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-rw-r--r--arch/powerpc/kernel/idle_book3s.S20
-rw-r--r--arch/powerpc/mm/init_64.c3
2 files changed, 18 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 995728736677..6fd08219248d 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -449,9 +449,23 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
_GLOBAL(pnv_wakeup_tb_loss)
ld r1,PACAR1(r13)
/*
- * Before entering any idle state, the NVGPRs are saved in the stack
- * and they are restored before switching to the process context. Hence
- * until they are restored, they are free to be used.
+ * Before entering any idle state, the NVGPRs are saved in the stack.
+ * If there was a state loss, or PACA_NAPSTATELOST was set, then the
+ * NVGPRs are restored. If we are here, it is likely that state is lost,
+ * but not guaranteed -- neither ISA207 nor ISA300 tests to reach
+ * here are the same as the test to restore NVGPRS:
+ * PACA_THREAD_IDLE_STATE test for ISA207, PSSCR test for ISA300,
+ * and SRR1 test for restoring NVGPRs.
+ *
+ * We are about to clobber NVGPRs now, so set NAPSTATELOST to
+ * guarantee they will always be restored. This might be tightened
+ * with careful reading of specs (particularly for ISA300) but this
+ * is already a slow wakeup path and it's simpler to be safe.
+ */
+ li r0,1
+ stb r0,PACA_NAPSTATELOST(r13)
+
+ /*
*
* Save SRR1 and LR in NVGPRs as they might be clobbered in
* opal_call() (called in CHECK_HMI_INTERRUPT). SRR1 is required
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index 9be992083d2a..c22f207aa656 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -397,8 +397,7 @@ static void early_check_vec5(void)
void __init mmu_early_init_devtree(void)
{
/* Disable radix mode based on kernel command line. */
- /* We don't yet have the machinery to do radix as a guest. */
- if (disable_radix || !(mfmsr() & MSR_HV))
+ if (disable_radix)
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
/*