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Commit Graph

112 Commits

Author SHA1 Message Date
Michael Ellerman
1507589787 powerpc/xmon: Fix timeout loop in get_output_lock()
As far as I can tell, our 70s era timeout loop in get_output_lock() is
generating no code.

This leads to the hostile takeover happening more or less simultaneously
on all cpus. The result is "interesting", some example output that is
more readable than most:

    cpu 0x1: Vector: 100 (Scypsut e0mx bR:e setV)e catto xc0p:u[ c 00
    c0:0  000t0o0V0erc0td:o5 rfc28050000]0c00 0 0  0 6t(pSrycsV1ppuot
    uxe 1m 2 0Rx21e3:0s0ce000c00000t00)00 60602oV2SerucSayt0y 0p 1sxs

Fix it by using udelay() in the timeout loop. The wait time and check
frequency are arbitrary, but seem to work OK. We already rely on
udelay() working so this is not a new dependency.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-02-11 11:24:51 +11:00
Michael Ellerman
730efb6193 powerpc/xmon: Don't loop forever in get_output_lock()
If we enter with xmon_speaker != 0 we skip the first cmpxchg(), we also
skip the while loop because xmon_speaker != last_speaker (0) - meaning we
skip the second cmpxchg() also.

Following that code path the compiler sees no memory barriers and so is
within its rights to never reload xmon_speaker. The end result is we loop
forever.

This manifests as all cpus being in xmon ('c' command), but they refuse
to take control when you switch to them ('c x' for cpu # x).

I have seen this deadlock in practice and also checked the generated code to
confirm this is what's happening.

The simplest fix is just to always try the cmpxchg().

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-02-11 11:24:50 +11:00
Mahesh Salgaonkar
729b0f7153 powerpc/book3s: Introduce exclusive emergency stack for machine check exception.
This patch introduces exclusive emergency stack for machine check exception.
We use emergency stack to handle machine check exception so that we can save
MCE information (srr1, srr0, dar and dsisr) before turning on ME bit and be
ready for re-entrancy. This helps us to prevent clobbering of MCE information
in case of nested machine checks.

The reason for using emergency stack over normal kernel stack is that the
machine check might occur in the middle of setting up a stack frame which may
result into improper use of kernel stack.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-05 16:02:05 +11:00
Paul Mackerras
fd3bb91287 powerpc/xmon: Fix printing of set of CPUs in xmon
Commit 24ec2125f3 ("powerpc/xmon: Use cpumask iterator to avoid warning")
replaced a loop from 0 to NR_CPUS-1 with a for_each_possible_cpu() loop,
which means that if the last possible cpu is in xmon, we print the
wrong value for the end of the range.  For example, if 4 cpus are
possible, NR_CPUS is 128, and all cpus are in xmon, we print "0-7f"
rather than "0-3".  The code also assumes that the set of possible
cpus is contiguous, which may not necessarily be true.

This fixes the code to check explicitly for contiguity, and to print
the ending value correctly.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-05 17:29:19 +10:00
Michael Ellerman
660e034ce1 powerpc: Add more trap names to xmon
We haven't updated these for a while it seems, it's nice to have in the
oops output.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-27 14:44:29 +10:00
Linus Torvalds
5a148af669 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc update from Benjamin Herrenschmidt:
 "The main highlights this time around are:

   - A pile of addition POWER8 bits and nits, such as updated
     performance counter support (Michael Ellerman), new branch history
     buffer support (Anshuman Khandual), base support for the new PCI
     host bridge when not using the hypervisor (Gavin Shan) and other
     random related bits and fixes from various contributors.

   - Some rework of our page table format by Aneesh Kumar which fixes a
     thing or two and paves the way for THP support.  THP itself will
     not make it this time around however.

   - More Freescale updates, including Altivec support on the new e6500
     cores, new PCI controller support, and a pile of new boards support
     and updates.

