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2840 commits

Author SHA1 Message Date
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
Anton Blanchard
eca590f402 powerpc/rtas: Only sleep in rtas_busy_delay if we have useful work to do
RTAS returns extended error codes as a hint of how long the
OS might want to wait before retrying a call. If we have nothing
else useful to do we may as well call back straight away.

This was found when testing the new dynamic dma window feature.
Firmware split the zeroing of the TCE table into 32k chunks but
returned 9901 (which is a suggested wait of 10ms). All up this took
about 10 minutes to complete since msleep is jiffies based and will
round 10ms up to 20ms.

With the patch below we take 3 seconds to complete the same test.
The hint firmware is returning in the RTAS call should definitely
be decreased, but even if we slept 1ms each iteration this would
take 32s.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 14:18:50 +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
Michael Ellerman
73706c3283 powerpc/irq: Dump chip data pointer in virq_mapping
This can be useful for differentiating interrupts on the same host
but with different chip data.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 14:18:37 +10:00
Michael Ellerman
69b123684b powerpc/pci: Properly initialize IO workaround "private"
Even when no initfunc is provided.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 14:18:33 +10:00
Michael Ellerman
d1109b7529 powerpc/pci: Make IO workarounds init implicit when first bus is registered
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 14:18:31 +10:00
Michael Ellerman
3cc30d0726 powerpc/pci: Move IO workarounds to the common kernel dir
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 14:18:29 +10:00
Alexey Kardashevskiy
efcac6589a powerpc: Per process DSCR + some fixes (try#4)
The DSCR (aka Data Stream Control Register) is supported on some
server PowerPC chips and allow some control over the prefetch
of data streams.

This patch allows the value to be specified per thread by emulating
the corresponding mfspr and mtspr instructions. Children of such
threads inherit the value. Other threads use a default value that
can be specified in sysfs - /sys/devices/system/cpu/dscr_default.

If a thread starts with non default value in the sysfs entry,
all children threads inherit this non default value even if
the sysfs value is changed later.

Signed-off-by: Alexey Kardashevskiy <aik@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 14:18:19 +10:00
Jack Miller
f0aae3238f powerpc/book3e: Flush IPROT protected TLB entries leftover by firmware
When we set up the TLB for ourselves on Book3E, we need to flush out any
old mappings established by the firmware or bootloader.  At present we
attempt this with a tlbilx to flush everything, but this will leave behind
any entries with the IPROT bit set.

There are several good reason firmware might establish mappings with IPROT,
and in fact ePAPR compliant firmwares are required to establish their
initial mapped area with IPROT.

This patch, therefore adds more complex code to scan through the TLB upon
entry and flush away any entries that are not our own.

Signed-off-by: Jack Miller <jack@codezen.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 13:02:16 +10:00
Benjamin Herrenschmidt
1a51dde139 powerpc/book3e: Use way 3 for linear mapping bolted entry
An erratum on A2 can lead to the bolted entry we insert for the linear
mapping being evicted, to avoid that write the bolted entry to way 3.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 13:02:14 +10:00
Michael Ellerman
ca1769f7a3 powerpc: Index crit/dbg/mcheck stacks using cpu number on 64bit
In exc_lvl_ctx_init() we index into the crit/dbg/mcheck stacks using
the hard cpu id, but that assumes the hard cpu id is zero based and
contiguous. That is not the case on A2.

The root of the problem is that the 32bit code has no equivalent of the
paca to allow it to do the hard->soft mapping in assembler. Until the
32bit code is updated to handle that, index the stacks using the soft
cpu ids on 64bit and hard on 32 bit.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 13:02:12 +10:00
Benjamin Herrenschmidt
76b4eda866 powerpc: Add A2 cpu support
Add the cputable entry, regs and setup & restore entries for
the PowerPC A2 core.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27 13:02:02 +10:00
Michael Ellerman
de30097476 powerpc/smp: smp_ops->kick_cpu() should be able to fail
When we start a cpu we use smp_ops->kick_cpu(), which currently
returns void, it should be able to fail. Convert it to return
int, and update all uses.

