Currently for kexec the PTE tear down on 1TB segment systems normally
requires 3 hcalls for each PTE removal. On a machine with 32GB of
memory it can take around a minute to remove all the PTEs.

This optimises the path so that we only remove PTEs that are valid.
It also uses the read 4 PTEs at once HCALL.  For the common case where
a PTEs is invalid in a 1TB segment, this turns the 3 HCALLs per PTE
down to 1 HCALL per 4 PTEs.

This gives an > 10x speedup in kexec times on PHYP, taking a 32GB
machine from around 1 minute down to a few seconds.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

While most users of the hcall tracepoints will only want the opcode
and return code, some will want all the arguments.  To avoid the
complexity of using varargs we pass a pointer to the register save
area, which contains all the arguments.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add hcall_entry and hcall_exit tracepoints.  This replaces the inline
assembly HCALL_STATS code and converts it to use the new tracepoints.

To keep the disabled case as quick as possible, we embed a status word
in the TOC so we can get at it with a single load.  By doing so we
keep the overhead at a minimum.  Time taken for a null hcall:

No tracepoint code:	135.79 cycles
Disabled tracepoints:	137.95 cycles

For reference, before this patch enabling HCALL_STATS resulted in a null
hcall of 201.44 cycles!
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

pr_debug() can now result in code being generated even when DEBUG
is not defined. That's not really desirable in some places.

In particular, pSeries_lpar_hpte_insert() goes from 185 instructions
to 77 instructions as a result of this patch. Luckily that code
isn't called very often ...

With CONFIG_DYNAMIC_DEBUG=y:

size before:
   text    data     bss     dec     hex filename
   7284    1552     296    9132    23ac platforms/pseries/lpar.o

size after:
   text    data     bss     dec     hex filename
   5806    1096     296    7198    1c1e platforms/pseries/lpar.o
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Adds support for the "unused" page hint which can be used in shared
memory partitions to flag pages not in use, which will then be stolen
before active pages by the hypervisor when memory needs to be moved to
LPARs in need of additional memory.  Failure to mark pages as 'unused'
makes the LPAR slower to give up unused memory to other partitions.

This adds the kernel parameter 'cmo_free_hint' to disable this
functionality.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

It is okay for both _PAGE_GUARDED and _PAGE_COHERENT (G and M) to be set
in the same pte.  In fact, even if that were not the case, there doesn't
seem to be any place where G is set without also setting I (_PAGE_NO_CACHE),
so the test for I is sufficient as a condition to clear _PAGE_COHERENT
when filling the hash table.
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The current low level hash code on LPAR configurations clears
_PAGE_COHERENT (M) when either _PAGE_GUARDED (G) or _PAGE_NO_CACHE (I)
is set. This conflicts with _PAGE_SAO which has M, I and W bits sets at
once (normally invalid combo) to indicate the new SAO attribute.

This changes the code to allow that case.
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Don't return void in pseries/iommu.c
Make mce_data_buf static in pseries/ras.c
Make things static in pseries/rtasd.c
Make things static in pseries/setup.c
vtermno may as well be static in platforms/pseries/lpar.c
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

In pseries/lpar.c, fix some printf specifier mismatches, and add
a newline to one printk.

In pseries/rtasd.c add "rtasd" to some messages to make it clear
where they're coming from.

In pseries/scanlog.c remove the hand-rolled runtime debugging support
in there. This file has been largely unchanged for eons, if we need to
debug it in future we can recompile.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

On pseries LPAR we can call the udbg routines, and the udbg console very
early. So mark the udbg console as safe to call early in boot, and register
the udbg console as soon as the udbg routines are hooked up.

This allows platforms/pseries code to use printk() and pr_debug() rather
than needing to call udbg_printf() directly for early debugging. This is
nice because a) it's standard, b) it goes via the printk buffer, and c)
you can get printk time stamps.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

There is logic in platforms/peries/lpars.c which checks if the user has
specified a console on the command line, and refrains from adding a
preferred console entry for the hvc/hvsi console if they have.

This trips up if you use "netconsole=foo" on the command line, and has
the result that you get _only_ the netconsole, because the hvc device is
never added as a preferred console. Worse still if you get the netconsole
configuration wrong somehow, you end up with no console at all.

