When running an SMP kernel on a single-CPU machine, we can speed up the
CAS code by replacing the LDCW sync barrier with NOP.
Signed-off-by: Helge Deller <deller@gmx.de>
2: stw %r24, 0(%r26)
/* Free lock */
#ifdef CONFIG_SMP
2: stw %r24, 0(%r26)
/* Free lock */
#ifdef CONFIG_SMP
- LDCW 0(%sr2,%r20), %r1 /* Barrier */
+98: LDCW 0(%sr2,%r20), %r1 /* Barrier */
+99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
#endif
stw %r20, 0(%sr2,%r20)
#if ENABLE_LWS_DEBUG
#endif
stw %r20, 0(%sr2,%r20)
#if ENABLE_LWS_DEBUG
/* Error occurred on load or store */
/* Free lock */
#ifdef CONFIG_SMP
/* Error occurred on load or store */
/* Free lock */
#ifdef CONFIG_SMP
- LDCW 0(%sr2,%r20), %r1 /* Barrier */
+98: LDCW 0(%sr2,%r20), %r1 /* Barrier */
+99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
#endif
stw %r20, 0(%sr2,%r20)
#if ENABLE_LWS_DEBUG
#endif
stw %r20, 0(%sr2,%r20)
#if ENABLE_LWS_DEBUG
cas2_end:
/* Free lock */
#ifdef CONFIG_SMP
cas2_end:
/* Free lock */
#ifdef CONFIG_SMP
- LDCW 0(%sr2,%r20), %r1 /* Barrier */
+98: LDCW 0(%sr2,%r20), %r1 /* Barrier */
+99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
#endif
stw %r20, 0(%sr2,%r20)
/* Enable interrupts */
#endif
stw %r20, 0(%sr2,%r20)
/* Enable interrupts */
/* Error occurred on load or store */
/* Free lock */
#ifdef CONFIG_SMP
/* Error occurred on load or store */
/* Free lock */
#ifdef CONFIG_SMP
- LDCW 0(%sr2,%r20), %r1 /* Barrier */
+98: LDCW 0(%sr2,%r20), %r1 /* Barrier */
+99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
#endif
stw %r20, 0(%sr2,%r20)
ssm PSW_SM_I, %r0
#endif
stw %r20, 0(%sr2,%r20)
ssm PSW_SM_I, %r0