Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 92 insertions, 0 deletions

diff --git a/arch/parisc/include/asm/tlbflush.h b/arch/parisc/include/asm/tlbflush.h
new file mode 100644
index 000000000..14668bd52
--- /dev/null
+++ b/arch/parisc/include/asm/tlbflush.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _PARISC_TLBFLUSH_H
+#define _PARISC_TLBFLUSH_H
+
+/* TLB flushing routines.... */
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <asm/mmu_context.h>
+
+
+/* This is for the serialisation of PxTLB broadcasts.  At least on the
+ * N class systems, only one PxTLB inter processor broadcast can be
+ * active at any one time on the Merced bus.  This tlb purge
+ * synchronisation is fairly lightweight and harmless so we activate
+ * it on all systems not just the N class.
+
+ * It is also used to ensure PTE updates are atomic and consistent
+ * with the TLB.
+ */
+extern spinlock_t pa_tlb_lock;
+
+#define purge_tlb_start(flags)	spin_lock_irqsave(&pa_tlb_lock, flags)
+#define purge_tlb_end(flags)	spin_unlock_irqrestore(&pa_tlb_lock, flags)
+
+extern void flush_tlb_all(void);
+extern void flush_tlb_all_local(void *);
+
+#define smp_flush_tlb_all()	flush_tlb_all()
+
+int __flush_tlb_range(unsigned long sid,
+	unsigned long start, unsigned long end);
+
+#define flush_tlb_range(vma, start, end) \
+	__flush_tlb_range((vma)->vm_mm->context, start, end)
+
+#define flush_tlb_kernel_range(start, end) \
+	__flush_tlb_range(0, start, end)
+
+/*
+ * flush_tlb_mm()
+ *
+ * The code to switch to a new context is NOT valid for processes
+ * which play with the space id's.  Thus, we have to preserve the
+ * space and just flush the entire tlb.  However, the compilers,
+ * dynamic linker, etc, do not manipulate space id's, so there
+ * could be a significant performance benefit in switching contexts
+ * and not flushing the whole tlb.
+ */
+
+static inline void flush_tlb_mm(struct mm_struct *mm)
+{
+	BUG_ON(mm == &init_mm); /* Should never happen */
+
+#if 1 || defined(CONFIG_SMP)
+	/* Except for very small threads, flushing the whole TLB is
+	 * faster than using __flush_tlb_range.  The pdtlb and pitlb
+	 * instructions are very slow because of the TLB broadcast.
+	 * It might be faster to do local range flushes on all CPUs
+	 * on PA 2.0 systems.
+	 */
+	flush_tlb_all();
+#else
+	/* FIXME: currently broken, causing space id and protection ids
+	 * to go out of sync, resulting in faults on userspace accesses.
+	 * This approach needs further investigation since running many
+	 * small applications (e.g., GCC testsuite) is faster on HP-UX.
+	 */
+	if (mm) {
+		if (mm->context != 0)
+			free_sid(mm->context);
+		mm->context = alloc_sid();
+		if (mm == current->active_mm)
+			load_context(mm->context);
+	}
+#endif
+}
+
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+	unsigned long addr)
+{
+	unsigned long flags, sid;
+
+	sid = vma->vm_mm->context;
+	purge_tlb_start(flags);
+	mtsp(sid, 1);
+	pdtlb(addr);
+	if (unlikely(split_tlb))
+		pitlb(addr);
+	purge_tlb_end(flags);
+}
+#endif