Alignment was the last user of the ENABLE_INTS macro, which we can
now remove. All non-syscall exceptions now disable interrupts on
entry, they get re-enabled conditionally from C code. Don't
unconditionally re-enable in program check either, check the
original context.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We had a case where we could turn on hard interrupts while
leaving the PACA_IRQ_HARD_DIS bit set in the PACA. This can
in turn cause a BUG_ON() to hit in __check_irq_replay() due
to interrupt state getting out of sync.

The assembly code was also way too convoluted. Instead, we
now leave it to the C code to do the right thing which ends
up being smaller and more readable.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Fixes these build warnings:

drivers/macintosh/windfarm_smu_sat.c: In function 'wf_sat_probe':
drivers/macintosh/windfarm_smu_sat.c:290:3: warning: passing argument 1 of 'snprintf' discards qualifiers from pointer target type
include/linux/kernel.h:323:5: note: expected 'char *' but argument is of type 'const char *'
drivers/macintosh/windfarm_smu_sat.c:317:3: warning: passing argument 1 of 'snprintf' discards qualifiers from pointer target type
include/linux/kernel.h:323:5: note: expected 'char *' but argument is of type 'const char *'

Introduced by commit e074d08e ("powerpc/windfarm: const'ify and add
"priv" field to controls & sensors").
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Fixes this warning:

drivers/macintosh/windfarm_pm91.c: In function 'wf_smu_cpu_fans_tick':
drivers/macintosh/windfarm_pm91.c:237:2: warning: passing argument 1 of 'wf_sensor_get' from incompatible pointer type
drivers/macintosh/windfarm.h:124:19: note: expected 'struct wf_sensor *' but argument is of type 'struct wf_sensor **'

Introduced by commit 33e6820b ("powerpc/windfarm: Add useful
accessors").
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

PowerPC has non standard getregs calls that only dump the GPRs or
FPRs and have their arguments reversed. commit e17666ba (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 <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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

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

Now we require gcc 4.0 on 64-bit we can remove the pre gcc 4.0
-maltivec workaround.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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

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

This replaces the old therm_pm72 using the same windfarm infrastructure
that was used for other PowerMac G5 models. The fan speeds and sensors
should now be visible in the same location in sysfs.

The driver is split into separate core modules for PowerMac7,2 (and 7,3)
and RackMac3,1, with a lot of the shared code now in the separate sensor
and control modules.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The FCU operates the fans on the earlier generation G5 machines,
this module will be used by upcoming windfarm drivers.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This allows those modules to load on PowerMac7,2 PowerMac7,3
and RackMac3,1 and add the sensor name conversion for those
machines.

This will be used by the corresponding new windfarm modules
for those machines.

Note that since therm_pm72 is linked first, it will still
take priority on those i2c devices if built-in. If using modules
it will depend which is loaded first, but you should avoid building
therm_pm72 if you are using the new windfarm drivers
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

For use by the upcoming windfarm_rm31
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

For user by the upcoming windfarm_pm72 and windfarm_rm31
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Makes the code more readable
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Controls registered as RPM and PWM fans are now displayed
with the "RPM" or "%" suffix respectively to make it
clearer to the user what the value actually means since
the fan type isn't otherwise obvious.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The windfarm core will do it, so this is a duplicate.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

const'ify the sensor ops and name and add a void* for use by
the control and sensor drivers to point back to their private
data, avoiding the need to create a wrapper data structure
per sensor or control instance.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This simplifies the driver to stop using the deprecated attach interface.

While at it we also implement teardown properly and fix the refcounting
by using a kref.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This simplifies the driver to stop using the deprecated attach interface
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This simplifies the driver to stop using the deprecated attach interface
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This simplifies the driver to stop using the deprecated attach interface,
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This causes i2c-powermac to register i2c devices exposed in the
device-tree, enabling new-style probing of devices.

Note that we prefix the IDs with "MAC," in order to prevent the
generic drivers from matching. This is done on purpose as we only
want drivers specifically tested/designed to operate on powermacs
to match.

