AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2025-02-04 23:35:27 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

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

Browse Source 
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: Gustavo Romero <gromero@linux.ibm.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200919150025.9609-1-gromero@linux.ibm.com
This commit is contained in:
Gustavo Romero 2020-09-19 12:00:25 -03:00 committed by Michael Ellerman
parent 35d64734b6
commit d0ffdee8ff
3 changed files with 33 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/powerpc/include/asm/processor.h
View File

@ -220,6 +220,7 @@ struct thread_struct {
unsigned long tm_tar;
unsigned long tm_ppr;
unsigned long tm_dscr;
unsigned long tm_amr;
/*
* Checkpointed FP and VSX 0-31 register set.

1
arch/powerpc/kernel/asm-offsets.c
View File

@ -176,6 +176,7 @@ int main(void)
OFFSET(THREAD_TM_TAR, thread_struct, tm_tar);
OFFSET(THREAD_TM_PPR, thread_struct, tm_ppr);
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(THREAD_CKVRSTATE, thread_struct, ckvr_state.vr);
OFFSET(THREAD_CKVRSAVE, thread_struct, ckvrsave);

35
arch/powerpc/kernel/tm.S
View File

@ -122,6 +122,13 @@ _GLOBAL(tm_reclaim)
std r3, STK_PARAM(R3)(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. */
mfmsr r14
mr r15, r14
@ -245,7 +252,7 @@ _GLOBAL(tm_reclaim)
* but is used in signal return to 'wind back' to the abort handler.
*/
/* ******************** CR,LR,CCR,MSR ********** */
/* ***************** CTR, LR, CR, XER ********** */
mfctr r3
mflr r4
mfcr r5
@ -256,7 +263,6 @@ _GLOBAL(tm_reclaim)
std r5, _CCR(r7)
std r6, _XER(r7)
/* ******************** TAR, DSCR ********** */
mfspr r3, SPRN_TAR
mfspr r4, SPRN_DSCR
@ -264,6 +270,10 @@ _GLOBAL(tm_reclaim)
std r3, THREAD_TM_TAR(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.
*/
@ -308,7 +318,9 @@ _GLOBAL(tm_reclaim)
std r3, THREAD_TM_TFHAR(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 */
ld r14, TM_FRAME_L0(r1) /* Orig MSR */
@ -355,6 +367,13 @@ _GLOBAL(__tm_recheckpoint)
*/
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 */
addi r7, r3, PT_CKPT_REGS /* Thread's ckpt_regs */
@ -404,7 +423,7 @@ _GLOBAL(__tm_recheckpoint)
restore_gprs:
/* ******************** CR,LR,CCR,MSR ********** */
/* ****************** CTR, LR, XER ************* */
ld r4, _CTR(r7)
ld r5, _LINK(r7)
ld r8, _XER(r7)
@ -417,6 +436,10 @@ restore_gprs:
ld r4, THREAD_TM_TAR(r3)
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 */
ld r5, THREAD_TM_DSCR(r3)
ld r6, THREAD_TM_PPR(r3)
@ -509,6 +532,10 @@ restore_gprs:
li r4, MSR_RI
mtmsrd r4, 1
/* Restore kernel live AMR */
ld r8, TM_FRAME_L0(r1)
mtspr SPRN_AMR, r8
REST_NVGPRS(r1)
addi r1, r1, TM_FRAME_SIZE