Now that smp_ops->smp_message_pass is always called with an (online) cpu
number for the target remove the checks for MSG_ALL and MSG_ALL_BUT_SELF.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The only user of MSG_ALL_BUT_SELF in the whole kernel tree is powerpc,
and it only uses it to start the debugger. Both debuggers always call
smp_send_debugger_break with MSG_ALL_BUT_SELF, and only mpic can do
anything more optimal than a loop over all online cpus, but all message
passing implementations have to code for this special delivery target.
Convert smp_send_debugger_break to take void and loop calling the smp_ops
message_pass function for each of the other cpus in the online cpumask.
Use raw_smp_processor_id() because we are either entering the debugger
or trying to start kdump and the additional warning it not useful were
it to trigger.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
c1854e0072 (powerpc: Set nr_cpu_ids early
and use it to free PACAs) copied the formerly static setup_nr_cpu_ids
from init/main.c but 34db18a054 (smp:
move smp setup functions to kernel/smp.c) moved it to kernel/smp.c
with a declaration in include/linux/smp.h, so we can call it instead of
replicating it.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Now that we never set a cpu above nr_cpu_ids possible we can
limit our initial paca allocation to nr_cpu_ids. We can then
clamp the number of cpus in platforms/iseries/setup.c.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We should not set cpus above nr_cpu_ids to possible. While we
will trigger a warning with CONFIG_CPUMASK_DEBUG, even then the mask
initializers will set the bits beyond what the iterators check and cause
nr_cpu_ids to increase.
Respecting nr_cpu_ids during setup will allow us to use it in our initial
paca allocation. It can be reduced from NR_CPUS by the existing early param
nr_cpus=, which was added in 2b633e3fac (smp:
Use nr_cpus= to set nr_cpu_ids early). We already call parse_early_parms
between finding the command line and allocating the pacas.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Starting with 1426d5a3bd (powerpc:
Dynamically allocate pacas) the space for pacas beyond cpu_possible
is freed, but we failed to update the loop in crash.c.
Since c1854e0072 (powerpc: Set nr_cpu_ids
early and use it to free PACAs) the number of pacas allocated is
always nr_cpu_ids.
Signed-off-by: Milton Miller <miltonm@bga.com>
Cc: <stable@kernel.org> # .34.x
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Starting with 1426d5a3bd (powerpc:
Dynamically allocate pacas) we free the memory for pacas beyond
cpu_possible, but we failed to update the loop the secondary cpus use
to find their paca. If the system has running cpu threads for which
the kernel did not allocate a paca for they will search the memory that
was freed. For instance this could happen when the device tree for
a kdump kernel was not updated after a cpu hotplug, or the kernel is
running with more cpus than the kernel was configured.
Since c1854e0072 (powerpc: Set nr_cpu_ids
early and use it to free PACAs) we set nr_cpu_ids before telling the
cpus to advance, so use that to limit the search.
We can't reference nr_cpu_ids without CONFIG_SMP because it is defined
as 1 instead of a memory location, but any extra threads should be sent
to kexec_wait in that case anyways, so make that explicit and remove
the search loop for UP.
Note to stable: The fix also requires
c1854e0072 (powerpc: Set
nr_cpu_ids early and use it to free PACAs) to function. Also
9d07bc841c (Properly handshake CPUs going
out of boot spin loop) affects the second chunk, specifically the branch
target was 3b before and is 4b after that patch, and there was a blank
line before the #ifdef CONFIG_SMP that was removed
Cc: <stable@kernel.org> # .34.x: c1854e0072 powerpc: Set nr_cpu_ids early
Cc: <stable@kernel.org> # .34.x
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit 1fc711f7ff (powerpc/kexec: Fix race
in kexec shutdown) moved the write to signal the cpu had exited the kernel
from before the transition to real mode in kexec_smp_wait to kexec_wait.
Unfornately it missed that kexec_wait is used both by cpus leaving the
kernel and by secondary slave cpus that were not allocated a paca for
what ever reason -- they could be beyond nr_cpus or not described in
the current device tree for whatever reason (for example, kexec-load
was not refreshed after a cpu hotplug operation). Cpus coming through
that path they will write to paca[NR_CPUS] which is beyond the space
allocated for the paca data and overwrite memory not allocated to pacas
but very likely still real mode accessable).
