[RESEND PATCH v7 1/8] x86/tlb: Add APIs manipulating tlb batch's arch data

From: Byungchul Park
Date: Thu Feb 08 2024 - 01:26:32 EST

This is a preparation for migrc mechanism that needs to recognize
read-only TLB entries during batched TLB flush by separating tlb batch's
arch data into two, one is for read-only entries and the other is for
writable ones, and merging those two when needed.

Migrc also needs to optimize CPUs to flush by clearing ones that have
already performed TLB flush needed.

To support it, added APIs manipulating arch data for x86.

Signed-off-by: Byungchul Park <byungchul@xxxxxx>
arch/x86/include/asm/tlbflush.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 25726893c6f4..fa7e16dbeb44 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -5,6 +5,7 @@
#include <linux/mm_types.h>
#include <linux/mmu_notifier.h>
#include <linux/sched.h>
+#include <linux/cpumask.h>

#include <asm/processor.h>
#include <asm/cpufeature.h>
@@ -293,6 +294,23 @@ static inline void arch_flush_tlb_batched_pending(struct mm_struct *mm)

extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);

+static inline void arch_tlbbatch_clear(struct arch_tlbflush_unmap_batch *batch)
+ cpumask_clear(&batch->cpumask);
+static inline void arch_tlbbatch_fold(struct arch_tlbflush_unmap_batch *bdst,
+ struct arch_tlbflush_unmap_batch *bsrc)
+ cpumask_or(&bdst->cpumask, &bdst->cpumask, &bsrc->cpumask);
+static inline bool arch_tlbbatch_done(struct arch_tlbflush_unmap_batch *bdst,
+ struct arch_tlbflush_unmap_batch *bsrc)
+ return cpumask_andnot(&bdst->cpumask, &bdst->cpumask, &bsrc->cpumask);
static inline bool pte_flags_need_flush(unsigned long oldflags,
unsigned long newflags,
bool ignore_access)