Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:
scheduler switch to idle task
enable interrupts
Window starts here
----> interrupt happens (does not set NEED_RESCHED)
irq_exit() stops the tick
----> interrupt happens (does set NEED_RESCHED)
return from schedule()
cpu_idle(): preempt_disable();
Window ends here
The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.
The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.
Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.
cpu_idle()
{
preempt_disable();
while(1) {
tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we
are in the idle loop
while (!need_resched())
halt();
tick_nohz_restart_sched_tick(); <- disables NOHZ mode
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
In hindsight we should have done this forever, but ...
/me grabs a large brown paperbag.
Debugged-by: Jack Ren <jack.ren@marvell.com>,
Debugged-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The way iSeries manages PCI IO and Memory resources is a bit strange
and is based on overriding the content of those resources with home
cooked ones afterward.
This changes it a bit to better integrate with the new resource handling
so that the "virtual" tokens that iSeries replaces resources with are
done from the proper per-device fixup hook, and bridge resources are
set to enclose that token space. This fixes various things such as
the output of /proc/iomem & ioports, among others. This also fixes up
various boot messages as well.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/platforms/iseries/setup.c:111:27: warning: constant 0x100000000 is so big it is long
arch/powerpc/platforms/iseries/setup.c:113:23: warning: constant 0x100000000 is so big it is long
arch/powerpc/platforms/iseries/setup.c:117:27: warning: constant 0x000fffffffffffff is so big it is long
arch/powerpc/platforms/iseries/setup.c:127:28: warning: constant 0x100000000 is so big it is long
arch/powerpc/platforms/iseries/setup.c:129:24: warning: constant 0x100000000 is so big it is long
arch/powerpc/platforms/iseries/setup.c:233:5: warning: constant 0x000fffffffffffff is so big it is long
arch/powerpc/platforms/iseries/setup.c:235:5: warning: constant 0x000fffffffffffff is so big it is long
arch/powerpc/platforms/iseries/setup.c:319:6: warning: symbol 'mschunks_alloc' was not declared. Should it be static?
arch/powerpc/platforms/iseries/setup.c:661:6: warning: symbol 'iSeries_early_setup' was not declared. Should it be static?
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Fixes sparse warning:
arch/powerpc/platforms/iseries/pci.c:169:13: warning: symbol 'iSeries_pci_final_fixup' was not declared. Should it be static?
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
ppc_md.init_IRQ is not called if it is NULL, so we don't need an empty
routine in the non PCI case.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This removes several duplicate includes from arch/powerpc/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently iSeries will recalibrate the cputime_factors in the first
settimeofday() call.
It seems the reason for doing this is to ensure a resaonable time delta after
time_init(). On current kernels (with udev), this call is made 40-60 seconds
into the boot process, by moving it to a late initcall it is called
approximately 5 seconds after time_init() is called. This is sufficient to
recalibrate the timebase.
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
check_legacy_ioport makes only sense on PREP, CHRP and pSeries.
They may have an isa node with PS/2, parport, floppy and serial ports.
Remove the check_legacy_ioport call from ppc_md, it's not needed
anymore. Hardware capabilities come from the device-tree.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Clearing the progress indicator should only be done if we are running
on legacy iSeries.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Remove CPU_FTR_16M_PAGE from the cupfeatures mask at runtime on iSeries.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds code to look at the properties firmware puts in the device
tree to determine what compatibility mode the partition is in on
POWER6 machines, and set the ELF aux vector AT_HWCAP and AT_PLATFORM
entries appropriately.
Specifically, we look at the cpu-version property in the cpu node(s).
If that contains a "logical" PVR value (of the form 0x0f00000x), we
call identify_cpu again with this PVR value. A value of 0x0f000001
indicates the partition is in POWER5+ compatibility mode, and a value
of 0x0f000002 indicates "POWER6 architected" mode, with various
extensions disabled. We also look for various other properties:
ibm,dfp, ibm,purr and ibm,spurr.
