rcu: Fix unrecovered RCU user mode in syscall_trace_leave()

On x86-64 syscall exit, 3 non exclusive events may happen
looping in the following order:

1) Check if we need resched for user preemption, if so call
schedule_user()

2) Check if we have pending signals, if so call do_notify_resume()

3) Check if we do syscall tracing, if so call syscall_trace_leave()

However syscall_trace_leave() has been written assuming it directly
follows the syscall and forget about the above possible 1st and 2nd
steps.

Now schedule_user() and do_notify_resume() exit in RCU user mode
because they have most chances to resume userspace immediately and
this avoids an rcu_user_enter() call in the syscall fast path.

So by the time we call syscall_trace_leave(), we may well be in RCU
user mode. To fix this up, simply call rcu_user_exit() in the beginning
of this function.

This fixes some reported RCU uses in extended quiescent state.

Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
perf, powerpc: Fix hw breakpoints returning -ENOSPC

I've been trying to get hardware breakpoints with perf to work
on POWER7 but I'm getting the following:

  % perf record -e mem:0x10000000 true

    Error: sys_perf_event_open() syscall returned with 28 (No space left on device).  /bin/dmesg may provide additional information.

    Fatal: No CONFIG_PERF_EVENTS=y kernel support configured?

  true: Terminated

(FWIW adding -a and it works fine)

Debugging it seems that __reserve_bp_slot() is returning ENOSPC
because it thinks there are no free breakpoint slots on this
CPU.

I have a 2 CPUs, so perf userspace is doing two perf_event_open
syscalls to add a counter to each CPU [1].  The first syscall
succeeds but the second is failing.

On this second syscall, fetch_bp_busy_slots() sets slots.pinned
to be 1, despite there being no breakpoint on this CPU.  This is
because the call the task_bp_pinned, checks all CPUs, rather
than just the current CPU. POWER7 only has one hardware
breakpoint per CPU (ie. HBP_NUM=1), so we return ENOSPC.

The following patch fixes this by checking the associated CPU
for each breakpoint in task_bp_pinned.  I'm not familiar with
this code, so it's provided as a reference to the above issue.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Jovi Zhang <bookjovi@gmail.com>
Cc: K Prasad <prasad@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1351268936-2956-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf header: Fix numa topology printing

Andrew reported that the commit 7e94cfcc9d20 ("perf header: Use pre-
processed session env when printing") regresses the header output.  It
was because of a missed string pointer calculation in the loop.

Reported-by: Andrew Jones <drjones@redhat.com>
Tested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andrew Jones <drjones@redhat.com>
Link: http://lkml.kernel.org/r/1350999890-6920-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tools: Fix strbuf_addf() when the buffer needs to grow

This was found during chasing down the header output regression.  The
strbuf_addf() was checking buffer length with a result of vscnprintf()
which cannot be greater than that of strbuf_avail().

Since numa topology and pmu mapping info in header were converted to use
strbuf, it sometimes caused uninteresting behaviors with the broken
strbuf.

Fix it by using vsnprintf() which returns desired output string length
regardless of the available buffer size and grow the buffer if needed.

Reported-by: Andrew Jones <drjones@redhat.com>
Tested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andrew Jones <drjones@redhat.com>
Link: http://lkml.kernel.org/r/1350999890-6920-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
x86: Export asm/{svm.h,vmx.h,perf_regs.h}

Export asm/{svm.h,vmx.h,perf_regs.h} so that they can be disintegrated.

It looks from previous commits that the first two should have been exported,
but the header-y lines weren't added to the Kbuild.

I'm guessing that asm/perf_regs.h should be exported too.

Signed-off-by: David Howells <dhowells@redhat.com>
Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

 *  Fix numa topology printing, from Namhyung Kim.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent

Pull syscall tracing fix from Paul E. McKenney.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
arm: mvebu: support for the PlatHome OpenBlocks AX3-4 board

This platform, available in Japan from PlatHome, has a dual-core
Armada XP, the MV78260. For now, only the two serial ports and the
three front LEDs are supported. Support for SMP, network, SATA, USB
and other peripherals will be added as drivers for them become
available for Armada XP in mainline.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

---
This is 3.8 material.

Changes since v2:

 * Renamed the .dts file to armada-xp-openblocks-ax3-4.dts

 * Removed the compatible string from armada-370-xp.c (which now only
   lists the common SoC compatible string)

Changes since v1:

 * Renamed the board to OpenBlocks AX3-4, since there is a variant
   called AX3-2 which has less RAM, and no mini PCIe port. Requested
   by Andrew Lunn.

 * Fix the amount of memory to 3 GB. In fact, the board has 1 GB
   soldered, and 2 GB in a SODIMM slot (which is therefore
   removable). But as the board is delivered as is, we'll assume it
   has 3 GB of memory by default.
arm: mvebu: support for the Globalscale Mirabox board

This platform, available from Globalscale has an Armada 370. For now,
only the serial port is supported. Support for network, USB and other
peripherals will be added as drivers for them become available for
Armada 370 in mainline.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
This is 3.8 material.

