100 Commits
Author SHA1 Message Date
Anton Blanchard 0e3849836b powerpc: Lack of firmware flash support is not an error
Reduce the severity of the warning given when firmware flash is
not supported. Not all platforms have it.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-27 11:42:33 +10:00
Anton Blanchard fd297b3a73 powerpc: Enable pseries hardware RNG and crypto modules
Enable the hardware RNG and crypto modules. I verified they both
autoload via the VIO subsystem, so there is no need to build them in.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-27 11:42:32 +10:00
Anton Blanchard ac46a46238 be2net: Missing byteswap in be_get_fw_log_level causes oops on PowerPC
We are seeing an oops in be_get_fw_log_level on ppc64 where we walk
off the end of memory.

commit 941a77d582 (be2net: Fix to allow get/set of debug levels in
the firmware.) requires byteswapping of num_modes and num_modules.

Cc: [email protected] # 3.5+
Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: Sathya Perla <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2012-07-25 15:24:13 -07:00
Anton Blanchard 18ad51dd34 powerpc: Add VDSO version of getcpu
We have a request for a fast method of getting CPU and NUMA node IDs
from userspace. This patch implements a getcpu VDSO function,
similar to x86.

Ben suggested we use SPRG3 which is userspace readable. SPRG3 can be
modified by a KVM guest, so we save the SPRG3 value in the paca and
restore it when transitioning from the guest to the host.

I have a glibc patch that implements sched_getcpu on top of this.
Testing on a POWER7:

baseline: 538 cycles
vdso:      30 cycles

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-11 14:18:40 +10:00
Anton Blanchard d6b9a81b2a powerpc: IOMMU fault injection
Add the ability to inject IOMMU faults. We enable this per device
via a fail_iommu sysfs property, similar to fault injection on other
subsystems.

An example:

...
0003:01:00.1 Ethernet controller: Emulex Corporation OneConnect 10Gb NIC (be3) (rev 02)

To inject one error to this device:

echo 1 > /sys/bus/pci/devices/0003:01:00.1/fail_iommu
echo 1 > /sys/kernel/debug/fail_iommu/probability
echo 1 > /sys/kernel/debug/fail_iommu/times

As feared, the first failure injected on the be3 results in an
unrecoverable error, taking down both functions of the card
permanently:

be2net 0003:01:00.1: Unrecoverable error in the card

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-10 19:18:59 +10:00
Anton Blanchard a980349725 powerpc: Call dma_debug_add_bus for PCI and VIO buses
The DMA API debug code has hooks to verify all DMA entries have been
freed at time of hot unplug. We need to call dma_debug_add_bus for
this to work.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-10 19:18:57 +10:00
Anton Blanchard 44b372d8a0 powerpc/vio: Separate vio bus probe and device probe
Similar to PCI, separate the bus probe from device probe. This allows
us to attach bus notifiers for DMA debug and IOMMU fault injection
before devices have been probed.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-10 19:18:54 +10:00
Anton Blanchard 62761d1f68 powerpc/vio: Remove dma not supported warnings
During boot we see a number of these warnings:

vio 30000000: Warning: IOMMU dma not supported: mask 0xffffffffffffffff, table unavailable

The reason for this is that we set IOMMU properties for all VIO
devices even if they are not DMA capable.

Only set DMA ops, table and mask for devices with a DMA window.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-10 19:18:51 +10:00
Anton Blanchard 6da7094810 powerpc/perf: Use perf_instruction_pointer in callchains
We use SIAR or regs->nip for the instruction pointer depending on
the PMU configuration, but we always use regs->nip in the callchain.

Use perf_instruction_pointer so the backtrace is consistent.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-10 19:18:46 +10:00
Anton Blanchard 5c093efa6f powerpc/perf: Always use pt_regs for userspace samples
At the moment we always use the SIAR if the PMU supports continuous
sampling. Unfortunately the SIAR and the PMU exception are not
synchronised for non marked events so we can end up with callchains
that dont make sense.

The following patch checks the HV and PR bits for samples coming from
userspace and always uses pt_regs for them. Userspace will never have
interrupts off so there is no real advantage to using the SIAR for
non marked events in userspace.

I had experimented with a patch that did a similar thing for kernel
samples but we lost a significant amount of information. I was
unable to profile any of our early exception code for example.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-10 19:18:43 +10:00
Anton Blanchard 75382aa72f powerpc/perf: Move code to select SIAR or pt_regs into perf_read_regs
The logic to choose whether to use the SIAR or get the information
out of pt_regs is going to get more complicated, so do it once in
perf_read_regs.

We overload regs->result which is gross but we are already doing it
with regs->dsisr.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-10 19:18:41 +10:00
Anton Blanchard 68b30bb9f0 powerpc/perf: Create mmcra_sihv/mmcra_sipv helpers
We want to access the MMCRA_SIHV and MMCRA_SIPR bits elsewhere so
create mmcra_sihv and mmcra_sipr which hide the differences between
the old and new layout of the bits.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-10 19:18:38 +10:00
Anton Blanchard 8299d62843 [media] winbond-cir: Initialise timeout, driver_type and allowed_protos
We need to set a timeout so we can go idle on no activity.

Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: David Härdeman <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
2012-07-06 19:36:38 -03:00
Anton Blanchard 57f4422f7b [media] winbond-cir: Fix txandrx module info
We aren't getting any module info for the txandx option because
of a typo:

parm:           txandrx:bool

Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: David Härdeman <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
2012-07-06 19:36:37 -03:00
Anton Blanchard c6cff16926 [media] cx23885: Silence unknown command warnings
I am seeing a constant stream of warnings on my cx23885 based card:
	cx23885_tuner_callback(): Unknown command 0x2.

Add a check in cx23885_tuner_callback to silence it.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
2012-07-06 19:36:37 -03:00
Anton Blanchard cf8fb5533f powerpc: Optimise the 64bit optimised __clear_user
I blame Mikey for this. He elevated my slightly dubious testcase:

to benchmark status. And naturally we need to be number 1 at creating
zeros. So lets improve __clear_user some more.

As Paul suggests we can use dcbz for large lengths. This patch gets
the destination cacheline aligned then uses dcbz on whole cachelines.

Before:
10485760000 bytes (10 GB) copied, 0.414744 s, 25.3 GB/s

After:
10485760000 bytes (10 GB) copied, 0.268597 s, 39.0 GB/s

39 GB/s, a new record.

Signed-off-by: Anton Blanchard <[email protected]>
Tested-by: Olof Johansson <[email protected]>
Acked-by: Olof Johansson <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:48 +10:00
Anton Blanchard b4c3a8729a powerpc/iommu: Implement IOMMU pools to improve multiqueue adapter performance
At the moment all queues in a multiqueue adapter will serialise
against the IOMMU table lock. This is proving to be a big issue,
especially with 10Gbit ethernet.

