While cross-building for PPC64 I've got

WARNING: vmlinux.o(.text.unlikely+0x1ba): Section mismatch in
reference from the function .prom_rtas_call() to the variable
.init.data:dt_string_start The function .prom_rtas_call() references
the variable __initdata dt_string_start.  This is often because
.prom_rtas_call lacks a __initdata annotation or the annotation of
dt_string_start is wrong.

WARNING: vmlinux.o(.meminit.text+0xeb0): Section mismatch in reference
from the function .free_area_init_core.isra.47() to the function
.init.text:.set_pageblock_order() The function __meminit
.free_area_init_core.isra.47() references a function __init
.set_pageblock_order().  If .set_pageblock_order is only used by
.free_area_init_core.isra.47 then annotate .set_pageblock_order with a
matching annotation.

Fix it by proper annotation of prom_rtas_call.
Signed-off-by: NVladimir Murzin <murzin.v@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

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

We have a bunch of CONFIG_PPC_EARLY_DEBUG_* options that are intended
for bringup/debug only. They hard wire a machine specific udbg backend
very early on (before we even probe the platform), and use whatever
tricks are available on each machine/cpu to be able to get some kind
of output out there early on.

So far, on powermac with no serial ports, we have CONFIG_PPC_EARLY_DEBUG_BOOTX
to use the low-level btext engine on the screen, but it doesn't do much, at
least on 64-bit. It only really gets enabled after the platform has been
probed and the MMU enabled.

This adds a way to enable it much earlier. From prom_init.c (while still
running with Open Firmware), we grab the screen details and set things up
using the physical address of the frame buffer.

Then btext itself uses the "rm_ci" feature of the 970 processor (Real
Mode Cache Inhibited) to access it while in real mode.

We need to do a little bit of reorg of the btext code to inline things
better, in order to limit how much we touch memory while in this mode as
the consequences might be ... interesting.

This successfully allowed me to debug problems early on with the G5
(related to gold being broken vs. ppc64 kernels).
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

POWER8 comes with two different PVRs.  This patch enables the additional
PVR in the cputable.

The existing entry (PVR=0x4b) is renamed to POWER8E and the new entry
(PVR=0x4d) is given POWER8.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The Linux kernel and platform firmware negotiate their mutual support
of the PRRN option via the ibm,client-architecture-support interface.
This patch simply sets the appropriate fields in the client architecture
vector to indicate Linux support for PRRN and will allow the firmware to
report PRRN events via the RTAS event-scan mechanism.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The firmware_has_feature() function makes it easy to check for supported
features of the hypervisor. This patch extends the capability of
firmware_has_feature() to include checking for specified bits
in vector 5 of the architecture vector as reported in the device tree.

As part of this the #defines used for the architecture vector are re-defined
such that each option has the index into vector 5 and the feature bit encoded
into it. This makes checking for architecture bits when initiating data
for firmware_has_feature much easier.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

As part of handling of PRRN events we need to check vector 5 of the
architecture vector bits reported in the device tree to ensure PRRN event
handling is enabled. To do this firmware_has_feature() is updated (in a
subsequent patch) to make this check vector 5 bits. To avoid having to
re-define bits in the architecture vector the bit definitions are moved
to prom.h.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Commit 5ac47f7a (powerpc: Relocate prom_init.c on 64bit) made
prom_init.c position independent by manually relocating its entries
in the TOC.

We get the address of the TOC entries with the __prom_init_toc_start
linker symbol. If __prom_init_toc_start ends up as an entry in the
TOC then we need to add an offset to get the current address. This is
the case for older toolchains.

On the other hand, if we have a newer toolchain that supports
-mcmodel=medium then __prom_init_toc_start will be created by a
relative offset from r2 (the TOC pointer). Since r2 has already been
relocated, nothing more needs to be done.  Adding an offset in this
case is wrong and Aaro Koskinen and Alexander Graf have noticed noticed
G5 and OpenBIOS breakage.

Alan Modra suggested we just use r2 to get at the TOC which is simpler
and works with both old and new toolchains.
Reported-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Tested-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Now we relocate prom_init.c on 64bit we can finally remove the
nasty RELOC() macro.

Finally a patch that I can claim has a net positive effect on
the kernel. It doesn't happen very often.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The ppc64 kernel can get loaded at any address which means
our very early init code in prom_init.c must be relocatable. We do
this with a pretty nasty RELOC() macro that we wrap accesses of
variables with. It is very fragile and sometimes we forget to add a
RELOC() to an uncommon path or sometimes a compiler change breaks it.