This removes the special case we had for the AMS driver, and updates
the driver's match table instead.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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

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

Reformat lppaca.h to match Linux coding standards.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Remove all the iseries specific fields in the lppaca.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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

At the moment system call entry looks like:

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

commit bd19c899 ([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 <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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

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

syscall_dotrace_cont and syscall_error_cont tend to complicate perf
output so make them local.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Following commit a79dd5ae titled "tty/serial/pmac_zilog: Fix suspend & resume",
my Powerbook G4 Titanium showed the following stack dump:

[   36.878225] irq 23: nobody cared (try booting with the "irqpoll" option)
[   36.878251] Call Trace:
[   36.878291] [dfff3f00] [c000984c] show_stack+0x7c/0x194 (unreliable)
[   36.878322] [dfff3f40] [c00a6868] __report_bad_irq+0x44/0xf4
[   36.878339] [dfff3f60] [c00a6b04] note_interrupt+0x1ec/0x2ac
[   36.878356] [dfff3f80] [c00a48d0] handle_irq_event_percpu+0x250/0x2b8
[   36.878372] [dfff3fd0] [c00a496c] handle_irq_event+0x34/0x54
[   36.878389] [dfff3fe0] [c00a753c] handle_fasteoi_irq+0xb4/0x124
[   36.878412] [dfff3ff0] [c000f5bc] call_handle_irq+0x18/0x28
[   36.878428] [deef1f10] [c000719c] do_IRQ+0x114/0x1cc
[   36.878446] [deef1f40] [c0015868] ret_from_except+0x0/0x1c
[   36.878484] --- Exception: 501 at 0xf497610
[   36.878489]     LR = 0xfdc3dd0
[   36.878497] handlers:
[   36.878510] [<c02b7424>] pmz_interrupt
[   36.878520] Disabling IRQ #23

From an E-mail exchange about this problem, Andreas Schwab noticed a typo
that resulted in the wrong condition being tested.

The patch also corrects 2 typos that incorrectly report why an error branch
is being taken.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Recently, Ryan Wang tried to compile PPC pSeries platform without
CONFIG_EEH and eventually run into errors. Nishanth Aravamudan
helped to narrow down the root cause. Actually, the pSeries platform
depends on CONFIG_EEH heavily and that won't work properly without
EEH support.

According to Ben's suggestion, the patch make CONFIG_EEH invisible
and keep it as always selected on pSeries platform.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The switch from using irq_map to irq_alloc_desc*() for managing irq
number allocations introduced new bugs in some of the powerpc
interrupt code.  Several functions rely on the value of NR_IRQS to
determine the maximum irq number that could get allocated.  However,
with sparse_irq and using irq_alloc_desc*() the maximum possible irq
number is now specified with 'nr_irqs' which may be a number larger
than NR_IRQS.  This has caused breakage on powermac when
CONFIG_NR_IRQS is set to 32.

This patch removes most of the direct references to NR_IRQS in the
powerpc code and replaces them with either a nr_irqs reference or by
using the common for_each_irq_desc() macro.  The powerpc-specific
for_each_irq() macro is removed at the same time.

Also, the Cell axon_msi driver is refactored to remove the global
build assumption on the size of NR_IRQS and instead add a limit to the
maximum irq number when calling irq_domain_add_nomap().
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The mpc8xx driver uses a reference to NR_IRQS that is buggy.  It uses
NR_IRQs for the array size of the ppc_cached_irq_mask bitmap, but
NR_IRQs could be smaller than the number of hardware irqs that
ppc_cached_irq_mask tracks.

Also, while fixing that problem, it became apparent that the interrupt
controller only supports 32 interrupt numbers, but it is written as if
it supports multiple register banks which is more complicated.

This patch pulls out the buggy reference to NR_IRQs and fixes the size
of the ppc_cached_irq_mask to match the number of HW irqs.  It also
drops the now-unnecessary code since ppc_cached_irq_mask is no longer
an array.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>