   - The usual batch of trivial cleanups & fixes"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits)
  powerpc: Fix build error for book3e
  powerpc: Context switch the new EBB SPRs
  powerpc: Turn on the EBB H/FSCR bits
  powerpc: Replace CPU_FTR_BCTAR with CPU_FTR_ARCH_207S
  powerpc: Setup BHRB instructions facility in HFSCR for POWER8
  powerpc: Fix interrupt range check on debug exception
  powerpc: Update tlbie/tlbiel as per ISA doc
  powerpc: Print page size info during boot
  powerpc: print both base and actual page size on hash failure
  powerpc: Fix hpte_decode to use the correct decoding for page sizes
  powerpc: Decode the pte-lp-encoding bits correctly.
  powerpc: Use encode avpn where we need only avpn values
  powerpc: Reduce PTE table memory wastage
  powerpc: Move the pte free routines from common header
  powerpc: Reduce the PTE_INDEX_SIZE
  powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format
  powerpc: New hugepage directory format
  powerpc: Don't truncate pgd_index wrongly
  powerpc: Don't hard code the size of pte page
  powerpc: Save DAR and DSISR in pt_regs on MCE
  ...
2013-05-02 10:16:16 -07:00
zhangwei(Jovi)
90a102e59a powerpc/xmon/sysrq: fix inconstistent help message of sysrq key
Currently help message of /proc/sysrq-trigger highlight its
upper-case characters, like below:

      SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E)
      memory-full-oom-kill(F) kill-all-tasks(I) ...

this would confuse user trigger sysrq by upper-case character, which is
inconsistent with the real lower-case character registed key.

This inconsistent help message will also lead more confused when
26 upper-case letters put into use in future.

This patch fix powerpc xmon sysrq key: "xmon(x)"

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:10 -07:00
Aneesh Kumar K.V
ce54152f42 powerpc: Save DAR and DSISR in pt_regs on MCE
We were not saving DAR and DSISR on MCE. Save then and also print the values
along with exception details in xmon.

Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-30 15:59:42 +10:00
Michael Neuling
b9818c3312 powerpc: Rename set_break to avoid naming conflict
With allmodconfig we are getting:
  drivers/tty/synclink_gt.c:160:12: error: conflicting types for 'set_break'
  arch/powerpc/include/asm/debug.h:49:5: note: previous declaration of 'set_break' was here

  drivers/tty/synclinkmp.c:526:12: error: conflicting types for 'set_break'
  arch/powerpc/include/asm/debug.h:49:5: note: previous declaration of 'set_break' was here

This renames set_break to set_breakpoint to avoid this naming conflict

Signed-off-by: Michael Neuling <mikey@neuling.org>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-16 05:25:47 +11:00
Michael Neuling
9422de3e95 powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers
This is a rewrite so that we don't assume we are using the DABR throughout the
code.  We now use the arch_hw_breakpoint to store the breakpoint in a generic
manner in the thread_struct, rather than storing the raw DABR value.

The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from
userspace.  We keep this functionality, so that future changes (like the POWER8
DAWR), will still fake the DABR to userspace.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10 17:01:44 +11:00
Anton Blanchard
1fbe9cf259 powerpc: Build kernel with -mcmodel=medium
Finally remove the two level TOC and build with -mcmodel=medium.

Unfortunately we can't build modules with -mcmodel=medium due to
the tricks the kernel module loader plays with percpu data:

# -mcmodel=medium breaks modules because it uses 32bit offsets from
# the TOC pointer to create pointers where possible. Pointers into the
# percpu data area are created by this method.
#
# The kernel module loader relocates the percpu data section from the
# original location (starting with 0xd...) to somewhere in the base
# kernel percpu data space (starting with 0xc...). We need a full
# 64bit relocation for this to work, hence -mcmodel=large.

On older kernels we fall back to the two level TOC (-mminimal-toc)

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10 17:00:31 +11:00
Michael Ellerman
b2bb65f680 powerpc/xmon: Fallback to printk() in xmon_printf() if udbg is not setup
It is possible to configure a kernel which has xmon enabled, but has no
udbg backend to provide IO. This can make xmon rather confusing, as it
produces no output, blocks for two seconds, and then returns.

As a last resort we can instead try to printk(), which may deadlock or
otherwise crash, but tries quite hard not to.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 13:00:02 +11:00
Michael Ellerman
0104cd6839 powerpc/xmon: Fiddle xmon_depth_to_print logic in xmon_show_stack()
Currently xmon_depth_to_print is static and global, but it's only
ever used in xmon_show_stack().

At least with a modern compiler it's inlined, so there's no point
in it being static, we could #define it but it's only used in one
place.

