Prevent a preemption event causing the initialized VFP state being
overwritten by ensuring that the VFP hardware access is disabled
prior to starting initialization. We can then do this in safety
while still allowing preemption to occur.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix a hole in the VFP thread migration. Lets define two threads.
Thread 1, we'll call 'interesting_thread' which is a thread which is
running on CPU0, using VFP (so vfp_current_hw_state[0] =
&interesting_thread->vfpstate) and gets migrated off to CPU1, where
it continues execution of VFP instructions.
Thread 2, we'll call 'new_cpu0_thread' which is the thread which takes
over on CPU0. This has also been using VFP, and last used VFP on CPU0,
but doesn't use it again.
The following code will be executed twice:
cpu = thread->cpu;
/*
* On SMP, if VFP is enabled, save the old state in
* case the thread migrates to a different CPU. The
* restoring is done lazily.
*/
if ((fpexc & FPEXC_EN) && vfp_current_hw_state[cpu]) {
vfp_save_state(vfp_current_hw_state[cpu], fpexc);
vfp_current_hw_state[cpu]->hard.cpu = cpu;
}
/*
* Thread migration, just force the reloading of the
* state on the new CPU in case the VFP registers
* contain stale data.
*/
if (thread->vfpstate.hard.cpu != cpu)
vfp_current_hw_state[cpu] = NULL;
The first execution will be on CPU0 to switch away from 'interesting_thread'.
interesting_thread->cpu will be 0.
So, vfp_current_hw_state[0] points at interesting_thread->vfpstate.
The hardware state will be saved, along with the CPU number (0) that
it was executing on.
'thread' will be 'new_cpu0_thread' with new_cpu0_thread->cpu = 0.
Also, because it was executing on CPU0, new_cpu0_thread->vfpstate.hard.cpu = 0,
and so the thread migration check is not triggered.
This means that vfp_current_hw_state[0] remains pointing at interesting_thread.
The second execution will be on CPU1 to switch _to_ 'interesting_thread'.
So, 'thread' will be 'interesting_thread' and interesting_thread->cpu now
will be 1. The previous thread executing on CPU1 is not relevant to this
so we shall ignore that.
We get to the thread migration check. Here, we discover that
interesting_thread->vfpstate.hard.cpu = 0, yet interesting_thread->cpu is
now 1, indicating thread migration. We set vfp_current_hw_state[1] to
NULL.
So, at this point vfp_current_hw_state[] contains the following:
[0] = &interesting_thread->vfpstate
[1] = NULL
Our interesting thread now executes a VFP instruction, takes a fault
which loads the state into the VFP hardware. Now, through the assembly
we now have:
[0] = &interesting_thread->vfpstate
[1] = &interesting_thread->vfpstate
CPU1 stops due to ptrace (and so saves its VFP state) using the thread
switch code above), and CPU0 calls vfp_sync_hwstate().
if (vfp_current_hw_state[cpu] == &thread->vfpstate) {
vfp_save_state(&thread->vfpstate, fpexc | FPEXC_EN);
BANG, we corrupt interesting_thread's VFP state by overwriting the
more up-to-date state saved by CPU1 with the old VFP state from CPU0.
Fix this by ensuring that we have sane semantics for the various state
describing variables:
1. vfp_current_hw_state[] points to the current owner of the context
information stored in each CPUs hardware, or NULL if that state
information is invalid.
2. thread->vfpstate.hard.cpu always contains the most recent CPU number
which the state was loaded into or NR_CPUS if no CPU owns the state.
So, for a particular CPU to be a valid owner of the VFP state for a
particular thread t, two things must be true:
vfp_current_hw_state[cpu] == &t->vfpstate && t->vfpstate.hard.cpu == cpu.
and that is valid from the moment a CPU loads the saved VFP context
into the hardware. This gives clear and consistent semantics to
interpreting these variables.
This patch also fixes thread copying, ensuring that t->vfpstate.hard.cpu
is invalidated, otherwise CPU0 may believe it was the last owner. The
hole can happen thus:
- thread1 runs on CPU2 using VFP, migrates to CPU3, exits and thread_info
freed.
- New thread allocated from a previously running thread on CPU2, reusing
memory for thread1 and copying vfp.hard.cpu.
At this point, the following are true:
new_thread1->vfpstate.hard.cpu == 2
&new_thread1->vfpstate == vfp_current_hw_state[2]
Lastly, this also addresses thread flushing in a similar way to thread
copying. Hole is:
- thread runs on CPU0, using VFP, migrates to CPU1 but does not use VFP.
- thread calls execve(), so thread flush happens, leaving
vfp_current_hw_state[0] intact. This vfpstate is memset to 0 causing
thread->vfpstate.hard.cpu = 0.
- thread migrates back to CPU0 before using VFP.