This patch creates 4 pools and tries to spread the load across
them. If the table is under 1GB in size we revert back to the
original behaviour of 1 pool and 1 largealloc pool.

We create a hash to map CPUs to pools. Since we prefer interrupts to
be affinitised to primary CPUs, without some form of hashing we are
very likely to end up using the same pool. As an example, POWER7
has 4 way SMT and with 4 pools all primary threads will map to the
same pool.

The largealloc pool is reduced from 1/2 to 1/4 of the space to
partially offset the overhead of breaking the table up into pools.

Some performance numbers were obtained with a Chelsio T3 adapter on
two POWER7 boxes, running a 100 session TCP round robin test.

Performance improved 69% with this patch applied.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:48 +10:00
Anton Blanchard d362213722 powerpc/iommu: Push spinlock into iommu_range_alloc and __iommu_free
In preparation for IOMMU pools, push the spinlock into
iommu_range_alloc and __iommu_free.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:47 +10:00
Anton Blanchard 67ca141567 powerpc/iommu: Reduce spinlock coverage in iommu_free
This patch moves tce_free outside of the lock in iommu_free.

Some performance numbers were obtained with a Chelsio T3 adapter on
two POWER7 boxes, running a 100 session TCP round robin test.

Performance improved 25% with this patch applied.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:47 +10:00
Anton Blanchard 0e4bc95d87 powerpc/iommu: Reduce spinlock coverage in iommu_alloc and iommu_free
We currently hold the IOMMU spinlock around tce_build and tce_flush.
This causes our spinlock hold times to be much higher than required
and can impact multiqueue adapters.

This patch moves tce_build and tce_flush outside of the lock in
iommu_alloc, and tce_flush outside of the lock in iommu_free.

Some performance numbers were obtained with a Chelsio T3 adapter on
two POWER7 boxes, running a 100 session TCP round robin test.

Performance improved 32% with this patch applied.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:47 +10:00
Anton Blanchard c1703e85a7 powerpc/pseries: Disable interrupts around IOMMU percpu data accesses
tce_buildmulti_pSeriesLP uses a per cpu page to communicate with the
hypervisor. We currently rely on the IOMMU table spinlock but
subsequent patches will be removing that so disable interrupts
around all accesses of tce_page.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:46 +10:00
Anton Blanchard b3f271e86e powerpc: POWER7 optimised memcpy using VMX and enhanced prefetch
Implement a POWER7 optimised memcpy using VMX and enhanced prefetch
instructions.

This is a copy of the POWER7 optimised copy_to_user/copy_from_user
loop. Detailed implementation and performance details can be found in
commit a66086b819 (powerpc: POWER7 optimised
copy_to_user/copy_from_user using VMX).

I noticed memcpy issues when profiling a RAID6 workload:

	.memcpy
	.async_memcpy
	.async_copy_data
	.__raid_run_ops
	.handle_stripe
	.raid5d
	.md_thread

I created a simplified testcase by building a RAID6 array with 4 1GB
ramdisks (booting with brd.rd_size=1048576):

# mdadm -CR -e 1.2 /dev/md0 --level=6 -n4 /dev/ram[0-3]

I then timed how long it took to write to the entire array:

# dd if=/dev/zero of=/dev/md0 bs=1M

Before: 892 MB/s
After:  999 MB/s

A 12% improvement.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:46 +10:00
Anton Blanchard bce4b4bd91 powerpc: Use enhanced touch instructions in POWER7 copy_to_user/copy_from_user
Version 2.06 of the POWER ISA introduced enhanced touch instructions,
allowing us to specify a number of attributes including the length of
a stream.

This patch adds a software stream for both loads and stores in the
POWER7 copy_tofrom_user loop. Since the setup is quite complicated
and we have to use an eieio to ensure correct ordering of the "GO"
command we only do this for copies above 4kB.

To quantify any performance improvements we need a working set
bigger than the caches so we operate on a 1GB file:

# dd if=/dev/zero of=/tmp/foo bs=1M count=1024

And we compare how fast we can read the file:

# dd if=/tmp/foo of=/dev/null bs=1M

before: 7.7 GB/s
after:  9.6 GB/s

A 25% improvement.

The worst case for this patch will be a completely L1 cache contained
copy of just over 4kB. We can test this with the copy_to_user
testcase we used to tune copy_tofrom_user originally:

http://ozlabs.org/~anton/junkcode/copy_to_user.c

# time ./copy_to_user2 -l 4224 -i 10000000

before: 6.807 s
after:  6.946 s

A 2% slowdown, which seems reasonable considering our data is unlikely
to be completely L1 contained.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:45 +10:00
Anton Blanchard fde69282b7 powerpc: POWER7 optimised copy_page using VMX and enhanced prefetch
Implement a POWER7 optimised copy_page using VMX and enhanced
prefetch instructions. We use enhanced prefetch hints to prefetch
both the load and store side. We copy a cacheline at a time and
fall back to regular loads and stores if we are unable to use VMX
(eg we are in an interrupt).

The following microbenchmark was used to assess the impact of
the patch:

http://ozlabs.org/~anton/junkcode/page_fault_file.c

We test MAP_PRIVATE page faults across a 1GB file, 100 times:

# time ./page_fault_file -p -l 1G -i 100

Before: 22.25s
After:  18.89s

17% faster

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:44 +10:00
Anton Blanchard 6f7839e542 powerpc: Rename copyuser_power7_vmx.c to vmx-helper.c
Subsequent patches will add more VMX library functions and it makes
sense to keep all the c-code helper functions in the one file.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:43 +10:00
Anton Blanchard ac1dc36558 powerpc: Clear RI and EE at the same time in system call exit
mtmsrd is an expensive instruction, we save a few cycles by
doing it once instead of twice.

Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:43 +10:00
Anton Blanchard a9514dc69d powerpc: Use enhanced touch instructions in POWER7 copy_to_user/copy_from_user
Version 2.06 of the POWER ISA introduced enhanced touch instructions,
allowing us to specify a number of attributes including the length of
a stream.

This patch adds a software stream for both loads and stores in the
POWER7 copy_tofrom_user loop. Since the setup is quite complicated
and we have to use an eieio to ensure correct ordering of the "GO"
command we only do this for copies above 4kB.

To quantify any performance improvements we need a working set
bigger than the caches so we operate on a 1GB file:

# dd if=/dev/zero of=/tmp/foo bs=1M count=1024

And we compare how fast we can read the file:

# dd if=/tmp/foo of=/dev/null bs=1M

before: 7.7 GB/s
after:  9.6 GB/s

A 25% improvement.