Convert all the current error cases to return -ENOENT, which is
what would eventually be returned by __cpu_up() currently when
it doesn't detect the cpu as coming up in time.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 17:01:18 +10:00
Benjamin Herrenschmidt
af2771493a powerpc: Improve prom_printf()
Adds the ability to print decimal numbers and adds some more
format string variants

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:25 +10:00
Benjamin Herrenschmidt
dd79773864 powerpc: Perform an isync to synchronize CPUs coming out of secondary_hold
We need to do that to guarantee they see any code change done by
dynamic patching during boot.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:25 +10:00
Benjamin Herrenschmidt
948cf67c47 powerpc: Add NAP mode support on Power7 in HV mode
Wakeup comes from the system reset handler with a potential loss of
the non-hypervisor CPU state. We save the non-volatile state on the
stack and a pointer to it in the PACA, which the system reset handler
uses to restore things

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:24 +10:00
Benjamin Herrenschmidt
9d07bc841c powerpc: Properly handshake CPUs going out of boot spin loop
We need to wait a bit for them to have done their CPU setup
or we might end up with translation and EE on with different
LPCR values between threads

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:24 +10:00
Benjamin Herrenschmidt
ad0693ee72 powerpc: Call CPU ->restore callback earlier on secondary CPUs
We do it before we loop on the PACA start flag. This way, we get a
chance to set critical SPRs on all CPUs before Linux tries to start
them up, which avoids problems when changing some bits such as LPCR
bits that need to be identical on all threads of a core or similar
things like that. Ideally, some of that should also be done before
the MMU is enabled, but that's a separate issue which would require
moving some of the SMP startup code earlier, let's not get there
for now, it works with that change alone.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:24 +10:00
Benjamin Herrenschmidt
b144871cb5 powerpc: Initialize TLB and LPID register on HV mode Power7
In case entry from the bootloader isn't "clean"

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:24 +10:00
Benjamin Herrenschmidt
895796a8ab powerpc: Initialize LPCR:DPFD on power7 to a sane default
This sets the default data stream prefetch size for operating
systems that don't set their own value in DSCR. We use 4 which
is "medium".

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:23 +10:00
Paul Mackerras
673b189a2e powerpc: Always use SPRN_SPRG_HSCRATCH0 when running in HV mode
This uses feature sections to arrange that we always use HSPRG1
as the scratch register in the interrupt entry code rather than
SPRG2 when we're running in hypervisor mode on POWER7.  This will
ensure that we don't trash the guest's SPRG2 when we are running
KVM guests.  To simplify the code, we define GET_SCRATCH0() and
SET_SCRATCH0() macros like the GET_PACA/SET_PACA macros.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:23 +10:00
Benjamin Herrenschmidt
b3e6b5dfcf powerpc: More work to support HV exceptions
Rework exception macros a bit to split offset from vector and add
some basic support for HDEC, HDSI, HISI and a few more.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:23 +10:00
Benjamin Herrenschmidt
a5d4f3ad3a powerpc: Base support for exceptions using HSRR0/1
Pass the register type to the prolog, also provides alternate "HV"
version of hardware interrupt (0x500) and adjust LPES accordingly

We tag those interrupts by setting bit 0x2 in the trap number

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:22 +10:00
Benjamin Herrenschmidt
2dd60d79e0 powerpc: In HV mode, use HSPRG0 for PACA
When running in Hypervisor mode (arch 2.06 or later), we store the PACA
in HSPRG0 instead of SPRG1. The architecture specifies that SPRGs may be
lost during a "nap" power management operation (though they aren't
currently on POWER7) and this enables use of SPRG1 by KVM guests.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:22 +10:00
Benjamin Herrenschmidt
24cc67de62 powerpc: Define CPU feature for Architected 2.06 HV mode
This bit indicates that we are operating in hypervisor mode on a CPU
compliant to architecture 2.06 or later (currently server only).

We set it on POWER7 and have a boot-time CPU setup function that
clears it if MSR:HV isn't set (booting under a hypervisor).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 11:03:22 +10:00
Eric B Munson
86c74ab317 powerpc/perf_event: Skip updating kernel counters if register value shrinks
Because of speculative event roll back, it is possible for some event coutners
to decrease between reads on POWER7.  This causes a problem with the way that
counters are updated.  Delta calues are calculated in a 64 bit value and the
top 32 bits are masked.  If the register value has decreased, this leaves us
with a very large positive value added to the kernel counters.  This patch
protects against this by skipping the update if the delta would be negative.
This can lead to a lack of precision in the coutner values, but from my testing
the value is typcially fewer than 10 samples at a time.

Signed-off-by: Eric B Munson <emunson@mgebm.net>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-18 13:08:23 +10:00
Anton Blanchard
84ffae55af powerpc: Fix oops if scan_dispatch_log is called too early
We currently enable interrupts before the dispatch log for the boot
cpu is setup. If a timer interrupt comes in early enough we oops in
scan_dispatch_log:

Unable to handle kernel paging request for data at address 0x00000010

...