As it turns out we don't need to worry about checking the command line.
If the user has specified "console=foo", then foo will be set as the
preferred console when the command line is parsed in start_kernel(), much
later than the pseries code, and so the latter setting will take effect.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Move the prototype for find_udbg_vterm() into pseries.h, removing
it from setup.c.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

For memory remove, we need to clean up htab mappings for the
section of the memory we are removing.

This implements support for removing htab bolted mappings for pSeries
logical partitions.  Other sub-archs may need to implement similar
functionality for hotplug memory remove to work on them.
Signed-off-by: NBadari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Commit 473980a9 added a call to clear
the SLB shadow buffer before registering it.  Unfortunately this means
that we clear out the entries that slb_initialize has previously set in
there.  On POWER6, the hypervisor uses the SLB shadow buffer when doing
partition switches, and that means that after the next partition switch,
each non-boot CPU has no SLB entries to map the kernel text and data,
which causes it to crash.

This fixes it by reverting most of 473980a9 and instead clearing the
3rd entry explicitly in slb_initialize.  This fixes the problem that
473980a9 was trying to solve, but without breaking POWER6.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Before we register the SLB shadow buffer, we need to invalidate the
entries in the buffer, otherwise we can end up stale entries from when
we previously offlined the CPU.

This does this invalidate as well as unregistering the buffer with
PHYP before we offline the cpu.  Tested and fixes crashes seen on
970MP (thanks to tonyb) and POWER5.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This makes the kernel use 1TB segments for all kernel mappings and for
user addresses of 1TB and above, on machines which support them
(currently POWER5+, POWER6 and PA6T).

We detect that the machine supports 1TB segments by looking at the
ibm,processor-segment-sizes property in the device tree.

We don't currently use 1TB segments for user addresses < 1T, since
that would effectively prevent 32-bit processes from using huge pages
unless we also had a way to revert to using 256MB segments.  That
would be possible but would involve extra complications (such as
keeping track of which segment size was used when HPTEs were inserted)
and is not addressed here.

Parts of this patch were originally written by Ben Herrenschmidt.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This removes several duplicate includes from arch/powerpc/.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

On Power machines supporting VRMA, Kexec/Kdump does not work.
VRMA (virtual real-mode area) means that accesses with IR/DR = 0
(i.e. the MMU "off") actually still go through the hash table,
using entries put there by the hypervisor.

This means that when we clear out the hash table on kexec, we need to
make sure these entries are left untouched.

This also adds plpar_pte_read_raw() on the lines of
plpar_pte_remove_raw().

Signed-off-by : Sachin Sant <sachinp@in.ibm.com>
Signed-off-by : Mohan Kumar M <mohan@in.ibm.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

for consistency with other Open Firmware interfaces (and Sparc).

This is just a straight replacement.

This leaves the compatibility define in place.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

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

kexec invokes plpar_hcall hypervisor call in real mode.  plpar_hcall
refers to per cpu variables for accounting hypervisor statistics.
These variables may not be in the RMO region, so accesses to them
in real mode may result in a data storage exception.

This fixes this problem by using a new plpar_hcall_raw function which
does not update the hypervisor call statistics.  Thanks to Anton for
suggesting this idea.
Signed-off-by: NMohan Kumar M <mohan@in.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The previous patch changing pSeries to use H_BULK_REMOVE broke the
JS20 blade, where the firmware doesn't support H_BULK_REMOVE.  This
adds a firmware check so that on machines that don't have H_BULK_REMOVE,
we just use the H_REMOVE call as before.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

H_BULK_REMOVE lets us remove 4 entries from the MMU hash table with one
hypervisor call.  This uses it in pSeries_lpar_hpte_invalidate so we
can tear down mappings with fewer hypervisor calls.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Change the powerpc hpte_insert routines now called through ppc_md to
static scope.
Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This adds a shadow buffer for the SLBs and regsiters it with PHYP.
Only the bolted SLB entries (top 3) are shadowed.

