From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Wed, 30 Aug 2017 08:25:59 +0000
Subject: Initial file dump from open source release

---
 arch/xtensa/mm/tlb.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)
 create mode 100644 arch/xtensa/mm/tlb.c

(limited to 'arch/xtensa/mm/tlb.c')

diff --git a/arch/xtensa/mm/tlb.c b/arch/xtensa/mm/tlb.c
new file mode 100644
index 00000000..5411aa67
--- /dev/null
+++ b/arch/xtensa/mm/tlb.c
@@ -0,0 +1,142 @@
+/*
+ * arch/xtensa/mm/tlb.c
+ *
+ * Logic that manipulates the Xtensa MMU.  Derived from MIPS.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2003 Tensilica Inc.
+ *
+ * Joe Taylor
+ * Chris Zankel	<chris@zankel.net>
+ * Marc Gauthier
+ */
+
+#include <linux/mm.h>
+#include <asm/processor.h>
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+
+
+static inline void __flush_itlb_all (void)
+{
+	int w, i;
+
+	for (w = 0; w < ITLB_ARF_WAYS; w++) {
+		for (i = 0; i < (1 << XCHAL_ITLB_ARF_ENTRIES_LOG2); i++) {
+			int e = w + (i << PAGE_SHIFT);
+			invalidate_itlb_entry_no_isync(e);
+		}
+	}
+	asm volatile ("isync\n");
+}
+
+static inline void __flush_dtlb_all (void)
+{
+	int w, i;
+
+	for (w = 0; w < DTLB_ARF_WAYS; w++) {
+		for (i = 0; i < (1 << XCHAL_DTLB_ARF_ENTRIES_LOG2); i++) {
+			int e = w + (i << PAGE_SHIFT);
+			invalidate_dtlb_entry_no_isync(e);
+		}
+	}
+	asm volatile ("isync\n");
+}
+
+
+void flush_tlb_all (void)
+{
+	__flush_itlb_all();
+	__flush_dtlb_all();
+}
+
+/* If mm is current, we simply assign the current task a new ASID, thus,
+ * invalidating all previous tlb entries. If mm is someone else's user mapping,
+ * wie invalidate the context, thus, when that user mapping is swapped in,
+ * a new context will be assigned to it.
+ */
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+	if (mm == current->active_mm) {
+		unsigned long flags;
+		local_save_flags(flags);
+		__get_new_mmu_context(mm);
+		__load_mmu_context(mm);
+		local_irq_restore(flags);
+	}
+	else
+		mm->context = 0;
+}
+
+#define _ITLB_ENTRIES (ITLB_ARF_WAYS << XCHAL_ITLB_ARF_ENTRIES_LOG2)
+#define _DTLB_ENTRIES (DTLB_ARF_WAYS << XCHAL_DTLB_ARF_ENTRIES_LOG2)
+#if _ITLB_ENTRIES > _DTLB_ENTRIES
+# define _TLB_ENTRIES _ITLB_ENTRIES
+#else
+# define _TLB_ENTRIES _DTLB_ENTRIES
+#endif
+
+void flush_tlb_range (struct vm_area_struct *vma,
+		      unsigned long start, unsigned long end)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	unsigned long flags;
+
+	if (mm->context == NO_CONTEXT)
+		return;
+
+#if 0
+	printk("[tlbrange<%02lx,%08lx,%08lx>]\n",
+			(unsigned long)mm->context, start, end);
+#endif
+	local_save_flags(flags);
+
+	if (end-start + (PAGE_SIZE-1) <= _TLB_ENTRIES << PAGE_SHIFT) {
+		int oldpid = get_rasid_register();
+		set_rasid_register (ASID_INSERT(mm->context));
+		start &= PAGE_MASK;
+		if (vma->vm_flags & VM_EXEC)
+			while(start < end) {
+				invalidate_itlb_mapping(start);
+				invalidate_dtlb_mapping(start);
+				start += PAGE_SIZE;
+			}
+		else
+			while(start < end) {
+				invalidate_dtlb_mapping(start);
+				start += PAGE_SIZE;
+			}
+
+		set_rasid_register(oldpid);
+	} else {
+		flush_tlb_mm(mm);
+	}
+	local_irq_restore(flags);
+}
+
+void flush_tlb_page (struct vm_area_struct *vma, unsigned long page)
+{
+	struct mm_struct* mm = vma->vm_mm;
+	unsigned long flags;
+	int oldpid;
+
+	if(mm->context == NO_CONTEXT)
+		return;
+
+	local_save_flags(flags);
+
+	oldpid = get_rasid_register();
+
+	if (vma->vm_flags & VM_EXEC)
+		invalidate_itlb_mapping(page);
+	invalidate_dtlb_mapping(page);
+
+	set_rasid_register(oldpid);
+
+	local_irq_restore(flags);
+}
-- 
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