diff options
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 42e9d908914a..d82878c4daa6 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -97,6 +97,24 @@ system_call_common: addi r9,r1,STACK_FRAME_OVERHEAD ld r11,exception_marker@toc(r2) std r11,-16(r9) /* "regshere" marker */ +#if defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR) +BEGIN_FW_FTR_SECTION + beq 33f + /* if from user, see if there are any DTL entries to process */ + ld r10,PACALPPACAPTR(r13) /* get ptr to VPA */ + ld r11,PACA_DTL_RIDX(r13) /* get log read index */ + ld r10,LPPACA_DTLIDX(r10) /* get log write index */ + cmpd cr1,r11,r10 + beq+ cr1,33f + bl .accumulate_stolen_time + REST_GPR(0,r1) + REST_4GPRS(3,r1) + REST_2GPRS(7,r1) + addi r9,r1,STACK_FRAME_OVERHEAD +33: +END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) +#endif /* CONFIG_VIRT_CPU_ACCOUNTING && CONFIG_PPC_SPLPAR */ + #ifdef CONFIG_TRACE_IRQFLAGS bl .trace_hardirqs_on REST_GPR(0,r1) @@ -202,7 +220,9 @@ syscall_exit: bge- syscall_error syscall_error_cont: ld r7,_NIP(r1) +BEGIN_FTR_SECTION stdcx. r0,0,r1 /* to clear the reservation */ +END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) andi. r6,r8,MSR_PR ld r4,_LINK(r1) /* @@ -419,6 +439,17 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) sync #endif /* CONFIG_SMP */ + /* + * If we optimise away the clear of the reservation in system + * calls because we know the CPU tracks the address of the + * reservation, then we need to clear it here to cover the + * case that the kernel context switch path has no larx + * instructions. + */ +BEGIN_FTR_SECTION + ldarx r6,0,r1 +END_FTR_SECTION_IFSET(CPU_FTR_STCX_CHECKS_ADDRESS) + addi r6,r4,-THREAD /* Convert THREAD to 'current' */ std r6,PACACURRENT(r13) /* Set new 'current' */ @@ -576,7 +607,16 @@ ALT_FW_FTR_SECTION_END_IFCLR(FW_FEATURE_ISERIES) andi. r0,r3,MSR_RI beq- unrecov_restore + /* + * Clear the reservation. If we know the CPU tracks the address of + * the reservation then we can potentially save some cycles and use + * a larx. On POWER6 and POWER7 this is significantly faster. + */ +BEGIN_FTR_SECTION stdcx. r0,0,r1 /* to clear the reservation */ +FTR_SECTION_ELSE + ldarx r4,0,r1 +ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) /* * Clear RI before restoring r13. If we are returning to |