Verify memory entitlement updates can be handled by vio.
Signed-off-by: NNathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This is a large patch but the normal code path is not affected.  For
non-pSeries platforms the code is ifdef'ed out and for non-CMO enabled
pSeries systems this does not affect the normal code path.  Devices that
do not perform DMA operations do not need modification with this patch.
The function get_desired_dma was renamed from get_io_entitlement for
clarity.

Overview

Cooperative Memory Overcommitment (CMO) allows for a set of OS partitions
to be run with less RAM than the aggregate needs of the group of
partitions.  The firmware will balance memory between the partitions
and page in/out memory as needed.  Based on the number and type of IO
adpaters preset each partition is allocated an amount of memory for
DMA operations and this allocation will be guaranteed to the partition;
this is referred to as the partition's 'entitlement'.

Partitions running in a CMO environment can only have virtual IO devices
present.  The VIO bus layer will manage the IO entitlement for the system.
Accounting, at a system and per-device level, is tracked in the VIO bus
code and exposed via sysfs.  A set of dma_ops functions are added to
the bus to allow for this accounting.

Bus initialization

At initialization, the bus will calculate the minimum needs of the system
based on providing each device present with a standard minimum entitlement
along with a spare allocation for the bus to handle hotplug events.
If the minimum needs can not be met the system boot will be halted.

Device changes

The significant changes for devices while running under CMO are that the
devices must specify how much dedicated IO entitlement they desire and
must also handle DMA mapping errors that can occur due to constrained
IO memory.  The virtual IO drivers are modified to silence errors when
DMA mappings fail for CMO and handle these failures gracefully.

Each devices will be guaranteed a minimum entitlement that can always
be mapped.  Devices will specify how much entitlement they desire and
the VIO bus will attempt to provide for this.  Devices can change their
desired entitlement level at any point in time to address particular needs
(via vio_cmo_set_dev_desired()), not just at device probe time.

VIO bus changes

The system will have a particular entitlement level available from which
it can provide memory to the devices.  The bus defines two pools of memory
within this entitlement, the reserved and excess pools.  Each device is
provided with it's own entitlement no less than a system defined minimum
entitlement and no greater than what the device has specified as it's
desired entitlement.  The entitlement provided to devices comes from the
reserve pool.  The reserve pool can also contain a spare allocation as
large as the system defined minimum entitlement which is used for device
hotplug events.  Any entitlement not needed to fulfill the needs of a
reserve pool is placed in the excess pool.  Each device is guaranteed
that it can map up to it's entitled level; additional mapping are possible
as long as there is unmapped memory in the excess pool.

Bus probe

As the system starts, each device is given an entitlement equal only
to the system defined minimum entitlement.  The reserve pool is equal
to the sum of these entitlements, plus a spare allocation.  The VIO bus
also tracks the aggregate desired entitlement of all the devices.  If the
system desired entitlement is greater than the size of the reserve pool,
when devices unmap IO memory it will be reserved and a balance operation
will be scheduled for some time in the future.

Entitlement balancing

The balance function tries to fairly distribute entitlement between the
devices in the system with the goal of providing each device with it's
desired amount of entitlement.  Devices using more than what would be
ideal will have their entitled set-point adjusted; this will effectively
set a goal for lower IO memory usage as future mappings can fail and
deallocations will trigger a balance operation to distribute the newly
unmapped memory.  A fair distribution of entitlement can take several
balance operations to achieve.  Entitlement changes and device DLPAR
events will alter the state of CMO and will trigger balance operations.

Hotplug events

The VIO bus allows for changes in system entitlement at run-time via
'vio_cmo_entitlement_update()'.  When devices are added the hotplug
device event will be preceded by a system entitlement increase and this
is reversed when devices are removed.

The following changes are made that the VIO bus layer for CMO:
 * add IO memory accounting per device structure.
 * add IO memory entitlement query function to driver structure.
 * during vio bus probe, if CMO is enabled, check that driver has
   memory entitlement query function defined.  Fail if function not defined.
 * fail to register driver if io entitlement function not defined.
 * create set of dma_ops at vio level for CMO that will track allocations
   and return DMA failures once entitlement is reached.  Entitlement will
   limited by overall system entitlement.  Devices will have a reserved
   quantity of memory that is guaranteed, the rest can be used as available.
 * expose entitlement, current allocation, desired allocation, and the
   allocation error counter for devices to the user through sysfs
 * provide mechanism for changing a device's desired entitlement at run time
   for devices as an exported function and sysfs tunable
 * track any DMA failures for entitled IO memory for each vio device.
 * check entitlement against available system entitlement on device add
 * track entitlement metrics (high water mark, current usage)
 * provide function to reset high water mark
 * provide minimum and desired entitlement numbers at a bus level
 * provide drivers with a minimum guaranteed entitlement
 * balance available entitlement between devices to satisfy their needs
 * handle system entitlement changes and device hotplug
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

To support Cooperative Memory Overcommitment (CMO), we need to check
for failure from some of the tce hcalls.