The worst case for this patch will be a completely L1 cache contained
copy of just over 4kB. We can test this with the copy_to_user
testcase we used to tune copy_tofrom_user originally:

http://ozlabs.org/~anton/junkcode/copy_to_user.c

# time ./copy_to_user2 -l 4224 -i 10000000

before: 6.807 s
after:  6.946 s

A 2% slowdown, which seems reasonable considering our data is unlikely
to be completely L1 contained.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:42 +10:00
Anton Blanchard 17968fbbd1 powerpc: 64bit optimised __clear_user
I noticed __clear_user high up in a profile of one of my RAID stress
tests. The testcase was doing a dd from /dev/zero which ends up
calling __clear_user.

__clear_user is basically a loop with a single 4 byte store which
is horribly slow. We can do much better by aligning the desination
and doing 32 bytes of 8 byte stores in a loop.

The following testcase was used to verify the patch:

http://ozlabs.org/~anton/junkcode/stress_clear_user.c

To show the improvement in performance I ran a dd from /dev/zero
to /dev/null on a POWER7 box:

Before:

# dd if=/dev/zero of=/dev/null bs=1M count=10000
10485760000 bytes (10 GB) copied, 3.72379 s, 2.8 GB/s

After:

# time dd if=/dev/zero of=/dev/null bs=1M count=10000
10485760000 bytes (10 GB) copied, 0.728318 s, 14.4 GB/s

Over 5x faster.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:41 +10:00
Anton Blanchard d136e27326 powerpc: tracing: Avoid tracepoint duplication with DECLARE_EVENT_CLASS
irq_entry, irq_exit, timer_interrupt_entry and timer_interrupt_exit
all do the same thing so use DECLARE_EVENT_CLASS to avoid duplicating
everything 4 times.

This saves quite a lot of space in both instruction text and data:

   text    data     bss     dec     hex filename
   9265   19622      16   28903    70e7 arch/powerpc/kernel/irq.o
   6817   19019      16   25852    64fc arch/powerpc/kernel/irq.o

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:41 +10:00
Anton Blanchard 641bd53a61 powerpc: Enable jump label support
When looking through some instruction traces I noticed our tracepoint
checks were inline. It turns out we don't have CONFIG_JUMP_LABEL
enabled.

By enabling CONFIG_JUMP_LABEL we replace a load/compare/branch with
a nop at every tracepoint call. For example in do_IRQ:

CONFIG_JUMP_LABEL disabled:
        stdx 3,11,9
        lwz 0,8(29)
        cmpwi 7,0,0
        bne- 7,.L124
        bl .irq_enter

CONFIG_JUMP_LABEL enabled:
        stdx 3,11,9
        nop
        bl .irq_enter

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-03 14:14:40 +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 <[email protected]>
CC: <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-07-02 14:30:11 +10:00
Anton Blanchard 0b17ba7258 powerpc: check_and_cede_processor() never cedes
Commit f948501b36 ("Make hard_irq_disable() actually hard-disable
interrupts") caused check_and_cede_processor to stop working.
->irq_happened will never be zero right after a hard_irq_disable
so the compiler removes the call to cede_processor completely.

The bug was introduced back in the lazy interrupt handling rework
of 3.4 but was hidden until recently because hard_irq_disable did
nothing.

This issue will eventually appear in 3.4 stable since the
hard_irq_disable fix is marked stable, so mark this one for stable
too.

Signed-off-by: Anton Blanchard <[email protected]>
Cc: [email protected]
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-06-29 14:35:37 +10:00
Anton Blanchard f39cdaebb8 fault-inject: avoid call to random32() if fault injection is disabled
After enabling CONFIG_FAILSLAB I noticed random32 in profiles even if slub
fault injection wasn't enabled at runtime.

should_fail forces a comparison against random32() even if probability is
0:

        if (attr->probability <= random32() % 100)
                return false;

Add a check up front for probability == 0 and avoid all of the more
complicated checks.

Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: Akinobu Mita <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2012-06-20 14:39:36 -07:00
Anton Blanchard 0fd7bee1e9 powerpc: Fix size of st_nlink on 64bit
commit e57f93cc53 (powerpc: get rid of nlink_t uses, switch to
explicitly-sized type) changed the size of st_nlink on ppc64 from
a long to a short, resulting in boot failures.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Al Viro <[email protected]>
2012-06-02 10:44:11 -04:00
Anton Blanchard ec34a68149 powerpc: Remove old powerpc specific ptrace getregs/setregs calls
PowerPC has non standard getregs calls that only dump the GPRs or
FPRs and have their arguments reversed. commit e17666ba48 (ptrace
updates & new, better requests) in 2.6.3 deprecated them and introduced
more standard versions.

It's been about 5 years and I know of no users of the old calls so
lets remove them.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:28 +10:00
Anton Blanchard 14fb1fa6e2 powerpc: Use WARN instead of dump_stack when printing EEH error backtrace
When we get an EEH error we just print a backtrace with dump_stack
which is rather cryptic. We really should print something before
spewing out the backtrace.

Also switch from dump_stack to WARN so we get more information about
the fail - what modules were loaded, what process was running etc.
This was useful information when debugging a recent EEH subsystem bug.

The standard WARN output should also get picked up by monitoring
tools like kerneloops.

The register dump is of questionable value here but I figured it was
better to use something standard and not roll my own.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:27 +10:00
Anton Blanchard d23c6fb4eb powerpc: Add 64-bit CPU targets for gcc
Add a menu to select various 64-bit CPU targets for gcc. We
default to -mtune=power7 and if gcc doesn't understand that we
fallback to -mtune=power4.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:27 +10:00
Anton Blanchard 894a65c857 powerpc: Remove altivec fix for gcc versions before 4.0
Now we require gcc 4.0 on 64-bit we can remove the pre gcc 4.0
-maltivec workaround.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:26 +10:00
Anton Blanchard 82a8508406 powerpc: Require gcc 4.0 on 64-bit
Older versions of gcc had issues with using -maltivec together with
-mcpu of a non altivec capable CPU. We work around it by specifying
-mcpu=970, but the logic is complicated.

In preparation for adding more -mcpu targets, remove the workaround
and just require gcc 4.0 for 64-bit builds.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:26 +10:00
Anton Blanchard 694caf0255 powerpc: Remove CONFIG_POWER4_ONLY
Remove CONFIG_POWER4_ONLY, the option is badly named and only does two
things:

- It wraps the MMU segment table code. With feature fixups there is
  little downside to compiling this in.

