diff options
authorDavid Daney <david.daney@cavium.com>2013-06-14 11:13:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-06-14 19:24:42 -1000
commitf21afc25f9ed45b8ffe200d0f071b0caec3ed2ef (patch)
parentd0ff9348810c5bc9fc7a3f022bdfae9b44b62f00 (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>
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