diff options
Diffstat (limited to 'arch/powerpc/kernel/tm.S')
| -rw-r--r-- | arch/powerpc/kernel/tm.S | 95 |
1 files changed, 60 insertions, 35 deletions
diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S index 6bffbc5affe7..9fabdce255cd 100644 --- a/arch/powerpc/kernel/tm.S +++ b/arch/powerpc/kernel/tm.S @@ -92,13 +92,14 @@ _GLOBAL(tm_abort) blr EXPORT_SYMBOL_GPL(tm_abort); -/* void tm_reclaim(struct thread_struct *thread, +/* + * void tm_reclaim(struct thread_struct *thread, * uint8_t cause) * * - Performs a full reclaim. This destroys outstanding - * transactions and updates thread->regs.tm_ckpt_* with the - * original checkpointed state. Note that thread->regs is - * unchanged. + * transactions and updates thread.ckpt_regs, thread.ckfp_state and + * thread.ckvr_state with the original checkpointed state. Note that + * thread->regs is unchanged. * * Purpose is to both abort transactions of, and preserve the state of, * a transactions at a context switch. We preserve/restore both sets of process @@ -163,26 +164,41 @@ _GLOBAL(tm_reclaim) */ TRECLAIM(R4) /* Cause in r4 */ - /* ******************** GPRs ******************** */ - /* Stash the checkpointed r13 away in the scratch SPR and get the real - * paca + /* + * ******************** GPRs ******************** + * Stash the checkpointed r13 in the scratch SPR and get the real paca. */ SET_SCRATCH0(r13) GET_PACA(r13) - /* Stash the checkpointed r1 away in paca tm_scratch and get the real - * stack pointer back + /* + * Stash the checkpointed r1 away in paca->tm_scratch and get the real + * stack pointer back into r1. */ std r1, PACATMSCRATCH(r13) ld r1, PACAR1(r13) - /* Store the PPR in r11 and reset to decent value */ std r11, GPR11(r1) /* Temporary stash */ + /* + * Move the saved user r1 to the kernel stack in case PACATMSCRATCH is + * clobbered by an exception once we turn on MSR_RI below. + */ + ld r11, PACATMSCRATCH(r13) + std r11, GPR1(r1) + + /* + * Store r13 away so we can free up the scratch SPR for the SLB fault + * handler (needed once we start accessing the thread_struct). + */ + GET_SCRATCH0(r11) + std r11, GPR13(r1) + /* Reset MSR RI so we can take SLB faults again */ li r11, MSR_RI mtmsrd r11, 1 + /* Store the PPR in r11 and reset to decent value */ mfspr r11, SPRN_PPR HMT_MEDIUM @@ -195,23 +211,24 @@ _GLOBAL(tm_reclaim) addi r7, r12, PT_CKPT_REGS /* Thread's ckpt_regs */ - /* Make r7 look like an exception frame so that we - * can use the neat GPRx(n) macros. r7 is NOT a pt_regs ptr! + /* + * Make r7 look like an exception frame so that we can use the neat + * GPRx(n) macros. r7 is NOT a pt_regs ptr! */ subi r7, r7, STACK_FRAME_OVERHEAD /* Sync the userland GPRs 2-12, 14-31 to thread->regs: */ SAVE_GPR(0, r7) /* user r0 */ - SAVE_GPR(2, r7) /* user r2 */ + SAVE_GPR(2, r7) /* user r2 */ SAVE_4GPRS(3, r7) /* user r3-r6 */ SAVE_GPR(8, r7) /* user r8 */ SAVE_GPR(9, r7) /* user r9 */ SAVE_GPR(10, r7) /* user r10 */ - ld r3, PACATMSCRATCH(r13) /* user r1 */ + ld r3, GPR1(r1) /* user r1 */ ld r4, GPR7(r1) /* user r7 */ ld r5, GPR11(r1) /* user r11 */ ld r6, GPR12(r1) /* user r12 */ - GET_SCRATCH0(8) /* user r13 */ + ld r8, GPR13(r1) /* user r13 */ std r3, GPR1(r7) std r4, GPR7(r7) std r5, GPR11(r7) @@ -223,7 +240,8 @@ _GLOBAL(tm_reclaim) /* ******************** NIP ******************** */ mfspr r3, SPRN_TFHAR std r3, _NIP(r7) /* Returns to failhandler */ - /* The checkpointed NIP is ignored when rescheduling/rechkpting, + /* + * The checkpointed NIP is ignored when rescheduling/rechkpting, * but is used in signal return to 'wind