Move the write back to kexec_smp_wait, which is used only by cpus that
found their paca, but after the transition to real mode.
Signed-off-by: Milton Miller <miltonm@bga.com>
Cc: <stable@kernel.org> # (1fc711f was backported to 2.6.32)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
After looking at our system call path, Mary Brown suggested that we
should put all mfspr SRR* instructions before any mtspr SRR*.
To test this I used a very simple null syscall (actually getppid)
testcase at http://ozlabs.org/~anton/junkcode/null_syscall.c
I tested with the following changes against the pseries_defconfig:
CONFIG_VIRT_CPU_ACCOUNTING=n
CONFIG_AUDIT=n
to remove the overhead of virtual CPU accounting and syscall
auditing.
POWER6:
baseline: mean = 757.2 cycles sd = 2.108
modified: mean = 759.1 cycles sd = 2.020
POWER7:
baseline: mean = 411.4 cycles sd = 0.138
modified: mean = 404.1 cycles sd = 0.109
So we have 1.77% improvement on POWER7 which looks significant. The
POWER6 suggest a 0.25% slowdown, but the results are within 1
standard deviation and may be in the noise.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
A static branch hint will override dynamic branch prediction on
recent POWER CPUs. Since we are about to use more altivec in the
kernel remove the static hint in giveup_altivec that assumes
a userspace task is using altivec.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To make it easier to add optimised versions of copy_page, remove
the 4kB loop for 64kB pages and just do all the work in copy_page.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The patch below removes an unused config variable found by using a kernel
cleanup script.
Note: I did try to cross compile these but hit erros while doing so..
(gcc is not setup to cross compile) and am unsure if anymore needs to be done.
Please have a look if/when anybody has free time.
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
commit c56e58537d breaks SMP support in PPC_47x chip.
secondary_ti must be set to current thread info before callin kick_cpu or else
start_secondary_47x will jump into void when trying to return to c-code.
In the current setup secondary_ti is initialized before the CPU idle task is started
and only the boot core will start. I am not sure this is the correct solution, but it
makes SMP possible in my chip.
Note! The HOTPLUG support probably need some fixing to, There is no trampoline code
available in head_44x.S - start_secondary_resume?
Signed-off-by: Kerstin Jonsson <kerstin.jonsson@ericsson.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit b987812b3f left
crash_kexec_wait_realmode() undefined for UP.
Commit 7c7a81b53e defined it for UP but
left it undefined for 32-bit SMP.
Seems like people are getting confused by nested #ifdef's, so move the
definitions of crash_kexec_wait_realmode() after the #ifdef CONFIG_SMP
section.
Compile-tested with 32-bit UP, 32-bit SMP and 64-bit SMP configurations.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On some arches (x86, sh, arm, unicore, powerpc) the oops message would
print out the last sysfs file accessed.
This was very useful in finding a number of sysfs and driver core bugs
in the 2.5 and early 2.6 development days, but it has been a number of
years since this file has actually helped in debugging anything that
couldn't also be trivially determined from the stack traceback.
So it's time to delete the line. This is good as we need all the space
we can get for oops messages at times on consoles.
Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch drops the reference to a global 'cmd_line' variable from
early_init_dt_scan_chosen, and instead passes the pointer to the command
line string via the *data argument. Each architecture does something
slightly different with the initial command line, so it makes sense for
the architecture to be able to specify the variable name.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
We make use of ptrace_get_breakpoints() / ptrace_put_breakpoints() to
protect ptrace_set_debugreg() even if CONFIG_HAVE_HW_BREAKPOINT if off.
However in this case, these APIs are not implemented.
To fix this, push the protection down inside the relevant ifdef.
Best would be to export the code inside
CONFIG_HAVE_HW_BREAKPOINT into a standalone function to cleanup
the ifdefury there and call the breakpoint ref API inside. But
as it is more invasive, this should be rather made in an -rc1.
Fixes this build error:
arch/powerpc/kernel/ptrace.c:1594: error: implicit declaration of function 'ptrace_get_breakpoints' make[2]: ***
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: LPPC <linuxppc-dev@lists.ozlabs.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: v2.6.33.. <stable@kernel.org>
Link: http://lkml.kernel.org/r/1304639598-4707-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jack Miller <jack@codezen.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Add a platform for the Wire Speed Processor, based on the PPC A2.