These changes for the pseries platform affect the powerpc architecture;
patches for the other affected platforms are included in this patch.

pSeries platform IOMMU code changes:
 * platform TCE functions must handle H_NOT_ENOUGH_RESOURCES errors and
   return an error.

Architecture IOMMU code changes:
 * Calls to ppc_md.tce_build need to check return values and return
   DMA_MAPPING_ERROR for transient errors.

Architecture changes:
 * struct machdep_calls for tce_build*_pSeriesLP functions need to change
   to indicate failure.
 * all other platforms will need updates to iommu functions to match the new
   calling semantics; they will return 0 on success.  The other platforms
   default configs have been built, but no further testing was performed.
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

With the addition of Cooperative Memory Overcommitment (CMO) support
for IBM Power Systems, two fields have been added to the VPA to report
paging statistics.  Add support in lparcfg to report them to userspace.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Split the retrieval of processor entitlement data returned in the H_GET_PPP
hcall into its own helper routine.
Signed-off-by: NNathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Update /proc/ppc64/lparcfg to display Cooperative Memory
Overcommitment statistics as reported by the H_GET_MPP hcall.  This
also updates the lparcfg interface to allow setting memory entitlement
and weight.
Signed-off-by: NNathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Split the retrieval and setting of processor entitlement and weight into
helper routines.  This also removes the printing of the raw values
returned from h_get_ppp, the values are already parsed and printed.
Signed-off-by: NNathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Remove the extraneous error reporting used when a hcall made from lparcfg fails.
Signed-off-by: NNathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

My previous patch to fix compilation with binutils-2.17 causes
a "file truncated" build error from ld with binutils 2.15 (and
possibly older), and a warning with 2.16 and 2.17.

This fixes it.
Signed-off-by: NSegher Boessenkool <segher@kernel.crashing.org>
Acked-by: NChuck Meade <chuckmeade@mindspring.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch implements support for HW based watchpoint via the
DBSR_DAC (Data Address Compare) facility of the BookE processors.

It does so by interfacing with the existing DABR breakpoint code
and adding the necessary bits and pieces for the new bits to
be properly set or cleared
Signed-off-by: NLuis Machado <luisgpm@br.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

A struct sysdev_attribute * parameter was added to the show routine by
commit 4a0b2b4d "sysdev: Pass the
attribute to the low level sysdev show/store function".

This eliminates a warning:

arch/powerpc/kernel/sysfs.c:538: warning: initialization from incompatible pointer type
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Stash the first platform string matched by identify_cpu() in
powerpc_base_platform, and supply that to the ELF loader for the value
of AT_BASE_PLATFORM.
Signed-off-by: NNathan Lynch <ntl@pobox.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit
boundary. For example:

	u64 val = PAGE_ALIGN(size);

always returns a value < 4GB even if size is greater than 4GB.

The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for
example):

#define PAGE_SHIFT      12
#define PAGE_SIZE       (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK       (~(PAGE_SIZE-1))
...
#define PAGE_ALIGN(addr)       (((addr)+PAGE_SIZE-1)&PAGE_MASK)

The "~" is performed on a 32-bit value, so everything in "and" with
PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary.
Using the ALIGN() macro seems to be the right way, because it uses
typeof(addr) for the mask.

Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in
include/linux/mm.h.

See also lkml discussion: http://lkml.org/lkml/2008/6/11/237

[akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c]
[akpm@linux-foundation.org: fix v850]
[akpm@linux-foundation.org: fix powerpc]
[akpm@linux-foundation.org: fix arm]
[akpm@linux-foundation.org: fix mips]
[akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c]
[akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c]
[akpm@linux-foundation.org: fix powerpc]
Signed-off-by: NAndrea Righi <righi.andrea@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch removes the old kgdb reminants from ARCH=powerpc and
implements the new style arch specific stub for the common kgdb core
interface.

It is possible to have xmon and kgdb in the same kernel, but you
cannot use both at the same time because there is only one set of
debug hooks.

