Merge tag 'powerpc-4.11-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull more powerpc fixes from Michael Ellerman:
 "These are all pretty minor. The fix for idle wakeup would be a bad bug
  but has not been observed in practice.

  The update to the gcc-plugins docs was Cc'ed to Kees and Jon, Kees
  OK'ed it going via powerpc and I didn't hear from Jon.

   - cxl: Route eeh events to all slices for pci_channel_io_perm_failure state

   - powerpc/64s: Fix idle wakeup potential to clobber registers

   - Revert "powerpc/64: Disable use of radix under a hypervisor"

   - gcc-plugins: update architecture list in documentation

  Thanks to: Andrew Donnellan, Nicholas Piggin, Paul Mackerras, Vaibhav
  Jain"

* tag 'powerpc-4.11-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  gcc-plugins: update architecture list in documentation
  Revert "powerpc/64: Disable use of radix under a hypervisor"
  powerpc/64s: Fix idle wakeup potential to clobber registers
  cxl: Route eeh events to all slices for pci_channel_io_perm_failure state

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;
 
 	/*