At this point, the following are true:
thread->vfpstate.hard.cpu == 0
&thread->vfpstate == vfp_current_hw_state[0]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rename this branch to more accurately reflect why its taken, rather
than what the following code does. It is the only caller of this code.
This helps to clarify following changes, yet this change results in no
actual code change.
Document the VFP hardware state at the target of this branch.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rename the slightly confusing 'last_VFP_context' variable to be more
descriptive of what it actually is. This variable stores a pointer
to the current owner's vfpstate structure for the context held in the
VFP hardware.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'at91/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-2.6-arm-soc:
AT91: Change nand buswidth logic to match hardware default configuration
at91: Use "pclk" as con_id on at91cap9 and at91rm9200
at91: fix udc, ehci and mmc clock device name for cap9/9g45/9rl
atmel_serial: fix internal port num
at91: fix at91_set_serial_console: use platform device id
The recently modified nand buswitth configuration is not aligned with
board reality: the double footprint on boards is always populated with 8bits
buswidth nand flashes.
So we have to consider that without particular configuration the 8bits
buswidth is selected by default.
Moreover, the previous logic was always using !board_have_nand_8bit(), we
change it to a simpler: board_have_nand_16bit().
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* 'stable/bug.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/pci: Use the INT_SRC_OVR IRQ (instead of GSI) to preset the ACPI SCI IRQ.
xen/mmu: Fix for linker errors when CONFIG_SMP is not defined.
* 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-3.x:
sh: use printk_ratelimited instead of printk_ratelimit
sh: Fix up unmet dependency warnings with USB EHCI/OHCI selects.
sh: fix the value of sh_dmae_slave_config in setup-sh7757
sh: fix the INTC vector for IRQ and IRL in setup-sh7757
sh: add to select the new configuration for USB EHCI/OHCI
sh: add platform_device of EHCI/OHCI to setup-sh7757
sh: fix compile error using sh7757lcr_defconfig
* 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-3.x:
ARM: mach-shmobile: make a struct in board-ap4evb.c static
ARM: mach-shmobile: ag5evm: consistently name sdhi info structures
ARM: mach-shmobile: mackerel: change usbhs devices order
In the past we would use the GSI value to preset the ACPI SCI
IRQ which worked great as GSI == IRQ:
ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level)
While that is most often seen, there are some oddities:
ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level)
which means that GSI 20 (or pin 20) is to be overriden for IRQ 9.
Our code that presets the interrupt for ACPI SCI however would
use the GSI 20 instead of IRQ 9 ending up with:
xen: sci override: global_irq=20 trigger=0 polarity=1
xen: registering gsi 20 triggering 0 polarity 1
xen: --> pirq=20 -> irq=20
xen: acpi sci 20
.. snip..
calling acpi_init+0x0/0xbc @ 1
ACPI: SCI (IRQ9) allocation failed
ACPI Exception: AE_NOT_ACQUIRED, Unable to install System Control Interrupt handler (20110413/evevent-119)
ACPI: Unable to start the ACPI Interpreter
as the ACPI interpreter made a call to 'acpi_gsi_to_irq' which got nine.
It used that value to request an IRQ (request_irq) and since that was not
present it failed.
The fix is to recognize that for interrupts that are overriden (in our
case we only care about the ACPI SCI) we should use the IRQ number
to present the IRQ instead of the using GSI. End result is that we get:
xen: sci override: global_irq=20 trigger=0 polarity=1
xen: registering gsi 20 triggering 0 polarity 1
xen: --> pirq=20 -> irq=9 (gsi=9)
xen: acpi sci 9
which fixes the ACPI interpreter failing on startup.
CC: stable@kernel.org
Reported-by: Liwei <xieliwei@gmail.com>
Tested-by: Liwei <xieliwei@gmail.com>
[http://lists.xensource.com/archives/html/xen-devel/2011-06/msg01727.html]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Simple enough - we use an extern defined symbol which is not
defined when CONFIG_SMP is not defined. This fixes the linker
dying.
CC: stable@kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
struct soc_camera_link imx074_link in board-ap4evb.c doesn't have
to be global.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
arch/powerpc: use printk_ratelimited instead of printk_ratelimit
powerpc/rtas-rtc: remove sideeffects of printk_ratelimit
powerpc/pseries: remove duplicate SCSI_BNX2_ISCSI in pseries_defconfig
powerpc/e500: fix breakage with fsl_rio_mcheck_exception
powerpc/p1022ds: fix audio-related properties in the device tree
powerpc/85xx: fix NAND_CMD_READID read bytes number
Fix the value of chcr for SCIF[2-4]_RX and RIIC[0-9]_RX and
the value of mid_rid for some RIIC.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
%rip-relative addressing is relative to the first byte of the next instruction,
so we need to add %rip only after we've fetched any immediate bytes.
Based on original patch by Li Xin <xin.li@intel.com>.
Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Li Xin <xin.li@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Since printk_ratelimit() shouldn't be used anymore (see comment in
include/linux/printk.h), replace it with printk_ratelimited.
Signed-off-by: Christian Dietrich <christian.dietrich@informatik.uni-erlangen.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Don't use printk_ratelimit() as an additional condition for returning
on an error. Because when the ratelimit is reached, printk_ratelimit
will return 0 and e.g. in rtas_get_boot_time won't check for an error
condition.
Signed-off-by: Christian Dietrich <christian.dietrich@informatik.uni-erlangen.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Remove duplicate assignment of SCSI_BNX2_ISCSI in pseries_defconfig
introduced by:
37e0c21e powerpc/pseries: Enable iSCSI support for a number of cards
causes warning:
arch/powerpc/configs/pseries_defconfig:151:warning: override: reassigning to symbol SCSI_BNX2_ISCSI
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
serial: bcm63xx_uart: fix irq storm after rx fifo overrun.
amba pl011: platform data for reg lockup and glitch v2
amba pl011: workaround for uart registers lockup
tty: n_gsm: improper skb_pull() use was leaking framed data
tty: n_gsm: Fixed logic to decode break signal from modem status
TTY: ntty, add one more sanity check
TTY: ldisc, do not close until there are readers
8250: Fix capabilities when changing the port type
8250_pci: Fix missing const from merges
ARM: SAMSUNG: serial: Fix on handling of one clock source for UART
serial: ioremap warning fix for jsm driver.
8250_pci: add -ENODEV code for Intel EG20T PCH
Trying to build the Intel SCU Watchdog fails for me with gcc 4.6.0 -
$ gcc --version | head -n 1
gcc (GCC) 4.6.0 20110513 (prerelease)
like this :
CC drivers/watchdog/intel_scu_watchdog.o
In file included from drivers/watchdog/intel_scu_watchdog.c:49:0:
/home/jj/src/linux-2.6/arch/x86/include/asm/apb_timer.h: In function ‘apbt_time_init’:
/home/jj/src/linux-2.6/arch/x86/include/asm/apb_timer.h:65:42: warning: ‘return’ with a value, in function returning void [enabled by default]
drivers/watchdog/intel_scu_watchdog.c: In function ‘intel_scu_watchdog_init’:
drivers/watchdog/intel_scu_watchdog.c:468:2: error: implicit declaration of function ‘sfi_get_mtmr’ [-Werror=implicit-function-declaration]
drivers/watchdog/intel_scu_watchdog.c:468:32: warning: assignment makes pointer from integer without a cast [enabled by default]
cc1: some warnings being treated as errors
make[1]: *** [drivers/watchdog/intel_scu_watchdog.o] Error 1
make: *** [drivers/watchdog/intel_scu_watchdog.o] Error 2
Additionally, linux/types.h is needlessly being included twice in
drivers/watchdog/intel_scu_watchdog.c
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
To make SLUB work on UML we need this_cpu_cmpxchg from
asm-generic/percpu.h.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 21a3c96 uses node_start/end_pfn(nid) for detection start/end
of nodes. But, it's not defined in linux/mmzone.h but defined in
/arch/???/include/mmzone.h which is included only under
CONFIG_NEED_MULTIPLE_NODES=y.
Then, we see
mm/page_cgroup.c: In function 'page_cgroup_init':
mm/page_cgroup.c:308: error: implicit declaration of function 'node_start_pfn'
mm/page_cgroup.c:309: error: implicit declaration of function 'node_end_pfn'
So, fixiing page_cgroup.c is an idea...
But node_start_pfn()/node_end_pfn() is a very generic macro and
should be implemented in the same manner for all archs.
(m32r has different implementation...)
This patch removes definitions of node_start/end_pfn() in each archs
and defines a unified one in linux/mmzone.h. It's not under
CONFIG_NEED_MULTIPLE_NODES, now.
A result of macro expansion is here (mm/page_cgroup.c)
for !NUMA
start_pfn = ((&contig_page_data)->node_start_pfn);
end_pfn = ({ pg_data_t *__pgdat = (&contig_page_data); __pgdat->node_start_pfn + __pgdat->node_spanned_pages;});
for NUMA (x86-64)
start_pfn = ((node_data[nid])->node_start_pfn);
end_pfn = ({ pg_data_t *__pgdat = (node_data[nid]); __pgdat->node_start_pfn + __pgdat->node_spanned_pages;});
Changelog:
- fixed to avoid using "nid" twice in node_end_pfn() macro.
Reported-and-acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
[S390] allow setting of upper 32 bit in smp_ctl_set_bit
[S390] hwsampler: Set a sane default sampling rate
[S390] s390: enforce HW limits for the initial sampling rate
[S390] kvm-s390: fix kconfig dependencies
Hello,
I am not 100% sure this is the right thing to do, but it makes the
atmel-ssc driver happy on my at91rm9200 board.