By reworking the logic we can drop count and just decrement the
max value as a loop counter. Also switch to a while loop so we
actually print no more than 64 frames as you'd expect based on the
variable name.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 12:59:59 +11:00
Michael Ellerman
c4de38093e powerpc/xmon: Use STACK_FRAME_OVERHEAD in xmon_show_stack()
We use STACK_FRAME_OVERHEAD in the exception vectors to establish
the exception frame, so it should be good enough to use here.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 12:59:55 +11:00
Michael Ellerman
c5c5714d50 powerpc/xmon: Remove unused #defines
Neither REGS_PER_LINE or LAST_VOLATILE are used, nor have they ever
been as far back as I can see.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 12:59:52 +11:00
Michael Ellerman
b3dc19cddc powerpc/xmon: Remove renaming #defines of scanhex() and skipbl()
We have two #defines that rename scanhex() and skipbl() to
xmon_scanhex() and xmon_skipbl() - but no one ever uses those
names.

So the only effect is to rename the actual symbols in the generated
code, and AFACIS there is no reason to do that, so drop them.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 12:59:49 +11:00
Michael Ellerman
33b5cd6866 powerpc/xmon: Merge start.c into nonstdio.c
The routines in start.c are only ever called from nonstdio.c, so if we
move them in there they can become static which is nice.

I suspect the idea behind the separation was that start.c could be
replaced in order to build xmon in userland. If anyone still cares about
doing that we could handle that with an ifdef or two.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 12:59:46 +11:00
Michael Ellerman
88c6d62641 powerpc/xmon: Make xmon_getchar() static
xmon_getchar() is only called from within nonstdio.c, so make it static.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 12:59:43 +11:00
Michael Ellerman
08702c73a6 powerpc/xmon: Remove empty xmon_map_scc()
This has been empty since 2005, commit 51d3082 "Unify udbg (#2)".

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 12:59:40 +11:00
Michael Ellerman
eb1c2abb61 powerpc/xmon: Remove unused xmon_expect() & xmon_read_poll()
It looks like xmon_expect() was used for doing xmon over a modem (!?),
that code was dropped in 2005 in commit 51d3082 "Unify udbg (#2)".

Once xmon_expect() is gone xmon_read_poll() is unused, drop it too.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 12:59:37 +11:00
Michael Ellerman
ddadb6b8e8 powerpc: Add an xmon command to dump one or all pacas
This was originally motivated by a desire to see the mapping between
logical and hardware cpu numbers.

But it seemed that it made more sense to just add a command to dump
(most of) the paca.

With no arguments "dp" will dump the paca for the current cpu.

It also takes an argument, eg. "dp 3" which is the logical cpu number
in hex. This form does not check if the cpu is possible, but displays
the paca regardless, as well as the cpu's state in the possible, present
and online masks.

Thirdly, "dpa" will display the paca for all possible cpus. If there are
no possible cpus, like early in boot, it will tell you that.

Sample output, number in brackets is the offset into the struct:

2:mon> dp 3
paca for cpu 0x3 @ c00000000ff20a80:
 possible         = yes
 present          = yes
 online           = yes
 lock_token       = 0x8000            	(0x8)
 paca_index       = 0x3               	(0xa)
 kernel_toc       = 0xc00000000144f990	(0x10)
 kernelbase       = 0xc000000000000000	(0x18)
 kernel_msr       = 0xb000000000001032	(0x20)
 stab_real        = 0x0               	(0x28)
 stab_addr        = 0x0               	(0x30)
 emergency_sp     = 0xc00000003ffe4000	(0x38)
 data_offset      = 0xa40000          	(0x40)
 hw_cpu_id        = 0x9               	(0x50)
 cpu_start        = 0x1               	(0x52)
 kexec_state      = 0x0               	(0x53)
 __current        = 0xc00000007e568680	(0x218)
 kstack           = 0xc00000007e5a3e30	(0x220)
 stab_rr          = 0x1a              	(0x228)
 saved_r1         = 0xc00000007e7cb450	(0x230)
 trap_save        = 0x0               	(0x240)
 soft_enabled     = 0x0               	(0x242)
 irq_happened     = 0x0               	(0x243)
 io_sync          = 0x0               	(0x244)
 irq_work_pending = 0x0               	(0x245)
 nap_state_lost   = 0x0               	(0x246)

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-18 15:02:36 +10:00
Michael Neuling
4474ef055c powerpc: Rework set_dabr so it can take a DABRX value as well
Rework set_dabr to take a DABRX value as well.

