The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.
This removes all the arch/metag uses of the __cpuinit macros from
all C files. Currently metag does not have any __CPUINIT used in
assembly files.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: James Hogan <james.hogan@imgtec.com>
Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Pull Metag architecture changes from James Hogan:
- Infrastructure and DT files for TZ1090 SoC (pin control drivers
already merged via pinctrl tree).
- Panic on boot instead of just warning if cache aliasing possible.
- Various SMP/hotplug fixes.
- Various other randconfig/sparse fixes.
* tag 'metag-for-v3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (24 commits)
metag: move EXPORT_SYMBOL(csum_partial) to metag_ksyms.c
metag: cpu hotplug: route_irq: preserve irq mask
metag: kick: add missing irq_enter/exit to kick_handler()
metag: smp: don't spin waiting for CPU to start
metag: smp: enable irqs after set_cpu_online
metag: use clear_tasks_mm_cpumask()
metag: tz1090: select and instantiate pinctrl-tz1090-pdc
metag: tz1090: select and instantiate pinctrl-tz1090
metag: don't check for cache aliasing on smp cpu boot
metag: panic if cache aliasing possible
metag: *.dts: include using preprocessor
metag: add <dt-bindings/> symlink
metag/.gitignore: Extend the *.dtb pattern to match the dtb.S files
metag/traps: include setup.h for the per_cpu_trap_init declaration
metag/traps: Mark die() as __noreturn to match the declaration.
metag/processor.h: Add missing cpuinfo_op declaration.
metag/setup: Restrict scope for the capabilities variable
metag/mm/cache: Restrict scope for metag_lnkget_probe
metag/asm/irq.h: Declare init_IRQ
metag/kernel/irq.c: Declare root_domain as static
...
Move EXPORT_SYMBOL(csum_partial) from lib/checksum.c into metag_ksyms.c
so that it doesn't get omitted by the static linker if it's not used by
any other statically linked code, which can result in undefined symbols
when building modules.
For example a randconfig caused the following error:
ERROR: "csum_partial" [fs/reiserfs/reiserfs.ko] undefined!
Signed-off-by: James Hogan <james.hogan@imgtec.com>
The route_irq() function needs to preserve the irq mask by using the
_irqsave/irqrestore variants of raw spin lock functions instead of the
_irq variants. This is because it is called from __cpu_disable() (via
migrate_irqs()), which is called with IRQs disabled, so using the _irq
variants re-enables IRQs.
This appears to have been causing occasional hits of the
BUG_ON(!irqs_disabled()) in __irq_work_run() during CPU hotplug soak
testing:
BUG: failure at kernel/irq_work.c:122/__irq_work_run()!
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
kick_handler() doesn't have an irq_enter/exit pair, but it's used for
handling SMP IPIs which require work to be done in softirqs, which are
invoked from irq_exit() when the hard irq nest count reaches 0.
The scheduler_ipi() callback in the IPI handler calls irq_enter/exit
itself, but this is inside kick_handler()'s spin lock critical section,
so if an invoked softirq issues an IPI the kick_handler() will be
re-entered on the same CPU and will deadlock.
This is easily fixed by adding the missing irq_enter/exit to
kick_handler() so that the hard irq nest count doesn't reach 0 until
after the spin lock has been released.
Ideally the spin lock protected handler list will also be replaced by a
lockless RCU protected list since it is certainly mostly read. That can
be done in a later change though.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Use a completion to block until a secondary CPU has started up, like ARM
do, instead of a loop of udelays.
On Meta, SMP is really SMT, with each "CPU" being a different hardware
thread on the same Meta processor core, so as well as being more
efficient and latency friendly, using a completion prevents the bogomips
of the secondary CPU from being drastically skewed every time by the
execution of the tight in-cache udelay loop on the other CPU.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
In secondary_start_kernel() interrupts should be enabled with
local_irq_enable() after the cpu is marked as online with
set_cpu_online(). Otherwise it's possible for a timer interrupt to
trigger a softirq, which if the cpu is marked as offline may have it's
affinity altered.
Reported-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Checking for process->mm is not enough because process' main thread may
exit or detach its mm via use_mm(), but other threads may still have a
valid mm.
To fix this we would need to use find_lock_task_mm(), which would walk
up all threads and returns an appropriate task (with task lock held).
clear_tasks_mm_cpumask() was introduced in v3.5-rc1 to fix this issue,
so let's use it for metag too.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
The cache configuration of the boot cpu is now duplicated to secondary
cpus, so there's no need to check for cache aliasing again when a
secondary cpu is booted. Therefore remove the check from
secondary_start_kernel().
Signed-off-by: James Hogan <james.hogan@imgtec.com>
If the cache and page size configuration allows for cache aliasing to
occur we warn on boot, but the log messages are easy to miss and will
result is random crashes occuring in userland. Let's panic too in this
case so that the user immediately knows they need to fix the cache
configuration or configured page size.
Also fix the warning messages which display the cache and page sizes to
include newlines, and add the word "Potential" since an actual cache
alias hasn't been detected.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
It is only referenced within the irq.c file, so restrict it's scope
as appropriate.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Log core clock and Meta timer frequencies during init in architecture
generic code, removing the need for equivalent log messages in SoC
specific code.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
If the common clock framework is enabled, call of_clk_init(NULL) in
time_init() to register device tree clocks with the clock framework.