This includes code for the ICS & OPB interrupt controllers, as well
as a SCOM backend, and SCOM based cpu bringup.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Jack Miller <jack@codezen.org>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
slb0_limit() wasn't a very descriptive name. This changes it along with
a comment explaining what it's used for, and provides a 64-bit BookE
implementation.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Adds support for page coalescing, which is a feature on IBM Power servers
which allows for coalescing identical pages between logical partitions.
Hint text pages as coalesce candidates, since they are the most likely
pages to be able to be coalesced between partitions. This patch also
exports some page coalescing statistics available from firmware via
lparcfg.
[BenH: Moved a couple of things around to fix compile problems]
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit b987812b3f left
crash_kexec_wait_realmode() undefined for UP.
Commit 7c7a81b53e defined it for UP but
left it undefined for 32-bit SMP.
Seems like people are getting confused by nested #ifdef's, so move the
definitions of crash_kexec_wait_realmode() after the #ifdef CONFIG_SMP
section.
Compile-tested with 32-bit UP, 32-bit SMP and 64-bit SMP configurations.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Adapt new API.
Almost change is trivial. Most important change is the below line
because we plan to change task->cpus_allowed implementation.
- ctx->cpus_allowed = current->cpus_allowed;
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Recent 64-bit server processors (POWER6 and POWER7) have a "Come-From
Address Register" (CFAR), that records the address of the most recent
branch or rfid (return from interrupt) instruction for debugging purposes.
This saves the value of the CFAR in the exception entry code and stores
it in the exception frame. We also make xmon print the CFAR value in
its register dump code.
Rather than extend the pt_regs struct at this time, we steal the orig_gpr3
field, which is only used for system calls, and use it for the CFAR value
for all exceptions/interrupts other than system calls. This means we
don't save the CFAR on system calls, which is not a great problem since
system calls tend not to happen unexpectedly, and also avoids adding the
overhead of reading the CFAR to the system call entry path.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When we take an interrupt or exception from kernel mode and the stack
pointer is obviously not a kernel address (i.e. the top bit is 0), we
switch to an emergency stack, save register values and panic. However,
on 64-bit server machines, we don't actually save the values of r9 - r13
at the time of the interrupt, but rather values corrupted by the
exception entry code for r12-r13, and nothing at all for r9-r11.
This fixes it by passing a pointer to the register save area in the paca
through to the bad_stack code in r3. The register values are saved in
one of the paca register save areas (depending on which exception this
is). Using the pointer in r3, the bad_stack code now retrieves the
saved values of r9 - r13 and stores them in the exception frame on the
emergency stack. This also stores the normal exception frame marker
("regshere") in the exception frame.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Some of the 64bit PPC CPU features are MMU-related, so this patch moves
them to MMU_FTR_ bits. All cpu_has_feature()-style tests are moved to
mmu_has_feature(), and seven feature bits are freed as a result.
Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
RTAS returns extended error codes as a hint of how long the
OS might want to wait before retrying a call. If we have nothing
else useful to do we may as well call back straight away.
This was found when testing the new dynamic dma window feature.
Firmware split the zeroing of the TCE table into 32k chunks but
returned 9901 (which is a suggested wait of 10ms). All up this took
about 10 minutes to complete since msleep is jiffies based and will
round 10ms up to 20ms.
With the patch below we take 3 seconds to complete the same test.
The hint firmware is returning in the RTAS call should definitely
be decreased, but even if we slept 1ms each iteration this would
take 32s.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Use the new MSR_64BIT in a few places. Some of these are already ifdef'ed
for BOOKE vs BOOKS, but it's still clearer, MSR_SF does not immediately
parse as "MSR bit for 64bit".
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This can be useful for differentiating interrupts on the same host
but with different chip data.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Even when no initfunc is provided.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The DSCR (aka Data Stream Control Register) is supported on some
server PowerPC chips and allow some control over the prefetch
of data streams.
This patch allows the value to be specified per thread by emulating
the corresponding mfspr and mtspr instructions. Children of such
threads inherit the value. Other threads use a default value that
can be specified in sysfs - /sys/devices/system/cpu/dscr_default.
