[PATCH v9 0/4] Fix issues with huge mapping in ioremap for ARM64

From: Chintan Pandya
Date: Mon Apr 30 2018 - 03:42:01 EST

This series of patches takes Toshi Kani <toshi.kani@xxxxxxx>'s
patches ("fix memory leak/panic in ioremap huge pages") as base
and re-bring huge_vmap back for arm64.

This series of patches are tested on 4.16 kernel with Cortex-A75
based SoC.

The test used for verifying these patches is a stress test on
ioremap/unmap which tries to re-use same io-address but changes
size of mapping randomly i.e. 4K to 2M to 16K etc. The same test
used to reproduce 3rd level translation fault without these fixes
(and also of course with Revert "arm64: Enforce BBM for huge IO/VMAP
mappings" being part of the tree).

These patches can also go into '-stable' branch (if accepted)
for 4.6 onwards.

>From V8->V9:
- Used __TLBI_VADDR macros in new TLB flush API

>From V7->V8:
- Properly fixed compilation issue in x86 file

>From V6->V7:
- Fixed compilation issue in x86 case
- V6 patches were not properly enumarated

>From V5->V6:
- Use __flush_tlb_kernel_pgtable() for both PUD and PMD. Remove
"bool tlb_inv" based variance as it is not need now
- Re-naming for consistency

>From V4->V5:
- Add new API __flush_tlb_kernel_pgtable(unsigned long addr)
for kernel addresses

>From V3->V4:
- Add header for 'addr' in x86 implementation
- Re-order pmd/pud clear and table free
- Avoid redundant TLB invalidatation in one perticular case

>From V2->V3:
- Use the exisiting page table free interface to do arm64
specific things

>From V1->V2:
- Rebased my patches on top of "[PATCH v2 1/2] mm/vmalloc:
Add interfaces to free unmapped page table"
- Honored BBM for ARM64

Chintan Pandya (4):
ioremap: Update pgtable free interfaces with addr
arm64: tlbflush: Introduce __flush_tlb_kernel_pgtable
arm64: Implement page table free interfaces
Revert "arm64: Enforce BBM for huge IO/VMAP mappings"

arch/arm64/include/asm/tlbflush.h | 6 ++++++
arch/arm64/mm/mmu.c | 37 +++++++++++++++++++++++++------------
arch/x86/mm/pgtable.c | 8 +++++---
include/asm-generic/pgtable.h | 8 ++++----
lib/ioremap.c | 4 ++--
5 files changed, 42 insertions(+), 21 deletions(-)

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