1 files changed, 129 insertions, 0 deletions
diff --git a/arch/s390/include/asm/tlbflush.h b/arch/s390/include/asm/tlbflush.h
new file mode 100644
index 000000000..a6e2cd89b
--- /dev/null
+++ b/arch/s390/include/asm/tlbflush.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _S390_TLBFLUSH_H
+#define _S390_TLBFLUSH_H
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <asm/processor.h>
+
+/*
+ * Flush all TLB entries on the local CPU.
+ */
+static inline void __tlb_flush_local(void)
+{
+	asm volatile("ptlb" : : : "memory");
+}
+
+/*
+ * Flush TLB entries for a specific ASCE on all CPUs
+ */
+static inline void __tlb_flush_idte(unsigned long asce)
+{
+	unsigned long opt;
+
+	opt = IDTE_PTOA;
+	if (MACHINE_HAS_TLB_GUEST)
+		opt |= IDTE_GUEST_ASCE;
+	/* Global TLB flush for the mm */
+	asm volatile("idte 0,%1,%0" : : "a" (opt), "a" (asce) : "cc");
+}
+
+/*
+ * Flush all TLB entries on all CPUs.
+ */
+static inline void __tlb_flush_global(void)
+{
+	unsigned int dummy = 0;
+
+	csp(&dummy, 0, 0);
+}
+
+/*
+ * Flush TLB entries for a specific mm on all CPUs (in case gmap is used
+ * this implicates multiple ASCEs!).
+ */
+static inline void __tlb_flush_mm(struct mm_struct *mm)
+{
+	unsigned long gmap_asce;
+
+	/*
+	 * If the machine has IDTE we prefer to do a per mm flush
+	 * on all cpus instead of doing a local flush if the mm
+	 * only ran on the local cpu.
+	 */
+	preempt_disable();
+	atomic_inc(&mm->context.flush_count);
+	/* Reset TLB flush mask */
+	cpumask_copy(mm_cpumask(mm), &mm->context.cpu_attach_mask);
+	barrier();
+	gmap_asce = READ_ONCE(mm->context.gmap_asce);
+	if (MACHINE_HAS_IDTE && gmap_asce != -1UL) {
+		if (gmap_asce)
+			__tlb_flush_idte(gmap_asce);
+		__tlb_flush_idte(mm->context.asce);
+	} else {
+		/* Global TLB flush */
+		__tlb_flush_global();
+	}
+	atomic_dec(&mm->context.flush_count);
+	preempt_enable();
+}
+
+static inline void __tlb_flush_kernel(void)
+{
+	if (MACHINE_HAS_IDTE)
+		__tlb_flush_idte(init_mm.context.asce);
+	else
+		__tlb_flush_global();
+}
+
+static inline void __tlb_flush_mm_lazy(struct mm_struct * mm)
+{
+	spin_lock(&mm->context.lock);
+	if (mm->context.flush_mm) {
+		mm->context.flush_mm = 0;
+		__tlb_flush_mm(mm);
+	}
+	spin_unlock(&mm->context.lock);
+}
+
+/*
+ * TLB flushing:
+ *  flush_tlb() - flushes the current mm struct TLBs
+ *  flush_tlb_all() - flushes all processes TLBs
+ *  flush_tlb_mm(mm) - flushes the specified mm context TLB's
+ *  flush_tlb_page(vma, vmaddr) - flushes one page
+ *  flush_tlb_range(vma, start, end) - flushes a range of pages
+ *  flush_tlb_kernel_range(start, end) - flushes a range of kernel pages
+ */
+
+/*
+ * flush_tlb_mm goes together with ptep_set_wrprotect for the
+ * copy_page_range operation and flush_tlb_range is related to
+ * ptep_get_and_clear for change_protection. ptep_set_wrprotect and
+ * ptep_get_and_clear do not flush the TLBs directly if the mm has
+ * only one user. At the end of the update the flush_tlb_mm and
+ * flush_tlb_range functions need to do the flush.
+ */
+#define flush_tlb()				do { } while (0)
+#define flush_tlb_all()				do { } while (0)
+#define flush_tlb_page(vma, addr)		do { } while (0)
+
+static inline void flush_tlb_mm(struct mm_struct *mm)
+{
+	__tlb_flush_mm_lazy(mm);
+}
+
+static inline void flush_tlb_range(struct vm_area_struct *vma,
+				   unsigned long start, unsigned long end)
+{
+	__tlb_flush_mm_lazy(vma->vm_mm);
+}
+
+static inline void flush_tlb_kernel_range(unsigned long start,
+					  unsigned long end)
+{
+	__tlb_flush_kernel();
+}
+
+#endif /* _S390_TLBFLUSH_H */