linux.git/arch/arm/kernel/machine_kexec.c, branch v3.14 Linux kernel source tree ARM: 7897/1: kexec: Use the right ISA for relocate_new_kernel 2013-11-30T22:21:02+00:00 Dave Martin dave.martin@linaro.org 2013-11-25T13:54:47+00:00 e2ccba49085ab5d71b092de2a5176eb9b19cc876 Copying a function with memcpy() and then trying to execute the result isn't trivially portable to Thumb. This patch modifies the kexec soft restart code to copy its assembler trampoline relocate_new_kernel() using fncpy() instead, so that relocate_new_kernel can be in the same ISA as the rest of the kernel without problems. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Reported-by: Taras Kondratiuk <taras.kondratiuk@linaro.org> Tested-by: Taras Kondratiuk <taras.kondratiuk@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Copying a function with memcpy() and then trying to execute the
result isn't trivially portable to Thumb.

This patch modifies the kexec soft restart code to copy its
assembler trampoline relocate_new_kernel() using fncpy() instead,
so that relocate_new_kernel can be in the same ISA as the rest of
the kernel without problems.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reported-by: Taras Kondratiuk <taras.kondratiuk@linaro.org>
Tested-by: Taras Kondratiuk <taras.kondratiuk@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7815/1: kexec: offline non panic CPUs on Kdump panic 2013-08-19T23:14:46+00:00 Vijaya Kumar K vijay.kilari@gmail.com 2013-08-14T12:28:28+00:00 4f9b4fb7a2091eec339413a460b1665758401828 In case of normal kexec kernel load, all cpu's are offlined before calling machine_kexec().But in case crash panic cpus are relaxed in machine_crash_nonpanic_core() SMP function but not offlined. When crash kernel is loaded with kexec and on panic trigger machine_kexec() checks for number of cpus online. If more than one cpu is online machine_kexec() fails to load with below error kexec: error: multiple CPUs still online In machine_crash_nonpanic_core() SMP function, offline CPU before cpu_relax Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
In case of normal kexec kernel load, all cpu's are offlined
before calling machine_kexec().But in case crash panic cpus
are relaxed in machine_crash_nonpanic_core() SMP function
but not offlined.

When crash kernel is loaded with kexec and on panic trigger
machine_kexec() checks for number of cpus online.
If more than one cpu is online machine_kexec() fails to load
with below error

kexec: error: multiple CPUs still online

In machine_crash_nonpanic_core() SMP function, offline CPU
before cpu_relax

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7807/1: kexec: validate CPU hotplug support 2013-08-13T19:23:18+00:00 Stephen Warren swarren@nvidia.com 2013-08-02T19:52:49+00:00 2103f6cba61a8b8bea3fc1b63661d830a2125e76 Architectures should fully validate whether kexec is possible as part of machine_kexec_prepare(), so that user-space's kexec_load() operation can report any problems. Performing validation in machine_kexec() itself is too late, since it is not allowed to return. Prior to this patch, ARM's machine_kexec() was testing after-the-fact whether machine_kexec_prepare() was able to disable all but one CPU. Instead, modify machine_kexec_prepare() to validate all conditions necessary for machine_kexec_prepare()'s to succeed. BUG if the validation succeeded, yet disabling the CPUs didn't actually work. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Architectures should fully validate whether kexec is possible as part of
machine_kexec_prepare(), so that user-space's kexec_load() operation can
report any problems. Performing validation in machine_kexec() itself is
too late, since it is not allowed to return.

Prior to this patch, ARM's machine_kexec() was testing after-the-fact
whether machine_kexec_prepare() was able to disable all but one CPU.
Instead, modify machine_kexec_prepare() to validate all conditions
necessary for machine_kexec_prepare()'s to succeed. BUG if the validation
succeeded, yet disabling the CPUs didn't actually work.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7759/1: decouple CPU offlining from reboot/shutdown 2013-06-17T20:35:25+00:00 Stephen Warren swarren@nvidia.com 2013-06-14T15:14:14+00:00 19ab428f4b7988ef3ac727c680efc193ef53ce14 Add comments to machine_shutdown()/halt()/power_off()/restart() that describe their purpose and/or requirements re: CPUs being active/not. In machine_shutdown(), replace the call to smp_send_stop() with a call to disable_nonboot_cpus(). This completely disables all but one CPU, thus satisfying the requirement that only a single CPU be active for kexec. Adjust Kconfig dependencies for this change. In machine_halt()/power_off()/restart(), call smp_send_stop() directly, rather than via machine_shutdown(); these functions don't need to completely de-activate all CPUs using hotplug, but rather just quiesce them. Remove smp_kill_cpus(), and its call from smp_send_stop(). smp_kill_cpus() was indirectly calling smp_ops.cpu_kill() without calling smp_ops.cpu_die() on the target CPUs first. At least some implementations of smp_ops had issues with this; it caused cpu_kill() to hang on Tegra, for example. Since smp_send_stop() is only used for shutdown, halt, and power-off, there is no need to attempt any kind of CPU hotplug here. Adjust Kconfig to reflect that machine_shutdown() (and hence kexec) relies upon disable_nonboot_cpus(). However, this alone doesn't guarantee that hotplug will work, or even that hotplug is implemented for a particular piece of HW that a multi-platform zImage runs on. Hence, add error-checking to machine_kexec() to determine whether it did work. Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Will Deacon <will.deacon@arm.com> Tested-by: Zhangfei Gao <zhangfei.gao@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Add comments to machine_shutdown()/halt()/power_off()/restart() that
describe their purpose and/or requirements re: CPUs being active/not.

