Commit d0ffdee8 authored by Gustavo Romero's avatar Gustavo Romero Committed by Michael Ellerman

powerpc/tm: Save and restore AMR on treclaim and trechkpt

Althought AMR is stashed in the checkpoint area, currently we don't save
it to the per thread checkpoint struct after a treclaim and so we don't
restore it either from that struct when we trechkpt. As a consequence when
the transaction is later rolled back the kernel space AMR value when the
trechkpt was done appears in userspace.

That commit saves and restores AMR accordingly on treclaim and trechkpt.
Since AMR value is also used in kernel space in other functions, it also
takes care of stashing kernel live AMR into the stack before treclaim and
before trechkpt, restoring it later, just before returning from tm_reclaim
and __tm_recheckpoint.

Is also fixes two nonrelated comments about CR and MSR.
Signed-off-by: default avatarGustavo Romero <gromero@linux.ibm.com>
Tested-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200919150025.9609-1-gromero@linux.ibm.com
parent 35d64734
...@@ -220,6 +220,7 @@ struct thread_struct { ...@@ -220,6 +220,7 @@ struct thread_struct {
unsigned long tm_tar; unsigned long tm_tar;
unsigned long tm_ppr; unsigned long tm_ppr;
unsigned long tm_dscr; unsigned long tm_dscr;
unsigned long tm_amr;
/* /*
* Checkpointed FP and VSX 0-31 register set. * Checkpointed FP and VSX 0-31 register set.
......
...@@ -176,6 +176,7 @@ int main(void) ...@@ -176,6 +176,7 @@ int main(void)
OFFSET(THREAD_TM_TAR, thread_struct, tm_tar); OFFSET(THREAD_TM_TAR, thread_struct, tm_tar);
OFFSET(THREAD_TM_PPR, thread_struct, tm_ppr); OFFSET(THREAD_TM_PPR, thread_struct, tm_ppr);
OFFSET(THREAD_TM_DSCR, thread_struct, tm_dscr); OFFSET(THREAD_TM_DSCR, thread_struct, tm_dscr);
OFFSET(THREAD_TM_AMR, thread_struct, tm_amr);
OFFSET(PT_CKPT_REGS, thread_struct, ckpt_regs); OFFSET(PT_CKPT_REGS, thread_struct, ckpt_regs);
OFFSET(THREAD_CKVRSTATE, thread_struct, ckvr_state.vr); OFFSET(THREAD_CKVRSTATE, thread_struct, ckvr_state.vr);
OFFSET(THREAD_CKVRSAVE, thread_struct, ckvrsave); OFFSET(THREAD_CKVRSAVE, thread_struct, ckvrsave);
......
...@@ -122,6 +122,13 @@ _GLOBAL(tm_reclaim) ...@@ -122,6 +122,13 @@ _GLOBAL(tm_reclaim)
std r3, STK_PARAM(R3)(r1) std r3, STK_PARAM(R3)(r1)
SAVE_NVGPRS(r1) SAVE_NVGPRS(r1)
/*
* Save kernel live AMR since it will be clobbered by treclaim
* but can be used elsewhere later in kernel space.
*/
mfspr r3, SPRN_AMR
std r3, TM_FRAME_L1(r1)
/* We need to setup MSR for VSX register save instructions. */ /* We need to setup MSR for VSX register save instructions. */
mfmsr r14 mfmsr r14
mr r15, r14 mr r15, r14
...@@ -245,7 +252,7 @@ _GLOBAL(tm_reclaim) ...@@ -245,7 +252,7 @@ _GLOBAL(tm_reclaim)
* but is used in signal return to 'wind back' to the abort handler. * but is used in signal return to 'wind back' to the abort handler.
*/ */
/* ******************** CR,LR,CCR,MSR ********** */ /* ***************** CTR, LR, CR, XER ********** */
