Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 206 insertions, 0 deletions

diff --git a/include/asm-sh/mmu_context.h b/include/asm-sh/mmu_context.h
new file mode 100644
index 00000000000..6760d064bd0
--- /dev/null
+++ b/include/asm-sh/mmu_context.h
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 1999 Niibe Yutaka
+ * Copyright (C) 2003 Paul Mundt
+ *
+ * ASID handling idea taken from MIPS implementation.
+ */
+#ifndef __ASM_SH_MMU_CONTEXT_H
+#define __ASM_SH_MMU_CONTEXT_H
+#ifdef __KERNEL__
+
+#include <asm/cpu/mmu_context.h>
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+/*
+ * The MMU "context" consists of two things:
+ *    (a) TLB cache version (or round, cycle whatever expression you like)
+ *    (b) ASID (Address Space IDentifier)
+ */
+
+/*
+ * Cache of MMU context last used.
+ */
+extern unsigned long mmu_context_cache;
+
+#define MMU_CONTEXT_ASID_MASK		0x000000ff
+#define MMU_CONTEXT_VERSION_MASK	0xffffff00
+#define MMU_CONTEXT_FIRST_VERSION	0x00000100
+#define NO_CONTEXT			0
+
+/* ASID is 8-bit value, so it can't be 0x100 */
+#define MMU_NO_ASID			0x100
+
+/*
+ * Virtual Page Number mask
+ */
+#define MMU_VPN_MASK	0xfffff000
+
+#ifdef CONFIG_MMU
+/*
+ * Get MMU context if needed.
+ */
+static __inline__ void
+get_mmu_context(struct mm_struct *mm)
+{
+	extern void flush_tlb_all(void);
+	unsigned long mc = mmu_context_cache;
+
+	/* Check if we have old version of context. */
+	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 exhaust ASID of this version.
+		 * Flush all TLB and start new cycle.
+		 */
+		flush_tlb_all();
+		/*
+		 * Fix version; Note that we avoid version #0
+		 * to distingush 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)
+{
+	unsigned long __dummy;
+
+	__asm__ __volatile__ ("mov.l	%2, %0\n\t"
+			      "and	%3, %0\n\t"
+			      "or	%1, %0\n\t"
+			      "mov.l	%0, %2"
+			      : "=&r" (__dummy)
+			      : "r" (asid), "m" (__m(MMU_PTEH)),
+			        "r" (0xffffff00));
+}
+
+static __inline__ unsigned long get_asid(void)
+{
+	unsigned long asid;
+
+	__asm__ __volatile__ ("mov.l	%1, %0"
+			      : "=r" (asid)
+			      : "m" (__m(MMU_PTEH)));
+	asid &= MMU_CONTEXT_ASID_MASK;
+	return asid;
+}
+
+/*
+ * After we have set current->mm to a new value, this activates
+ * the context for the new mm so we see the new mappings.
+ */
+static __inline__ void activate_context(struct mm_struct *mm)
+{
+	get_mmu_context(mm);
+	set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
+}
+
+/* MMU_TTB can be used for optimizing the fault handling.
+   (Currently not used) */
+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;
+
+		__asm__ __volatile__("mov.l	%0, %1"
+				     : /* no output */
+				     : "r" (__pgdir), "m" (__m(MMU_TTB)));
+		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)
+{
+}
+#else /* !CONFIG_MMU */
+#define get_mmu_context(mm)		do { } while (0)
+#define init_new_context(tsk,mm)	(0)
+#define destroy_context(mm)		do { } while (0)
+#define set_asid(asid)			do { } while (0)
+#define get_asid()			(0)
+#define activate_context(mm)		do { } while (0)
+#define switch_mm(prev,next,tsk)	do { } while (0)
+#define deactivate_mm(tsk,mm)		do { } while (0)
+#define activate_mm(prev,next)		do { } while (0)
+#define enter_lazy_tlb(mm,tsk)		do { } while (0)
+#endif /* CONFIG_MMU */
+
+#if defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
+/*
+ * If this processor has an MMU, we need methods to turn it off/on ..
+ * paging_init() will also have to be updated for the processor in
+ * question.
+ */
+static inline void enable_mmu(void)
+{
+	/* Enable MMU */
+	ctrl_outl(MMU_CONTROL_INIT, MMUCR);
+
+	/* The manual suggests doing some nops after turning on the MMU */
+	__asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop\n\t");
+
+	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)
+{
+	unsigned long cr;
+
+	cr = ctrl_inl(MMUCR);
+	cr &= ~MMU_CONTROL_INIT;
+	ctrl_outl(cr, MMUCR);
+	__asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop\n\t");
+}
+#else
+/*
+ * MMU control handlers for processors lacking memory
+ * management hardware.
+ */
+#define enable_mmu()	do { BUG(); } while (0)
+#define disable_mmu()	do { BUG(); } while (0)
+#endif
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_SH_MMU_CONTEXT_H */