To allow debuggers to unwind through signal frames, we create a fake
stack unwinding prologue containing the link register and frame pointer
of the interrupted context. The signal frame is then offset by 16 bytes
to make room for the two saved registers which are pushed onto the frame
of the *interrupted* context, rather than placed directly above the
signal stack.

This doesn't work when an alternative signal stack is set up for a SEGV
handler, which is raised in response to RLIMIT_STACK being reached. In
this case, we try to push the unwinding prologue onto the full stack and
subsequently take a fault which we fail to resolve, causing setup_return
to return -EFAULT and handle_signal to force_sigsegv on the current task.

This patch fixes the problem by including the unwinding prologue as part
of the rt_sigframe definition, which is populated during setup_sigframe,
ensuring that it always ends up on the signal stack.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>

This patch updates the arm64 asm/Kbuild file to include the clkdev.h
generic header.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NViresh Kumar <Viresh.kumar@linaro.org>

Force all platforms to use the common clk framework to ensure that we do
not end up with platform-specific implementations ala ARM32.
Signed-off-by: NDeepak Saxena <dsaxena@linaro.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Commit f483a853 ("arm64: mm: fix booting on systems with no memory
below 4GB") sets max_dma32 to the minimum of the maximum pfn and
MAX_DMA32_PFN. This value is later used as the base of the NORMAL zone,
which is incorrect when MAX_DMA32_PFN is below the minimum pfn (i.e. all
memory is above 4GB).

This patch fixes the problem by ensuring that max_dma32 is always set to
the end of the DMA32 zone.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

For user space faults the kernel reports "unhandled page fault" and it
gives the ESR value. With this patch the error message looked up in the
fault info array to give a better description.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

We tried linking in a single built object to hold the device table,
but only works if all of the sparc64 crypto modules get built the same
way (modular vs. non-modular).

Just include the device ID stub into each driver source file so that
the table gets compiled into the correct result in all cases.
Reported-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sparc32 already supported it, as a consequence of using the
generic atomic64 implementation.  And the sparc64 implementation
is rather trivial.

This allows us to set ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE for all
of sparc, and avoid the annoying warning from lib/atomic64_test.c
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This bug-fix makes sure that of_address_to_resource is defined extern for sparc
so that the sparc-specific implementation of of_address_to_resource() is once
again used when including include/linux/of_address.h in a sparc context. A
number of drivers in mainline relies on this function working for sparc.

The bug was introduced in a850a755, "of/address:
add empty static inlines for !CONFIG_OF". Contrary to that commit title, the
static inlines are added for !CONFIG_OF_ADDRESS, and CONFIG_OF_ADDRESS is never
defined for sparc. This is good behavior for the other functions in
include/linux/of_address.h, as the extern functions defined in
drivers/of/address.c only gets linked when OF_ADDRESS is configured. However,
for of_address_to_resource there exists a sparc-specific implementation in
arch/sparc/arch/sparc/kernel/of_device_common.c

Solution suggested by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndreas Larsson <andreas@gaisler.com>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If an irq is being unlinked concurrently with leon_handle_ext_irq,
irq_map[eirq] might be null in leon_handle_ext_irq. Make sure that
this is not dereferenced.
Signed-off-by: NAndreas Larsson <andreas@gaisler.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The commit 911dec0d
"xen/arm: Fix compile errors when drivers are compiled as modules." exports
the neccessary functions. But to guard ourselves against out-of-tree modules
and future drivers hitting this, lets export all of the relevant
hypercalls.
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Fix the build error

  lib/atomic64.c: In function 'lock_addr':
  lib/atomic64.c:40:11: error: 'L1_CACHE_SHIFT' undeclared (first use in this function)
  lib/atomic64.c:40:11: note: each undeclared identifier is reported only once for each function it appears in
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Booting on a system with all of its memory above the 4GB boundary breaks
for two reasons:

	(1) We still try to create a non-empty DMA32 zone
	(2) no-bootmem limits allocations to 0xffffffff