mfctr r3 mfctr r3
mflr r4 mflr r4
mfcr r5 mfcr r5
...@@ -256,7 +263,6 @@ _GLOBAL(tm_reclaim) ...@@ -256,7 +263,6 @@ _GLOBAL(tm_reclaim)
std r5, _CCR(r7) std r5, _CCR(r7)
std r6, _XER(r7) std r6, _XER(r7)
/* ******************** TAR, DSCR ********** */ /* ******************** TAR, DSCR ********** */
mfspr r3, SPRN_TAR mfspr r3, SPRN_TAR
mfspr r4, SPRN_DSCR mfspr r4, SPRN_DSCR
...@@ -264,6 +270,10 @@ _GLOBAL(tm_reclaim) ...@@ -264,6 +270,10 @@ _GLOBAL(tm_reclaim)
std r3, THREAD_TM_TAR(r12) std r3, THREAD_TM_TAR(r12)
std r4, THREAD_TM_DSCR(r12) std r4, THREAD_TM_DSCR(r12)
/* ******************** AMR **************** */
mfspr r3, SPRN_AMR
std r3, THREAD_TM_AMR(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.
*/ */
...@@ -308,7 +318,9 @@ _GLOBAL(tm_reclaim) ...@@ -308,7 +318,9 @@ _GLOBAL(tm_reclaim)
std r3, THREAD_TM_TFHAR(r12) std r3, THREAD_TM_TFHAR(r12)
std r4, THREAD_TM_TFIAR(r12) std r4, THREAD_TM_TFIAR(r12)
/* AMR is checkpointed too, but is unsupported by Linux. */ /* Restore kernel live AMR */
ld r8, TM_FRAME_L1(r1)
mtspr SPRN_AMR, r8
/* Restore original MSR/IRQ state & clear TM mode */ /* Restore original MSR/IRQ state & clear TM mode */
ld r14, TM_FRAME_L0(r1) /* Orig MSR */ ld r14, TM_FRAME_L0(r1) /* Orig MSR */
...@@ -355,6 +367,13 @@ _GLOBAL(__tm_recheckpoint) ...@@ -355,6 +367,13 @@ _GLOBAL(__tm_recheckpoint)
*/ */
SAVE_NVGPRS(r1) SAVE_NVGPRS(r1)
/*
* Save kernel live AMR since it will be clobbered for trechkpt
* but can be used elsewhere later in kernel space.
*/
mfspr r8, SPRN_AMR
std r8, TM_FRAME_L0(r1)
/* Load complete register state from ts_ckpt* registers */ /* Load complete register state from ts_ckpt* registers */
addi r7, r3, PT_CKPT_REGS /* Thread's ckpt_regs */ addi r7, r3, PT_CKPT_REGS /* Thread's ckpt_regs */
...@@ -404,7 +423,7 @@ _GLOBAL(__tm_recheckpoint) ...@@ -404,7 +423,7 @@ _GLOBAL(__tm_recheckpoint)
restore_gprs: restore_gprs:
/* ******************** CR,LR,CCR,MSR ********** */ /* ****************** CTR, LR, XER ************* */
ld r4, _CTR(r7) ld r4, _CTR(r7)
ld r5, _LINK(r7) ld r5, _LINK(r7)
ld r8, _XER(r7) ld r8, _XER(r7)
...@@ -417,6 +436,10 @@ restore_gprs: ...@@ -417,6 +436,10 @@ restore_gprs:
ld r4, THREAD_TM_TAR(r3) ld r4, THREAD_TM_TAR(r3)
mtspr SPRN_TAR, r4 mtspr SPRN_TAR, r4
/* ******************** AMR ******************** */
ld r4, THREAD_TM_AMR(r3)
mtspr SPRN_AMR, r4
/* Load up the PPR and DSCR in GPRs only at this stage */ /* Load up the PPR and DSCR in GPRs only at this stage */
ld r5, THREAD_TM_DSCR(r3) ld r5, THREAD_TM_DSCR(r3)
ld r6, THREAD_TM_PPR(r3) ld r6, THREAD_TM_PPR(r3)
...@@ -509,6 +532,10 @@ restore_gprs: ...@@ -509,6 +532,10 @@ restore_gprs:
li r4, MSR_RI li r4, MSR_RI
mtmsrd r4, 1 mtmsrd r4, 1
/* Restore kernel live AMR */
ld r8, TM_FRAME_L0(r1)
mtspr SPRN_AMR, r8
REST_NVGPRS(r1) REST_NVGPRS(r1)
addi r1, r1, TM_FRAME_SIZE addi r1, r1, TM_FRAME_SIZE
......
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