- It uses the newer mtocrf instruction in various assembly functions.
  Instead of making this a compile option just do it at runtime via
  a feature fixup.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:26 +10:00
Anton Blanchard 35000870fc powerpc: Optimise enable_kernel_altivec
Add two optimisations to enable_kernel_altivec:

- enable_kernel_altivec has already determined if we need to
save the previous task's state but we call giveup_altivec
in both cases, requiring an extra branch in giveup_altivec. Create
giveup_altivec_notask which only turns on the VMX bit in the
MSR.

- We write the VMX MSR bit each time we call enable_kernel_altivec
even it was already set. Check the bit and branch out if we have
already set it. The classic case for this is vectored IO
where we have to copy multiple buffers to or from userspace.

The following testcase was used to confirm this patch improves
performance:

http://ozlabs.org/~anton/junkcode/copy_to_user.c

Since the current breakpoint for using VMX in copy_tofrom_user is
4096 bytes, I'm using buffers of 4096 + 1 cacheline (4224) bytes.
A benchmark of 16 entry readvs (-s 16):

time copy_to_user -l 4224 -s 16 -i 1000000

completes 5.2% faster on a POWER7 PS700.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:17 +10:00
Anton Blanchard 8cd3c23df7 powerpc: Remove empty giveup_altivec function on book3e CPUs
Use an empty inline instead of an empty function to implement
giveup_altivec on book3e CPUs, similar to flush_altivec_to_thread.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:16 +10:00
Anton Blanchard 59c19cb2f6 powerpc: Reformat lppaca.h
Reformat lppaca.h to match Linux coding standards.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:16 +10:00
Anton Blanchard 448054a650 powerpc: Remove iseries specific fields in lppaca
Remove all the iseries specific fields in the lppaca.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:16 +10:00
Anton Blanchard cf8a056a22 powerpc: Clean up lppaca->cede_latency_hint
We have a union containing fields from the old iseries hypervisor
that has been reused for the cede latency hint. Since we no
longer support iseries, remove the union completely.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:15 +10:00
Anton Blanchard fd6c40f3b0 powerpc: Better scheduling of CR save code in system call path
At the moment system call entry looks like:

crclr	so
...
mfcr	r9
...
std	r9,_CCR(r1)

commit bd19c8994a ([POWERPC] system call micro optimisation) put
some space between the crclr and mfcr in order to avoid a stall.

There is still a stall seen between the mfcr and std. We can avoid
the crclr by doing it in a GPR with rlwinm which gives us more room
to better schedule the sequence.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:37:14 +10:00
Anton Blanchard 82087414c6 powerpc: No need to preserve count register across system call
The count register is volatile so we don't need to preserve it.
Store zero to the entry in the exception frame.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:35:10 +10:00
Anton Blanchard 823df43552 powerpc: No need to save XER in a system call
The XER is a volatile register so there is no need to save and restore
it over a system call - zero it out in the exception stack frame
instead.

This should fix a 5 cycle stall of the mfxer/std seen on POWER7.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:34:44 +10:00
Anton Blanchard d14299dec7 powerpc: Hide some system call labels from profile tools
syscall_dotrace_cont and syscall_error_cont tend to complicate perf
output so make them local.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-04-30 15:34:43 +10:00
Anton Blanchard 9012899781 powerpc/pseries: Cut down on enthusiastic use of defines in RAS code
So many defines for such a little file. Most of them can go.

Also remove the single entry changelog, we have git for that.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-03-28 11:32:01 +11:00
Anton Blanchard cc8b526366 powerpc/pseries: Clean up ras_error_interrupt code
The RAS error interrupt is no longer used but we may as well
mirror the changes we made to the EPOW interrupt.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-03-28 11:32:00 +11:00
Anton Blanchard 6f43747f6a powerpc/pseries: Remove RTAS_POWERMGM_EVENTS
IBM bit 2 in the rtas event-scan and check-exception calls is
marked reserved in the PAPR, so remove it from our RAS code.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-03-28 11:32:00 +11:00
Anton Blanchard 587f83e8dd powerpc/pseries: Use rtas_get_sensor in RAS code
We have rtas_get_sensor so we may as well use it.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-03-28 11:31:59 +11:00
Anton Blanchard 55fc0c5617 powerpc/pseries: Parse and handle EPOW interrupts
We have code to take environmental and power warning (EPOW)
interrupts but it simply prints a terse error message:

EPOW <0x6240040000000b8 0x0 0x0>

which tells us nothing about what happened. Even worse, if we
don't correctly respond to the interrupt we may get terminated
by firmware.

Add code to printk some useful information when we get EPOW events.
We want to make it clear that we have an error, that it was
reported by firmware and that the RTAS error log will have more
detailed information. eg:

	Ambient temperature too high reported by firmware.
	Check RTAS error log for details

Depending on the error encountered, we now issue an immediate or
an orderly power down.

Move initialization of the EPOW interrupt earlier in boot since we
want to respond to them as early as possible.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-03-28 11:31:59 +11:00
Anton Blanchard 6431f20879 powerpc: Make function that parses RTAS error logs global
The IO event interrupt code has a function that finds specific
sections in an RTAS error log. We want to use it in the EPOW
code so make it global.

Rename things to make it less cryptic:

find_xelog_section() -> get_pseries_errorlog()
struct pseries_elog_section -> struct pseries_errorlog

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-03-28 11:31:58 +11:00
Anton Blanchard c017386352 afs: Remote abort can cause BUG in rxrpc code
When writing files to afs I sometimes hit a BUG:

kernel BUG at fs/afs/rxrpc.c:179!

With a backtrace of:

	afs_free_call
	afs_make_call
	afs_fs_store_data
	afs_vnode_store_data
	afs_write_back_from_locked_page
	afs_writepages_region
	afs_writepages

The cause is:

	ASSERT(skb_queue_empty(&call->rx_queue));

Looking at a tcpdump of the session the abort happens because we
are exceeding our disk quota:

	rx abort fs reply store-data error diskquota exceeded (32)

So the abort error is valid. We hit the BUG because we haven't
freed all the resources for the call.

