patch-2.3.48 linux/include/asm-mips64/mmu_context.h

• Lines: 94
• Date: Thu Feb 24 22:53:35 2000
• Orig file: v2.3.47/linux/include/asm-mips64/mmu_context.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.47/linux/include/asm-mips64/mmu_context.h linux/include/asm-mips64/mmu_context.h
@@ -0,0 +1,93 @@
+/* $Id: mmu_context.h,v 1.4 2000/02/23 00:41:38 ralf Exp $
+ *
+ * Switch a MMU context.
+ *
+ * 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) 1996, 1997, 1998, 1999 by Ralf Baechle
+ * Copyright (C) 1999 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_MMU_CONTEXT_H
+#define _ASM_MMU_CONTEXT_H
+
+#include <linux/config.h>
+#include <asm/pgalloc.h>
+
+/* Fuck.  The f-word is here so you can grep for it :-)  */
+extern unsigned long asid_cache;
+extern pgd_t *current_pgd;
+
+#define ASID_INC	0x1
+#define ASID_MASK	0xff
+
+static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk, unsigned cpu)
+{
+}
+
+/*
+ *  All unused by hardware upper bits will be considered
+ *  as a software asid extension.
+ */
+#define ASID_VERSION_MASK  ((unsigned long)~(ASID_MASK|(ASID_MASK-1)))
+#define ASID_FIRST_VERSION ((unsigned long)(~ASID_VERSION_MASK) + 1)
+
+extern inline void
+get_new_mmu_context(struct mm_struct *mm, unsigned long asid)
+{
+	if (! ((asid += ASID_INC) & ASID_MASK) ) {
+		flush_tlb_all(); /* start new asid cycle */
+		if (!asid)      /* fix version if needed */
+			asid = ASID_FIRST_VERSION;
+	}
+	mm->context = asid_cache = asid;
+}
+
+/*
+ * Initialize the context related info for a new mm_struct
+ * instance.
+ */
+extern inline void
+init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+	mm->context = 0;
+}
+
+extern inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+                             struct task_struct *tsk, unsigned cpu)
+{
+	unsigned long asid = asid_cache;
+
+	/* Check if our ASID is of an older version and thus invalid */
+	if ((next->context ^ asid) & ASID_VERSION_MASK)
+		get_new_mmu_context(next, asid);
+
+	current_pgd = next->pgd;
+	set_entryhi(next->context);
+}
+
+/*
+ * Destroy context related info for an mm_struct that is about
+ * to be put to rest.
+ */
+extern inline void destroy_context(struct mm_struct *mm)
+{
+	/* Nothing to do.  */
+}
+
+/*
+ * After we have set current->mm to a new value, this activates
+ * the context for the new mm so we see the new mappings.
+ */
+extern inline void
+activate_mm(struct mm_struct *prev, struct mm_struct *next)
+{
+	/* Unconditionally get a new ASID.  */
+	get_new_mmu_context(next, asid_cache);
+
+	current_pgd = next->pgd;
+	set_entryhi(next->context);
+}
+
+#endif /* _ASM_MMU_CONTEXT_H */