In machine_shutdown(), replace the call to smp_send_stop() with a call to
disable_nonboot_cpus(). This completely disables all but one CPU, thus
satisfying the requirement that only a single CPU be active for kexec.
Adjust Kconfig dependencies for this change.

In machine_halt()/power_off()/restart(), call smp_send_stop() directly,
rather than via machine_shutdown(); these functions don't need to
completely de-activate all CPUs using hotplug, but rather just quiesce
them.

Remove smp_kill_cpus(), and its call from smp_send_stop().
smp_kill_cpus() was indirectly calling smp_ops.cpu_kill() without calling
smp_ops.cpu_die() on the target CPUs first. At least some implementations
of smp_ops had issues with this; it caused cpu_kill() to hang on Tegra,
for example. Since smp_send_stop() is only used for shutdown, halt, and
power-off, there is no need to attempt any kind of CPU hotplug here.

Adjust Kconfig to reflect that machine_shutdown() (and hence kexec)
relies upon disable_nonboot_cpus(). However, this alone doesn't guarantee
that hotplug will work, or even that hotplug is implemented for a
particular piece of HW that a multi-platform zImage runs on. Hence, add
error-checking to machine_kexec() to determine whether it did work.

Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by:  Zhangfei Gao <zhangfei.gao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7555/1: kexec: fix segment memory addresses check 2012-10-18T10:05:19+00:00 Aaro Koskinen aaro.koskinen@iki.fi 2012-10-16T18:35:14+00:00 2456f44dd7a9aaffc2cd21a13f78198b3d94da08 Commit c564df4db85aac8d1d65a56176a0a25f46138064 (ARM: 7540/1: kexec: Check segment memory addresses) added a safety check with accidentally reversed condition, and broke kexec functionality on ARM. Fix this. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Commit c564df4db85aac8d1d65a56176a0a25f46138064 (ARM: 7540/1: kexec:
Check segment memory addresses) added a safety check with accidentally
reversed condition, and broke kexec functionality on ARM. Fix this.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7540/1: kexec: Check segment memory addresses 2012-09-26T21:58:39+00:00 Matthew Leach matthew.leach@arm.com 2012-09-21T17:56:11+00:00 c564df4db85aac8d1d65a56176a0a25f46138064 Ensure that the memory regions that are set within the segments correspond to physical contiguous memory regions. Reviewed-by: Simon Horman <horms@verge.net.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Matthew Leach <matthew.leach@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Ensure that the memory regions that are set within the segments
correspond to physical contiguous memory regions.

Reviewed-by: Simon Horman <horms@verge.net.au>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7539/1: kexec: scan for dtb magic in segments 2012-09-26T21:58:36+00:00 Matthew Leach matthew.leach@arm.com 2012-09-21T17:56:02+00:00 4cabd1d9625c7d88acd143f4021fbef75394f154 This patch allows a dtb to be passed to a new kernel using the kexec mechinism. When loading segments from userspace, scan each segment's first four bytes for the dtb magic. If this is found set the kexec_boot_atags parameter to the relocate_kernel code to the phyical address of this segment. Reviewed-by: Simon Horman <horms@verge.net.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Matthew Leach <matthew.leach@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
This patch allows a dtb to be passed to a new kernel using the kexec
mechinism.

When loading segments from userspace, scan each segment's first four
bytes for the dtb magic. If this is found set the kexec_boot_atags
parameter to the relocate_kernel code to the phyical address of this
segment.