By freeing any skbs in call->rx_queue before calling afs_free_call
we avoid hitting leaking memory and avoid hitting the BUG.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: David Howells <[email protected]>
Cc: <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2012-03-16 17:01:41 -07:00
Anton Blanchard 2c724fb927 afs: Read of file returns EBADMSG
A read of a large file on an afs mount failed:

# cat junk.file > /dev/null
cat: junk.file: Bad message

Looking at the trace, call->offset wrapped since it is only an
unsigned short. In afs_extract_data:

        _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
...

        if (call->offset < count) {
                if (last) {
                        _leave(" = -EBADMSG [%d < %zu]", call->offset, count);
                        return -EBADMSG;
                }

Which matches the trace:

[cat   ] ==> afs_extract_data({65132},{524},1,,65536)
[cat   ] <== afs_extract_data() = -EBADMSG [0 < 65536]

call->offset went from 65132 to 0. Fix this by making call->offset an
unsigned int.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: David Howells <[email protected]>
Cc: <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2012-03-16 17:01:41 -07:00
Anton Blanchard b832796caa perf tools: Incorrect use of snprintf results in SEGV
I have a workload where perf top scribbles over the stack and we SEGV.
What makes it interesting is that an snprintf is causing this.

The workload is a c++ gem that has method names over 3000 characters
long, but snprintf is designed to avoid overrunning buffers. So what
went wrong?

The problem is we assume snprintf returns the number of characters
written:

    ret += repsep_snprintf(bf + ret, size - ret, "[%c] ", self->level);
...
    ret += repsep_snprintf(bf + ret, size - ret, "%s", self->ms.sym->name);

Unfortunately this is not how snprintf works. snprintf returns the
number of characters that would have been written if there was enough
space. In the above case, if the first snprintf returns a value larger
than size, we pass a negative size into the second snprintf and happily
scribble over the stack. If you have 3000 character c++ methods thats a
lot of stack to trample.

This patch fixes repsep_snprintf by clamping the value at size - 1 which
is the maximum snprintf can write before adding the NULL terminator.

I get the sinking feeling that there are a lot of other uses of snprintf
that have this same bug, we should audit them all.

Cc: David Ahern <[email protected]>
Cc: Eric B Munson <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Yanmin Zhang <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/20120307114249.44275ca3@kryten
Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2012-03-14 12:36:19 -03:00
Anton Blanchard a6cf7ed511 powerpc/atomic: Implement atomic*_inc_not_zero
Implement atomic_inc_not_zero and atomic64_inc_not_zero. At the
moment we use atomic*_add_unless which requires us to put 0 and
1 constants into registers. We can also avoid a subtract by
saving the original value in a second temporary.

This removes 3 instructions from fget:

- c0000000001b63c0:       39 00 00 00     li      r8,0
- c0000000001b63c4:       39 40 00 01     li      r10,1
...
- c0000000001b63e8:       7c 0a 00 50     subf    r0,r10,r0

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-03-07 17:06:08 +11:00
Anton Blanchard b1ada6010e atomic: Allow atomic_inc_not_zero to be overridden
We want to implement a ppc64 specific version of atomic_inc_not_zero
so wrap it in an ifdef to allow it to be overridden.

Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: Mike Frysinger <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-03-07 17:06:08 +11:00
Anton Blanchard 9a45a9407c powerpc/perf: power_pmu_start restores incorrect values, breaking frequency events
perf on POWER stopped working after commit e050e3f0a7 (perf: Fix
broken interrupt rate throttling). That patch exposed a bug in
the POWER perf_events code.

Since the PMCs count upwards and take an exception when the top bit
is set, we want to write 0x80000000 - left in power_pmu_start. We were
instead programming in left which effectively disables the counter
until we eventually hit 0x80000000. This could take seconds or longer.

With the patch applied I get the expected number of samples:

          SAMPLE events:       9948

Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: Paul Mackerras <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
Cc: <[email protected]>
2012-02-16 16:24:35 +11:00
Anton Blanchard a5ccfee05a powerpc: Fix RCU idle and hcall tracing
Tracepoints should not be called inside an rcu_idle_enter/rcu_idle_exit
region. Since pSeries calls H_CEDE in the idle loop, we were violating
this rule.

commit a7b152d534 (powerpc: Tell RCU about idle after hcall tracing)
tried to work around it by delaying the rcu_idle_enter until after we
called the hcall tracepoint, but there are a number of issues with it.

The hcall tracepoint trampoline code is called conditionally when the
tracepoint is enabled. If the tracepoint is not enabled we never call
rcu_idle_enter. The idle_uses_rcu check was also done at compile time
which breaks multiplatform builds.

The simple fix is to avoid tracing H_CEDE and rely on other tracepoints
and the hypervisor dispatch trace log to work out if we called H_CEDE.

This fixes a hang during boot on pSeries.

Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2012-01-11 11:54:20 +11:00
Anton Blanchard b206590c04 powerpc: Fix comment explaining our VSID layout
We support 16TB of user address space and half a million contexts
so update the comment to reflect this.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-19 14:41:22 +11:00
Anton Blanchard a66086b819 powerpc: POWER7 optimised copy_to_user/copy_from_user using VMX
Implement a POWER7 optimised copy_to_user/copy_from_user using VMX.
For large aligned copies this new loop is over 10% faster, and for
large unaligned copies it is over 200% faster.

If we take a fault we fall back to the old version, this keeps
things relatively simple and easy to verify.

On POWER7 unaligned stores rarely slow down - they only flush when
a store crosses a 4KB page boundary. Furthermore this flush is
handled completely in hardware and should be 20-30 cycles.

Unaligned loads on the other hand flush much more often - whenever
crossing a 128 byte cache line, or a 32 byte sector if either sector
is an L1 miss.

Considering this information we really want to get the loads aligned
and not worry about the alignment of the stores. Microbenchmarks
confirm that this approach is much faster than the current unaligned
copy loop that uses shifts and rotates to ensure both loads and
stores are aligned.

We also want to try and do the stores in cacheline aligned, cacheline
sized chunks. If the store queue is unable to merge an entire
cacheline of stores then the L2 cache will have to do a
read/modify/write. Even worse, we will serialise this with the stores
in the next iteration of the copy loop since both iterations hit
the same cacheline.

Based on this, the new loop does the following things:

1 - 127 bytes
Get the source 8 byte aligned and use 8 byte loads and stores. Pretty
boring and similar to how the current loop works.

128 - 4095 bytes
Get the source 8 byte aligned and use 8 byte loads and stores,
1 cacheline at a time. We aren't doing the stores in cacheline
aligned chunks so we will potentially serialise once per cacheline.
Even so it is much better than the loop we have today.

4096 - bytes
If both source and destination have the same alignment get them both
16 byte aligned, then get the destination cacheline aligned. Do
cacheline sized loads and stores using VMX.

If source and destination do not have the same alignment, we get the
destination cacheline aligned, and use permute to do aligned loads.

In both cases the VMX loop should be optimal - we always do aligned
loads and stores and are always doing stores in cacheline aligned,
cacheline sized chunks.

To be able to use VMX we must be careful about interrupts and
sleeping. We don't use the VMX loop when in an interrupt (which should
be rare anyway) and we wrap the VMX loop in disable/enable_pagefault
and fall back to the existing copy_tofrom_user loop if we do need to
sleep.