Both the pseries and PS3 hypervisors do some checks on the DABRX
values that are passed in the hcall.  This patch stops bogus values
from being passed to hypervisor.  Also, in the case where we are
clearing the breakpoint, where DABR and DABRX are zero, we modify the
DABRX value to make it valid so that the hcall won't fail.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10 09:59:10 +10:00
Michael Ellerman
e3bc8049e5 powerpc: Fixup whitespace in xmon
There are a few whitespace goolies in xmon.c, some of them appear to
be my fault. Fix them all in one go.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-08-24 20:26:03 +10:00
Michael Ellerman
ca5dd3954a powerpc: Fix xmon dl command for new printk implementation
Since the printk internals were reworked the xmon 'dl' command which
dumps the content of __log_buf has stopped working.

It is now a structured buffer, so just dumping it doesn't really work.

Use the helpers added for kgdb to print out the content.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-08-24 20:26:03 +10:00
Anton Blanchard
bc1d770291 powerpc/xmon: Use cpumask iterator to avoid warning
We have a bug report where the kernel hits a warning in the cpumask
code:

WARNING: at include/linux/cpumask.h:107

Which is:
        WARN_ON_ONCE(cpu >= nr_cpumask_bits);

The backtrace is:
        cpu_cmd
        cmds
        xmon_core
        xmon
        die

xmon is iterating through 0 to NR_CPUS. I'm not sure why we are still
open coding this but iterating above nr_cpu_ids is definitely a bug.

This patch iterates through all possible cpus, in case we issue a
system reset and CPUs in an offline state call in.

Perhaps the old code was trying to handle CPUs that were in the
partition but were never started (eg kexec into a kernel with an
nr_cpus= boot option). They are going to die way before we get into
xmon since we haven't set any kernel state up for them.

Signed-off-by: Anton Blanchard <anton@samba.org>
CC: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-02 14:30:11 +10:00
Linus Torvalds
0195c00244 Disintegrate and delete asm/system.h
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...
2012-03-28 15:58:21 -07:00
David Howells
ae3a197e3d Disintegrate asm/system.h for PowerPC
Disintegrate asm/system.h for PowerPC.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
cc: linuxppc-dev@lists.ozlabs.org
2012-03-28 18:30:02 +01:00
Linus Torvalds
ed2d265d12 The following text was taken from the original review request:
"[RFC - PATCH 0/7] consolidation of BUG support code."
 		https://lkml.org/lkml/2012/1/26/525
 --
 
 The changes shown here are to unify linux's BUG support under
 the one <linux/bug.h> file.  Due to historical reasons, we have
 some BUG code in bug.h and some in kernel.h -- i.e. the support for
 BUILD_BUG in linux/kernel.h predates the addition of linux/bug.h,
 but old code in kernel.h wasn't moved to bug.h at that time.  As
 a band-aid, kernel.h was including <asm/bug.h> to pseudo link them.
 
 This has caused confusion[1] and general yuck/WTF[2] reactions.
 Here is an example that violates the principle of least surprise:
 
       CC      lib/string.o
       lib/string.c: In function 'strlcat':
       lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
       make[2]: *** [lib/string.o] Error 1
       $
       $ grep linux/bug.h lib/string.c
       #include <linux/bug.h>
       $
 
 We've included <linux/bug.h> for the BUG infrastructure and yet we
 still get a compile fail!  [We've not kernel.h for BUILD_BUG_ON.]
 Ugh - very confusing for someone who is new to kernel development.
 
 With the above in mind, the goals of this changeset are:
 
 1) find and fix any include/*.h files that were relying on the
    implicit presence of BUG code.
 2) find and fix any C files that were consuming kernel.h and
    hence relying on implicitly getting some/all BUG code.
 3) Move the BUG related code living in kernel.h to <linux/bug.h>
 4) remove the asm/bug.h from kernel.h to finally break the chain.
 
 During development, the order was more like 3-4, build-test, 1-2.
 But to ensure that git history for bisect doesn't get needless
 build failures introduced, the commits have been reorderd to fix
 the problem areas in advance.
 
 [1]  https://lkml.org/lkml/2012/1/3/90
 [2]  https://lkml.org/lkml/2012/1/17/414
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Merge tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

Pull <linux/bug.h> cleanup from Paul Gortmaker:
 "The changes shown here are to unify linux's BUG support under the one
  <linux/bug.h> file.  Due to historical reasons, we have some BUG code
  in bug.h and some in kernel.h -- i.e.  the support for BUILD_BUG in
  linux/kernel.h predates the addition of linux/bug.h, but old code in
  kernel.h wasn't moved to bug.h at that time.  As a band-aid, kernel.h
  was including <asm/bug.h> to pseudo link them.

