[PATCH v7 07/12] x86/mm: use INVLPGB in flush_tlb_all

Rik van Riel
2025-01-23T04:26:53Z

The flush_tlb_all() function is not used a whole lot, but we might
as well use broadcast TLB flushing there, too.

Signed-off-by: Rik van Riel <riel@surriel.com>
---
arch/x86/mm/tlb.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 2c9e9b7482dd..e2a0b7fc5fed 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -1065,6 +1065,19 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
}

+static bool broadcast_flush_tlb_all(void)
+{
+ if (!IS_ENABLED(CONFIG_X86_BROADCAST_TLB_FLUSH))
+ return false;
+
+ if (!cpu_feature_enabled(X86_FEATURE_INVLPGB))
+ return false;
+
+ guard(preempt)();
+ invlpgb_flush_all();
+ return true;
+}
+
static void do_flush_tlb_all(void *info)
{
count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED);
@@ -1073,6 +1086,8 @@ static void do_flush_tlb_all(void *info)

void flush_tlb_all(void)
{
+ if (broadcast_flush_tlb_all())
+ return;
count_vm_tlb_event(NR_TLB_REMOTE_FLUSH);
on_each_cpu(do_flush_tlb_all, NULL, 1);
}
--
2.47.1