After this time_init() calls a new function init_metag_clocks(), which
looks for a clock named "core" in the node compatible with "img,meta"
(usually the root node). If found the get_core_freq machine callback is
overridden to obtain the core clock frequency using that clock.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: devicetree-discuss@lists.ozlabs.org
show_regs() is inherently arch-dependent but it does make sense to print
generic debug information and some archs already do albeit in slightly
different forms. This patch introduces a generic function to print debug
information from show_regs() so that different archs print out the same
information and it's much easier to modify what's printed.
show_regs_print_info() prints out the same debug info as dump_stack()
does plus task and thread_info pointers.
* Archs which didn't print debug info now do.
alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
um, xtensa
* Already prints debug info. Replaced with show_regs_print_info().
The printed information is superset of what used to be there.
arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86
* s390 is special in that it used to print arch-specific information
along with generic debug info. Heiko and Martin think that the
arch-specific extra isn't worth keeping s390 specfic implementation.
Converted to use the generic version.
Note that now all archs print the debug info before actual register
dumps.
An example BUG() dump follows.
kernel BUG at /work/os/work/kernel/workqueue.c:4841!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7
Hardware name: empty empty/S3992, BIOS 080011 10/26/2007
task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
RIP: 0010:[<ffffffff8234a07e>] [<ffffffff8234a07e>] init_workqueues+0x4/0x6
RSP: 0000:ffff88007c861ec8 EFLAGS: 00010246
RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001
RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a
RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650
0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760
Call Trace:
[<ffffffff81000312>] do_one_initcall+0x122/0x170
[<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
[<ffffffff81c47760>] ? rest_init+0x140/0x140
[<ffffffff81c4776e>] kernel_init+0xe/0xf0
[<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0
[<ffffffff81c47760>] ? rest_init+0x140/0x140
...
v2: Typo fix in x86-32.
v3: CPU number dropped from show_regs_print_info() as
dump_stack_print_info() has been updated to print it. s390
specific implementation dropped as requested by s390 maintainers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com> [tile bits]
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Both dump_stack() and show_stack() are currently implemented by each
architecture. show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack(). On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.
The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task which
triggered dump_stack().
There's no reason to require archs to implement two separate but mostly
identical functions. It leads to unnecessary subtle information.
This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin. Blackfin's
dump_stack() does something wonky that I don't understand.
Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information. This is used
in blackfin.
This patch brings the following behavior changes.
* On some archs, an extra level in backtrace for show_stack() could be
printed. This is because the top frame was determined in
dump_stack() on those archs while generic dump_stack() can't do that
reliably. It can be compensated by inlining dump_stack() but not
sure whether that'd be necessary.
* Most archs didn't use to print debug info on dump_stack(). They do
now.
An example WARN dump follows.
WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
Hardware name: empty
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
Call Trace:
[<ffffffff81c614dc>] dump_stack+0x19/0x1b
[<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
[<ffffffff8234a071>] init_workqueues+0x35/0x505
...
v2: CPU number added to the generic debug info as requested by s390
folks and dropped the s390 specific dump_stack(). This loses %ksp
from the debug message which the maintainers think isn't important
enough to keep the s390-specific dump_stack() implementation.
dump_stack_print_info() is moved to kernel/printk.c from
lib/dump_stack.c. Because linkage is per objecct file,
dump_stack_print_info() living in the same lib file as generic
dump_stack() means that archs which implement custom dump_stack()
- at this point, only blackfin - can't use dump_stack_print_info()
as that will bring in the generic version of dump_stack() too. v1
The v1 patch broke build on blackfin due to this issue. The build
breakage was reported by Fengguang Wu.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390 bits]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull arch/metag update from James Hogan:
- Various fixes for the interrupting perf counter handling in metag's
perf backend.
- Add OProfile support based on perf.
- Sets up cache partitions for SMP so bootloader doesn't have to.
- Patch from Paul Bolle to remove ARCH_POPULATES_NODE_MAP again
(touches microblaze too).
- Add TLS pointer regset to metag ptrace api.
- Add exported metag DSP extended context handling header <asm/ech.h>.
- Increase defconfig log buffer size to 128KiB.
- Various fixes, typos, missing exports.
* tag 'metag-for-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
metag: defconfigs: increase log buffer 8KiB => 128KiB
metag: avoid unnecessary builtin dtb rebuilds
metag: add exported <asm/ech.h> for extended context handling
metag: export _metag_da_present and cpu_2_hwthread_id
metag: ptrace: Implement NT_METAG_TLS
memblock: Kill ARCH_POPULATES_NODE_MAP once more
metag: cachepart: fix get_global_dcache_size() typo
metag: cachepart: take into account small cache bits
metag: smp: copy cache partition and enable GCOn
metag: OProfile support
metag: perf: prepare for use by oprofile
metag: perf: don't reset TXTACTCYC
metag: perf: use hard_processor_id() to get thread
metag: perf: fix frequency sampling (dynamic period)
metag: perf: add missing prev_count updates
metag: perf: fixes for interrupting perf counters
metag: perf: fix wrap handling in delta calculation
metag: perf: fix core internal / perf channel mux
Export the symbols _metag_da_present and cpu_2_hwthread_id to modules
(GPL only) to allow the imgdafs file system to be built as a module.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Implement functionality to get the TLS pointer for the metag
architecture using regsets.
This provides multi-threaded debug support for GDB.
Signed-off-by: Paul Clothier <Paul.Clothier@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Compilation is broken when the kernel is destined to live in the global
part of the virtual address space:
arch/metag/kernel/cachepart.c In function 'get_thread_cache_size':
arch/metag/kernel/cachepart.c +71 : error: implicit declaration of function 'get_global_dache_size'
Fix the typo.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