.scan_dispatch_log+0xb0/0x170
.account_system_vtime+0xa0/0x220
.irq_enter+0x88/0xc0
.do_IRQ+0x48/0x230

The patch below adds a check to scan_dispatch_log to ensure the
dispatch log has been allocated.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-18 13:08:19 +10:00
Paul Gortmaker
7c7a81b53e powerpc/kexec: Fix regression causing compile failure on UP
Recent commit b987812b3f caused
a compile failure on UP because a considerably large block
of the file was included within CONFIG_SMP, hence making a stub
function not exposed on UP builds when it needed to be.

Relocate the stub to the #else /* ! CONFIG_SMP */ section
and also annotate the relevant else/endif so that nobody
else falls into the same trap I did.

Reported-by: Michael Guntsche <mike@it-loops.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-18 13:06:45 +10:00
Benjamin Herrenschmidt
8f3dda75cb Merge remote branch 'kumar/merge' into merge 2011-04-18 12:09:37 +10:00
Kumar Gala
11ed0db9f6 powerpc/book3e: Fix CPU feature handling on 64-bit e5500
The CPU_FTRS_POSSIBLE and CPU_FTRS_ALWAYS defines did not encompass
e5500 CPU features when built for 64-bit.  This causes issues with
cpu_has_feature() as it utilizes the POSSIBLE & ALWAYS defines as part
of its check.

Create a unique CPU_FTRS_E5500 (as its different from CPU_FTRS_E500MC),
created a new group for 64-bit Book3e based CPUs and add CPU_FTRS_E5500
to that group.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2011-04-12 06:29:21 -05:00
Prabhakar Kushwaha
07d9fce24d powerpc: Check device status before adding serial device
serial port nodes with the property status="disabled" are not usable and so
avoid adding "disabled" port with the system.

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2011-04-12 06:29:21 -05:00
Rafael J. Wysocki
1f112cee07 PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKS
Xen save/restore is going to use hibernate device callbacks for
quiescing devices and putting them back to normal operations and it
would need to select CONFIG_HIBERNATION for this purpose.  However,
that also would cause the hibernate interfaces for user space to be
enabled, which might confuse user space, because the Xen kernels
don't support hibernation.  Moreover, it would be wasteful, as it
would make the Xen kernels include a substantial amount of code that
they would never use.

To address this issue introduce new power management Kconfig option
CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code
that is necessary for the hibernate device callbacks to work and make
CONFIG_HIBERNATION select it.  Then, Xen save/restore will be able to
select CONFIG_HIBERNATE_CALLBACKS without dragging the entire
hibernate code along with it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
2011-04-11 22:54:42 +02:00
Linus Torvalds
42933bac11 Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6
* 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6:
  Fix common misspellings
2011-04-07 11:14:49 -07:00
Ryan Grimm
c1854e0072 powerpc: Set nr_cpu_ids early and use it to free PACAs
Without this, "holes" in the CPU numbering can cause us to
free too many PACAs

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-05 16:22:11 +10:00
Paul Gortmaker
b987812b3f powerpc/kexec: Fix mismatched ifdefs for PPC64/SMP.
Commit b3df895aeb "powerpc/kexec: Add support for FSL-BookE"
introduced the original PPC_STD_MMU_64 checks around the function
crash_kexec_wait_realmode().   Then commit c2be05481f
"powerpc: Fix default_machine_crash_shutdown #ifdef botch" changed
the ifdef around the calling site to add a check on SMP, but the
ifdef around the function itself was left unchanged, leaving an
unused function for PPC_STD_MMU_64=y and SMP=n

Rather than have two ifdefs that can get out of sync like this,
simply put the corrected conditional around the function and use
a stub to get rid of one set of ifdefs completely.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-05 16:22:10 +10:00
Benjamin Herrenschmidt
aeeafbfa7a powerpc/smp: Increase vdso_data->processorCount, not just decrease it
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:36 +11:00
Benjamin Herrenschmidt
c56e58537d powerpc/smp: Create idle threads on demand and properly reset them
Instead of creating idle threads at boot for all possible CPUs, we
create them on demand, like x86 or ARM, and we properly call init_idle
to re-initialize an idle thread when a CPU was unplugged and is now
re-plugged.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:34 +11:00
Benjamin Herrenschmidt
105765f451 powerpc/smp: Don't expose per-cpu "cpu_state" array
Instead, keep it static, expose an accessor and use that from
the PowerMac code. Avoids easy namespace collisions and will
make it easier to consolidate with other implementations.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:33 +11:00
Benjamin Herrenschmidt
d72944457b powerpc/smp: Add a smp_ops->bringup_up() done callback
This allows us to stop abusing smp_ops->setup_cpu() for cleanup
tasks that have to take place after the initial boot time CPU
bringup.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:29 +11:00
Benjamin Herrenschmidt
62cc67b9df powerpc/pmac/smp: Properly NAP offlined CPU on G5
The current code soft-disables, and then goes to NAP mode which
turns interrupts on. That means that if an interrupt occurs, we
will hit the masked interrupt code path which isn't what we want,
as it will return with EE off, which will either get us out of
NAP mode, or fail to enter it (according to spec).

