Some devices have a dma-window that starts at the address 0. This allows
DMA addresses to be mapped to this address and returned to drivers as a
valid DMA address. Some drivers may not behave well in this case, since
the address 0 is considered an error or not allocated.

The solution to avoid this kind of error from happening is reserve the
page addressed as 0 so it cannot be allocated for a DMA mapping.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Commit 41151e77 ("powerpc: Hugetlb for BookE") added some
#ifdef CONFIG_MM_SLICES conditionals to hugetlb_get_unmapped_area()
and vma_mmu_pagesize().  Unfortunately this is not the correct config
symbol; it should be CONFIG_PPC_MM_SLICES.  The result is that
attempting to use hugetlbfs on 64-bit Power server processors results
in an infinite stack recursion between get_unmapped_area() and
hugetlb_get_unmapped_area().

This fixes it by changing the #ifdef to use CONFIG_PPC_MM_SLICES
in those functions and also in book3e_hugetlb_preload().
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Activate all MPC512x related boards. Also enable GPIO-driver, SPI driver
and at25 to test SPI. Enable DEVTMPFS. Bump to 3.1-rc6.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Anatolij Gustschin <agust@denx.de>

Move the driver to the place where it is expected to be nowadays. Also
rename its CONFIG-name to match the rest and adapt the defconfigs.
Finally, move selection of REQUIRE_GPIOLIB or WANTS_OPTIONAL_GPIOLIB to
the platforms, because this option is per-platform and not per-driver.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Anatolij Gustschin <agust@denx.de>

Audio support for the MPC5200 exists, so enable it by default.
Signed-off-by: Timur Tabi <timur@freescale.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>

We use both MSCAN controllers on this board, so do not disable
them in the device tree.
Signed-off-by: Anatolij Gustschin <agust@denx.de>

timer0 and timer1 pins are used as simple GPIO on this board.
Add gpio-controller and #gpio-cells properties to timer nodes
so that we can control gpio lines using available MPC52xx
GPT driver.
Signed-off-by: Anatolij Gustschin <agust@denx.de>

Add new nodes to describe more hardware the board is
equipped with:
 - two can nodes for SJA1000 on localbus
 - pci node to support Coral-PA graphics controller
 - serial node for SC28L92 DUART on localbus
 - spi node for MSP430 device

Also correct i2c eeprom node name.
Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>

Both, #address-cells and #size-cells properties are required
for spi bus node, so add them.
Signed-off-by: Anatolij Gustschin <agust@denx.de>

perf events, powerpc: Add POWER7 stalled-cycles-frontend/backend events

Extent the POWER7 PMU driver with definitions for generic front-end and back-end
stall events.

As explained in Ingo's original comment(8f622422
), the exact definitions of the stall events are very much processor specific as

different things mean different in their respective instruction pipeline. These
two Power7 raw events are the closest approximation to the concept detailed in
Ingo's comment.

[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = 0x100f8, /* GCT_NOSLOT_CYC */
It means cycles when the Global Completion Table has no slots from this thread

[PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = 0x4000a,  /* CMPLU_STALL */
It means no groups completed and GCT not empty for this thread
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The firmware doesn't wait after lifting the PCI reset. However it does
timestamp it in the device tree. We use that to ensure we wait long
enough (3s is our current arbitrary setting) from that timestamp to
actually probing the bus.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This implements support for MSIs on p5ioc2 PHBs. We only support
MSIs on the PCIe PHBs, not the PCI-X ones as the later hasn't been
properly verified in HW.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This adds support for PCI-X and PCIe on the p5ioc2 IO hub using
OPAL. This includes allocating & setting up TCE tables and config
space access routines.

This also supports fallbacks via RTAS when OPAL is absent, using
legacy TCE format pre-allocated via the device-tree (BML style)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

OPAL can handle various interrupt for us such as Machine Checks (it
performs all sorts of recovery tasks and passes back control to us with
informations about the error), Hardware Management Interrupts and Softpatch
interrupts.

This wires up the mechanisms and prints out specific informations returned
by HAL when a machine check occurs.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We do the minimum which is to "pass" interrupts to HAL, which
makes the console smoother and will allow us to implement
interrupt based completion and console.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

OPAL handles HW access to the various ICS or equivalent chips
for us (with the exception of p5ioc2 based HEA which uses a

different backend) similarily to what RTAS does on pSeries.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Implements OPAL RTC and NVRAM support and wire all that up to
the powernv platform.

