Several platforms use their own copy of what is essentially the same code,
using RTAS to synchronize the timebases when bringing up new CPUs. This
moves it all into a single common implementation and additionally
turns the spinlock into a raw spinlock since the former can rely on
the timebase not being frozen when spinlock debugging is enabled, and finally
masks interrupts while the timebase is disabled.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
RTAS currently uses a normal spinlock. However it can be called from
contexts where this is not necessarily a good idea. For example, it
can be called while syncing timebases, with the core timebase being
frozen. Unfortunately, that will deadlock in case of lock contention
when spinlock debugging is enabled as the spin lock debugging code
will try to use __delay() which ... relies on the timebase being
enabled.
Also RTAS can be used in some low level IRQ handling code path so it
may as well be a raw spinlock for -rt sake.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
While testing partition migration with heavy CPU load using
shared processors, it was observed that sometimes the migration
would never complete and would appear to hang. Currently, the
migration code assumes that if H_SUCCESS is returned from the H_JOIN
then the migration is complete and the processor is waking up on
the target system. If there was an outstanding PROD to the processor
when the H_JOIN is called, however, it will return H_SUCCESS on the source
system, causing the migration to hang, or in some scenarios cause
the kernel to crash on the complete call waking the caller
of rtas_percpu_suspend_me. Fix this by calling H_JOIN multiple times
if necessary during the migration.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Since "Factor out cpu joining/unjoining the GIQ"
(b4963255ad) the WARN_ON in
xics_set_cpu_giq() is being triggered during boot on JS20 because the
GIQ indicator is not available on that platform. While the warning is
harmless and the system runs normally, it's nicer to check for the
existence of the indicator before trying to manipulate it.
Implement rtas_indicator_present(), which searches the
/rtas/rtas-indicators property for the given indicator token, and use
this function in xics_set_cpu_giq().
Also use a WARN statement in xics_set_cpu_giq to get better
information on failure.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Acked-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The kernel copy of the rtas args struct contains the return
value(s) for the specified rtas call. These are copied back
to user space with the assumption that every value has been
set by the rtas call, which turns out to be not always true.
Thus userspace can see random values and think the call failed
when in fact it succeeded, but for some reason didn't set one
of the return values.
This fixes the problem by zeroing out the return value fields
of the rtas args struct before processing the rtas call.
Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Make a few things static in lparcfg.c
Make init and exit routines static in rtas_flash.c
Make things static in rtas_pci.c
Make some functions static in rtas.c
Make fops static in rtas-proc.c
Remove unneeded extern for do_gtod in smp.c
Make clocksource_init() static in time.c
Make last_tick_len and ticklen_to_xs static in time.c
Move the declaration of the pvr per-cpu into smp.h
Make kexec_smp_down() and kexec_stack static in machine_kexec_64.c
Don't return void in arch_teardown_msi_irqs() in msi.c
Move declaration of GregorianDay()into asm/time.h
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (202 commits)
[POWERPC] Fix compile breakage for 64-bit UP configs
[POWERPC] Define copy_siginfo_from_user32
[POWERPC] Add compat handler for PTRACE_GETSIGINFO
[POWERPC] i2c: Fix build breakage introduced by OF helpers
[POWERPC] Optimize fls64() on 64-bit processors
[POWERPC] irqtrace support for 64-bit powerpc
[POWERPC] Stacktrace support for lockdep
[POWERPC] Move stackframe definitions to common header
[POWERPC] Fix device-tree locking vs. interrupts
[POWERPC] Make pci_bus_to_host()'s struct pci_bus * argument const
[POWERPC] Remove unused __max_memory variable
[POWERPC] Simplify xics direct/lpar irq_host setup
[POWERPC] Use pseries_setup_i8259_cascade() in pseries_mpic_init_IRQ()
[POWERPC] Turn xics_setup_8259_cascade() into a generic pseries_setup_i8259_cascade()
[POWERPC] Move xics_setup_8259_cascade() into platforms/pseries/setup.c
[POWERPC] Use asm-generic/bitops/find.h in bitops.h
[POWERPC] 83xx: mpc8315 - fix USB UTMI Host setup
[POWERPC] 85xx: Fix the size of qe muram for MPC8568E
[POWERPC] 86xx: mpc86xx_hpcn - Temporarily accept old dts node identifier.
