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authorDavid S. Miller <davem@davemloft.net>2013-12-18 16:42:06 -0500
committerDavid S. Miller <davem@davemloft.net>2013-12-18 16:42:06 -0500
commit143c9054949436cb05e468439dc5e46231f33d09 (patch)
treec2e972d8188fb1b36368e9acb5b6b59466c9d903 /include/asm-generic
parent0b6807034791160d5e584138943d2daea765436d (diff)
parent35eecf052250f663f07a4cded7d3503fd1b50729 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/ethernet/intel/i40e/i40e_main.c drivers/net/macvtap.c Both minor merge hassles, simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/preempt.h35
-rw-r--r--include/asm-generic/word-at-a-time.h8
2 files changed, 19 insertions, 24 deletions
diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h
index ddf2b420ac8f..1cd3f5d767a8 100644
--- a/include/asm-generic/preempt.h
+++ b/include/asm-generic/preempt.h
@@ -3,13 +3,11 @@
#include <linux/thread_info.h>
-/*
- * We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users
- * that think a non-zero value indicates we cannot preempt.
- */
+#define PREEMPT_ENABLED (0)
+
static __always_inline int preempt_count(void)
{
- return current_thread_info()->preempt_count & ~PREEMPT_NEED_RESCHED;
+ return current_thread_info()->preempt_count;
}
static __always_inline int *preempt_count_ptr(void)
@@ -17,11 +15,6 @@ static __always_inline int *preempt_count_ptr(void)
return &current_thread_info()->preempt_count;
}
-/*
- * We now loose PREEMPT_NEED_RESCHED and cause an extra reschedule; however the
- * alternative is loosing a reschedule. Better schedule too often -- also this
- * should be a very rare operation.
- */
static __always_inline void preempt_count_set(int pc)
{
*preempt_count_ptr() = pc;
@@ -41,28 +34,17 @@ static __always_inline void preempt_count_set(int pc)
task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \
} while (0)
-/*
- * We fold the NEED_RESCHED bit into the preempt count such that
- * preempt_enable() can decrement and test for needing to reschedule with a
- * single instruction.
- *
- * We invert the actual bit, so that when the decrement hits 0 we know we both
- * need to resched (the bit is cleared) and can resched (no preempt count).
- */
-
static __always_inline void set_preempt_need_resched(void)
{
- *preempt_count_ptr() &= ~PREEMPT_NEED_RESCHED;
}
static __always_inline void clear_preempt_need_resched(void)
{
- *preempt_count_ptr() |= PREEMPT_NEED_RESCHED;
}
static __always_inline bool test_preempt_need_resched(void)
{
- return !(*preempt_count_ptr() & PREEMPT_NEED_RESCHED);
+ return false;
}
/*
@@ -81,7 +63,12 @@ static __always_inline void __preempt_count_sub(int val)
static __always_inline bool __preempt_count_dec_and_test(void)
{
- return !--*preempt_count_ptr();
+ /*
+ * Because of load-store architectures cannot do per-cpu atomic
+ * operations; we cannot use PREEMPT_NEED_RESCHED because it might get
+ * lost.
+ */
+ return !--*preempt_count_ptr() && tif_need_resched();
}
/*
@@ -89,7 +76,7 @@ static __always_inline bool __preempt_count_dec_and_test(void)
*/
static __always_inline bool should_resched(void)
{
- return unlikely(!*preempt_count_ptr());
+ return unlikely(!preempt_count() && tif_need_resched());
}
#ifdef CONFIG_PREEMPT
diff --git a/include/asm-generic/word-at-a-time.h b/include/asm-generic/word-at-a-time.h
index 3f21f1b72e45..d3909effd725 100644
--- a/include/asm-generic/word-at-a-time.h
+++ b/include/asm-generic/word-at-a-time.h
@@ -49,4 +49,12 @@ static inline bool has_zero(unsigned long val, unsigned long *data, const struct
return (val + c->high_bits) & ~rhs;
}
+#ifndef zero_bytemask
+#ifdef CONFIG_64BIT
+#define zero_bytemask(mask) (~0ul << fls64(mask))
+#else
+#define zero_bytemask(mask) (~0ul << fls(mask))
+#endif /* CONFIG_64BIT */
+#endif /* zero_bytemask */
+
#endif /* _ASM_WORD_AT_A_TIME_H */