MIPS: jump_label: Remove redundant nops

Both arch_static_branch() & arch_static_branch_jump() emit a control
transfer instruction (ie. branch or jump) without disabling assembler
re-ordering. As such the assembler will automatically fill their delay
slots.

Both functions follow their branch or jump with an explicit nop that at
first appears to be there to fill the delay slot, but given that the
assembler will do that the explicit nops serve no purpose & we end up
with our branch or jump followed by 2 nops. Remove the redundant nops.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org

diff --git a/arch/mips/include/asm/jump_label.h b/arch/mips/include/asm/jump_label.h
index e4456e450f946d5c9c55b52d78aeee60d3a2a0e2..df04449b261b0b24ddec2b90f065278f8a0322dc 100644 (file)
--- a/arch/mips/include/asm/jump_label.h
+++ b/arch/mips/include/asm/jump_label.h
@@ -29,7 +29,7 @@
 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
 {
        asm_volatile_goto("1:\t" B_INSN " 2f\n\t"
 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
 {
        asm_volatile_goto("1:\t" B_INSN " 2f\n\t"

-               "2:\tnop\n\t"
+               "2:\t.insn\n\t"

                ".pushsection __jump_table,  \"aw\"\n\t"
                WORD_INSN " 1b, %l[l_yes], %0\n\t"
                ".popsection\n\t"
                ".pushsection __jump_table,  \"aw\"\n\t"
                WORD_INSN " 1b, %l[l_yes], %0\n\t"
                ".popsection\n\t"


@@ -43,7 +43,6 @@ l_yes:
 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
 {
        asm_volatile_goto("1:\tj %l[l_yes]\n\t"
 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
 {
        asm_volatile_goto("1:\tj %l[l_yes]\n\t"

-               "nop\n\t"

                ".pushsection __jump_table,  \"aw\"\n\t"
                WORD_INSN " 1b, %l[l_yes], %0\n\t"
                ".popsection\n\t"
                ".pushsection __jump_table,  \"aw\"\n\t"
                WORD_INSN " 1b, %l[l_yes], %0\n\t"
                ".popsection\n\t"