The SLB shadow buffer tells the hypervisor what the kernel needs to
have in the SLB for the kernel to be able to function.  The hypervisor
can use this information to speed up partition context switches.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul 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: NAnton Blanchard <anton@samba.org>
--
Signed-off-by: NPaul 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.

pseries platform changes.

Built for pseries_defconfig
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

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: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This extends the HCALL interface for InfiniBand usage. I've
made the patch against the linux-2.6 git tree and Segher's patch:
[PATCH] Change H_StudlyCaps to H_SHOUTING_CAPS

We moved this into the common powerpc code based on comments we
got after posting the first eHCA InfiniBand device driver patch.
Signed-off-by: NHeiko j Schick <schickhj@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Also cleans up some nearby whitespace problems.
Signed-off-by: NSegher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

At present the lppaca - the structure shared with the iSeries
hypervisor and phyp - is contained within the PACA, our own low-level
per-cpu structure.  This doesn't have to be so, the patch below
removes it, making a separate array of lppaca structures.

This saves approximately 500*NR_CPUS bytes of image size and kernel
memory, because we don't need aligning gap between the Linux and
hypervisor portions of every PACA.  On the other hand it means an
extra level of dereference in many accesses to the lppaca.

The patch also gets rid of several places where we assign the paca
address to a local variable for no particular reason.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The udbg low level io layer has an issue with udbg_getc() returning a
char (unsigned on ppc) instead of an int, thus the -1 if you had no
available input device could end up turned into 0xff, filling your
display with bogus characters. This fixes it, along with adding a little
blob to xmon to do a delay before exiting when getting an EOF and fixing
the detection of ADB keyboards in udbg_adb.c
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This patch unifies udbg for both ppc32 and ppc64 when building the
merged achitecture. xmon now has a single "back end". The powermac udbg
stuff gets enriched with some ADB capabilities and btext output. In
addition, the early_init callback is now called on ppc32 as well,
approx. in the same order as ppc64 regarding device-tree manipulations.
The init sequences of ppc32 and ppc64 are getting closer, I'll unify
them in a later patch.

For now, you can force udbg to the scc using "sccdbg" or to btext using
"btextdbg" on powermacs. I'll implement a cleaner way of forcing udbg
output to something else than the autodetected OF output device in a
later patch.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This moves the discovery of legacy serial ports to a separate file,
makes it common to ppc32 and ppc64, and reworks it to use the new OF
address translators to get to the ports early. This new version can also
detect some PCI serial cards using legacy chips and will probably match
those discovered port with the default console choice.

Only ppc64 gets udbg still yet, unifying udbg isn't finished yet.

It also adds some speed-probing code to udbg so that the default console
can come up at the same speed it was set to by the firmware.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Some debug code wasn't properly removed from the initial 64k pages
patch, and while it's harmless, it's also slowing down significantly a
very hot code path, thus it should really be removed.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul 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: NPaul Mackerras <paulus@samba.org>

The ancient ppcdebug/PPCDBG mechanism is now only used in two places.
First, in the hash setup code, one of the bits allows the size of the
hash table to be reduced by a factor of 8 - which would be better
accomplished with a command line option for that purpose.  The other
was a bunch of bus walking related messages in the iSeries code, which
would seem to be insufficient reason to keep the mechanism.

This patch removes the last traces of this mechanism.

Built and booted on iSeries and pSeries POWER5 LPAR (ARCH=powerpc).
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Adds a new CONFIG_PPC_64K_PAGES which, when enabled, changes the kernel
base page size to 64K.  The resulting kernel still boots on any
hardware.  On current machines with 4K pages support only, the kernel
will maintain 16 "subpages" for each 64K page transparently.

Note that while real 64K capable HW has been tested, the current patch
will not enable it yet as such hardware is not released yet, and I'm
still verifying with the firmware architects the proper to get the
information from the newer hypervisors.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

register_vpa() doesn't actually do a VPA register call it just uses the flags
you pass it, so rename it to vpa_call() to be clearer.

We can then define register_vpa() and unregister_vpa() which are both simple
wrappers around vpa_call(). (we'll need unregister_vpa() for kexec soon)

We can then cleanup vpa_init(), and because vpa_init() is only called from
platforms/pseries we remove the definition in asm-ppc64/smp.h.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>