Instead, let's just rely on the fact that it is safe to take
decrementer interrupts on an offline CPU and leave interrupts
enabled. We can also get rid of the special case in asm for
power4_cpu_offline_powersave() and just use power4_idle().

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:25 +11:00
Benjamin Herrenschmidt
1c91cc5705 powerpc/pmac/smp: Rename fixup_irqs() to migrate_irqs() and use it on ppc32
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:18 +11:00
Benjamin Herrenschmidt
7a53a4fe70 powerpc/smp: Remove unused smp_ops->cpu_enable()
Remove the last remnants of cpu_enable(), everybody uses the normal
__cpu_up() path now

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:14 +11:00
Benjamin Herrenschmidt
b527d07114 powerpc/smp: Remove unused generic_cpu_enable()
Nobody uses it, besides we should always use the normal __cpu_up
path anyways

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:12 +11:00
Benjamin Herrenschmidt
4fcb8833af powerpc/smp: Fix generic_mach_cpu_die()
This is used by some "soft" hotplug implementations. I needs to
call idle_task_exit() when the CPU is going away, and we remove
the now no-longer needed set_cpu_online() and local_irq_enable()
which are handled by the return to start_secondary

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:10 +11:00
Benjamin Herrenschmidt
fa3f82c8bb powerpc/smp: soft-replugged CPUs must go back to start_secondary
Various thing are torn down when a CPU is hot-unplugged. That CPU
is expected to go back to start_secondary when re-plugged to re
initialize everything, such as clock sources, maps, ...

Some implementations just return from cpu_die() callback
in the idle loop when the CPU is "re-plugged". This is not enough.

We fix it using a little asm trampoline which resets the stack
and calls back into start_secondary as if we were all fresh from
boot. The trampoline already existed on ppc64, but we add it for
ppc32

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:09 +11:00
Benjamin Herrenschmidt
963e5d3b76 powerpc: Make decrementer interrupt robust against offlined CPUs
With some implementations, it is possible that a timer interrupt
occurs every few seconds on an offline CPU. In this case, just
re-arm the decrementer and return immediately

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:07 +11:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Benjamin Herrenschmidt
84493804bb powerpc/mm: Move the STAB0 location to 0x8000 to make room in low memory
Recent upstream builds with allmodconfig fail due to lack of space
between 0x3000 and 0x6000. We have a hard block at 0x7000 but we can
spare a page by moving the STAB0 from 0x6000 to 0x8000.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-30 10:44:20 +11:00
Anton Blanchard
ad5d1c888e powerpc: Fix accounting of softirq time when idle
commit cf9efce0ce (powerpc: Account time using timebase rather
than PURR) used in_irq() to detect if the time was spent in
interrupt processing. This only catches hardirq context so if we
are in softirq context and in the idle loop we end up accounting it
as idle time. If we instead use in_interrupt() we catch both softirq
and hardirq time.

The issue was found when running a network intensive workload. top
showed the following:

0.0%us,  1.1%sy,  0.0%ni, 85.7%id,  0.0%wa,  9.9%hi,  3.3%si,  0.0%st

85.7% idle. But this was wildly different to the perf events data.
To confirm the suspicion I ran something to keep the core busy:

# yes > /dev/null &

8.2%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa, 10.3%hi, 81.4%si,  0.0%st

We only got 8.2% of the CPU for the userspace task and softirq has
shot up to 81.4%.

With the patch below top shows the correct stats:

0.0%us,  0.0%sy,  0.0%ni,  5.3%id,  0.0%wa, 13.3%hi, 81.3%si,  0.0%st

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-30 10:44:18 +11:00
Benjamin Herrenschmidt
6090912c4a powerpc: Implement dma_mmap_coherent()
This is used by Alsa to mmap buffers allocated with dma_alloc_coherent()
into userspace. We need a special variant to handle machines with
non-coherent DMAs as those buffers have "special" virt addresses and
require non-cachable mappings

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-30 10:44:00 +11:00