Commit 09539f9b authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman

powerpc/perf: POWER9 PMU stops after idle workaround

POWER9 DD2 PMU can stop after a state-loss idle in some conditions.

A solution is to set then clear MMCRA[60] after wake from state-loss
idle. MMCRA[60] is a non-architected bit, see the user manual for
details.
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Acked-by: default avatarMadhavan Srinivasan <maddy@linux.vnet.ibm.com>
Reviewed-by: default avatarVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Acked-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent f29bb786
......@@ -460,11 +460,17 @@ pnv_restore_hyp_resource_arch300:
/*
* Workaround for POWER9, if we lost resources, the ERAT
* might have been mixed up and needs flushing. We also need
* to reload MMCR0 (see comment above).
* to reload MMCR0 (see comment above). We also need to set
* then clear bit 60 in MMCRA to ensure the PMU starts running.
*/
blt cr3,1f
PPC_INVALIDATE_ERAT
ld r1,PACAR1(r13)
mfspr r4,SPRN_MMCRA
ori r4,r4,(1 << (63-60))
mtspr SPRN_MMCRA,r4
xori r4,r4,(1 << (63-60))
mtspr SPRN_MMCRA,r4
ld r4,_MMCR0(r1)
mtspr SPRN_MMCR0,r4
1:
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment