[PATCH v1 8/9] mm/mmu_gather: add tlb_remove_tlb_entries()

David Hildenbrand
2024-01-29T14:33:14Z

Let's add a helper that lets us batch-process multiple consecutive PTEs.

Note that the loop will get optimized out on all architectures except on
powerpc. We have to add an early define of __tlb_remove_tlb_entry() on
ppc to make the compiler happy (and avoid making tlb_remove_tlb_entries() a
macro).

Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/powerpc/include/asm/tlb.h | 2 ++
include/asm-generic/tlb.h | 20 ++++++++++++++++++++
2 files changed, 22 insertions(+)

diff --git a/arch/powerpc/include/asm/tlb.h b/arch/powerpc/include/asm/tlb.h
index b3de6102a907..1ca7d4c4b90d 100644
--- a/arch/powerpc/include/asm/tlb.h
+++ b/arch/powerpc/include/asm/tlb.h
@@ -19,6 +19,8 @@

#include <linux/pagemap.h>

+static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
+ unsigned long address);
#define __tlb_remove_tlb_entry __tlb_remove_tlb_entry

#define tlb_flush tlb_flush
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 428c3f93addc..bd00dd238b79 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -616,6 +616,26 @@ static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
__tlb_remove_tlb_entry(tlb, ptep, address); \
} while (0)

+/**
+ * tlb_remove_tlb_entries - remember unmapping of multiple consecutive ptes for
+ * later tlb invalidation.
+ *
+ * Similar to tlb_remove_tlb_entry(), but remember unmapping of multiple
+ * consecutive ptes instead of only a single one.
+ */
+static inline void tlb_remove_tlb_entries(struct mmu_gather *tlb,
+ pte_t *ptep, unsigned int nr, unsigned long address)
+{
+ tlb_flush_pte_range(tlb, address, PAGE_SIZE * nr);
+ for (;;) {
+ __tlb_remove_tlb_entry(tlb, ptep, address);
+ if (--nr == 0)
+ break;
+ ptep++;
+ address += PAGE_SIZE;
+ }
+}
+
#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
do { \
unsigned long _sz = huge_page_size(h); \
--
2.43.0