If a thread starts with non default value in the sysfs entry,
all children threads inherit this non default value even if
the sysfs value is changed later.
Signed-off-by: Alexey Kardashevskiy <aik@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When we set up the TLB for ourselves on Book3E, we need to flush out any
old mappings established by the firmware or bootloader. At present we
attempt this with a tlbilx to flush everything, but this will leave behind
any entries with the IPROT bit set.
There are several good reason firmware might establish mappings with IPROT,
and in fact ePAPR compliant firmwares are required to establish their
initial mapped area with IPROT.
This patch, therefore adds more complex code to scan through the TLB upon
entry and flush away any entries that are not our own.
Signed-off-by: Jack Miller <jack@codezen.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
An erratum on A2 can lead to the bolted entry we insert for the linear
mapping being evicted, to avoid that write the bolted entry to way 3.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In exc_lvl_ctx_init() we index into the crit/dbg/mcheck stacks using
the hard cpu id, but that assumes the hard cpu id is zero based and
contiguous. That is not the case on A2.
The root of the problem is that the 32bit code has no equivalent of the
paca to allow it to do the hard->soft mapping in assembler. Until the
32bit code is updated to handle that, index the stacks using the soft
cpu ids on 64bit and hard on 32 bit.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Add the cputable entry, regs and setup & restore entries for
the PowerPC A2 core.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
While the tracer accesses ptrace breakpoints, the child task may
concurrently exit due to a SIGKILL and thus release its breakpoints
at the same time. We can then dereference some freed pointers.
To fix this, hold a reference on the child breakpoints before
manipulating them.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Prasad <prasad@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: v2.6.33.. <stable@kernel.org>
Link: http://lkml.kernel.org/r/1302284067-7860-4-git-send-email-fweisbec@gmail.com
When we start a cpu we use smp_ops->kick_cpu(), which currently
returns void, it should be able to fail. Convert it to return
int, and update all uses.
Convert all the current error cases to return -ENOENT, which is
what would eventually be returned by __cpu_up() currently when
it doesn't detect the cpu as coming up in time.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We need to do that to guarantee they see any code change done by
dynamic patching during boot.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Wakeup comes from the system reset handler with a potential loss of
the non-hypervisor CPU state. We save the non-volatile state on the
stack and a pointer to it in the PACA, which the system reset handler
uses to restore things
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We need to wait a bit for them to have done their CPU setup
or we might end up with translation and EE on with different
LPCR values between threads
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We do it before we loop on the PACA start flag. This way, we get a
chance to set critical SPRs on all CPUs before Linux tries to start
them up, which avoids problems when changing some bits such as LPCR
bits that need to be identical on all threads of a core or similar
things like that. Ideally, some of that should also be done before
the MMU is enabled, but that's a separate issue which would require
moving some of the SMP startup code earlier, let's not get there
for now, it works with that change alone.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This sets the default data stream prefetch size for operating
systems that don't set their own value in DSCR. We use 4 which
is "medium".
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This uses feature sections to arrange that we always use HSPRG1
as the scratch register in the interrupt entry code rather than
SPRG2 when we're running in hypervisor mode on POWER7. This will
ensure that we don't trash the guest's SPRG2 when we are running
KVM guests. To simplify the code, we define GET_SCRATCH0() and
SET_SCRATCH0() macros like the GET_PACA/SET_PACA macros.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Rework exception macros a bit to split offset from vector and add
some basic support for HDEC, HDSI, HISI and a few more.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pass the register type to the prolog, also provides alternate "HV"
version of hardware interrupt (0x500) and adjust LPES accordingly
We tag those interrupts by setting bit 0x2 in the trap number
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When running in Hypervisor mode (arch 2.06 or later), we store the PACA
in HSPRG0 instead of SPRG1. The architecture specifies that SPRGs may be
lost during a "nap" power management operation (though they aren't
currently on POWER7) and this enables use of SPRG1 by KVM guests.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This bit indicates that we are operating in hypervisor mode on a CPU
compliant to architecture 2.06 or later (currently server only).