The arch specific kgdb implementation saves the previous state of the
debug hooks and restores them if you unconfigure the kgdb I/O driver.
Kgdb should have no impact on a kernel that has no kgdb I/O driver
configured.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

This allow to dynamically generate attributes and share show/store
functions between attributes. Right now most attributes are generated
by special macros and lots of duplicated code. With the attribute
passed it's instead possible to attach some data to the attribute
and then use that in shared low level functions to do different things.

I need this for the dynamically generated bank attributes in the x86
machine check code, but it'll allow some further cleanups.

I converted all users in tree to the new show/store prototype. It's a single
huge patch to avoid unbisectable sections.

Runtime tested: x86-32, x86-64
Compiled only: ia64, powerpc
Not compile tested/only grep converted: sh, arm, avr32
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

binutils < 2.18 has a bug that makes it misbehave when taking an
ELF file with all segments at load address 0 as input.  This
happens when running "strip" on vmlinux, because of the AT() magic
in this linker script.  People using GCC >= 4.2 won't run into
this problem, because the "build-id" support will put some data
into the "notes" segment (at a non-zero load address).

To work around this, we force some data into both the "dummy"
segment and the kernel segment, so the dummy segment will get a
non-zero load address.  It's not enough to always create the
"notes" segment, since if nothing gets assigned to it, its load
address will be zero.
Signed-off-by: NSegher Boessenkool <segher@kernel.crashing.org>
Tested-By: NMilton Miller <miltonm@bga.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

While running on a system with new hardware and a kernel where the
cpu_specs[] table does not recognize the new hardware, the identify_cpu()
routine will select the default case as it searches through cpu_specs[]
in an attempt to match the real PVR. Once the default case is selected,
non of the oprofile counters and/or fields have been set up or defined.

When identify_cpu() is called once more with the logical PVR, some of
the cpu specific fields are replaced with the exception of the oprofile
related ones. However, in the case where we have actually taken the
default case while searching for the real PVR, we need to tell
oprofile that we are now running in compatibility mode so it can pick up
the correct counters. We do this by setting the oprofile_cpu_type field
to be that taken from the cpu_specs[] for the cpu we are now emulating.

This change will detect that we are now altering the real PVR and determine
if we also need to update the oprofile_cpu_type field.
Signed-off-by: NTorez Smith <lnxtorez@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The OF parsing code for PCI addresses isn't always treating properly
the address space indication 0b11 (ie. 0x3) as meaning 64 bits
memory space.

This means that it fails to parse addresses for PCI BARs that have
this encoding set by the firmware, which happens on some SLOF
versions and breaks offb palette handling on Powerstation.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NSegher Boessenkool <segher@kernel.crashing.org>

We need to pass the kernel stack pointer instead of the user space
stack pointer in save_stack_trace_tsk().
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Update iommu_alloc() to take the struct dma_attrs and pass them on to
tce_build(). This change propagates down to the tce_build functions of
all the platforms.
Signed-off-by: NMark Nelson <markn@au1.ibm.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:

	scheduler switch to idle task
	enable interrupts

Window starts here

	----> interrupt happens (does not set NEED_RESCHED)
	      	irq_exit() stops the tick

	----> interrupt happens (does set NEED_RESCHED)

	return from schedule()
	
	cpu_idle(): preempt_disable();

Window ends here

The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.

The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.

Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.

cpu_idle()
{
	preempt_disable();

	while(1) {
		 tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we
		 			          are in the idle loop

		 while (!need_resched())
		       halt();

		 tick_nohz_restart_sched_tick(); <- disables NOHZ mode
		 preempt_enable_no_resched();
		 schedule();
		 preempt_disable();
	}
}

In hindsight we should have done this forever, but ... 

/me grabs a large brown paperbag.

Debugged-by: Jack Ren <jack.ren@marvell.com>, 
Debugged-by: Neric miao <eric.y.miao@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Use the TLBSYNC macro defined in ppc_asm.h rather than our own ifdefs.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

This converts the FSL Book-E PTE access and TLB miss handling to match
with the recent changes to 44x that introduce support for non-atomic PTE
operations in pgtable-ppc32.h and removes write back to the PTE from
the TLB miss handlers. In addition, the DSI interrupt code no longer
tries to fixup write permission, this is left to generic code, and
_PAGE_HWWRITE is gone.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Push the sync below the secondary smp init hold loop and comment its purpose.
This should speed up boot by reducing global traffic during the single-threaded
portion of boot.
Signed-off-by: NSonny Rao <sonnyrao@us.ibm.com>
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

VSX loads and stores will take an alignment exception when the address
is not on a 4 byte boundary.

This add support for these alignment exceptions and will emulate the
requested load or store.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

giveup_vsx didn't save the FPU and VMX regsiters.  Change it to be
like giveup_fpr/altivec which save these registers.