This patch fixes these issues for ARM64.
Tested-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Commit 149c2415 ("ARM: SMP: use a timing out completion for cpu
hotplug") modified arm's CPU up path to use completions. It seems that
we only got half of this patch for arm64, so add the missing call to
complete.
Reported-by: NJon Brawn <jon.brawn@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

struct user_fp does not exist for arm64, so use struct user_fpsimd_state
instead for the ELF core dumping definitions. Furthermore, since we use
regset-based core dumping, we do not need definitions for dump_task_regs
and dump_fpu.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Commit c1d7e01d ("ipc: use Kconfig options for
__ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION") replaced the
__ARCH_WANT_COMPAT_IPC_PARSE_VERSION token with a corresponding Kconfig
option instead.

This patch updates arm64 to use the latter, rather than #define an
unused token.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

We currently use a fake event encoding (0xFF) to indicate CPU cycles so
that we don't waste an event counter and can target the hardware cycle
counter instead.

The problem with this approach is that the event space defined by the
architecture permits an implementation to allocate 0xFF for some other
event.

This patch uses the architected cycle counter encoding (0x11) so that
we avoid potentially clashing with event encodings on future CPU
implementations.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

We end up with:

ERROR: "HYPERVISOR_event_channel_op" [drivers/xen/xen-gntdev.ko] undefined!
ERROR: "privcmd_call" [drivers/xen/xen-privcmd.ko] undefined!
ERROR: "HYPERVISOR_grant_table_op" [drivers/net/xen-netback/xen-netback.ko] undefined!

and this patch exports said function (which is implemented in hypercall.S).
Acked-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The early mini sclp driver may be called in zArch mode either in
31 or 64 bit addressing mode.
If called in 31 bit addressing mode the new external interrupt psw
however would switch to 64 bit addressing mode. This would cause an
addressing exception within the interrupt handler, since the code
didn't expect the zArch/31 bit addressing mode combination.

Fix this by setting the new psw addressing mode bits so they fit
the current addressing mode.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There's no need to keep __MAX_SUBCHANNEL and __MAX_SSID private to the
common I/O layer when __MAX_CSSID is usable by everybody.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

While copying the argument structures in HYPERVISOR_event_channel_op()
and HYPERVISOR_physdev_op() into the local variable is sufficiently
safe even if the actual structure is smaller than the container one,
copying back eventual output values the same way isn't: This may
collide with on-stack variables (particularly "rc") which may change
between the first and second memcpy() (i.e. the second memcpy() could
discard that change).

Move the fallback code into out-of-line functions, and handle all of
the operations known by this old a hypervisor individually: Some don't
require copying back anything at all, and for the rest use the
individual argument structures' sizes rather than the container's.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJan Beulich <jbeulich@suse.com>
[v2: Reduce #define/#undef usage in HYPERVISOR_physdev_op_compat().]
[v3: Fix compile errors when modules use said hypercalls]
[v4: Add xen_ prefix to the HYPERCALL_..]
[v5: Alter the name and only EXPORT_SYMBOL_GPL one of them]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The variables here are really not used uninitialized.

arch/arm/mm/alignment.c: In function 'do_alignment':
arch/arm/mm/alignment.c:327:15: warning: 'offset.un' may be used uninitialized in this function [-Wmaybe-uninitialized]
arch/arm/mm/alignment.c:748:21: note: 'offset.un' was declared here
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Just get %icc2 into the state we would have after local_irq_disable()
and physical IRQ having happened since then.  Then we can simply
use preempt_schedule_irq() and be done with the whole mess.
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The kernel_thread() changes for FRV don't work, and FRV fails to boot,
starting with:

	commit 02ce496f
	Author: Al Viro <viro@zeniv.linux.org.uk>
	Date:   Tue Sep 18 22:18:51 2012 -0400
	Subject: frv: split ret_from_fork, simplify kernel_thread() a lot

The problem is that the userspace registers are completely cleared when a
kernel thread is created and all subsequent user threads are then copied from
that.  Unfortunately, however, the TBR and PSR registers are restored from the
pt_regs and the values they should be set to are clobbered by the memset.