We set it on POWER7 and have a boot-time CPU setup function that
clears it if MSR:HV isn't set (booting under a hypervisor).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Because of speculative event roll back, it is possible for some event coutners
to decrease between reads on POWER7. This causes a problem with the way that
counters are updated. Delta calues are calculated in a 64 bit value and the
top 32 bits are masked. If the register value has decreased, this leaves us
with a very large positive value added to the kernel counters. This patch
protects against this by skipping the update if the delta would be negative.
This can lead to a lack of precision in the coutner values, but from my testing
the value is typcially fewer than 10 samples at a time.
Signed-off-by: Eric B Munson <emunson@mgebm.net>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We currently enable interrupts before the dispatch log for the boot
cpu is setup. If a timer interrupt comes in early enough we oops in
scan_dispatch_log:
Unable to handle kernel paging request for data at address 0x00000010
...
.scan_dispatch_log+0xb0/0x170
.account_system_vtime+0xa0/0x220
.irq_enter+0x88/0xc0
.do_IRQ+0x48/0x230
The patch below adds a check to scan_dispatch_log to ensure the
dispatch log has been allocated.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Recent commit b987812b3f caused
a compile failure on UP because a considerably large block
of the file was included within CONFIG_SMP, hence making a stub
function not exposed on UP builds when it needed to be.
Relocate the stub to the #else /* ! CONFIG_SMP */ section
and also annotate the relevant else/endif so that nobody
else falls into the same trap I did.
Reported-by: Michael Guntsche <mike@it-loops.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
For future rework of try_to_wake_up() we'd like to push part of that
function onto the CPU the task is actually going to run on.
In order to do so we need a generic callback from the existing scheduler IPI.
This patch introduces such a generic callback: scheduler_ipi() and
implements it as a NOP.
BenH notes: PowerPC might use this IPI on offline CPUs under rare conditions!
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl
The CPU_FTRS_POSSIBLE and CPU_FTRS_ALWAYS defines did not encompass
e5500 CPU features when built for 64-bit. This causes issues with
cpu_has_feature() as it utilizes the POSSIBLE & ALWAYS defines as part
of its check.
Create a unique CPU_FTRS_E5500 (as its different from CPU_FTRS_E500MC),
created a new group for 64-bit Book3e based CPUs and add CPU_FTRS_E5500
to that group.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
serial port nodes with the property status="disabled" are not usable and so
avoid adding "disabled" port with the system.
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Xen save/restore is going to use hibernate device callbacks for
quiescing devices and putting them back to normal operations and it
would need to select CONFIG_HIBERNATION for this purpose. However,
that also would cause the hibernate interfaces for user space to be
enabled, which might confuse user space, because the Xen kernels
don't support hibernation. Moreover, it would be wasteful, as it
would make the Xen kernels include a substantial amount of code that
they would never use.
To address this issue introduce new power management Kconfig option
CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code
that is necessary for the hibernate device callbacks to work and make
CONFIG_HIBERNATION select it. Then, Xen save/restore will be able to
select CONFIG_HIBERNATE_CALLBACKS without dragging the entire
hibernate code along with it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Commit b3df895aeb "powerpc/kexec: Add support for FSL-BookE"
introduced the original PPC_STD_MMU_64 checks around the function
crash_kexec_wait_realmode(). Then commit c2be05481f
"powerpc: Fix default_machine_crash_shutdown #ifdef botch" changed
the ifdef around the calling site to add a check on SMP, but the
ifdef around the function itself was left unchanged, leaving an
unused function for PPC_STD_MMU_64=y and SMP=n
Rather than have two ifdefs that can get out of sync like this,
simply put the corrected conditional around the function and use
a stub to get rid of one set of ifdefs completely.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Instead of creating idle threads at boot for all possible CPUs, we
create them on demand, like x86 or ARM, and we properly call init_idle
to re-initialize an idle thread when a CPU was unplugged and is now
re-plugged.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Instead, keep it static, expose an accessor and use that from
the PowerMac code. Avoids easy namespace collisions and will
make it easier to consolidate with other implementations.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This allows us to stop abusing smp_ops->setup_cpu() for cleanup
tasks that have to take place after the initial boot time CPU
bringup.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The current code soft-disables, and then goes to NAP mode which
turns interrupts on. That means that if an interrupt occurs, we
will hit the masked interrupt code path which isn't what we want,
as it will return with EE off, which will either get us out of
NAP mode, or fail to enter it (according to spec).
