[PATCH 1/3] asm-generic/tlb: stub out pud_free_tlb() if __PAGETABLE_PUD_FOLDED ...

From: Vineet Gupta
Date: Wed Oct 09 2019 - 18:27:18 EST


... independent of __ARCH_HAS_4LEVEL_HACK

This came up when removing __ARCH_HAS_5LEVEL_HACK for ARC as code bloat
from pud_free_tlb() despite pud being folded (with 2 levels on ARC)

| bloat-o-meter2 vmlinux-B-elide-ARCH_USE_5LEVEL_HACK vmlinux-C-elide-pud_free_tlb
| add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-104 (-104)
| function old new delta
| free_pgd_range 656 552 -104
| Total: Before=4137276, After=4137172, chg -1.000000%

Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
include/asm-generic/4level-fixup.h | 2 --
include/asm-generic/tlb.h | 4 +++-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/asm-generic/4level-fixup.h b/include/asm-generic/4level-fixup.h
index e3667c9a33a5..d7c5ba1968d3 100644
--- a/include/asm-generic/4level-fixup.h
+++ b/include/asm-generic/4level-fixup.h
@@ -27,8 +27,6 @@
#define pud_page(pud) pgd_page(pud)
#define pud_page_vaddr(pud) pgd_page_vaddr(pud)

-#undef pud_free_tlb
-#define pud_free_tlb(tlb, x, addr) do { } while (0)
#define pud_free(mm, x) do { } while (0)
#define __pud_free_tlb(tlb, x, addr) do { } while (0)

diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 04c0644006fd..1f83188cb331 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -584,7 +584,7 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
} while (0)
#endif

-#ifndef __ARCH_HAS_4LEVEL_HACK
+#ifndef __PAGETABLE_PUD_FOLDED
#ifndef pud_free_tlb
#define pud_free_tlb(tlb, pudp, address) \
do { \
@@ -594,6 +594,8 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
__pud_free_tlb(tlb, pudp, address); \
} while (0)
#endif
+#else
+#define pud_free_tlb(tlb, pudp, address) do { } while (0)
#endif

#ifndef __ARCH_HAS_5LEVEL_HACK
--
2.20.1