Reviewed-by: Simon Horman <horms@verge.net.au>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2012-03-29T23:53:48+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-03-29T23:53:48+00:00 12679a2d7e3bfbdc7586e3e86d1ca90c46659363 Pull more ARM updates from Russell King. This got a fair number of conflicts with the <asm/system.h> split, but also with some other sparse-irq and header file include cleanups. They all looked pretty trivial, though. * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits) ARM: fix Kconfig warning for HAVE_BPF_JIT ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds ARM: 7349/1: integrator: convert to sparse irqs ARM: 7259/3: net: JIT compiler for packet filters ARM: 7334/1: add jump label support ARM: 7333/2: jump label: detect %c support for ARM ARM: 7338/1: add support for early console output via semihosting ARM: use set_current_blocked() and block_sigmask() ARM: exec: remove redundant set_fs(USER_DS) ARM: 7332/1: extract out code patch function from kprobes ARM: 7331/1: extract out insn generation code from ftrace ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format ARM: 7351/1: ftrace: remove useless memory checks ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path ARM: Versatile Express: add NO_IOPORT ARM: get rid of asm/irq.h in asm/prom.h ARM: 7319/1: Print debug info for SIGBUS in user faults ARM: 7318/1: gic: refactor irq_start assignment ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop ARM: 7315/1: perf: add support for the Cortex-A7 PMU ... 
Pull more ARM updates from Russell King.

This got a fair number of conflicts with the <asm/system.h> split, but
also with some other sparse-irq and header file include cleanups.  They
all looked pretty trivial, though.

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits)
  ARM: fix Kconfig warning for HAVE_BPF_JIT
  ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds
  ARM: 7349/1: integrator: convert to sparse irqs
  ARM: 7259/3: net: JIT compiler for packet filters
  ARM: 7334/1: add jump label support
  ARM: 7333/2: jump label: detect %c support for ARM
  ARM: 7338/1: add support for early console output via semihosting
  ARM: use set_current_blocked() and block_sigmask()
  ARM: exec: remove redundant set_fs(USER_DS)
  ARM: 7332/1: extract out code patch function from kprobes
  ARM: 7331/1: extract out insn generation code from ftrace
  ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format
  ARM: 7351/1: ftrace: remove useless memory checks
  ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path
  ARM: Versatile Express: add NO_IOPORT
  ARM: get rid of asm/irq.h in asm/prom.h
  ARM: 7319/1: Print debug info for SIGBUS in user faults
  ARM: 7318/1: gic: refactor irq_start assignment
  ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop
  ARM: 7315/1: perf: add support for the Cortex-A7 PMU
  ...
Disintegrate asm/system.h for ARM 2012-03-28T17:30:01+00:00 David Howells dhowells@redhat.com 2012-03-28T17:30:01+00:00 9f97da78bf018206fb623cd351d454af2f105fe0 Disintegrate asm/system.h for ARM. Signed-off-by: David Howells <dhowells@redhat.com> cc: Russell King <linux@arm.linux.org.uk> cc: linux-arm-kernel@lists.infradead.org 
Disintegrate asm/system.h for ARM.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Russell King <linux@arm.linux.org.uk>
cc: linux-arm-kernel@lists.infradead.org
ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path 2012-03-24T09:38:54+00:00 Will Deacon will.deacon@arm.com 2012-02-03T13:48:01+00:00 9141a003a491c7230d17b9c29677ce2be437b95c The kexec machine crash code can be called in interrupt context via a sysrq trigger made using the magic key combination. If the irq chip dealing with the serial interrupt is using the fasteoi flow handler, then we will never EOI the interrupt because the interrupt handler will be fatal. In the case of a GIC, this results in the crash kernel not receiving interrupts on that CPU interface. This patch adds code (based on the PowerPC implementation) to EOI any pending interrupts on the crash CPU before masking and disabling all interrupts. Secondary cores are not a problem since they are placed into a cpu_relax() loop via an IPI. Reported-by: Lei Wen <leiwen@marvell.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
The kexec machine crash code can be called in interrupt context via a
sysrq trigger made using the magic key combination. If the irq chip
dealing with the serial interrupt is using the fasteoi flow handler,
then we will never EOI the interrupt because the interrupt handler will
be fatal. In the case of a GIC, this results in the crash kernel not
receiving interrupts on that CPU interface.

This patch adds code (based on the PowerPC implementation) to EOI any
pending interrupts on the crash CPU before masking and disabling all
interrupts. Secondary cores are not a problem since they are placed into
a cpu_relax() loop via an IPI.

Reported-by: Lei Wen <leiwen@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>