This patch creates a macro that will be invoked on all entrance to the kernel, so, in kernel space the transaction will be completely reclaimed and not suspended anymore.
This patchset checks if we are coming from PR, if not, skip. This is useful when there is a irq_replay() being called after recheckpoint, when the IRQ is re-enable. In this case, we do not want to re-reclaim and re-recheckpoint, thus, if not coming from PR, skip it completely. This macro does not care about TM SPR also, it will only be saved and restore in the context switch code now on. This macro will return 0 or 1 in r3 register, to specify if a reclaim was executed or not. This patchset is based on initial work done by Cyril: https://patchwork.ozlabs.org/cover/875341/ Signed-off-by: Breno Leitao <lei...@debian.org> --- arch/powerpc/include/asm/exception-64s.h | 46 ++++++++++++++++++++++++ arch/powerpc/kernel/entry_64.S | 10 ++++++ arch/powerpc/kernel/exceptions-64s.S | 12 +++++-- 3 files changed, 66 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index 3b4767ed3ec5..931a74ba037b 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -36,6 +36,7 @@ */ #include <asm/head-64.h> #include <asm/feature-fixups.h> +#include <asm/tm.h> /* PACA save area offsets (exgen, exmc, etc) */ #define EX_R9 0 @@ -677,10 +678,54 @@ BEGIN_FTR_SECTION \ beql ppc64_runlatch_on_trampoline; \ END_FTR_SECTION_IFSET(CPU_FTR_CTRL) +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + +/* + * This macro will reclaim a transaction if called when coming from userspace + * (MSR.PR = 1) and if the transaction state is active or suspended. + * + * Since we don't want to reclaim when coming from kernel, for instance after + * a trechkpt. or a IRQ replay, the live MSR is not useful and instead of it the + * MSR from thread stack is used to check the MSR.PR bit. + * This macro has one argument which is the cause that will be used by treclaim. + * and returns in r3 '1' if the reclaim happens or '0' if reclaim didn't + * happen, which is useful to know what registers were clobbered. + * + * NOTE: If addition registers are clobbered here, make sure the callee + * function restores them before proceeding. + */ +#define TM_KERNEL_ENTRY(cause) \ + ld r3, _MSR(r1); \ + andi. r0, r3, MSR_PR; /* Coming from userspace? */ \ + beq 1f; /* Skip reclaim if MSR.PR != 1 */ \ + rldicl. r0, r3, (64-MSR_TM_LG), 63; /* Is TM enabled? */ \ + beq 1f; /* Skip reclaim if TM is off */ \ + rldicl. r0, r3, (64-MSR_TS_LG), 62; /* Is active */ \ + beq 1f; /* Skip reclaim if neither */ \ + /* \ + * If there is a transaction active or suspended, save the \ + * non-volatile GPRs if they are not already saved. \ + */ \ + bl save_nvgprs; \ + /* \ + * Soft disable the IRQs, otherwise it might cause a CPU hang. \ + */ \ + RECONCILE_IRQ_STATE(r10, r11); \ + li r3, cause; \ + bl tm_reclaim_current; \ + li r3, 1; /* Reclaim happened */ \ + b 2f; \ +1: li r3, 0; /* Reclaim didn't happen */ \ +2: +#else +#define TM_KERNEL_ENTRY(cause) +#endif + #define EXCEPTION_COMMON(area, trap, label, hdlr, ret, additions) \ EXCEPTION_PROLOG_COMMON(trap, area); \ /* Volatile regs are potentially clobbered here */ \ additions; \ + TM_KERNEL_ENTRY(TM_CAUSE_MISC); \ addi r3,r1,STACK_FRAME_OVERHEAD; \ bl hdlr; \ b ret @@ -695,6 +740,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CTRL) EXCEPTION_PROLOG_COMMON_3(trap); \ /* Volatile regs are potentially clobbered here */ \ additions; \ + TM_KERNEL_ENTRY(TM_CAUSE_MISC); \ addi r3,r1,STACK_FRAME_OVERHEAD; \ bl hdlr diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 7b1693adff2a..17484ebda66c 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -131,6 +131,16 @@ BEGIN_FW_FTR_SECTION END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) #endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE && CONFIG_PPC_SPLPAR */ +#if CONFIG_PPC_TRANSACTIONAL_MEM + TM_KERNEL_ENTRY(TM_CAUSE_SYSCALL) + cmpdi r3, 0x1 + bne 44f + /* Restore from r4 to r12 */ + REST_8GPRS(4,r1) +44: /* treclaim was not called, just restore r3 and r0 */ + REST_GPR(3, r1) + REST_GPR(0, r1) +#endif /* * A syscall should always be called with interrupts enabled * so we just unconditionally hard-enable here. When some kind diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 89d32bb79d5e..5c685a46202d 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -717,6 +717,7 @@ EXC_COMMON_BEGIN(alignment_common) std r3,_DAR(r1) std r4,_DSISR(r1) bl save_nvgprs + TM_KERNEL_ENTRY(TM_CAUSE_ALIGNMENT) RECONCILE_IRQ_STATE(r10, r11) addi r3,r1,STACK_FRAME_OVERHEAD bl alignment_exception @@ -751,6 +752,8 @@ EXC_COMMON_BEGIN(program_check_common) b 3f /* Jump into the macro !! */ 1: EXCEPTION_PROLOG_COMMON(0x700, PACA_EXGEN) bl save_nvgprs + ld r3, _MSR(r1) + TM_KERNEL_ENTRY(TM_CAUSE_FAC_UNAV) RECONCILE_IRQ_STATE(r10, r11) addi r3,r1,STACK_FRAME_OVERHEAD bl program_check_exception @@ -1650,7 +1653,9 @@ do_hash_page: /* Here we have a page fault that hash_page can't handle. */ handle_page_fault: -11: andis. r0,r4,DSISR_DABRMATCH@h +11: TM_KERNEL_ENTRY(TM_CAUSE_TLBI) + ld r4,_DSISR(r1) + andis. r0,r4,DSISR_DABRMATCH@h bne- handle_dabr_fault ld r4,_DAR(r1) ld r5,_DSISR(r1) @@ -1681,6 +1686,8 @@ handle_dabr_fault: */ 13: bl save_nvgprs mr r5,r3 + TM_KERNEL_ENTRY(TM_CAUSE_TLBI) + REST_GPR(3,r1) addi r3,r1,STACK_FRAME_OVERHEAD ld r4,_DAR(r1) bl low_hash_fault @@ -1695,7 +1702,8 @@ handle_dabr_fault: * the access, or panic if there isn't a handler. */ 77: bl save_nvgprs - mr r4,r3 + TM_KERNEL_ENTRY(TM_CAUSE_TLBI) + ld r4,_DAR(r1) addi r3,r1,STACK_FRAME_OVERHEAD li r5,SIGSEGV bl bad_page_fault -- 2.19.0
