1 files changed, 41 insertions, 0 deletions
diff --git a/arch/x86/include/asm/tlb.h b/arch/x86/include/asm/tlb.h
new file mode 100644
index 000000000..820082bd6
--- /dev/null
+++ b/arch/x86/include/asm/tlb.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_TLB_H
+#define _ASM_X86_TLB_H
+
+#define tlb_start_vma(tlb, vma) do { } while (0)
+#define tlb_end_vma(tlb, vma) do { } while (0)
+#define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0)
+
+#define tlb_flush tlb_flush
+static inline void tlb_flush(struct mmu_gather *tlb);
+
+#include <asm-generic/tlb.h>
+
+static inline void tlb_flush(struct mmu_gather *tlb)
+{
+	unsigned long start = 0UL, end = TLB_FLUSH_ALL;
+	unsigned int stride_shift = tlb_get_unmap_shift(tlb);
+
+	if (!tlb->fullmm && !tlb->need_flush_all) {
+		start = tlb->start;
+		end = tlb->end;
+	}
+
+	flush_tlb_mm_range(tlb->mm, start, end, stride_shift, tlb->freed_tables);
+}
+
+/*
+ * While x86 architecture in general requires an IPI to perform TLB
+ * shootdown, enablement code for several hypervisors overrides
+ * .flush_tlb_others hook in pv_mmu_ops and implements it by issuing
+ * a hypercall. To keep software pagetable walkers safe in this case we
+ * switch to RCU based table free (MMU_GATHER_RCU_TABLE_FREE). See the comment
+ * below 'ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE' in include/asm-generic/tlb.h
+ * for more details.
+ */
+static inline void __tlb_remove_table(void *table)
+{
+	free_page_and_swap_cache(table);
+}
+
+#endif /* _ASM_X86_TLB_H */