patch-2.3.8 linux/include/asm-alpha/mmu_context.h

• Lines: 184
• Date: Tue Jun 22 10:46:52 1999
• Orig file: v2.3.7/linux/include/asm-alpha/mmu_context.h
• Orig date: Wed Mar 24 07:41:55 1999

diff -u --recursive --new-file v2.3.7/linux/include/asm-alpha/mmu_context.h linux/include/asm-alpha/mmu_context.h
@@ -49,31 +49,24 @@
 # endif
 #endif
 
-#ifdef __SMP__
-#define WIDTH_THIS_PROCESSOR	5
 /*
- * last_asn[processor]:
+ * cpu_last_asn(processor):
  * 63                                            0
  * +-------------+----------------+--------------+
  * | asn version | this processor | hardware asn |
  * +-------------+----------------+--------------+
  */
-extern unsigned long last_asn[];
-#define asn_cache last_asn[p->processor]
 
+#ifdef __SMP__
+#include <asm/smp.h>
+#define cpu_last_asn(cpuid)	(cpu_data[cpuid].last_asn)
 #else
-#define WIDTH_THIS_PROCESSOR	0
-/*
- * asn_cache:
- * 63                                            0
- * +------------------------------+--------------+
- * |         asn version          | hardware asn |
- * +------------------------------+--------------+
- */
-extern unsigned long asn_cache;
+extern unsigned long last_asn;
+#define cpu_last_asn(cpuid)	last_asn
 #endif /* __SMP__ */
 
 #define WIDTH_HARDWARE_ASN	8
+#define WIDTH_THIS_PROCESSOR	5
 #define ASN_FIRST_VERSION (1UL << (WIDTH_THIS_PROCESSOR + WIDTH_HARDWARE_ASN))
 #define HARDWARE_ASN_MASK ((1UL << WIDTH_HARDWARE_ASN) - 1)
 
@@ -96,20 +89,46 @@
 
 extern void get_new_mmu_context(struct task_struct *p, struct mm_struct *mm);
 
-__EXTERN_INLINE void ev4_get_mmu_context(struct task_struct *p)
+static inline unsigned long
+__get_new_mmu_context(struct task_struct *p, struct mm_struct *mm)
 {
-	/* As described, ASN's are broken.  */
+	unsigned long asn = cpu_last_asn(smp_processor_id());
+	unsigned long next = asn + 1;
+
+	if ((next ^ asn) & ~MAX_ASN) {
+		tbiap();
+		next = (asn & ~HARDWARE_ASN_MASK) + ASN_FIRST_VERSION;
+	}
+	cpu_last_asn(smp_processor_id()) = next;
+	mm->context = next;                      /* full version + asn */
+	return next;
 }
 
-__EXTERN_INLINE void ev5_get_mmu_context(struct task_struct *p)
+__EXTERN_INLINE void
+ev4_get_mmu_context(struct task_struct *p)
+{
+	/* As described, ASN's are broken.  But we can optimize for
+	   switching between threads -- if the mm is unchanged from
+	   current we needn't flush.  */
+	if (current->mm != p->mm)
+		tbiap();
+}
+
+__EXTERN_INLINE void
+ev5_get_mmu_context(struct task_struct *p)
 {
-	struct mm_struct * mm = p->mm;
+	/* Check if our ASN is of an older version, or on a different CPU,
+	   and thus invalid.  */
 
-	if (mm) {
-		unsigned long asn = asn_cache;
-		/* Check if our ASN is of an older version and thus invalid */
-		if ((mm->context ^ asn) & ~HARDWARE_ASN_MASK)
-			get_new_mmu_context(p, mm);
+	long asn = cpu_last_asn(smp_processor_id());
+	struct mm_struct *mm = p->mm;
+	long mmc = mm->context;
+	
+	if ((p->tss.mm_context ^ asn) & ~HARDWARE_ASN_MASK) {
+		if ((mmc ^ asn) & ~HARDWARE_ASN_MASK)
+			mmc = __get_new_mmu_context(p, mm);
+		p->tss.mm_context = mmc;
+		p->tss.asn = mmc & HARDWARE_ASN_MASK;
 	}
 }
 
@@ -123,40 +142,40 @@
 # endif
 #endif
 
-extern inline void init_new_context(struct mm_struct *mm)
+extern inline void
+init_new_context(struct mm_struct *mm)
 {
 	mm->context = 0;
 }
 
-extern inline void destroy_context(struct mm_struct *mm)
+extern inline void
+destroy_context(struct mm_struct *mm)
 {
 	/* Nothing to do.  */
 }
 
+#ifdef __MMU_EXTERN_INLINE
+#undef __EXTERN_INLINE
+#undef __MMU_EXTERN_INLINE
+#endif
 
 /*
  * Force a context reload. This is needed when we change the page
  * table pointer or when we update the ASN of the current process.
  */
 
-#if defined(CONFIG_ALPHA_GENERIC)
-#define MASK_CONTEXT(tss) \
- ((struct thread_struct *)((unsigned long)(tss) & alpha_mv.mmu_context_mask))
-#elif defined(CONFIG_ALPHA_DP264)
-#define MASK_CONTEXT(tss) \
- ((struct thread_struct *)((unsigned long)(tss) & 0xfffffffffful))
-#else
-#define MASK_CONTEXT(tss)  (tss)
+/* Don't get into trouble with dueling __EXTERN_INLINEs.  */
+#ifndef __EXTERN_INLINE
+#include <asm/io.h>
 #endif
 
-__EXTERN_INLINE struct thread_struct *
+extern inline unsigned long
 __reload_tss(struct thread_struct *tss)
 {
-	register struct thread_struct *a0 __asm__("$16");
-	register struct thread_struct *v0 __asm__("$0");
-
-	a0 = MASK_CONTEXT(tss);
+	register unsigned long a0 __asm__("$16");
+	register unsigned long v0 __asm__("$0");
 
+	a0 = virt_to_phys(tss);
 	__asm__ __volatile__(
 		"call_pal %2 #__reload_tss"
 		: "=r"(v0), "=r"(a0)
@@ -166,27 +185,22 @@
 	return v0;
 }
 
-__EXTERN_INLINE void
+extern inline void
 reload_context(struct task_struct *task)
 {
 	__reload_tss(&task->tss);
 }
 
 /*
- * After we have set current->mm to a new value, this activates the
- * context for the new mm so we see the new mappings.
+ * After setting current->mm to a new value, activate the context for the
+ * new mm so we see the new mappings.
  */
 
-__EXTERN_INLINE void
+extern inline void
 activate_context(struct task_struct *task)
 {
-	get_mmu_context(task);
+	get_new_mmu_context(task, task->mm);
 	reload_context(task);
 }
-
-#ifdef __MMU_EXTERN_INLINE
-#undef __EXTERN_INLINE
-#undef __MMU_EXTERN_INLINE
-#endif
 
 #endif /* __ALPHA_MMU_CONTEXT_H */