This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / include / asm-avr32 / mmu_context.h

diff --git a/include/asm-avr32/mmu_context.h b/include/asm-avr32/mmu_context.h
new file mode 100644 (file)
index 0000000..31add1a
--- /dev/null
+++ b/include/asm-avr32/mmu_context.h
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * ASID handling taken from SH implementation.
+ *   Copyright (C) 1999 Niibe Yutaka
+ *   Copyright (C) 2003 Paul Mundt
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __ASM_AVR32_MMU_CONTEXT_H
+#define __ASM_AVR32_MMU_CONTEXT_H
+
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+#include <asm/sysreg.h>
+
+/*
+ * The MMU "context" consists of two things:
+ *    (a) TLB cache version
+ *    (b) ASID (Address Space IDentifier)
+ */
+#define MMU_CONTEXT_ASID_MASK          0x000000ff
+#define MMU_CONTEXT_VERSION_MASK       0xffffff00
+#define MMU_CONTEXT_FIRST_VERSION       0x00000100
+#define NO_CONTEXT                     0
+
+#define MMU_NO_ASID                    0x100
+
+/* Virtual Page Number mask */
+#define MMU_VPN_MASK   0xfffff000
+
+/* Cache of MMU context last used */
+extern unsigned long mmu_context_cache;
+
+/*
+ * Get MMU context if needed
+ */
+static inline void
+get_mmu_context(struct mm_struct *mm)
+{
+       unsigned long mc = mmu_context_cache;
+
+       if (((mm->context ^ mc) & MMU_CONTEXT_VERSION_MASK) == 0)
+               /* It's up to date, do nothing */
+               return;
+
+       /* It's old, we need to get new context with new version */
+       mc = ++mmu_context_cache;
+       if (!(mc & MMU_CONTEXT_ASID_MASK)) {
+               /*
+                * We have exhausted all ASIDs of this version.
+                * Flush the TLB and start new cycle.
+                */
+               flush_tlb_all();
+               /*
+                * Fix version. Note that we avoid version #0
+                * to distinguish NO_CONTEXT.
+                */
+               if (!mc)
+                       mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
+       }
+       mm->context = mc;
+}
+
+/*
+ * Initialize the context related info for a new mm_struct
+ * instance.
+ */
+static inline int init_new_context(struct task_struct *tsk,
+                                      struct mm_struct *mm)
+{
+       mm->context = NO_CONTEXT;
+       return 0;
+}
+
+/*
+ * Destroy context related info for an mm_struct that is about
+ * to be put to rest.
+ */
+static inline void destroy_context(struct mm_struct *mm)
+{
+       /* Do nothing */
+}
+
+static inline void set_asid(unsigned long asid)
+{
+       /* XXX: We're destroying TLBEHI[8:31] */
+       sysreg_write(TLBEHI, asid & MMU_CONTEXT_ASID_MASK);
+       cpu_sync_pipeline();
+}
+
+static inline unsigned long get_asid(void)
+{
+       unsigned long asid;
+
+       asid = sysreg_read(TLBEHI);
+       return asid & MMU_CONTEXT_ASID_MASK;
+}
+
+static inline void activate_context(struct mm_struct *mm)
+{
+       get_mmu_context(mm);
+       set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
+}
+
+static inline void switch_mm(struct mm_struct *prev,
+                                struct mm_struct *next,
+                                struct task_struct *tsk)
+{
+       if (likely(prev != next)) {
+               unsigned long __pgdir = (unsigned long)next->pgd;
+
+               sysreg_write(PTBR, __pgdir);
+               activate_context(next);
+       }
+}
+
+#define deactivate_mm(tsk,mm) do { } while(0)
+
+#define activate_mm(prev, next) switch_mm((prev), (next), NULL)
+
+static inline void
+enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+}
+
+
+static inline void enable_mmu(void)
+{
+       sysreg_write(MMUCR, (SYSREG_BIT(MMUCR_S)
+                            | SYSREG_BIT(E)
+                            | SYSREG_BIT(MMUCR_I)));
+       nop(); nop(); nop(); nop(); nop(); nop(); nop(); nop();
+
+       if (mmu_context_cache == NO_CONTEXT)
+               mmu_context_cache = MMU_CONTEXT_FIRST_VERSION;
+
+       set_asid(mmu_context_cache & MMU_CONTEXT_ASID_MASK);
+}
+
+static inline void disable_mmu(void)
+{
+       sysreg_write(MMUCR, SYSREG_BIT(MMUCR_S));
+}
+
+#endif /* __ASM_AVR32_MMU_CONTEXT_H */