This is not strictly required, because this iterates over logical
cpus and they are not (currently) discontigous. But, it's cleaner
code and more obvious what is going on
Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Normally logical and hard cpu ID are the same, however in same cases like
on the P3060 they may differ. Where the logical is 0..5, the hard id
goes 0,1,4..7. This can causes issues for places we utilize PIR to index
into array like in debug exception handlers for finding the exception
stack.
Move to setting up PIR with hard_smp_processor_id fixes the issue.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Commit 765342526246c97600e5344c0949824d94bb51c3 made some small changes to
IPI, message_pass in smp_ops was initialized to NULL for other platforms
but not for 85xx which causes us to always use the mpic for IPI's even
if we support doorbells in HW.
Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Under the FSL Hypervisor we triggered a BUG_ON in mpc85xx_smp_init that
expected smp_ops.message_pass to be explicity set. However recent
changes allows smp_ops.message_pass to be NULL and handled by default
code. Thus the BUG_ON isn't relevant anymore.
Signed-off-by: Laurentiu TUDOR <Laurentiu.Tudor@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
In cases like when the platform is used under hypervisor we will NOT
have an MPIC controller but still want doorbells setup.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
On many platforms (including pSeries), smp_ops->message_pass is always
smp_muxed_ipi_message_pass. This changes arch/powerpc/kernel/smp.c so
that if smp_ops->message_pass is NULL, it calls smp_muxed_ipi_message_pass
directly.
This means that a platform doesn't need to set both .message_pass and
.cause_ipi, only one of them. It is a slight performance improvement
in that it gets rid of an indirect function call at the expense of a
predictable conditional branch.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Consolidate the mux and demux of ipi messages into smp.c and call
a new smp_ops callback to actually trigger the ipi.
The powerpc architecture code is optimised for having 4 distinct
ipi triggers, which are mapped to 4 distinct messages (ipi many, ipi
single, scheduler ipi, and enter debugger). However, several interrupt
controllers only provide a single software triggered interrupt that
can be delivered to each cpu. To resolve this limitation, each smp_ops
implementation created a per-cpu variable that is manipulated with atomic
bitops. Since these lines will be contended they are optimialy marked as
shared_aligned and take a full cache line for each cpu. Distro kernels
may have 2 or 3 of these in their config, each taking per-cpu space
even though at most one will be in use.
This consolidation removes smp_message_recv and replaces the single call
actions cases with direct calls from the common message recognition loop.
The complicated debugger ipi case with its muxed crash handling code is
moved to debug_ipi_action which is now called from the demux code (instead
of the multi-message action calling smp_message_recv).
I put a call to reschedule_action to increase the likelyhood of correctly
merging the anticipated scheduler_ipi() hook coming from the scheduler
tree; that single required call can be inlined later.
The actual message decode is a copy of the old pseries xics code with its
memory barriers and cache line spacing, augmented with a per-cpu unsigned
long based on the book-e doorbell code. The optional data is set via a
callback from the implementation and is passed to the new cause-ipi hook
along with the logical cpu number. While currently only the doorbell
implemntation uses this data it should be almost zero cost to retrieve and
pass it -- it adds a single register load for the argument from the same
cache line to which we just completed a store and the register is dead
on return from the call. I extended the data element from unsigned int
to unsigned long in case some other code wanted to associate a pointer.
The doorbell check_self is replaced by a call to smp_muxed_ipi_resend,
conditioned on the CPU_DBELL feature. The ifdef guard could be relaxed
to CONFIG_SMP but I left it with BOOKE for now.
Also, the doorbell interrupt vector for book-e was not calling irq_enter
and irq_exit, which throws off cpu accounting and causes code to not
realize it is running in interrupt context. Add the missing calls.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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>
If the spin table is located in the linear mapping (which can happen if
we have 4G or more of memory) we need to access the spin table via a
cacheable coherent mapping like we do on ppc32 (and do explicit cache
flush).
See the following commit for the ppc32 version of this issue:
commit d1d47ec6e6
Author: Peter Tyser <ptyser@xes-inc.com>
Date: Fri Dec 18 16:50:37 2009 -0600
powerpc/85xx: Fix SMP when "cpu-release-addr" is in lowmem
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
When we do an mpic_reset_core we need to make sure the dcache is flushed.
Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Make kexec_down_cpus atmoic since it will be incremented by all cores as
they are coming down.
Remove duplicate calls to mpc85xx_smp_kexec_down, now it's called by the
crash and normal kexec pathway only once.
Increase the timeout to wait for other cores to shutdown.
Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
We no longer need to call this explicitly as a generic version is called
by default.
Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
arch/powerpc/platforms/built-in.o:(.toc1+0x18): undefined reference to `__early_start'
This is due to the 85xx/smp.c not handling the 64-bit side properly. We
need to set the entry point for secondary cores on ppc64e to
generic_secondary_smp_init instead of __early_start that we due on ppc32.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Adds support for kexec on 85xx machines for the BookE platform.
Including support for SMP machines
Based off work from Maxim Uvarov <muvarov@mvista.com>
Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
The doorbells use the content of the PIR register to match messages
from other CPUs. This may or may not be the same as our linux CPU
number, so using that as the "target" is no right.
Instead, we sample the PIR register at boot on every processor
and use that value subsequently when sending IPIs.
We also use a per-cpu message mask rather than a global array which
should limit cache line contention.
Note: We could use the CPU number in the device-tree instead of
the PIR register, as they are supposed to be equivalent. This
might prove useful if doorbells are to be used to kick CPUs out
of FW at boot time, thus before we can sample the PIR. This is
however not the case now and using the PIR just works.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Recent U-Boot commit 5ccd29c3679b3669b0bde5c501c1aa0f325a7acb caused
the "cpu-release-addr" device tree property to contain the physical RAM
location that secondary cores were spinning at. Previously, the
"cpu-release-addr" property contained a value referencing the boot page
translation address range of 0xfffffxxx, which then indirectly accessed
RAM.
The "cpu-release-addr" is currently ioremapped and the secondary cores
kicked. However, due to the recent change in "cpu-release-addr", it
sometimes points to a memory location in low memory that cannot be
ioremapped. For example on a P2020-based board with 512MB of RAM the
following error occurs on bootup:
<...>
mpic: requesting IPIs ...
__ioremap(): phys addr 0x1ffff000 is RAM lr c05df9a0
Unable to handle kernel paging request for data at address 0x00000014
Faulting instruction address: 0xc05df9b0
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=2 P2020 RDB
Modules linked in:
<... eventual kernel panic>
Adding logic to conditionally ioremap or access memory directly resolves
the issue.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Nate Case <ncase@xes-inc.com>
Reported-by: Dipen Dudhat <B09055@freescale.com>
Tested-by: Dipen Dudhat <B09055@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
The following commit introduced a compile error since it removed
the implementation of smp_85xx_basic_setup:
commit 77c0a700c1
Author: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Fri Aug 28 14:25:04 2009 +1000
powerpc: Properly start decrementer on BookE secondary CPUs
Make it so that smp_ops probe() and setup_cpu() can be set to NULL.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This moves the code to start the decrementer on 40x and BookE into
a separate function which is now called from time_init() and
secondary_time_init(), before the respective clock sources are
registered. We also remove the 85xx specific code for doing it
from the platform code.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Those definitions are currently declared extern in the .c file where
they are used, move them to a header file instead.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Use device tree to determine if we actually have an MPIC and use
CPU feature to decide if we should use doorbells for IPIs.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
There is a call to local_irq_restore in the normal exit case, so it would
seem that there should be one on an error return as well.
The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
expression l;
expression E,E1,E2;
@@
local_irq_save(l);
... when != local_irq_restore(l)
when != spin_unlock_irqrestore(E,l)
when any
when strict
(
if (...) { ... when != local_irq_restore(l)
when != spin_unlock_irqrestore(E1,l)
+ local_irq_restore(l);
return ...;
}
|
if (...)
+ {local_irq_restore(l);
return ...;
+ }
|
spin_unlock_irqrestore(E2,l);
|
local_irq_restore(l);
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Added 85xx specifc smp_ops structure. We use ePAPR style boot release
and the MPIC for IPIs at this point.
Additionally added routines for secondary cpu entry and initializtion.
Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Trent Piepho <tpiepho@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