[POWERPC] 86xx: mark functions static, other minor cleanups
...
None of these files use any of the functionality promised by
asm/semaphore.h. It's possible that they rely on it dragging in some
unrelated header file, but I can't build all these files, so we'll have
fix any build failures as they come up.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This reverts commit a2b51812a4.
It turns out that this change caused some machines to fail to come
back up when being rebooted, and generated an error in the hypervisor
error log on some machines. The platform architecture (PAPR) is a
little unclear on exactly when the RTAS ibm,os-term function should be
called. Until that is clarified I'm reverting this commit.
Signed-off-by: Paul Mackerras <paulus@samba.org>
The rtas_os_term() routine was being called at the wrong time.
The actual rtas call "os-term" will not ever return, and so
calling it from the panic notifier is too early. Instead,
call it from the machine_reset() call.
This splits the rtas_os_term() routine into two: one part to capture
the kernel panic message, invoked during the panic notifier, and
another part that is invoked during machine_reset().
Prior to this patch, the os-term call was never being made,
because panic_timeout was always non-zero. Calling os-term
helps keep the hypervisor happy! We have to keep the hypervisor
happy to avoid service, dump and error reporting problems.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There are several issues with the rtas_ibm_suspend_me code, which
enables platform-assisted suspension of an LPAR as covered in PAPR
2.2.
1.) rtas_ibm_suspend_me uses on_each_cpu() to invoke
rtas_percpu_suspend_me on all cpus via IPI:
if (on_each_cpu(rtas_percpu_suspend_me, &data, 1, 0))
...
'data' is on the calling task's stack, but rtas_ibm_suspend_me takes
no measures to ensure that all instances of rtas_percpu_suspend_me are
finished accessing 'data' before returning. This can result in the
IPI'd cpus accessing random stack data and getting stuck in H_JOIN.
This is addressed by using an atomic count of workers and a completion
on the stack.
2.) rtas_percpu_suspend_me is needlessly calling H_JOIN in a loop.
The only event that can cause a cpu to return from H_JOIN is an H_PROD
from another cpu or a NMI/system reset. Each cpu need call H_JOIN
only once per suspend operation.
Remove the loop and the now unnecessary 'waiting' state variable.
3.) H_JOIN must be called with MSR[EE] off, but lazy interrupt
disabling may cause the caller of rtas_ibm_suspend_me to call H_JOIN
with it on; the local_irq_disable() in on_each_cpu() is not
sufficient.
Fix this by explicitly saving the MSR and clearing the EE bit before
calling H_JOIN.
4.) H_PROD is being called with the Linux logical cpu number as the
parameter, not the platform interrupt server value. (It's also being
called for all possible cpus, which is harmless, but unnecessary.)
This is fixed by calling H_PROD for each online cpu using
get_hard_smp_processor_id(cpu) for the argument.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the
beginning of the declaration specifiers in a declaration is an
obsolescent feature.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
To test for the existence of an RTAS function, we typically do:
foo_token = rtas_token("foo");
if (foo_token == RTAS_UNKNOWN_SERVICE)
return;
Add a rtas_service_present method, which provides a more conventional
boolean interface for testing the existence of an RTAS method.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
As the first step in consolidating the pseries hotplug cpu code,
create platforms/pseries/hotplug-cpu.c and move rtas_stop_self()
into it. Do the rtas token initialisation in a new initcall, rather
than rtas_initialize().
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Per email discussion, it appears that rtas_stop_self()
and pSeries_mach_cpu_die() should not be compiled if
CONFIG_HOTPLUG_CPU is not defined. This patch adds
#ifdefs around these bits of code.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Only call into RTAS when booted with panic=0 because the RTAS call
does not return. The system has to be rebooted via the HMC or via the
management console right now. This is cumbersome and not what the
default panic=180 is supposed to do.
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The rtas console doesn't have to be Cell specific. If we get both
RTAS tokens, we should just enabled the console then and there.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Noticing the following might_sleep warning (dump_stack()) during kdump
testing when CONFIG_DEBUG_SPINLOCK_SLEEP is enabled. All secondary CPUs
will be calling rtas_set_indicator with interrupts disabled to remove
them from global interrupt queue.