  This has caused confusion[1] and general yuck/WTF[2] reactions.  Here
  is an example that violates the principle of least surprise:

      CC      lib/string.o
      lib/string.c: In function 'strlcat':
      lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
      make[2]: *** [lib/string.o] Error 1
      $
      $ grep linux/bug.h lib/string.c
      #include <linux/bug.h>
      $

  We've included <linux/bug.h> for the BUG infrastructure and yet we
  still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh -
  very confusing for someone who is new to kernel development.

  With the above in mind, the goals of this changeset are:

  1) find and fix any include/*.h files that were relying on the
     implicit presence of BUG code.
  2) find and fix any C files that were consuming kernel.h and hence
     relying on implicitly getting some/all BUG code.
  3) Move the BUG related code living in kernel.h to <linux/bug.h>
  4) remove the asm/bug.h from kernel.h to finally break the chain.

  During development, the order was more like 3-4, build-test, 1-2.  But
  to ensure that git history for bisect doesn't get needless build
  failures introduced, the commits have been reorderd to fix the problem
  areas in advance.

	[1]  https://lkml.org/lkml/2012/1/3/90
	[2]  https://lkml.org/lkml/2012/1/17/414"

Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul
and linux-next.

* tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
  kernel.h: doesn't explicitly use bug.h, so don't include it.
  bug: consolidate BUILD_BUG_ON with other bug code
  BUG: headers with BUG/BUG_ON etc. need linux/bug.h
  bug.h: add include of it to various implicit C users
  lib: fix implicit users of kernel.h for TAINT_WARN
  spinlock: macroize assert_spin_locked to avoid bug.h dependency
  x86: relocate get/set debugreg fcns to include/asm/debugreg.
2012-03-24 10:08:39 -07:00
Stephen Rothwell
f5339277eb powerpc: Remove FW_FEATURE ISERIES from arch code
This is no longer selectable, so just remove all the dependent code.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-21 11:16:11 +11:00
Benjamin Herrenschmidt
7230c56441 powerpc: Rework lazy-interrupt handling
The current implementation of lazy interrupts handling has some
issues that this tries to address.

We don't do the various workarounds we need to do when re-enabling
interrupts in some cases such as when returning from an interrupt
and thus we may still lose or get delayed decrementer or doorbell
interrupts.

The current scheme also makes it much harder to handle the external
"edge" interrupts provided by some BookE processors when using the
EPR facility (External Proxy) and the Freescale Hypervisor.

Additionally, we tend to keep interrupts hard disabled in a number
of cases, such as decrementer interrupts, external interrupts, or
when a masked decrementer interrupt is pending. This is sub-optimal.

This is an attempt at fixing it all in one go by reworking the way
we do the lazy interrupt disabling from the ground up.

The base idea is to replace the "hard_enabled" field with a
"irq_happened" field in which we store a bit mask of what interrupt
occurred while soft-disabled.

When re-enabling, either via arch_local_irq_restore() or when returning
from an interrupt, we can now decide what to do by testing bits in that
field.

We then implement replaying of the missed interrupts either by
re-using the existing exception frame (in exception exit case) or via
the creation of a new one from an assembly trampoline (in the
arch_local_irq_enable case).

This removes the need to play with the decrementer to try to create
fake interrupts, among others.

In addition, this adds a few refinements:

 - We no longer  hard disable decrementer interrupts that occur
while soft-disabled. We now simply bump the decrementer back to max
(on BookS) or leave it stopped (on BookE) and continue with hard interrupts
enabled, which means that we'll potentially get better sample quality from
performance monitor interrupts.

 - Timer, decrementer and doorbell interrupts now hard-enable
shortly after removing the source of the interrupt, which means
they no longer run entirely hard disabled. Again, this will improve
perf sample quality.

 - On Book3E 64-bit, we now make the performance monitor interrupt
act as an NMI like Book3S (the necessary C code for that to work
appear to already be present in the FSL perf code, notably calling
nmi_enter instead of irq_enter). (This also fixes a bug where BookE
perfmon interrupts could clobber r14 ... oops)

 - We could make "masked" decrementer interrupts act as NMIs when doing
timer-based perf sampling to improve the sample quality.