Signed-off-by: Paul Mackerras <paulus@samba.org>
powerpc: Merge 32 and 64 bits asm-powerpc/io.h
The rework on io.h done for the new hookable accessors made it easier,
so I just finished the work and merged 32 and 64 bits io.h for arch/powerpc.
arch/ppc still uses the old version in asm-ppc, there is just too much gunk
in there that I really can't be bothered trying to cleanup.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch reworks the way iSeries hooks on PCI IO operations (both MMIO
and PIO) and provides a generic way for other platforms to do so (we
have need to do that for various other platforms).
While reworking the IO ops, I ended up doing some spring cleaning in
io.h and eeh.h which I might want to split into 2 or 3 patches (among
others, eeh.h had a lot of useless stuff in it).
A side effect is that EEH for PIO should work now (it used to pass IO
ports down to the eeh address check functions which is bogus).
Also, new are MMIO "repeat" ops, which other archs like ARM already had,
and that we have too now: readsb, readsw, readsl, writesb, writesw,
writesl.
In the long run, I might also make EEH use the hooks instead
of wrapping at the toplevel, which would make things even cleaner and
relegate EEH completely in platforms/iseries, but we have to measure the
performance impact there (though it's really only on MMIO reads)
Since I also need to hook on ioremap, I shuffled the functions a bit
there. I introduced ioremap_flags() to use by drivers who want to pass
explicit flags to ioremap (and it can be hooked). The old __ioremap() is
still there as a low level and cannot be hooked, thus drivers who use it
should migrate unless they know they want the low level version.
The patch "arch provides generic iomap missing accessors" (should be
number 4 in this series) is a pre-requisite to provide full iomap
API support with this patch.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There are currently two versions of the functions for applying the
feature fixups, one for CPU features and one for firmware features. In
addition, they are both in assembly and with separate implementations
for 32 and 64 bits. identify_cpu() is also implemented in assembly and
separately for 32 and 64 bits.
This patch replaces them with a pair of C functions. The call sites are
slightly moved on ppc64 as well to be called from C instead of from
assembly, though it's a very small change, and thus shouldn't cause any
problem.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Remove the iSeries initrd logic, instead just store the initrd location and
size in the device tree so generic code can do the rest for us.
The iSeries code had a "feature" which the generic code lacks, ie. if the
compressed initrd is bigger than the configured ram disk size, we make
the ram disk size bigger. That's bogus, as the compressed size of the initrd
tells us nothing about how big the ram disk needs to be. If the ram disk
isn't big enough you just need to make CONFIG_BLK_DEV_RAM_SIZE larger.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This will help in the combined kernel as some really early things depend
on being able to check this.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Move ItLpNaca into platforms/iseries now that it's not used elsewhere.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
HvLpConfig_get(Primary)LpIndex are currently static inlines that return
fields from the itLpNaca, if we make them real functions we can make the
itLpNaca private to iSeries.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
This adds the new irq remapper core and removes the old one. Because
there are some fundamental conflicts with the old code, like the value
of NO_IRQ which I'm now setting to 0 (as per discussions with Linus),
etc..., this commit also changes the relevant platform and driver code
over to use the new remapper (so as not to cause difficulties later
in bisecting).
This patch removes the old pre-parsing of the open firmware interrupt
tree along with all the bogus assumptions it made to try to renumber
interrupts according to the platform. This is all to be handled by the
new code now.
For the pSeries XICS interrupt controller, a single remapper host is
created for the whole machine regardless of how many interrupt
presentation and source controllers are found, and it's set to match
any device node that isn't a 8259. That works fine on pSeries and
avoids having to deal with some of the complexities of split source
controllers vs. presentation controllers in the pSeries device trees.
The powerpc i8259 PIC driver now always requests the legacy interrupt
range. It also has the feature of being able to match any device node
(including NULL) if passed no device node as an input. That will help
porting over platforms with broken device-trees like Pegasos who don't
have a proper interrupt tree.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Initialise the ppc_md htab callbacks earlier, in the probe routines. This
allows us to call htab_finish_init() from htab_initialize(), and makes it
private to hash_utils_64.c. Move htab_finish_init() and make_bl() above
htab_initialize() to avoid forward declarations.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
None of this seems to be necessary, so let's see if can remove it and not
break anything. Booted on iSeries & pSeries here.