BUG: sleeping function called from invalid context at
arch/powerpc/kernel/rtas.c:463
in_atomic():1, irqs_disabled():1
Call Trace:
[C00000000FFFB970] [C000000000010234] .show_stack+0x68/0x1b0 (unreliable)
[C00000000FFFBA10] [C000000000059354] .__might_sleep+0xd8/0xf4
[C00000000FFFBA90] [C00000000001D1BC] .rtas_busy_delay+0x20/0x5c
[C00000000FFFBB20] [C00000000001D8A8] .rtas_set_indicator+0x6c/0xcc
[C00000000FFFBBC0] [C000000000048BF4] .xics_teardown_cpu+0x118/0x134
[C00000000FFFBC40] [C00000000004539C]
.pseries_kexec_cpu_down_xics+0x74/0x8c
[C00000000FFFBCC0] [C00000000002DF08] .crash_ipi_callback+0x15c/0x188
[C00000000FFFBD50] [C0000000000296EC] .smp_message_recv+0x84/0xdc
[C00000000FFFBDC0] [C000000000048E08] .xics_ipi_dispatch+0xf0/0x130
[C00000000FFFBE50] [C00000000009EF10] .handle_IRQ_event+0x7c/0xf8
[C00000000FFFBF00] [C0000000000A0A14] .handle_percpu_irq+0x90/0x10c
[C00000000FFFBF90] [C00000000002659C] .call_handle_irq+0x1c/0x2c
[C00000000058B9C0] [C00000000000CA10] .do_IRQ+0xf4/0x1a4
[C00000000058BA50] [C0000000000044EC] hardware_interrupt_entry+0xc/0x10
--- Exception: 501 at .plpar_hcall_norets+0x14/0x1c
LR = .pseries_dedicated_idle_sleep+0x190/0x1d4
[C00000000058BD40] [C00000000058BDE0] 0xc00000000058bde0 (unreliable)
[C00000000058BDF0] [C00000000001270C] .cpu_idle+0x10c/0x1e0
[C00000000058BE70] [C000000000009274] .rest_init+0x44/0x5c
To fix this issue, rtas_set_indicator_fast() is added so that will not
wait for RTAS 'busy' delay and this new function is used for kdump (in
xics_teardown_cpu()) and for CPU hotplug ( xics_migrate_irqs_away() and
xics_setup_cpu()).
Note that the platform architecture spec says that set-indicator
on the indicator we're using here is not permitted to return the
busy or extended busy status codes.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Our pseries hcall interfaces are out of control:
plpar_hcall_norets
plpar_hcall
plpar_hcall_8arg_2ret
plpar_hcall_4out
plpar_hcall_7arg_7ret
plpar_hcall_9arg_9ret
Create 3 interfaces to cover all cases:
plpar_hcall_norets: 7 arguments no returns
plpar_hcall: 6 arguments 4 returns
plpar_hcall9: 9 arguments 9 returns
There are only 2 cases in the kernel that need plpar_hcall9, hopefully
we can keep it that way.
Pass in a buffer to stash return parameters so we avoid the &dummy1,
&dummy2 madness.
Signed-off-by: Anton Blanchard <anton@samba.org>
--
Signed-off-by: Paul Mackerras <paulus@samba.org>
Now that get_property() returns a void *, there's no need to cast its
return value. Also, treat the return value as const, so we can
constify get_property later.
powerpc core changes.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add udbg hooks for the RTAS console, based on the RTAS put-term-char
and get-term-char calls. Along with my previous patches, this should
enable debugging as soon as early_init_dt_scan_rtas() is called.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Althought RTAS is instantiated when we enter the kernel, we can't actually
call into it until we know its entry point address. Currently we grab that
in rtas_initialize(), however that's quite late in the boot sequence.
To enable rtas_call() earlier, we can grab the RTAS entry etc. values while
we're scanning the flattened device tree. There's existing code to retrieve
the values from /chosen, however we don't store them there anymore, so remove
that code.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Move RTAS exports next to their declarations.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently it's unsafe to call rtas_call() prior to rtas_initialize(). This
is because the rtas.entry value hasn't been setup and so we don't know
where to enter, but we just try anyway.
