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linux-next/arch/sparc/kernel/jump_label.c
Peter Zijlstra 76b235c6bc jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP}
Since we've already stepped away from ENABLE is a JMP and DISABLE is a
NOP with the branch_default bits, and are going to make it even worse,
rename it to make it all clearer.

This way we don't mix multiple levels of logic attributes, but have a
plain 'physical' name for what the current instruction patching status
of a jump label is.

This is a first step in removing the naming confusion that has led to
a stream of avoidable bugs such as:

  a833581e37 ("x86, perf: Fix static_key bug in load_mm_cr4()")

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
[ Beefed up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03 11:34:12 +02:00

42 lines
791 B
C

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/cpu.h>
#include <linux/jump_label.h>
#include <linux/memory.h>
#include <asm/cacheflush.h>
#ifdef HAVE_JUMP_LABEL
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
u32 val;
u32 *insn = (u32 *) (unsigned long) entry->code;
if (type == JUMP_LABEL_JMP) {
s32 off = (s32)entry->target - (s32)entry->code;
#ifdef CONFIG_SPARC64
/* ba,pt %xcc, . + (off << 2) */
val = 0x10680000 | ((u32) off >> 2);
#else
/* ba . + (off << 2) */
val = 0x10800000 | ((u32) off >> 2);
#endif
} else {
val = 0x01000000;
}
get_online_cpus();
mutex_lock(&text_mutex);
*insn = val;
flushi(insn);
mutex_unlock(&text_mutex);
put_online_cpus();
}
#endif