Instead, let's just rely on the fact that it is safe to take
decrementer interrupts on an offline CPU and leave interrupts
enabled. We can also get rid of the special case in asm for
power4_cpu_offline_powersave() and just use power4_idle().
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Remove the last remnants of cpu_enable(), everybody uses the normal
__cpu_up() path now
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is used by some "soft" hotplug implementations. I needs to
call idle_task_exit() when the CPU is going away, and we remove
the now no-longer needed set_cpu_online() and local_irq_enable()
which are handled by the return to start_secondary
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Various thing are torn down when a CPU is hot-unplugged. That CPU
is expected to go back to start_secondary when re-plugged to re
initialize everything, such as clock sources, maps, ...
Some implementations just return from cpu_die() callback
in the idle loop when the CPU is "re-plugged". This is not enough.
We fix it using a little asm trampoline which resets the stack
and calls back into start_secondary as if we were all fresh from
boot. The trampoline already existed on ppc64, but we add it for
ppc32
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
With some implementations, it is possible that a timer interrupt
occurs every few seconds on an offline CPU. In this case, just
re-arm the decrementer and return immediately
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Recent upstream builds with allmodconfig fail due to lack of space
between 0x3000 and 0x6000. We have a hard block at 0x7000 but we can
spare a page by moving the STAB0 from 0x6000 to 0x8000.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
commit cf9efce0ce (powerpc: Account time using timebase rather
than PURR) used in_irq() to detect if the time was spent in
interrupt processing. This only catches hardirq context so if we
are in softirq context and in the idle loop we end up accounting it
as idle time. If we instead use in_interrupt() we catch both softirq
and hardirq time.
The issue was found when running a network intensive workload. top
showed the following:
0.0%us, 1.1%sy, 0.0%ni, 85.7%id, 0.0%wa, 9.9%hi, 3.3%si, 0.0%st
85.7% idle. But this was wildly different to the perf events data.
To confirm the suspicion I ran something to keep the core busy:
# yes > /dev/null &
8.2%us, 0.0%sy, 0.0%ni, 0.0%id, 0.0%wa, 10.3%hi, 81.4%si, 0.0%st
We only got 8.2% of the CPU for the userspace task and softirq has
shot up to 81.4%.
With the patch below top shows the correct stats:
0.0%us, 0.0%sy, 0.0%ni, 5.3%id, 0.0%wa, 13.3%hi, 81.3%si, 0.0%st
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is used by Alsa to mmap buffers allocated with dma_alloc_coherent()
into userspace. We need a special variant to handle machines with
non-coherent DMAs as those buffers have "special" virt addresses and
require non-cachable mappings
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Percpu allocator honors alignment request upto PAGE_SIZE and both the
percpu addresses in the percpu address space and the translated kernel
addresses should be aligned accordingly. The calculation of the
former depends on the alignment of percpu output section in the kernel
image.
The linker script macros PERCPU_VADDR() and PERCPU() are used to
define this output section and the latter takes @align parameter.
Several architectures are using @align smaller than PAGE_SIZE breaking
percpu memory alignment.
This patch removes @align parameter from PERCPU(), renames it to
PERCPU_SECTION() and makes it always align to PAGE_SIZE. While at it,
add PCPU_SETUP_BUG_ON() checks such that alignment problems are
reliably detected and remove percpu alignment comment recently added
in workqueue.c as the condition would trigger BUG way before reaching
there.
For um, this patch raises the alignment of percpu area. As the area
is in .init, there shouldn't be any noticeable difference.
This problem was discovered by David Howells while debugging boot
failure on mn10300.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
deal with races in /proc/*/{syscall,stack,personality}
proc: enable writing to /proc/pid/mem
proc: make check_mem_permission() return an mm_struct on success
proc: hold cred_guard_mutex in check_mem_permission()
proc: disable mem_write after exec
mm: implement access_remote_vm
mm: factor out main logic of access_process_vm
mm: use mm_struct to resolve gate vma's in __get_user_pages
mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm
mm: arch: make in_gate_area take an mm_struct instead of a task_struct
mm: arch: make get_gate_vma take an mm_struct instead of a task_struct
x86: mark associated mm when running a task in 32 bit compatibility mode
x86: add context tag to mark mm when running a task in 32-bit compatibility mode
auxv: require the target to be tracable (or yourself)
close race in /proc/*/environ
report errors in /proc/*/*map* sanely
pagemap: close races with suid execve
make sessionid permissions in /proc/*/task/* match those in /proc/*
fix leaks in path_lookupat()
Fix up trivial conflicts in fs/proc/base.c
The Xen PV drivers in a crashed HVM guest can not connect to the dom0
backend drivers because both frontend and backend drivers are still in
connected state. To run the connection reset function only in case of a
crashdump, the is_kdump_kernel() function needs to be available for the PV
driver modules.
Consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn into
kernel/crash_dump.c Also export elfcorehdr_addr to make is_kdump_kernel()
usable for modules.
Leave 'elfcorehdr' as early_param(). This changes powerpc from __setup()
to early_param(). It adds an address range check from x86 also on ia64
and powerpc.
[akpm@linux-foundation.org: additional #includes]
[akpm@linux-foundation.org: remove elfcorehdr_addr export]
[akpm@linux-foundation.org: fix for Tejun's mm/nobootmem.c changes]
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1. Add an option to include RapidIO support if the PCI is available.
2. Add FSL_RIO configuration option to enable controller selection.
3. Add RapidIO support option into x86 and MIPS architectures.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Micha Nelissen <micha@neli.hopto.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that gate vma's are referenced with respect to a particular mm and not a
particular task it only makes sense to propagate the change to this predicate as
well.
Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Morally, the question of whether an address lies in a gate vma should be asked
with respect to an mm, not a particular task. Moreover, dropping the dependency
on task_struct will help make existing and future operations on mm's more
flexible and convenient.
Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Morally, the presence of a gate vma is more an attribute of a particular mm than
a particular task. Moreover, dropping the dependency on task_struct will help
make both existing and future operations on mm's more flexible and convenient.
Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add a node parameter to alloc_thread_info(), and change its name to
alloc_thread_info_node()
This change is needed to allow NUMA aware kthread_create_on_cpu()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In some cases during a threaded core dump not all the threads will have
a full register set. This happens when the signal causing the core dump
races with a thread exiting. The race happens when the exiting thread
has entered the kernel for the last time before the signal arrives, but
doesn't get far enough through the exit code to avoid being included
in the core dump.
So we get a thread included in the core dump which is never going to go
out to userspace again and only has a partial register set recorded
Normally we would catch each thread as it is about to go into userspace
and capture the full register set then.
However, this exiting thread is never going to go out to userspace
again, so we have no way to capture its full register set. It doesn't
really matter, though, as this is a thread which is effectively
already dead.
So instead of hitting a BUG() in this case (a really bad choice of
action in the first place), we use a poison value for the register
values.
[BenH]: Some cosmetic/stylistic changes and fix build on ppc32
Signed-off-by: Mike Wolf <mjw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit b5d937de03 has a bug which causes
basically a NULL dereference in the PCI code during boot on ppc64
machines.
fetch_dev_dn() is called when dev->dev.of_node is NULL, so using that
as the starting point for the search makes no sense. It should instead
start from the device node of the PHB.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
trace, filters: Initialize the match variable in process_ops() properly
trace, documentation: Fix branch profiling location in debugfs
oprofile, s390: Cleanups
oprofile, s390: Remove hwsampler_files.c and merge it into init.c
perf: Fix tear-down of inherited group events
perf: Reorder & optimize perf_event_context to remove alignment padding on 64 bit builds
perf: Handle stopped state with tracepoints
perf: Fix the software events state check
perf, powerpc: Handle events that raise an exception without overflowing
perf, x86: Use INTEL_*_CONSTRAINT() for all PEBS event constraints
perf, x86: Clean up SandyBridge PEBS events
perf lock: Fix sorting by wait_min
perf tools: Version incorrect with some versions of grep
perf evlist: New command to list the names of events present in a perf.data file
perf script: Add support for H/W and S/W events
perf script: Add support for dumping symbols
perf script: Support custom field selection for output
perf script: Move printing of 'common' data from print_event and rename
perf tracing: Remove print_graph_cpu and print_graph_proc from trace-event-parse
perf script: Change process_event prototype
...
Milton Miller