back' to the abort handler. */ @@ -246,12 +264,13 @@ _GLOBAL(tm_reclaim) std r3, THREAD_TM_TAR(r12) std r4, THREAD_TM_DSCR(r12) - /* MSR and flags: We don't change CRs, and we don't need to alter - * MSR. + /* + * MSR and flags: We don't change CRs, and we don't need to alter MSR. */ - /* ******************** FPR/VR/VSRs ************ + /* + * ******************** FPR/VR/VSRs ************ * After reclaiming, capture the checkpointed FPRs/VRs. * * We enabled VEC/FP/VSX in the msr above, so we can execute these @@ -261,7 +280,7 @@ _GLOBAL(tm_reclaim) /* Altivec (VEC/VMX/VR)*/ addi r7, r3, THREAD_CKVRSTATE - SAVE_32VRS(0, r6, r7) /* r6 scratch, r7 transact vr state */ + SAVE_32VRS(0, r6, r7) /* r6 scratch, r7 ckvr_state */ mfvscr v0 li r6, VRSTATE_VSCR stvx v0, r7, r6 @@ -272,12 +291,13 @@ _GLOBAL(tm_reclaim) /* Floating Point (FP) */ addi r7, r3, THREAD_CKFPSTATE - SAVE_32FPRS_VSRS(0, R6, R7) /* r6 scratch, r7 transact fp state */ + SAVE_32FPRS_VSRS(0, R6, R7) /* r6 scratch, r7 ckfp_state */ mffs fr0 stfd fr0,FPSTATE_FPSCR(r7) - /* TM regs, incl TEXASR -- these live in thread_struct. Note they've + /* + * TM regs, incl TEXASR -- these live in thread_struct. Note they've * been updated by the treclaim, to explain to userland the failure * cause (aborted). */ @@ -313,7 +333,7 @@ _GLOBAL(tm_reclaim) blr - /* + /* * void __tm_recheckpoint(struct thread_struct *thread) * - Restore the checkpointed register state saved by tm_reclaim * when we switch_to a process. @@ -329,7 +349,8 @@ _GLOBAL(__tm_recheckpoint) std r2, STK_GOT(r1) stdu r1, -TM_FRAME_SIZE(r1) - /* We've a struct pt_regs at [r1+STACK_FRAME_OVERHEAD]. + /* + * We've a struct pt_regs at [r1+STACK_FRAME_OVERHEAD]. * This is used for backing up the NVGPRs: */ SAVE_NVGPRS(r1) @@ -338,8 +359,9 @@ _GLOBAL(__tm_recheckpoint) addi r7, r3, PT_CKPT_REGS /* Thread's ckpt_regs */ - /* Make r7 look like an exception frame so that we - * can use the neat GPRx(n) macros. r7 is now NOT a pt_regs ptr! + /* + * Make r7 look like an exception frame so that we can use the neat + * GPRx(n) macros. r7 is now NOT a pt_regs ptr! */ subi r7, r7, STACK_FRAME_OVERHEAD @@ -407,14 +429,15 @@ restore_gprs: REST_NVGPRS(r7) /* GPR14-31 */ - /* Load up PPR and DSCR here so we don't run with user values for long - */ + /* Load up PPR and DSCR here so we don't run with user values for long */ mtspr SPRN_DSCR, r5 mtspr SPRN_PPR, r6 - /* Do final sanity check on TEXASR to make sure FS is set. Do this + /* + * Do final sanity check on TEXASR to make sure FS is set. Do this * here before we load up the userspace r1 so any bugs we hit will get - * a call chain */ + * a call chain. + */ mfspr r5, SPRN_TEXASR srdi r5, r5, 16 li r6, (TEXASR_FS)@h @@ -422,8 +445,9 @@ restore_gprs: 1: tdeqi r6, 0 EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0 - /* Do final sanity check on MSR to make sure we are not transactional - * or suspended + /* + * Do final sanity check on MSR to make sure we are not transactional + * or suspended. */ mfmsr r6 li r5, (MSR_TS_MASK)@higher @@ -439,8 +463,8 @@ restore_gprs: REST_GPR(6, r7) /* - * Store r1 and r5 on the stack so that we can access them - * after we clear MSR RI. + * Store r1 and r5 on the stack so that we can access them after we + * clear MSR RI. */ REST_GPR(5, r7) @@ -470,7 +494,8 @@ restore_gprs: HMT_MEDIUM - /* Our transactional state has now changed. + /* + * Our transactional state has now changed. * * Now just get out of here. Transactional (current) state will be * updated once restore is called on the return path in the _switch-ed |