Make GTSE an MMU feature and enable it by default for radix.
However for guest, conditionally enable it if hypervisor supports
it via OV5 vector.

Having GTSE as an MMU feature will make it easy to enable radix
without GTSE. Currently radix assumes GTSE is enabled by default.

Signed-off-by: Bharata B Rao <bhar...@linux.ibm.com>
---
 arch/powerpc/include/asm/mmu.h    | 4 ++++
 arch/powerpc/kernel/dt_cpu_ftrs.c | 1 +
 arch/powerpc/mm/init_64.c         | 5 ++++-
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index f4ac25d4df05..884d51995934 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -28,6 +28,9 @@
  * Individual features below.
  */
 
+/* Guest Translation Shootdown Enable */
+#define MMU_FTR_GTSE                   ASM_CONST(0x00001000)
+
 /*
  * Support for 68 bit VA space. We added that from ISA 2.05
  */
@@ -173,6 +176,7 @@ enum {
 #endif
 #ifdef CONFIG_PPC_RADIX_MMU
                MMU_FTR_TYPE_RADIX |
+               MMU_FTR_GTSE |
 #ifdef CONFIG_PPC_KUAP
                MMU_FTR_RADIX_KUAP |
 #endif /* CONFIG_PPC_KUAP */
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c 
b/arch/powerpc/kernel/dt_cpu_ftrs.c
index 3a409517c031..fcb815b3a84d 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -337,6 +337,7 @@ static int __init feat_enable_mmu_radix(struct 
dt_cpu_feature *f)
 #ifdef CONFIG_PPC_RADIX_MMU
        cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
        cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
+       cur_cpu_spec->mmu_features |= MMU_FTR_GTSE;
        cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
 
        return 1;
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index c7ce4ec5060e..a7b571c60e90 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -408,12 +408,15 @@ static void __init early_check_vec5(void)
                if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
                                                OV5_FEAT(OV5_RADIX_GTSE))) {
                        pr_warn("WARNING: Hypervisor doesn't support RADIX with 
GTSE\n");
-               }
+                       cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
+               } else
+                       cur_cpu_spec->mmu_features |= MMU_FTR_GTSE;
                /* Do radix anyway - the hypervisor said we had to */
                cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
        } else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
                /* Hypervisor only supports hash - disable radix */
                cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
+               cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
        }
 }
 
-- 
2.21.3

Reply via email to