Signed-off-by-yet: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

v2:

- Add hard-enable to decrementer, timer and doorbells
- Fix CR clobber in masked irq handling on BookE
- Make embedded perf interrupt act as an NMI
- Add a PACA_HAPPENED_EE_EDGE for use by FSL if they want
  to retrigger an interrupt without preventing hard-enable

v3:

 - Fix or vs. ori bug on Book3E
 - Fix enabling of interrupts for some exceptions on Book3E

v4:

 - Fix resend of doorbells on return from interrupt on Book3E

v5:

 - Rebased on top of my latest series, which involves some significant
rework of some aspects of the patch.

v6:
 - 32-bit compile fix
 - more compile fixes with various .config combos
 - factor out the asm code to soft-disable interrupts
 - remove the C wrapper around preempt_schedule_irq

v7:
 - Fix a bug with hard irq state tracking on native power7
2012-03-09 13:25:06 +11:00
Benjamin Herrenschmidt
7ac21cd465 powerpc/xmon: Add display of soft & hard irq states
Also use local_paca instead of get_paca() to avoid getting into
the smp_processor_id() debugging code from the debugger

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-09 10:55:14 +11:00
Paul Gortmaker
50af5ead3b bug.h: add include of it to various implicit C users
With bug.h currently living right in linux/kernel.h there
are files that use BUG_ON and friends but are not including
the header explicitly.  Fix them up so we can remove the
presence in kernel.h file.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-29 17:15:08 -05:00
Jimi Xenidis
08f6d6abc3 powerpc/xmon: Fix #if typo for systems without MSR[RI]
Sorry, there was a typo in the #if

signed-off-by: Jimi Xenidis <jimix@pobox.com>

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:11:28 +11:00
Jimi Xenidis
79873e8df6 powerpc/xmon: Fix the 'u' command description
The 'u' command will print the TLB on book3e parts and the SLB on
Book3s parts, but the help system doesn't say that correctly.

Signed-off-by: Jimi Xenidis <jimix@pobox.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:11:28 +11:00
Linus Torvalds
32aaeffbd4 Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include <linux/module.h>
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include <linux/module.h>
  net: sch_generic remove redundant use of <linux/module.h>
  net: inet_timewait_sock doesnt need <linux/module.h>
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h
2011-11-06 19:44:47 -08:00
Paul Gortmaker
4b16f8e2d6 powerpc: various straight conversions from module.h --> export.h
All these files were including module.h just for the basic
EXPORT_SYMBOL infrastructure.  We can shift them off to the
export.h header which is a way smaller footprint and thus
realize some compile time gains.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:44 -04:00
Jimi Xenidis
66857b3a9e powerpc: Fix xmon for systems without MSR[RI]
Based on patch by David Gibson <dwg@au1.ibm.com>

xmon has a longstanding bug on systems which are SMP-capable but lack
the MSR[RI] bit.  In these cases, xmon invoked by IPI on secondary
CPUs will not properly keep quiet, but will print stuff, thereby
garbling the primary xmon's output.  This patch fixes it, by ignoring
the RI bit if the processor does not support it.

There's already a version of this for 4xx upstream, which we'll need
to extend to other RI-lacking CPUs at some point.  For now this adds
Book3e processors to the mix.

Signed-off-by: Jimi Xenidis <jimix@pobox.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-09-29 16:58:22 +10:00
Milton Miller
e047637132 powerpc: Remove call sites of MSG_ALL_BUT_SELF
The only user of MSG_ALL_BUT_SELF in the whole kernel tree is powerpc,
and it only uses it to start the debugger. Both debuggers always call
smp_send_debugger_break with MSG_ALL_BUT_SELF, and only mpic can do
anything more optimal than a loop over all online cpus, but all message
passing implementations have to code for this special delivery target.

Convert smp_send_debugger_break to take void and loop calling the smp_ops
message_pass function for each of the other cpus in the online cpumask.

Use raw_smp_processor_id() because we are either entering the debugger
or trying to start kdump and the additional warning it not useful were
it to trigger.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-19 14:30:46 +10:00
KOSAKI Motohiro
104699c0ab powerpc: Convert old cpumask API into new one
Adapt new API.

Almost change is trivial. Most important change is the below line
because we plan to change task->cpus_allowed implementation.