32bit has a much more elegant solution where we build prom_init.c
with -mrelocatable and then process the relocations manually.
Unfortunately we can't do the equivalent on 64bit and we would
have to build the entire kernel relocatable (-pie), resulting in a
large increase in kernel footprint (megabytes of relocation data).
The relocation data will be marked __initdata but it still creates
more pressure on our already tight memory layout at boot.

Alan Modra pointed out that the 64bit ABI is relocatable even
if we don't build with -pie, we just need to relocate the TOC.
This patch implements that idea and relocates the TOC entries of
prom_init.c. An added bonus is there are very few relocations to
process which helps keep boot times on simulators down.

gcc does not put 64bit integer constants into the TOC but to be
safe we may want a build time script which passes through the
prom_init.c TOC entries to make sure everything looks reasonable.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Update ibm,architecture.vec for POWER8 and allows us to support more
than one parition per core.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We have an old FIXME in reg.h which points out that we should standardise
on PVR_foo for our PVR #defines. Currently we use PVR_ on 32-bit and PV_
on 64-bit.

So do that rename and remove the FIXME.

Seeing as we're touching all but one usage of __is_processor(), rename it
to something less ugly and more indicative of what it does, which is
simply to check the PVR version.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch instantiate Stored Measurement Log (SML) and put the
log address and size in the device tree.
Signed-off-by: NAshley Lai <adlai@us.ibm.com>
Signed-off-by: NKent Yoder <key@linux.vnet.ibm.com>

This patch enables compression engine support in the
architecture vector.  This causes the Power hypervisor
to allow access to the nx comrpession accelerator.
Signed-off-by: NSeth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This patches tries to fix a couple of Section mismatch warnings like
following one:

WARNING: arch/powerpc/kernel/built-in.o(.text+0x2923c): Section mismatch
in reference from the function .prom_query_opal() to the
function .init.text:.call_prom()
The function .prom_query_opal() references
the function __init .call_prom().
This is often because .prom_query_opal lacks a __init
annotation or the annotation of .call_prom is wrong.
Signed-off-by: NLi Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch adds the cas bits to advertise support for the Platform
Facilities Option (PFO) based encryption accelerator device. The nx
device driver provides support for this hardware feature.
Signed-off-by: NKent Yoder <key@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch adds the cas bits to advertise support for the Platform
Facilities Option (PFO) based random number generator accerator.
The pseries-rng driver provides support for this hardware feature.
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: NKent Yoder <key@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch changes the architecture vector to advertise support for a
lower minimum virtual processor entitled capacity.  The default
minimum without this patch is 10%, this patch specifies 1%.
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Disintegrate asm/system.h for PowerPC.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
cc: linuxppc-dev@lists.ozlabs.org

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On a 16TB system (using AMS/CMO), I get:

WARNING: ignoring large property [/ibm,dynamic-reconfiguration-memory] ibm,dynamic-memory length 0x000000000017ffec

and significantly less memory is thus shown to the partition. As far as
I can tell, the constant used is arbitrary. Ben Herrenschmidt provided
additional background that

> The limit was originally set because of Apple machines carrying ROM
> images in the device-tree, at a time where we were much more memory
> constrained than we are now.

and that it is likely not very useful any longer.
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The current implementation of CONFIG_RELOCATABLE in BookE is based
on mapping the page aligned kernel load address to KERNELBASE. This
approach however is not enough for platforms, where the TLB page size
is large (e.g, 256M on 44x). So we are renaming the RELOCATABLE used
currently in BookE to DYNAMIC_MEMSTART to reflect the actual method.

The CONFIG_RELOCATABLE for PPC32(BookE) based on processing of the
dynamic relocations will be introduced in the later in the patch series.

This change would allow the use of the old method of RELOCATABLE for
platforms which can afford to enforce the page alignment (platforms with
smaller TLB size).

Changes since v3:

* Introduced a new config, NONSTATIC_KERNEL, to denote a kernel which is
  either a RELOCATABLE or DYNAMIC_MEMSTART(Suggested by: Josh Boyer)
Suggested-by: NScott Wood <scottwood@freescale.com>
Tested-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NSuzuki K. Poulose <suzuki@in.ibm.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux ppc dev <linuxppc-dev@lists.ozlabs.org>
Signed-off-by: NJosh Boyer <jwboyer@gmail.com>

We have an array of 16 entries and a loop of 32 iterations... oops.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

As the kernels and initrd's get bigger boot-loaders and possibly
kexec-tools will need to place the initrd outside the RMO.  When this
happens we end up with no lowmem and the boot doesn't get very far.

