linux-toradex.git/arch/powerpc/kernel/head_64.S, branch v3.2.36

powerpc: Fix CONFIG_RELOCATABLE=y CONFIG_CRASH_DUMP=n build

2013-01-03T03:33:09+00:00

commit 11ee7e99f35ecb15f59b21da6a82d96d2cd3fcc8 upstream.

If we build a kernel with CONFIG_RELOCATABLE=y CONFIG_CRASH_DUMP=n,
the kernel fails when we run at a non zero offset. It turns out
we were incorrectly wrapping some of the relocatable kernel code
with CONFIG_CRASH_DUMP.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings

powerpc/powernv: Support for OPAL console

2011-09-20T06:09:54+00:00

This adds a udbg and an hvc console backend for supporting a console
using the OPAL console interfaces.

On OPAL v1 we have hvc0 mapped to whatever console the system was
configured for (network or hvsi serial port) via the service
processor.

On OPAL v2 we have hvcN mapped to the Nth console provided by OPAL
which generally corresponds to:

	hvc0 : network console (raw protocol)
	hvc1 : serial port S1 (hvsi)
	hvc2 : serial port S2 (hvsi)

Note: At this point, early debug console only works with OPAL v1
and shouldn't be enabled in a normal kernel.

Signed-off-by: Benjamin Herrenschmidt

powerpc/powernv: Add OPAL takeover from PowerVM

2011-09-20T06:09:47+00:00

On machines supporting the OPAL firmware version 1, the system
is initially booted under pHyp. We then use a special hypercall
to verify if OPAL is available and if it is, we then trigger
a "takeover" which disables pHyp and loads the OPAL runtime
firmware, giving control to the kernel in hypervisor mode.

This patch add the necessary code to detect that the OPAL takeover
capability is present when running under PowerVM (aka pHyp) and
perform said takeover to get hypervisor control of the processor.

To perform the takeover, we must first use RTAS (within Open
Firmware runtime environment) to start all processors & threads,
in order to give control to OPAL on all of them. We then call
the takeover hypercall on everybody, OPAL will re-enter the kernel
main entry point passing it a flat device-tree.

Signed-off-by: Benjamin Herrenschmidt

powerpc/powernv: Don't clobber r9 in relative_toc()

2011-09-20T05:53:24+00:00

With OPAL, r8 and r9 will be used to pass the OPAL base and entry
for debugging purposes (those informations are also in the
device-tree). We don't want to clobber those registers that
early.

Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix early boot accounting of CPUs

2011-06-17T06:19:51+00:00

smp_release_cpus() waits for all cpus (including the bootcpu) due to an
off-by-one count on boot_cpu_count (which is all CPUs).  This patch replaces
that with spinning_secondaries (which is all secondary CPUs).

Signed-off-by: Matt Evans 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Don't search for paca in freed memory

2011-05-19T04:30:43+00:00

Starting with 1426d5a3bd07589534286375998c0c8c6fdc5260 (powerpc:
Dynamically allocate pacas) we free the memory for pacas beyond
cpu_possible, but we failed to update the loop the secondary cpus use
to find their paca.  If the system has running cpu threads for which
the kernel did not allocate a paca for they will search the memory that
was freed.  For instance this could happen when the device tree for
a kdump kernel was not updated after a cpu hotplug, or the kernel is
running with more cpus than the kernel was configured.

Since c1854e00727f50f7ac99e98d26ece04c087ef785 (powerpc: Set nr_cpu_ids
early and use it to free PACAs) we set nr_cpu_ids before telling the
cpus to advance, so use that to limit the search.

We can't reference nr_cpu_ids without CONFIG_SMP because it is defined
as 1 instead of a memory location, but any extra threads should be sent
to kexec_wait in that case anyways, so make that explicit and remove
the search loop for UP.

Note to stable: The fix also requires
c1854e00727f50f7ac99e98d26ece04c087ef785 (powerpc: Set
nr_cpu_ids early and use it to free PACAs) to function.  Also
9d07bc841c9779b4d7902e417f4e509996ce805d (Properly handshake CPUs going
out of boot spin loop) affects the second chunk, specifically the branch
target was 3b before and is 4b after that patch, and there was a blank
line before the #ifdef CONFIG_SMP that was removed

Cc:  # .34.x: c1854e0072 powerpc: Set nr_cpu_ids early
Cc:  # .34.x
Signed-off-by: Milton Miller 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Use MSR_64BIT in places

2011-04-27T04:18:44+00:00

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 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Perform an isync to synchronize CPUs coming out of secondary_hold

2011-04-20T01:03:25+00:00

We need to do that to guarantee they see any code change done by
dynamic patching during boot.

Signed-off-by: Benjamin Herrenschmidt

powerpc: Properly handshake CPUs going out of boot spin loop

2011-04-20T01:03:24+00:00

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

powerpc: Call CPU ->restore callback earlier on secondary CPUs

2011-04-20T01:03:24+00:00

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