-       ctx->cpus_allowed = current->cpus_allowed;

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-04 15:22:59 +10:00
Paul Mackerras
48404f2e95 powerpc: Save Come-From Address Register (CFAR) in exception frame
Recent 64-bit server processors (POWER6 and POWER7) have a "Come-From
Address Register" (CFAR), that records the address of the most recent
branch or rfid (return from interrupt) instruction for debugging purposes.

This saves the value of the CFAR in the exception entry code and stores
it in the exception frame.  We also make xmon print the CFAR value in
its register dump code.

Rather than extend the pt_regs struct at this time, we steal the orig_gpr3
field, which is only used for system calls, and use it for the CFAR value
for all exceptions/interrupts other than system calls.  This means we
don't save the CFAR on system calls, which is not a great problem since
system calls tend not to happen unexpectedly, and also avoids adding the
overhead of reading the CFAR to the system call entry path.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-04 15:22:09 +10:00
Matt Evans
44ae3ab335 powerpc: Free up some CPU feature bits by moving out MMU-related features
Some of the 64bit PPC CPU features are MMU-related, so this patch moves
them to MMU_FTR_ bits.  All cpu_has_feature()-style tests are moved to
mmu_has_feature(), and seven feature bits are freed as a result.

Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 14:18:52 +10:00
Michael Ellerman
9f0b079320 powerpc: Use MSR_64BIT in places
Use the new MSR_64BIT in a few places. Some of these are already ifdef'ed
for BOOKE vs BOOKS, but it's still clearer, MSR_SF does not immediately
parse as "MSR bit for 64bit".

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 14:18:44 +10:00
David Rientjes
b2b755b5f1 lib, arch: add filter argument to show_mem and fix private implementations
Commit ddd588b5dd ("oom: suppress nodes that are not allowed from
meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which
resulted in build warnings on all architectures that implement their own
versions of show_mem():

	lib/lib.a(show_mem.o): In function `show_mem':
	show_mem.c:(.text+0x1f4): multiple definition of `show_mem'
	arch/sparc/mm/built-in.o:(.text+0xd70): first defined here

The fix is to remove __show_mem() and add its argument to show_mem() in
all implementations to prevent this breakage.

Architectures that implement their own show_mem() actually don't do
anything with the argument yet, but they could be made to filter nodes
that aren't allowed in the current context in the future just like the
generic implementation.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-24 17:49:37 -07:00
matt mooney
4108d9ba90 powerpc/Makefiles: Change to new flag variables
Replace EXTRA_CFLAGS with ccflags-y and EXTRA_AFLAGS with asflags-y.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-10-13 16:19:22 +11:00
Dmitry Torokhov
1495cc9df4 Input: sysrq - drop tty argument from sysrq ops handlers
Noone is using tty argument so let's get rid of it.

Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-19 22:07:06 -07:00
Benjamin Herrenschmidt
03247157f7 powerpc/book3e: Add TLB dump in xmon for Book3E
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-07-14 14:13:52 +10:00
Anton Blanchard
5be3492f97 powerpc: Mark some variables in the page fault path __read_mostly
Using perf to trace L1 dcache misses and dumping data addresses I found a few
variables taking a lot of misses. Since they are almost never written, they
should go into the __read_mostly section.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-03 17:39:48 +11:00
Gautham R Shenoy
69ddb57cbe powerpc/pseries: Add extended_cede_processor() helper function.
This patch provides an extended_cede_processor() helper function
which takes the cede latency hint as an argument. This hint is to be passed
on to the hypervisor to cede to the corresponding state on platforms
which support it.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-24 14:33:03 +11:00
Josh Boyer
cdd3904dcc powerpc/booke: Fix xmon single step on PowerPC Book-E
Prior to the arch/ppc -> arch/powerpc transition, xmon had support for single
stepping on 4xx boards.  The functionality was lost when arch/ppc was removed.
This patch restores single step support for 44x boards, and Book-E in general.

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-27 16:42:40 +11:00
Josh Boyer
daf8f40391 powerpc/4xx: Fix erroneous xmon warning on PowerPC 4xx
The xmon code relies on MSR_RI being non-zero to indicate that an exception
is recoverable.  If it is not, it prints a warning message.  However, the
PowerPC 4xx cores do not have an MSR_RI bit and this warning is produced for
every xmon event.

This introduces an unrecoverable_excp function to determine if an exception
is recoverable or not.  This gets rid of the erroneous warnings on 4xx.

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-24 15:31:49 +10:00