Also update call sites where FPU and VMX are already saved to use the
original giveup_vsx (renamed to __giveup_vsx).
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Implement save_stack_trace_tsk on powerpc, so that we can run with
latencytop.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Background from Maynard Johnson:
As of POWER6, a set of 32 common events is defined that must be
supported on all future POWER processors.  The main impetus for this
compat set is the need to support partition migration, especially from
processor P(n) to processor P(n+1), where performance software that's
running in the new partition may not be knowledgeable about processor
P(n+1).  If a performance tool determines it does not support the
physical processor, but is told (via the
PPC_FEATURE_PSERIES_PERFMON_COMPAT bit) that the processor supports
the notion of the PMU compat set, then the performance tool can
surface just those events to the user of the tool.

PPC_FEATURE_PSERIES_PERFMON_COMPAT indicates that the PMU supports at
least this basic subset of events which is compatible across POWER
processor lines.
Signed-off-by: NNathan Lynch <ntl@pobox.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Today's linux-next build (powerpc allmodconfig) failed like this:

ERROR: ".save_stack_trace" [tests/backtracetest.ko] undefined!

But save_stack_trace is exported in arch/powerpc/kernel/stacktrace.c

I couldn't figure it out until I noticed these earlier warnings:

arch/powerpc/kernel/stacktrace.c:47: warning: data definition has no type or storage class
arch/powerpc/kernel/stacktrace.c:47: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL'
arch/powerpc/kernel/stacktrace.c:47: warning: parameter names (without types) in function declaration

I applied the patch below.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <linuxppc-dev@ozlabs.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For some reason long ago I decided that we should zero out the time base
when we calibrate the decrementer.  The problem is that this can be
harmful in SMP systems where the firmware has already synchronized the
time bases on the various cores.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

This is some preliminary work to improve TLB management on SW loaded
TLB powerpc platforms. This introduce support for non-atomic PTE
operations in pgtable-ppc32.h and removes write back to the PTE from
the TLB miss handlers. In addition, the DSI interrupt code no longer
tries to fixup write permission, this is left to generic code, and
_PAGE_HWWRITE is gone.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

regs is not used in emulate_fp_pair so remove it.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When the ucontext changed to add the VSX context, this broke backwards
compatibly on swapcontext.  swapcontext only compares the ucontext size
passed in from the user to the new kernel ucontext size.

This adds a check against the old ucontext size (with VMX but without
VSX).  It also adds some sanity check for ucontexts without VSX, but
where VSX is used according the MSR.  Fixes for both 32 and 64bit
processes on 64bit kernels

Kudos to Paulus for noticing.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Choose a more meaningful name for better System.map readability and
autopsy value etc.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Allow an application to enable Strong Access Ordering on specific pages of
memory on Power 7 hardware. Currently, power has a weaker memory model than
x86. Implementing a stronger memory model allows an emulator to more
efficiently translate x86 code into power code, resulting in faster code
execution.

On Power 7 hardware, storing 0b1110 in the WIMG bits of the hpte enables
strong access ordering mode for the memory page.  This patchset allows a
user to specify which pages are thus enabled by passing a new protection
bit through mmap() and mprotect().  I have defined PROT_SAO to be 0x10.
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This changes the oops and backtrace code to use the new %pS
printk extension to print out symbols rather than manually
calling print_symbol.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Move device_to_mask() to dma-mapping.h because we need to use it from
outside dma_64.c in a later patch.
Signed-off-by: NMark Nelson <markn@au1.ibm.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Update powerpc to use the new dma_*map*_attrs() interfaces. In doing so
update struct dma_mapping_ops to accept a struct dma_attrs and propagate
these changes through to all users of the code (generic IOMMU and the
64bit DMA code, and the iseries and ps3 platform code).

The old dma_*map_*() interfaces are reimplemented as calls to the
corresponding new interfaces.
Signed-off-by: NMark Nelson <markn@au1.ibm.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Make iommu_map_sg take a struct iommu_table. It did so before commit
740c3ce6 (iommu sg merging: ppc: make
iommu respect the segment size limits).

This stops the function looking in the archdata.dma_data for the iommu
table because in the future it will be called with a device that has
no table there.

This also has the nice side effect of making iommu_map_sg() match the
other map functions.
Signed-off-by: NMark Nelson <markn@au1.ibm.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There is dma_mask in of_device upon of_platform_device_create()
but we don't actually set coherent_dma_mask. This may cause weird
behavior of USB subsystem using of_device USB host drivers.
Signed-off-by: NVitaly Bordug <vitb@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>