Instead, copy across the old user registers as normal, and then merely alter
GR8 and GR9 in it if we're going to execute a kernel thread.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Fix the preemption handling in FRV code where the PREEMPT_ACTIVE value is
incorrectly loaded into the threadinfo flags rather than the threadinfo
preemption count.

Unfortunately, the code cannot be simply converted to use
preempt_schedule_irq() as is because FRV uses virtual interrupt disablement to
cut down on the cost of actually disabling interrupts and thus
local_irq_enable() doesn't actually enable interrupts.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: Al Viro <viro@ZenIV.linux.org.uk>

Don't let objcopy transfer the GNU build_id note into the loadable image as it
is located at address 0 and the image ends up >3G in size.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Add missing linux/export.h #inclusions to the FRV arch.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

After commit b3356bf0 (KVM: emulator: optimize "rep ins" handling),
the pieces of io data can be collected and write them to the guest memory
or MMIO together

Unfortunately, kvm splits the mmio access into 8 bytes and store them to
vcpu->mmio_fragments. If the guest uses "rep ins" to move large data, it
will cause vcpu->mmio_fragments overflow

The bug can be exposed by isapc (-M isapc):

[23154.818733] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[ ......]
[23154.858083] Call Trace:
[23154.859874]  [<ffffffffa04f0e17>] kvm_get_cr8+0x1d/0x28 [kvm]
[23154.861677]  [<ffffffffa04fa6d4>] kvm_arch_vcpu_ioctl_run+0xcda/0xe45 [kvm]
[23154.863604]  [<ffffffffa04f5a1a>] ? kvm_arch_vcpu_load+0x17b/0x180 [kvm]

Actually, we can use one mmio_fragment to store a large mmio access then
split it when we pass the mmio-exit-info to userspace. After that, we only
need two entries to store mmio info for the cross-mmio pages access
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

As Mukesh explained it, the MMUEXT_TLB_FLUSH_ALL allows the
hypervisor to do a TLB flush on all active vCPUs. If instead
we were using the generic one (which ends up being xen_flush_tlb)
we end up making the MMUEXT_TLB_FLUSH_LOCAL hypercall. But
before we make that hypercall the kernel will IPI all of the
vCPUs (even those that were asleep from the hypervisor
perspective). The end result is that we needlessly wake them
up and do a TLB flush when we can just let the hypervisor
do it correctly.

This patch gives around 50% speed improvement when migrating
idle guest's from one host to another.

Oracle-bug: 14630170

CC: stable@vger.kernel.org
Tested-by: NJingjie Jiang <jingjie.jiang@oracle.com>
Suggested-by: NMukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Use the new __HVC macro in hypercall.S.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Using the 'o' memory constraint in inline assembly can result in GCC
generating invalid immediate offsets for memory access instructions with
reduced addressing capabilities (i.e. smaller than 12-bit immediate
offsets):

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54983

As there is no constraint to specify the exact addressing mode we need,
fallback to using 'Q' exclusively for halfword I/O accesses. This may
emit an additional add instruction (using an extra register) in order
to construct the address but it will always be accepted by GAS.
Reported-by: NBastian Hecht <hechtb@googlemail.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

After commit 846a1368 ("ARM: vfp: fix
saving d16-d31 vfp registers on v6+ kernels"), the OMAP 2430SDP board
started crashing during boot with omap2plus_defconfig:

[    3.875122] mmcblk0: mmc0:e624 SD04G 3.69 GiB
[    3.915954]  mmcblk0: p1
[    4.086639] Internal error: Oops - undefined instruction: 0 [#1] SMP ARM
[    4.093719] Modules linked in:
[    4.096954] CPU: 0    Not tainted  (3.6.0-02232-g759e00b8 #570)
[    4.103149] PC is at vfp_reload_hw+0x1c/0x44
[    4.107666] LR is at __und_usr_fault_32+0x0/0x8

It turns out that the context save/restore fix unmasked a latent bug
in commit 5aaf2544 ("ARM: 6203/1: Make
VFPv3 usable on ARMv6").  When CONFIG_VFPv3 is set, but the kernel is
booted on a pre-VFPv3 core, the code attempts to save and restore the
d16-d31 VFP registers.  These are only present on non-D16 VFPv3+, so
this results in an undefined instruction exception.  The code didn't
crash before commit 846a1368 because the save and restore code was
only touching d0-d15, present on all VFP.