Changes from original version posted by Gregory:
 * Renamed .dts file to armada-370-mirabox.dts
 * Change compatible string to 'globalscale,mirabox'
 * Remove compatible string from armada-370-xp.c
 * Removed references to MBX0001
arm: mvebu: fix compatible string in armada-370-xp.dtsi

All the Device Tree files for Armada 370 and XP SoCs and boards use
the "armada-370-xp" common compatible string, except
armada-370-xp.dtsi which was specifying "armada_370_xp".

Fix this inconsistency by making armada-370-xp.dtsi declare a
compatible string of "armada-370-xp" like everyone else.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
arm: mvebu: don't list all boards in dt compat field for Armada 370/XP

Instead of listing explicitly all boards in the .dt_compat field of
the DT_MACHINE_START structure for Armada 370/XP, use instead a
compatible string that is common to all boards using the Armada
370/XP.

This allows to add new boards by just using a different Device Tree,
without having to modify the source code of the kernel.

Note that the name of the array containing the compatible string is
also renamed, to reflect the fact that it no longer contains the list
of all boards.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
arm: mvebu: fix typo in machine name for Armada 370/XP

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
arm: mvebu: add Ethernet controllers using mvneta driver for Armada 370/XP

The Armada 370 SoC has two network units, while the Armada XP has four
network units. The first two network units are common to both the
Armada XP and Armada 370, so they are added to armada-370-xp.dtsi,
while the other two network units are specific to the Armada XP and
therefore added to armada-xp.dtsi.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
arm: mvebu: enable Ethernet controllers on Armada 370/XP eval boards

This patch enables the two network interfaces of the Armada 370
official Marvell evaluation platform, and the four network interfaces
of the Armada XP official Marvell evaluation platform.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
arm: mvebu: enable Ethernet controllers on OpenBlocks AX3-4 platform

The PlatHome OpenBlocks AX3-4 platform has 4 Ethernet ports, connected
to a single quad-port PHY through SGMII.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
arm: mvebu: enable Ethernet controllers on Mirabox platform

The Globalscale Mirabox platform has two Ethernet interfaces,
connected to the SoC with a RGMII interface.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
net: mvmdio: new Marvell MDIO driver

This patch adds a separate driver for the MDIO interface of the
Marvell Ethernet controllers. There are two reasons to have a separate
driver rather than including it inside the MAC driver itself:

 *) The MDIO interface is shared by all Ethernet ports, so a driver
    must guarantee non-concurrent accesses to this MDIO interface. The
    most logical way is to have a separate driver that handles this
    single MDIO interface, used by all Ethernet ports.

 *) The MDIO interface is the same between the existing mv643xx_eth
    driver and the new mvneta driver. Even though it is for now only
    used by the mvneta driver, it will in the future be used by the
    mv643xx_eth driver as well.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: David S. Miller <davem@davemloft.net>
net: mvneta: driver for Marvell Armada 370/XP network unit

This patch contains a new network driver for the network unit of the
ARM Marvell Armada 370 and the Armada XP. Both SoCs use the PJ4B
processor, a Marvell-developed ARM core that implements the ARMv7
instruction set.

Compared to previous ARM Marvell SoCs (Kirkwood, Orion, Discovery),
the network unit in Armada 370 and Armada XP is highly different. This
is the reason why this new 'mvneta' driver is needed, while the older
ARM Marvell SoCs use the 'mv643xx_eth' driver.

Here is an overview of the most important hardware changes that
require a new, specific, driver for the network unit of Armada 370/XP:

 - The new network unit has a completely different design and layout
   for the RX and TX descriptors. They are now organized as a simple
   array (each RX and TX queue has base address and size of this
   array) rather than a linked list as in the old SoCs.

 - The new network unit has a different RXQ and TXQ management: this
   management is done using special read/write counter registers,
   while in the Old SocS, it was done using the Ownership bit in RX
   and TX descriptors.

 - The new network unit has different interrupt registers

 - The new network unit way of cleaning of interrupts is not done by
   writing to the cause register, but by updating per-queue counters

 - The new network unit has different GMAC registers (link, speed,
   duplex configuration) and different WRR registers.

 - The new network unit has lots of new units like PnC (Parser and
   Classifier), PMT, BM (Memory Buffer Management), xPON, and more.

The driver proposed in the current patch only handles the basic
features. Additional hardware features will progressively be supported
as needed.

This code has originally been written by Rami Rosen
<rosenr@marvell.com>, and then reviewed and cleaned up by Thomas
Petazzoni <thomas.petazzoni@free-electrons.com>.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: David S. Miller <davem@davemloft.net>
net: mvneta: update MAINTAINERS file for the mvneta maintainers

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: David S. Miller <davem@davemloft.net>
ARM: OMAP: Clean-up dmtimer reset code

Only OMAP1 devices use the omap_dm_timer_reset() and so require the
omap_dm_timer_wait_for_reset() and __omap_dm_timer_reset() functions.
Therefore combine these into a single function called omap_dm_timer_reset()
and simplify the code.

The omap_dm_timer_reset() function is now the only place that is using the
omap_dm_timer structure member "sys_stat". Therefore, remove this member and
just use the register offset definition to simplify and clean-up the code. The
TISTAT register is only present on revision 1 timers and so check for this in
the omap_dm_timer_reset() function.

Please note that for OMAP1 devices, the TIOCP_CFG register does not have the
clock-activity field and so when we reset the timer for an OMAP1 device we
only need to configure the idle-mode field in the TIOCP_CFG register.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>