Only use initrd_end as the limit for alloc_bottom if it's inside the
RMO.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The minimum RMO size field in ibm,client-architecture is currently
ignored, but a future firmware version will rectify that. Since we
always get at least 128MB of RMO right now, asking for 64MB is
likely to result in boot failures.

We should bump it to at least 128MB, but considering all the boot
issues we have on 128MB RMO boxes and all new machines have virtual
RMO, we may as well set our minimum to 256MB.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Open Firmware on OPAL machines seems to have issues if we close
stdin and/or we try to print things after calling "quiesce" so
we avoid doing both.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

I had to debug a strange situation where all manner of things were
failing. SMT threads, storage and network were all completely broken.

The root cause was we couldn't find enough memory to instantiate RTAS -
this was a network install so the initrd was huge.

Instead of limping along and failing in mysterious ways we should just
panic up front if RTAS exists and we can't allocate space for it.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The firmware on old 970 blades supports some kind of takeover called
"TNK takeover" which will crash if we try to probe for OPAL takeover,
so don't do it.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

OPAL v2 is instantiated in a way similar to RTAS using Open Firmware
client interface calls, and the resulting address and entry point are
put in the device-tree
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We stash it in boot_command_line which isn't in BSS and so won't
be overwritten. We then use that as a default cmd_line before
we walk the device-tree.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

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: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Add a newline to the panic messages in make_room. Also fix a
comment that suggested our chunk size is 4Mb. It's 1MB.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

I have a box that fails in OF during boot with:

DEFAULT CATCH!, exception-handler=fff00400
at   %SRR0: 49424d2c4c6f6768   %SRR1: 800000004000b002

ie "IBM,Logh". OF got corrupted with a device tree string.

Looking at make_room and alloc_up, we claim the first chunk (1 MB)
but we never claim any more. mem_end is always set to alloc_top
which is the top of our available address space, guaranteeing we will
never call alloc_up and claim more memory.

Also alloc_up wasn't setting alloc_bottom to the bottom of the
available address space.

This doesn't help the box to boot, but we at least fail with
an obvious error. We could relocate the device tree in a future
patch.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Adds support for page coalescing, which is a feature on IBM Power servers
which allows for coalescing identical pages between logical partitions.
Hint text pages as coalesce candidates, since they are the most likely
pages to be able to be coalesced between partitions. This patch also
exports some page coalescing statistics available from firmware via
lparcfg.

[BenH: Moved a couple of things around to fix compile problems]
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Adds the ability to print decimal numbers and adds some more
format string variants
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we look pretty stupid when printing out a bunch of things in
prom_init.c.  eg.

  Max number of cores passed to firmware: 0x0000000000000080

So I've change this to print in decimal:

  Max number of cores passed to firmware: 128 (NR_CPUS = 256)

This required adding a prom_print_dec() function and changing some
prom_printk() calls from %x to %lu.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

If we configure with CONFIG_SMP=n or set NR_CPUS less than the number of
SMT threads we will set the max cores property to 0 in the
ibm,client-architecture-support structure. On new versions of firmware that
understand this property it obliges and terminates our partition.

Use DIV_ROUND_UP so we handle not only the CONFIG_SMP=n case but also the
case where NR_CPUS isn't a multiple of the number of SMT threads.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Firmware changed the way it represents memory and cpu affinity on POWER7.
Unfortunately the old method now caps the topology to work around issues
with legacy operating systems. For Linux to get the correct topology we
need to use the new form 1 affinity information.

We set the form 1 field in the client architecture, and if we see "1" in the
ibm,associativity-form property firmware supports form 1 affinity and
we should look at the first field in the ibm,associativity-reference-points
array. If not we use the second field as we always have.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Updated variant of a patch by Joel Schopp.

The field containing the number of supported cores which we pass to
firmware via the ibm,client-architecture call was set by a previous
patch statically as high as is possible (NR_CPUS).

However, that value isn't quite right for a system that supports
multiple threads per core, thus permitting the firmware to assign
more cores to a Linux partition than it can really cope with.

This patch improves it by using the device-tree to determine the
number of threads supported by the processors in order to adjust
the value passed to firmware.
Signed-off-by: NJoel Schopp <jschopp@austin.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch adds 2 fields to the ibm_architecture_vec array.

The first of these fields indicates the number of cores which Linux can
boot.  It does not account for SMT, so it may result in cpus assigned to
Linux which cannot be booted.  A second patch follows that dynamically
updates this for SMT.

The second field just indicates that our OS is Linux, and not another
OS.  The system may or may not use this hint to performance tune
settings for Linux.
Signed-off-by: NJoel Schopp <jschopp@austin.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>