The VMX breakpoint of 4096 bytes was chosen using this microbenchmark:

http://ozlabs.org/~anton/junkcode/copy_to_user.c

Since we are using VMX and there is a cost to saving and restoring
the user VMX state there are two broad cases we need to benchmark:

- Best case - userspace never uses VMX

- Worst case - userspace always uses VMX

In reality a userspace process will sit somewhere between these two
extremes. Since we need to test both aligned and unaligned copies we
end up with 4 combinations. The point at which the VMX loop begins to
win is:

0% VMX
aligned		2048 bytes
unaligned	2048 bytes

100% VMX
aligned		16384 bytes
unaligned	8192 bytes

Considering this is a microbenchmark, the data is hot in cache and
the VMX loop has better store queue merging properties we set the
breakpoint to 4096 bytes, a little below the unaligned breakpoints.

Some future optimisations we can look at:

- Looking at the perf data, a significant part of the cost when a
  task is always using VMX is the extra exception we take to restore
  the VMX state. As such we should do something similar to the x86
  optimisation that restores FPU state for heavy users. ie:

        /*
         * If the task has used fpu the last 5 timeslices, just do a full
         * restore of the math state immediately to avoid the trap; the
         * chances of needing FPU soon are obviously high now
         */
        preload_fpu = tsk_used_math(next_p) && next_p->fpu_counter > 5;

  and

        /*
         * fpu_counter contains the number of consecutive context switches
         * that the FPU is used. If this is over a threshold, the lazy fpu
         * saving becomes unlazy to save the trap. This is an unsigned char
         * so that after 256 times the counter wraps and the behavior turns
         * lazy again; this to deal with bursty apps that only use FPU for
         * a short time
         */

- We could create a paca bit to mirror the VMX enabled MSR bit and check
  that first, avoiding multiple calls to calling enable_kernel_altivec.
  That should help with iovec based system calls like readv.

- We could have two VMX breakpoints, one for when we know the user VMX
  state is loaded into the registers and one when it isn't. This could
  be a second bit in the paca so we can calculate the break points quickly.

- One suggestion from Ben was to save and restore the VSX registers
  we use inline instead of using enable_kernel_altivec.

[BenH: Fixed a problem with preempt and fixed build without CONFIG_ALTIVEC]

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-19 14:40:40 +11:00
Anton Blanchard f6a290b419 [SCSI] mpt2sas: _scsih_smart_predicted_fault uses GFP_KERNEL in interrupt context
_scsih_smart_predicted_fault is called in an interrupt and therefore
must allocate memory using GFP_ATOMIC.

Signed-off-by: Anton Blanchard <[email protected]>
Cc: <[email protected]>
Signed-off-by: James Bottomley <[email protected]>
2011-12-12 12:20:49 +04:00
Anton Blanchard 7c637b04fb powerpc: Enable squashfs as a module
Most distros use it so we may as well enable it and get regular compile
testing.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:22:54 +11:00
Anton Blanchard 120a52c388 powerpc/nvram: Add spinlock to oops_to_nvram to prevent oops in compression code.
When issuing a system reset we almost always oops in the oops_to_nvram
code because multiple CPUs are using the deflate work area. Add a
spinlock to protect it.

To play it safe I'm using trylock to avoid locking up if the NVRAM
code oopses. This means we might miss multiple CPUs oopsing at exactly
the same time but I think it's best to play it safe for now. Once we
are happy with the reliability we can change it to a full spinlock.

Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: Jim Keniston <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:22:54 +11:00
Anton Blanchard 3339264042 powerpc/pseries: Increase minimum RMO size from 64MB to 256MB
The minimum RMO size field in ibm,client-architecture is currently
ignored, but a future firmware version will rectify that. Since we
always get at least 128MB of RMO right now, asking for 64MB is
likely to result in boot failures.

We should bump it to at least 128MB, but considering all the boot
issues we have on 128MB RMO boxes and all new machines have virtual
RMO, we may as well set our minimum to 256MB.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:22:53 +11:00
Anton Blanchard 2440c01e10 powerpc/kdump: Only save CPU state first time through the secondary CPU capture code
We might enter the secondary CPU capture code twice, eg if we have to
unstick some CPUs with a system reset. In this case we don't want to
overwrite the state on CPUs that had made it into the capture code OK,
so use the cpus_state_saved cpumask for that and make it local to
crash_ipi_callback.

For controlling progress now use atomic_t cpus_in_crash to count how
many CPUs have made it into the kdump code, and time_to_dump to tell
everyone it's time to dump.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:02:24 +11:00
Anton Blanchard 549e88a134 powerpc/kdump: Delay before sending IPI on a system reset
If we enter the kdump code via system reset, wait a bit before
sending the IPI to capture all secondary CPUs. Without it we race
with the hypervisor that is issuing the system reset to each CPU.
If the IPI gets there first the system reset oops output then shows
the register state of the IPI handler which is not what we want.

I took the opportunity to add defines for all the various delays
we have. There's no need for cpu_relax when we are doing an mdelay,
so remove them too.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:02:24 +11:00
Anton Blanchard 90e8f57cf8 powerpc/xics: Reset the CPPR if H_EOI fails
I have an intermittent kdump fail where the hypervisor fails an H_EOI.
As a result our CPPR is never reset to 0xff and we no longer accept
interrupts.

This patch calls icp_hv_set_cppr to reset the CPPR if H_EOI fails,
fixing the kdump fail.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:02:23 +11:00
Anton Blanchard a934904d8a powerpc: Reduce pseries panic timeout from 180s to 10s
We've had a 180 second panic timeout on ppc64 for as long as I
can remember. This patch reduces it to 10 seconds on pseries for a few
reasons:

- Almost all pseries machines have a hypervisor console so panic
  output will be available in a scrollback buffer.

- The 180 seconds impacts our availability, users (other than
  kernel hackers) just want the box to come back around so it
  can continue its work.

- I spend a lot of my life staring at the 180 second panic timeout.
  Many pseries machines take minutes to power cycle, so it's quicker
  to sit through the 180 seconds than it is to power cycle.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:02:23 +11:00
Anton Blanchard 760ca4dc90 powerpc: Rework die()
Our die() code was based off a very old x86 version. Update it to
mirror the current x86 code.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:02:23 +11:00
Anton Blanchard 8c27474a25 powerpc: Cleanup crash/kexec code
Remove some unnecessary defines and fix some spelling mistakes.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:02:23 +11:00
Anton Blanchard 07fe0c6132 powerpc/kdump: Use setjmp/longjmp to handle kdump and system reset recursion
We can handle recursion caused by system reset by reusing the crash
shutdown fault handler.