This unifies the con_id across all at91 machines.
The atmel-ssc driver expects the con_id to be "pclk" or it will fail probing.
Signed-off-by: Joachim Eastwood <joachim.eastwood@jotron.com>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
x86/PCI/ACPI: fix type mismatch
PCI: fix new kernel-doc warning
PCI: Fix warning in drivers/pci/probe.c on sparc64
Because the USB EHCI/OHCI driver has new configuration for SH,
the patch enables the EHCI and/or OHCI driver of the on-chip for
some CPUs.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Ensure that the TLS register is saved and restored over a suspend
cycle, so that userspace programs don't see a corrupted TLS value.
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add the missing suspend/resume pointers for the suspend code. This
is needed when building for multiple CPUs.
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The bit shift operation in smp_ctl_set_bit does not specify the type
of the shifted bit so integer is used as default. Therefore it is not
possible to set bits in the upper 32 bit of the control register if
the kernel runs in 64 bit mode. Fix this by specifying the type as
unsigned long.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The sampling interval for the hardware sampler is specified in cycles.
(see SA23-2260-01 The Load-Program-Parameter and the CPU-Measurement
Facilities)
The current default value will therefore result in millions of samples.
This patch changes the default sampling interval to 4M, which will
result in ~1500 samples per second on a z196 reducing the overhead
of sampling.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
On specific configurations with hwsampler opcontrol --start returns an
error on "echo 1 >/dev/oprofile/enable". Turns out that the hw sampling
interval is not checked against the hardware limits.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A user can create the Kconfig combination !VIRTUALIZATION, S390_GUEST
which results in the following warnings:
warning: (S390_GUEST) selects VIRTIO which has unmet direct dependencies (VIRTUALIZATION)
warning: (S390_GUEST && VIRTIO_PCI && VIRTIO_BALLOON) selects VIRTIO_RING which has unmet direct dependencies (VIRTUALIZATION && VIRTIO)
warning: (S390_GUEST) selects VIRTIO which has unmet direct dependencies (VIRTUALIZATION)
warning: (S390_GUEST && VIRTIO_PCI && VIRTIO_BALLOON) selects VIRTIO_RING which has unmet direct dependencies (VIRTUALIZATION && VIRTIO)
S390_GUEST has to select VIRTUALIZATION before selecting VIRTIO and
friends.
Reported-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The wrong MCSR bit was being used on e500mc. MCSR_BUS_RBERR only exists
on e500v1/v2. Use MCSR_LD on e500mc, and remove all MCSR checking
in fsl_rio_mcheck_exception as we now no longer call that function
if the appropriate bit in MCSR is not set.
If RIO support was enabled at compile-time, but was never probed, just
return from fsl_rio_mcheck_exception rather than dereference a NULL
pointer.
TODO: There is still a remaining, though comparitively minor, issue in
that this recovery mechanism will falsely engage if there's an unrelated
MCSR_LD event at the same time as a RIO error.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
On the Freescale P1022DS reference board, the SSI audio controller is
connected in "asynchronous" mode to the codec's clocks, so the device tree
needs an "fsl,ssi-asynchronous" property.
Also remove the clock-frequency property from the wm8776 node, because
the clock is enabled only if U-Boot enables it, and U-Boot will set the
property if the clock is enabled. A future version of the P1022DS audio
driver will configure the clock itself, but for now, the driver should
not be told that the clock is running when it isn't.
Also fix the FIFO depth to 15, instead of 16.
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
MN10300's asm/uaccess.h needs to #include linux/kernel.h to get might_sleep()
otherwise it fails to build on MN10300 allyesconfig. This fails in a few
places with messages like the following:
In file included from security/keys/trusted.c:14:
include/linux/uaccess.h: In function '__copy_from_user_nocache':
include/linux/uaccess.h:52: error: implicit declaration of function 'might_sleep'
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The iop13xx_defconfig didn't build since the platform code uses
defines from <asm/ptrace.h>. Simply add the include so it
compiles.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
It is easy to mis-maintain the proc_types table such that the
entries become wrongly-sized and misaligned when the kernel is
built in Thumb-2.
This patch adds an assembly-time check which will turn most common
size/alignment mistakes in this table into build failures, to avoid
having to debug the boot-time kernel hang which would happen if the
resulting kernel were actually booted.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When we bring a CPU online, we should wait for it to become active
before entering the idle thread, so we know that the scheduler and
thread migration is going to work.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Name the SDHI1 instance sh_sdhi1_info to be consistent with sh_sdhi0_info.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
USB1 can use IRQ interrupt and notify function for usbhs driver,
but USB0 is using polling for it.
The priority of usbhs devices order USB1 > USB0 is good idea
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
