From: "Gautham R. Shenoy" <e...@linux.vnet.ibm.com>
pnv_wakeup_tb_loss function currently expects the cr4 to be "eq" if
the CPU is waking up from a complete hypervisor state loss. Hence, it
currently restores the SPR contents only if cr4 is "eq".
However, after the commit bcef83a00dc4 ("powerpc/powernv: Add platform
support for stop instruction"), on ISA_V300 CPUs, the function
pnv_restore_hyp_resource sets cr4 to contain the result of the
comparison between state the CPU has woken up and the first deepest
stop state before calling pnv_wakeup_tb_loss.
Thus if the CPU woke up from a state that is deeper than the first
deepest stop state, cr4 have "gt" set and hence, pnv_wakeup_tb_loss
will fail to restore the SPRs on waking up from such a state.
Fix the code in pnv_wakeup_tb_loss to restore the SPR states when cr4 is
"eq" or "gt".
Fixes: Commit bcef83a00dc4 ("powerpc/powernv: Add platform support for
stop instruction")
Cc: Vaidyanathan Srinivasan <sva...@linux.vnet.ibm.com>
Cc: Michael Neuling <michael.neul...@au1.ibm.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Shreyas B. Prabhu <shreya...@gmail.com>
Signed-off-by: Gautham R. Shenoy <e...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/idle_book3s.S | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/idle_book3s.S
b/arch/powerpc/kernel/idle_book3s.S
index 2265c63..bd739fe 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -411,7 +411,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
*
* r13 - PACA
* cr3 - gt if waking up with partial/complete hypervisor state loss
- * cr4 - eq if waking up from complete hypervisor state loss.
+ * cr4 - gt or eq if waking up from complete hypervisor state loss.
*/
_GLOBAL(pnv_wakeup_tb_loss)
ld r1,PACAR1(r13)
@@ -453,7 +453,7 @@ lwarx_loop2:
* At this stage
* cr2 - eq if first thread to wakeup in core
* cr3- gt if waking up with partial/complete hypervisor state loss
- * cr4 - eq if waking up from complete hypervisor state loss.
+ * cr4 - gt or eq if waking up from complete hypervisor state loss.
*/
ori r15,r15,PNV_CORE_IDLE_LOCK_BIT
@@ -481,7 +481,7 @@ first_thread_in_subcore:
* If waking up from sleep, subcore state is not lost. Hence
* skip subcore state restore
*/
- bne cr4,subcore_state_restored
+ blt cr4,subcore_state_restored
/* Restore per-subcore state */
ld r4,_SDR1(r1)
@@ -526,7 +526,7 @@ timebase_resync:
* If waking up from sleep, per core state is not lost, skip to
* clear_lock.
*/
- bne cr4,clear_lock
+ blt cr4,clear_lock
/*
* First thread in the core to wake up and its waking up with
@@ -557,7 +557,7 @@ common_exit:
* If waking up from sleep, hypervisor state is not lost. Hence
* skip hypervisor state restore.
*/
- bne cr4,hypervisor_state_restored
+ blt cr4,hypervisor_state_restored
/* Waking up from winkle */
--
1.9.4