Since we don't have an OS triggerable NMI, if all CPUs don't make it
into kdump then we tell the user to issue a system reset. However if
we have a panic timeout set we cannot wait forever and must continue
the kdump.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:02:22 +11:00
Anton Blanchard 9b00ac0697 powerpc: Remove broken and complicated kdump system reset code
We have a lot of complicated logic that handles possible recursion between
kdump and a system reset exception. We can solve this in a much simpler
way using the same setjmp/longjmp tricks xmon does.

As a first step, this patch removes the old system reset code.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:02:22 +11:00
Anton Blanchard 58154c8ce7 powerpc: Give us time to get all oopses out before panicking
I've been seeing truncated output when people send system reset info
to me. We should see a backtrace for every CPU, but the panic() code
takes the box down before they all make it out to the console. The
panic code runs unlocked so we also see corrupted console output.

If we are going to panic, then delay 1 second before calling into the
panic code. Move oops_exit inside the die lock and put a newline
between oopses for clarity.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-12-08 14:02:22 +11:00
Anton Blanchard 38f6ae1e1b perf stat: Failure with "Operation not supported"
perf stat is failing on PowerPC:

  Error: open_counter returned with 95 (Operation not supported). /bin/dmesg may provide additional information.

  Fatal: Not all events could be opened.

commit 370faf1dd0 (perf stat: Fail softly on unsupported events)
added a check for failure returning ENOENT, but the POWER backend
returns EOPNOTSUPP. It looks like alpha, blackfin and mips do the
same.

With the patch applied, things work as expected:

 Performance counter stats for '/bin/true':

          0.362176 task-clock                #    0.623 CPUs utilized
                 0 context-switches          #    0.000 M/sec
                 0 CPU-migrations            #    0.000 M/sec
                28 page-faults               #    0.077 M/sec
         1,677,020 cycles                    #    4.630 GHz
   <not supported> stalled-cycles-frontend
   <not supported> stalled-cycles-backend
           431,220 instructions              #    0.26  insns per cycle
           101,889 branches                  #  281.325 M/sec
             4,145 branch-misses             #    4.07% of all branches

       0.000581361 seconds time elapsed

Cc: <[email protected]> # 3.0+
Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/20111202093833.5fef7226@kryten
Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2011-12-05 14:32:40 -02:00
Anton Blanchard 5cac98dd06 net: Fix corruption in /proc/*/net/dev_mcast
I just hit this during my testing. Isn't there another bug lurking?

BUG kmalloc-8: Redzone overwritten

INFO: 0xc0000000de9dec48-0xc0000000de9dec4b. First byte 0x0 instead of 0xcc
INFO: Allocated in .__seq_open_private+0x30/0xa0 age=0 cpu=5 pid=3896
	.__kmalloc+0x1e0/0x2d0
	.__seq_open_private+0x30/0xa0
	.seq_open_net+0x60/0xe0
	.dev_mc_seq_open+0x4c/0x70
	.proc_reg_open+0xd8/0x260
	.__dentry_open.clone.11+0x2b8/0x400
	.do_last+0xf4/0x950
	.path_openat+0xf8/0x480
	.do_filp_open+0x48/0xc0
	.do_sys_open+0x140/0x250
	syscall_exit+0x0/0x40

dev_mc_seq_ops uses dev_seq_start/next/stop but only allocates
sizeof(struct seq_net_private) of private data, whereas it expects
sizeof(struct dev_iter_state):

struct dev_iter_state {
	struct seq_net_private p;
	unsigned int pos; /* bucket << BUCKET_SPACE + offset */
};

Create dev_seq_open_ops and use it so we don't have to expose
struct dev_iter_state.

[ Problem added by commit f04565ddf5 (dev: use name hash for
  dev_seq_ops) -Eric ]

Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-11-28 18:07:29 -05:00
Anton Blanchard 3ce21cdfe9 powerpc/xics: Harden xics hypervisor backend
During kdump stress testing I sometimes see the kdump kernel panic
with:

  Interrupt 0x306 (real) is invalid, disabling it.
  Kernel panic - not syncing: bad return code EOI - rc = -4, value=ff000306

Instead of panicing print the error message, dump the stack the first
time it happens and continue on. Add some more information to the
debug messages as well.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-28 11:42:09 +11:00
Anton Blanchard 3bfd0c9c8f powerpc: Decode correct MSR bits in oops output
On a 64bit book3s machine I have an oops from a system reset that
claims the book3e CE bit was set:

MSR: 8000000000021032 <ME,CE,IR,DR>  CR: 24004082  XER: 00000010

On a book3s machine system reset sets IBM bit 46 and 47 depending on
the power saving mode. Separate the definitions by type and for
completeness add the rest of the bits in.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-28 11:42:09 +11:00
Anton Blanchard 7df1027542 powerpc/time: Optimise decrementer_check_overflow
decrementer_check_overflow is called from arch_local_irq_restore so
we want to make it as light weight as possible. As such, turn
decrementer_check_overflow into an inline function.

To avoid a circular mess of includes, separate out the two components
of struct decrementer_clock and keep the struct clock_event_device
part local to time.c.

The fast path improves from:

arch_local_irq_restore
     0:       mflr    r0
     4:       std     r0,16(r1)
     8:       stdu    r1,-112(r1)
     c:       stb     r3,578(r13)
    10:       cmpdi   cr7,r3,0
    14:       beq-    cr7,24 <.arch_local_irq_restore+0x24>
...
    24:       addi    r1,r1,112
    28:       ld      r0,16(r1)
    2c:       mtlr    r0
    30:       blr

to:

arch_local_irq_restore
    0:       std     r30,-16(r1)
    4:       ld      r30,0(r2)
    8:       stb     r3,578(r13)
    c:       cmpdi   cr7,r3,0
   10:       beq-    cr7,6c <.arch_local_irq_restore+0x6c>
...
   6c:       ld      r30,-16(r1)
   70:       blr

Unfortunately we still setup a local TOC (due to -mminimal-toc). Yet
another sign we should be moving to -mcmodel=medium.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-25 14:11:26 +11:00
Anton Blanchard 621692cb7e powerpc/time: Fix some style issues
Fix some formatting issues and use the DECREMENTER_MAX
define instead of 0x7fffffff.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-25 14:10:00 +11:00
Anton Blanchard 68568add2c powerpc/time: Remove unnecessary sanity check of decrementer expiration
The clockevents code uses max_delta_ns to avoid calling a
clockevent with too large a value.

Remove the redundant version of this in the timer_interrupt
code.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-25 14:09:59 +11:00
Anton Blanchard 11b8633ada powerpc/time: Use clocksource_register_hz
Use clocksource_register_hz which calculates the shift/mult
factors for us. Also remove the shift = 22 assumption in
vsyscall_update - thanks to Paul Mackerras and John Stultz for
catching that.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-25 14:09:59 +11:00
Anton Blanchard d8afc6fd95 powerpc/time: Use clockevents_calc_mult_shift
We can use clockevents_calc_mult_shift instead of doing all
the work ourselves.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-25 14:09:59 +11:00
Anton Blanchard 37fb9a0231 powerpc/time: Handle wrapping of decrementer
When re-enabling interrupts we have code to handle edge sensitive
decrementers by resetting the decrementer to 1 whenever it is negative.
If interrupts were disabled long enough that the decrementer wrapped to
positive we do nothing. This means interrupts can be delayed for a long
time until it finally goes negative again.

While we hope interrupts are never be disabled long enough for the
decrementer to go positive, we have a very good test team that can
drive any kernel into the ground. The softlockup data we get back
from these fails could be seconds in the future, completely missing
the cause of the lockup.

We already keep track of the timebase of the next event so use that
to work out if we should trigger a decrementer exception.

Signed-off-by: Anton Blanchard <[email protected]>
Cc: [email protected]
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-25 14:09:58 +11:00
Anton Blanchard 67c170a24f ehea: Use round_jiffies_relative to align workqueue
Use round_jiffies_relative to align the ehea workqueue and avoid
extra wakeups.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-11-23 19:14:20 -05:00
Anton Blanchard aa9084a01a ehea: Reduce memory usage in buffer pools
Now that we enable multiqueue by default the ehea driver is using
quite a lot of memory for its buffer pools. With 4 queues we
consume 64MB in the jumbo packet ring, 16MB in the medium packet
ring and 16MB in the tiny packet ring.

We should only fill the jumbo ring once the MTU is increased but
for now halve it's size so it consumes 32MB. Also reduce the tiny
packet ring, with 4 queues we had 16k entries which is overkill.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-11-23 19:14:20 -05:00
Anton Blanchard d715e433b7 powerpc: Copy down exception vectors after feature fixups
kdump fails because we try to execute an HV only instruction. Feature
fixups are being applied after we copy the exception vectors down to 0
so they miss out on any updates.

We have always had this issue but it only became critical in v3.0
when we added CFAR support (breaks POWER5) and v3.1 when we added
POWERNV (breaks everyone).

Signed-off-by: Anton Blanchard <[email protected]>
Cc: <[email protected]> [v3.0+]
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-16 14:47:54 +11:00
Anton Blanchard 6d1e2c6c1a powerpc: panic if we can't instantiate RTAS
I had to debug a strange situation where all manner of things were
failing. SMT threads, storage and network were all completely broken.

The root cause was we couldn't find enough memory to instantiate RTAS -
this was a network install so the initrd was huge.

Instead of limping along and failing in mysterious ways we should just
panic up front if RTAS exists and we can't allocate space for it.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-16 14:47:54 +11:00
Anton Blanchard c40dd2f766 powerpc: Add System RAM to /proc/iomem
We've resisted adding System RAM to /proc/iomem because it is
the wrong place for it. Unfortunately we continue to find tools
that rely on this behaviour so give up and add it in.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
2011-11-08 14:51:46 +11:00
Anton Blanchard f7c9c6bb14 [SCSI] Fix block queue and elevator memory leak in scsi_alloc_sdev
When looking at memory consumption issues I noticed quite a
lot of memory in the kmalloc-2048 bucket:

  OBJS ACTIVE  USE OBJ SIZE  SLABS OBJ/SLAB CACHE SIZE NAME
  6561   6471  98%    2.30K    243       27     15552K kmalloc-2048

Over 15MB. slub debug shows that cfq is responsible for almost
all of it:

# sort -nr /sys/kernel/slab/kmalloc-2048/alloc_calls
6402 .cfq_init_queue+0xec/0x460 age=43423/43564/43655 pid=1 cpus=4,11,13

In scsi_alloc_sdev we do scsi_alloc_queue but if slave_alloc
fails we don't free it with scsi_free_queue.

The patch below fixes the issue:

  OBJS ACTIVE  USE OBJ SIZE  SLABS OBJ/SLAB CACHE SIZE NAME
   135     72  53%    2.30K      5       27       320K kmalloc-2048

# cat /sys/kernel/slab/kmalloc-2048/alloc_calls
3 .cfq_init_queue+0xec/0x460 age=3811/3876/3925 pid=1 cpus=4,11,13

Signed-off-by: Anton Blanchard <[email protected]>
Cc: <[email protected]>		#2.6.38+
Signed-off-by: James Bottomley <[email protected]>
2011-11-03 11:19:50 +04:00
Anton Blanchard e6f8aa9b90 ehea: Remove unused tcp_end field in send WQ
The tcp_end field is not actually used by the hardware, so there
is no need to set it.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-10-17 19:00:55 -04:00
Anton Blanchard 3428414f71 ehea: Add GRO support
Add GRO support to the ehea driver.

v3:
[cascardo] no need to enable GRO, since it's enabled by default
[cascardo] vgrp was removed in the vlan cleanup

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-10-17 19:00:55 -04:00
Anton Blanchard 2cb1deb56f ehea: Remove LRO support
In preparation for adding GRO to ehea, remove LRO.

v3:
[cascardo] fixed conflict with vlan cleanup

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-10-17 19:00:55 -04:00
Anton Blanchard 239c562c94 ehea: Add 64bit statistics
Switch to using ndo_get_stats64 to get 64bit statistics.

v3:
[cascardo] use rtnl_link_stats64 as port stats

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-10-17 19:00:55 -04:00
Anton Blanchard 39874861f7 ehea: Remove some unused definitions
The queue macros are many levels deep and it makes it harder to
work your way through them when many of the versions are unused.
Remove the unused versions.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-10-17 19:00:55 -04:00
Anton Blanchard 30e2e90b4d ehea: Simplify type 3 transmit routine
If a nonlinear skb fits within the immediate area, use skb_copy_bits
instead of copying the frags by hand.

v3:
[cascardo] fixed conflict with use of skb frag API

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-10-17 19:00:55 -04:00
Anton Blanchard 13946f5e4e ehea: Merge swqe2 TSO and non TSO paths
write_swqe2_TSO and write_swqe2_nonTSO are almost identical.

For TSO we have to set the TSO and mss bits in the wqe and we only
put the header in the immediate area, no data. Collapse both
functions into write_swqe2_immediate.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2011-10-17 19:00:55 -04:00