We can't do anything intelligent without rtas.entry, so if it's not set, just
return. Code that calls rtas_call() early needs to be aware that the call
might fail.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Export both news RTAS delay functions, and change the scanlog module to
use the new delay functions.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently the kernel blindly halts all the processors and calls the
ibm,suspend-me rtas call. If the firmware is not in the correct
state, we then re-start all the processors and return. It is much
smarter to first check the firmware state, and only if it is waiting,
call the ibm,suspend-me call.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch attempts to handle RTAS "busy" return codes in a more simple
and consistent manner. Typical callers of RTAS shouldn't have to
manage wait times and delay calls.
This patch also changes the kernel to use msleep() rather than udelay()
when a runtime delay is necessary. This will avoid CPU soft lockups
for extended delay conditions.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Also cleans up some nearby whitespace problems.
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
for_each_cpu() actually iterates across all possible CPUs. We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs. This is inefficient and
possibly buggy.
We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.
This patch replaces for_each_cpu with for_each_possible_cpu.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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>
powerpc currently declares some of its own system calls
in <asm/unistd.h>, but not all of them. That place also
contains remainders of the now almost unused kernel syscall
hack.
- Add a new <asm/syscalls.h> with clean declarations
- Include that file from every source that implements one
of these
- Get rid of old declarations in <asm/unistd.h>
This patch is required as a base for implementing system
calls from an SPU, but also makes sense as a general
cleanup.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It turns out that we can't stop the watchdog from
triggering here. If we touch the timer (which just uses the current jiffie
value) before we enable interrupts, it does nothing because jiffies
are not mass-updated until after we enable interrupts. If we touch the
timer after we enable interrupts, its too late because the softlockup
watchdog will already have triggered. The touch_softlockup_watchdog
call removed below does nothing.
Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We need to prod everyone here since this is the only CPU that is
guaranteed to be running after the ibm,suspend-me RTAS call returns.
Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Correctly return the status from the RTAS call. rtas_call expects
to return the status as a return value.
Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/kernel/rtas.c is getting hvcall.h via spinlock.h, but when we're
building for UP we don't include spinlock.h.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Handle the ibm,suspend-me RTAS call specially. It needs
to be wrapped in a set of synchronization hypervisor calls
(H_Join). When the H_Join calls are made on all CPUs, the
intent is that only one will return with H_Continue, meaning
that he is the "last man standing". That CPU then issues the
ibm,suspend-me call. What is interesting, of course, is that
the CPU running when the rtas syscall is made, may NOT be the
CPU that ultimately executes the ibm,suspend-me rtas call.
Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch: Use <linux/capability.h> where capable() is used.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds Kconfig entries to control the early debugging options,
currently in setup_64.c.
Doing this via Kconfig rather than #defines means you can have one source tree,
which is buildable for multiple platforms - and you can enable the correct
early debug option for each platform via .config.
I made udbg_early_init() a static inline because otherwise GCC is to daft to
optimise it away when debugging is off.
Now that we have udbg_init_rtas() we can make call_rtas_display_status* static.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch merges platform codes. systemcfg->platform is no longer used,
systemcfg use in general is deprecated as much as possible (and renamed
_systemcfg before it gets completely moved elsewhere in a future patch),
_machine is now used on ppc64 along as ppc32. Platform codes aren't gone
yet but we are getting a step closer. A bunch of asm code in head[_64].S
is also turned into C code.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Building a PowerMac kernel with ARCH=powerpc causes a bunch of warnings,
this fixes some of them
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Mostly this involves adding #include <asm/smp.h>, since that defines
things like boot_cpuid[_phys] and [gs]et_hard_smp_processor_id, which
are SMP-related but still needed on UP. This incorporates fixes
posted by Olof Johansson and Heikki Lindholm.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This moves rtas-proc.c and rtas_flash.c into arch/powerpc/kernel, since
cell wants them as well as pseries (and chrp can use rtas-proc.c too,
at least in principle). rtas_fw.c is gone, with its bits moved into
rtas_flash.c and rtas.c.
Signed-off-by: Paul Mackerras <paulus@samba.org>
