff003bbf 00000000 00000001
[    0.000000] NIP [c01acce0] gen_pool_add_virt+0x14/0xdc
[    0.000000] LR [c0011068] cpm_muram_init+0xd4/0x18c
[    0.000000] Call Trace:
[    0.000000] [c0537f00] [00000200] 0x200 (unreliable)
[    0.000000] [c0537f20] [c0011068] cpm_muram_init+0xd4/0x18c
[    0.000000] [c0537f70] [c0494684] cpm_reset+0xb4/0xc8
[    0.000000] [c0537f90] [c0494c64] cmpc885_setup_arch+0x10/0x30
[    0.000000] [c0537fa0] [c0493cd4] setup_arch+0x130/0x168
[    0.000000] [c0537fb0] [c04906bc] start_kernel+0x88/0x380
[    0.000000] [c0537ff0] [c0002224] start_here+0x38/0x98
[    0.000000] Instruction dump:
[    0.000000] 91430010 91430014 80010014 83e1000c 7c0803a6 38210010 4e800020 7c0802a6
[    0.000000] 9421ffe0 bf61000c 90010024 7c7e1b78 <80630008> 7c9c2378 7cc31c30 3863001f
[    0.000000] ---[ end trace dc8fa200cb88537f ]---

fixes: 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram")
Cc: stable@vger.linux.org
Signed-off-by: Christophe Leroy 
[scottwood: Removed some string changes unrelated to bugfix]
Signed-off-by: Scott Wood

powerpc/mpic: use of_property_read_bool

2016-09-25T07:38:51+00:00

Use of_property_read_bool to check for the existence of a property.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// 
@@
expression e1,e2;
statement S2,S1;
@@
-       if (of_get_property(e1,e2,NULL))
+       if (of_property_read_bool(e1,e2))
        S1 else S2
// 

Signed-off-by: Julia Lawall 
Acked-by: Michael Ellerman 
Signed-off-by: Scott Wood

powerpc: Convert fsl_rstcr_restart to a reset handler

2016-09-25T07:38:50+00:00

Convert fsl_rstcr_restart into a function to be registered with
register_reset_handler().

Signed-off-by: Andrey Smirnov 
[scottwood: Converted mvme7100 as well]
Signed-off-by: Scott Wood