Fix by implementing a request from Russell King to add a new HWCAP
flag that affirmatively indicates the presence of the d16-d31
registers:

   http://marc.info/?l=linux-arm-kernel&m=135013547905283&w=2

and some feedback from Måns to clarify the name of the HWCAP flag.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Martin <dave.martin@linaro.org>
Cc: Måns Rullgård <mans.rullgard@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The scheduler imposes a requirement to sched_clock()
which is to stop the clock during suspend, if we don't
do that any RT thread will be rescheduled in the future
which might cause any sort of problems.

This became an issue on OMAP when we converted omap-i2c.c
to use threaded IRQs, it turned out that depending on how
much time we spent on suspend, the I2C IRQ thread would
end up being rescheduled so far in the future that I2C
transfers would timeout and, because omap_hsmmc depends
on an I2C-connected device to detect if an MMC card is
inserted in the slot, our rootfs would just vanish.

arch/arm/kernel/sched_clock.c already had an optional
implementation (sched_clock_needs_suspend()) which would
handle scheduler's requirement properly, what this patch
does is simply to make that implementation non-optional.

Note that this has the side-effect that printk timings
won't reflect the actual time spent on suspend so other
methods to measure that will have to be used.

This has been tested with beagleboard XM (OMAP3630) and
pandaboard rev A3 (OMAP4430). Suspend to RAM is now working
after this patch.

Thanks to Kevin Hilman for helping out with debugging.
Acked-by: NKevin Hilman <khilman@ti.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Document what's going on in asm/backoff.h with a large and descriptive
comment.  Refer to it above the cpu_relax() definition in
asm/processor_64.h

Rename the pause patching section to have "3insn" in it's name like
the other patching sections do.

Based upon feedback from Sam Ravnborg.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In atomic backoff and cpu_relax(), use the pause instruction
found on SPARC-T4 and later.

It makes the cpu strand unselectable for the given number of
cycles, unless an intervening disrupting trap occurs.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For atomic backoff, we just loop over an exponentially backed off
counter.  This is extremely ineffective as it doesn't actually yield
the cpu strand so that other competing strands can use the cpu core.

In cpus previous to SPARC-T4 we have to do this in a slightly hackish
way, by doing an operation with no side effects that also happens to
mark the strand as unavailable.

The mechanism we choose for this is three reads of the %ccr
(condition-code) register into %g0 (the zero register).

SPARC-T4 has an explicit "pause" instruction, and we'll make use of
that in a subsequent commit.

Yield strands also in cpu_relax().  We really should have done this a
very long time ago.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 92063cee, it
was applied prematurely, causing this build error for
imx_v4_v5_defconfig:

arch/arm/mach-imx/clk-imx25.c: In function 'mx25_clocks_init':
arch/arm/mach-imx/clk-imx25.c:206:26: error: 'pwm_ipg_per' undeclared (first use in this function)
arch/arm/mach-imx/clk-imx25.c:206:26: note: each undeclared identifier is reported only once for each function it appears in

Sascha Hauer explains:
> There are several gates missing in clk-imx25.c. I have a patch which
> adds support for them and I seem to have missed that the above depends
> on it.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

With the introduction of CONFIG_ARCH_MULTIPLATFORM, versatile is
no longer the default platform, so we need to enable
CONFIG_ARCH_VERSATILE explicitly in order for that to be selected
rather than the multiplatform configuration.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>