We use RTAS for RTC as a fallback if available. Using RTAS for nvram
is not supported yet, pending some rework/cleanup and generalization
of the pSeries & CHRP code. We also use RTAS fallbacks for power off
and reboot
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This calls the respective HAL functions, and spin on hal_poll_event()
to ensure the HAL has a chance to communicate with the FSP to trigger
the reboot or shutdown operation
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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

Add definition of OPAL interfaces along with  the wrappers to call
into OPAL runtime and the early device-tree parsing hook to locate
the OPAL runtime firmware.
Signed-off-by: Benjamin 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: Benjamin 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: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Unplugged CPU go into NAP mode in a loop until woken up
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We used to overwrite with CONFIG_CMDLINE if we found a chosen
node but failed to get bootargs out of it or they were empty,
unless CONFIG_CMDLINE_FORCE is set.

Instead change that to overwrite if "data" is non empty after
the bootargs check. It allows arch code to have other mechanisms
to retrieve the command line prior to parsing the device-tree.

Note: CONFIG_CMDLINE_FORCE case should ideally be handled elsewhere
as it won't work as it-is if the device-tree has no /chosen node
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: devicetree-discuss@lists-ozlabs.org
CC: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Grant Likely <grant.likely@secretlab.ca>

This adds a skeletton for the new Power "Non Virtualized"
platform which will be used by machines supporting running
without an hypervisor, for example in order to run KVM.

These machines will be using a new firmware called OPAL
for which the support will be provided by later patches.

The PowerNV platform is intended to be also usable under
the BML environment used internally for early CPU bringup
which is why the code also supports using RTAS instead of
OPAL in various places.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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 <benh@kernel.crashing.org>

This new function is used to properly setup the PCI Express Max Payload Size
(and in some circumstances Max Read Request Size).

Some systems will not operate properly if these aren't set correctly and
the firmware doesn't always do it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This adds more generic support for doing CPU hotplug with a simple
idle loop and no actual reset of the processors. The generic
smp_generic_kick_cpu() does the hotplug bringup trick if the PACA
shows that the CPU has already been started at boot and we provide
an accessor for the CPU state.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

It was preventing the global early debug selection whenever KVM was enabled
instead of only preventing the 440 specific one.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The Power platform requires the partner info buffer to be page aligned
otherwise it will fail the partner info hcall with H_PARAMETER. Switch
from using kmalloc to allocate this buffer to __get_free_page to ensure
page alignment.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The icswx code introduced an A-B B-A deadlock:

     CPU0                    CPU1
     ----                    ----
lock(&anon_vma->mutex);
                             lock(&mm->mmap_sem);
                             lock(&anon_vma->mutex);
lock(&mm->mmap_sem);

Instead of using the mmap_sem to keep mm_users constant, take the
page table spinlock.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

If we echo an address the hypervisor doesn't like to
/sys/devices/system/memory/probe we oops the box:

# echo 0x10000000000 > /sys/devices/system/memory/probe

kernel BUG at arch/powerpc/mm/hash_utils_64.c:541!

The backtrace is:

create_section_mapping
arch_add_memory
add_memory
memory_probe_store
sysdev_class_store
sysfs_write_file
vfs_write
SyS_write

In create_section_mapping we BUG if htab_bolt_mapping returned
an error. A better approach is to return an error which will
propagate back to userspace.

Rerunning the test with this patch applied:

# echo 0x10000000000 > /sys/devices/system/memory/probe
-bash: echo: write error: Invalid argument
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

While converting code to use for_each_node_by_type I noticed a
number of coding style issues.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Use for_each_node_by_type instead of open coding it.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

During memory hotplug testing, I got the following warning:

ERROR: Bad of_node_put() on /memory@0

of_node_release
kref_put
of_node_put
of_find_node_by_type
hot_add_node_scn_to_nid
hot_add_scn_to_nid
memory_add_physaddr_to_nid
...

of_find_node_by_type() loop does the of_node_put for us so we only
need the handle the case where we terminate the loop early.

As suggested by Stephen Rothwell we can do the of_node_put
unconditionally outside of the loop since of_node_put handles a
NULL argument fine.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We have two identical definitions of RECLAIM_DISTANCE, looks like
the patch got applied twice. Remove one.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

On big POWER7 boxes we see large amounts of CPU time in system
processes like workqueue and watchdog kernel threads.

We currently rebalance the entire machine each time a task goes
idle and this is very expensive on large machines. Disable newidle
balancing at the node level and rely on the scheduler tick to
rebalance across nodes.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The largest POWER7 boxes have 32 nodes. SD_NODES_PER_DOMAIN groups
nodes into chunks of 16 and adds a global balancing domain
(SD_ALLNODES) above it.

If we bump SD_NODES_PER_DOMAIN to 32, then we avoid this extra
level of balancing on our largest boxes.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We want to override the default value of SD_NODES_PER_DOMAIN on ppc64,
so move it into linux/topology.h.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>