diff options
| author | David Daney <david.daney@cavium.com> | 2013-06-14 11:13:59 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-06-14 19:24:42 -1000 |
| commit | f21afc25f9ed45b8ffe200d0f071b0caec3ed2ef (patch) | |
| tree | e3cd202f0830cc0f0b5fbe9318bfeebbc43ce4ea | |
| parent | d0ff9348810c5bc9fc7a3f022bdfae9b44b62f00 (diff) | |
smp.h: Use local_irq_{save,restore}() in !SMP version of on_each_cpu().
Thanks to commit f91eb62f71b3 ("init: scream bloody murder if interrupts
are enabled too early"), "bloody murder" is now being screamed.
With a MIPS OCTEON config, we use on_each_cpu() in our
irq_chip.irq_bus_sync_unlock() function. This gets called in early as a
result of the time_init() call. Because the !SMP version of
on_each_cpu() unconditionally enables irqs, we get:
WARNING: at init/main.c:560 start_kernel+0x250/0x410()
Interrupts were enabled early
CPU: 0 PID: 0 Comm: swapper Not tainted 3.10.0-rc5-Cavium-Octeon+ #801
Call Trace:
show_stack+0x68/0x80
warn_slowpath_common+0x78/0xb0
warn_slowpath_fmt+0x38/0x48
start_kernel+0x250/0x410
Suggested fix: Do what we already do in the SMP version of
on_each_cpu(), and use local_irq_save/local_irq_restore. Because we
need a flags variable, make it a static inline to avoid name space
issues.
[ Change from v1: Convert on_each_cpu to a static inline function, add
#include <linux/irqflags.h> to avoid build breakage on some files.
on_each_cpu_mask() and on_each_cpu_cond() suffer the same problem as
on_each_cpu(), but they are not causing !SMP bugs for me, so I will
defer changing them to a less urgent patch. ]
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/smp.h | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/include/linux/smp.h b/include/linux/smp.h index e6564c1dc552..c8488763277f 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -11,6 +11,7 @@ #include <linux/list.h> #include <linux/cpumask.h> #include <linux/init.h> +#include <linux/irqflags.h> extern void cpu_idle(void); @@ -139,13 +140,17 @@ static inline int up_smp_call_function(smp_call_func_t func, void *info) } #define smp_call_function(func, info, wait) \ (up_smp_call_function(func, info)) -#define on_each_cpu(func,info,wait) \ - ({ \ - local_irq_disable(); \ - func(info); \ - local_irq_enable(); \ - 0; \ - }) + +static inline int on_each_cpu(smp_call_func_t func, void *info, int wait) +{ + unsigned long flags; + + local_irq_save(flags); + func(info); + local_irq_restore(flags); + return 0; +} + /* * Note we still need to test the mask even for UP * because we actually can get an empty mask from |