sched: Extract the basic add/sub preempt_count modifiers

Rewrite the preempt_count macros in order to extract the 3 basic
preempt_count value modifiers:

  __preempt_count_add()
  __preempt_count_sub()

and the new:

  __preempt_count_dec_and_test()

And since we're at it anyway, replace the unconventional
$op_preempt_count names with the more conventional preempt_count_$op.

Since these basic operators are equivalent to the previous _notrace()
variants, do away with the _notrace() versions.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-ewbpdbupy9xpsjhg960zwbv8@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index e205ef598e97..12156176c7ca 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -124,7 +124,7 @@ void *kmap_coherent(struct page *page, unsigned long addr)
 
         BUG_ON(Page_dcache_dirty(page));
 
-        inc_preempt_count();
+        pagefault_disable();
         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 #ifdef CONFIG_MIPS_MT_SMTC
         idx += FIX_N_COLOURS * smp_processor_id() +
@@ -193,8 +193,7 @@ void kunmap_coherent(void)
         write_c0_entryhi(old_ctx);
         EXIT_CRITICAL(flags);
 #endif
-        dec_preempt_count();
-        preempt_check_resched();
+        pagefault_enable();
 }
 
 void copy_user_highpage(struct page *to, struct page *from,