NB. we don't remove the hvReleaseData, we just move it down so that the file
reads more clearly.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Use the PCI class code to choose a name for the PCI device nodes and
to guess a device_type. Failing that, base the name on the vendor and
device ids as specified in the spec.
Mark just about everything __init{data}.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Only scan the host bridges and then use the existing pci_devs_phb_init()
routine.
Also fix typo in setup of reg property.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Move the probing of PCI devices to setup.c and put them all into the
flattened device tree. The later probing is now done by traversing the
device tree.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We currently do mem= handling in three seperate places. And as benh pointed out
I wrote two of them. Now that we parse command line parameters earlier we can
clean this mess up.
Moving the parsing out of prom_init means the device tree might be allocated
above the memory limit. If that happens we'd have to move it. As it happens
we already have logic to do that for kdump, so just genericise it.
This also means we might have reserved regions above the memory limit, if we
do the bootmem allocator will blow up, so we have to modify
lmb_enforce_memory_limit() to truncate the reserves as well.
Tested on P5 LPAR, iSeries, F50, 44p. Tested moving device tree on P5 and
44p and F50.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Make their device_type entries more generic and their compatible entries
more specific.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Make it look more like the pSeries vdevice tree.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
These devices should have device_type block and a unique compatible entry.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Make the device-tree information more generic and more
like the pSeries virtual lan device. Also use the MAC
address from the device tree.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This requires the compatible properties having vaules that are empty
strings instead of just being empty properties.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
As an added bonus, since every vio_dev now has a device_node
associated with it, hotplug now works.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We do this by putting them in the flattened device tree at setup time.
This required the flattened device tree blob to be made bigger.
Currenly we don't do anything with these.
Also make a function static.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Not even the iSeries maintainer seems to have access to this legendary
piranha simulator. It adds a bit of ugliness in the common time init
code, and if it's no longer used we might as well be done with it and
remove the bloat.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
No need to write out what idle loop is used on every boot.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The iSeries Hypervisor only allows us to specify IRQ numbers up to 255 (it
has a u8 field to pass it in). This patch allows platforms to specify a
maximum to the virtual IRQ numbers we will use and has iSeries set that
to 255. If not set, the maximum is NR_IRQS - 1 (as before).
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
This removes statically assigned platform numbers and reworks the
powerpc platform probe code to use a better mechanism. With this,
board support files can simply declare a new machine type with a
macro, and implement a probe() function that uses the flattened
device-tree to detect if they apply for a given machine.
We now have a machine_is() macro that replaces the comparisons of
_machine with the various PLATFORM_* constants. This commit also
changes various drivers to use the new macro instead of looking at
_machine.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We need to export ppc64_firmware_features for modules. Before we do that
I think we should probably rename it to powerpc_firmware_features.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add the command line args to the device tree as /chosen/bootargs.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add /system-id, /model and /compatible to the iSeries device tree.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
These routines just call through to the mf routines, so point ppc_md straight
at the mf routines. We need to pass the cmd through to mf_reboot to make it
work, but that seems reasonable.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Some cleanups in the iSeries code.
- Make mf_display_progress() check mf_initialized rather than the caller.
- Set mf_initialized in mf_init() rather than in setup.c
- Then move mf_initialized into mf.c, the only place it's used.
- Move the mf related logic from iSeries_progress() to mf_display_progress()
- Use a #define to size the pending_event_prealloc array
- Use that define in the initialsation loop rather than sizeof jiggery pokery
- Remove stupid comment(s)
- Mark stuff static and/or __init
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It has been decreed that platform numbers are evil, so as a step in that
direction, replace platform_is_lpar() with a FW_FEATURE_LPAR bit.
Currently FW_FEATURE_LPAR really means i/pSeries LPAR, in the future we might
have to clean that up if we need to be more specific about what LPAR actually
means. But that's another patch ...
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The runlatch SPR can take a lot of time to write. My original runlatch
code would set it on every exception entry even though most of the time
this was not required. It would also continually set it in the idle
loop, which is an issue on an SMT capable processor.
Now we cache the runlatch value in a threadinfo bit, and only check for
it in decrementer and hardware interrupt exceptions as well as the idle
loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Thomas Gleixner