Merge with Linux 2.4.0-prerelease. Big Makefile rewrite, test your

Makefiles.

6 files changed, 84 insertions, 49 deletions

diff --git a/include/asm-alpha/mmu.h b/include/asm-alpha/mmu.h
new file mode 100644
index 000000000..3dc127779
--- /dev/null
+++ b/include/asm-alpha/mmu.h
@@ -0,0 +1,7 @@
+#ifndef __ALPHA_MMU_H
+#define __ALPHA_MMU_H
+
+/* The alpha MMU context is one "unsigned long" bitmap per CPU */
+typedef unsigned long mm_context_t[NR_CPUS];
+
+#endif
diff --git a/include/asm-alpha/mmu_context.h b/include/asm-alpha/mmu_context.h
index 219b8bd4e..492d29b7c 100644
--- a/include/asm-alpha/mmu_context.h
+++ b/include/asm-alpha/mmu_context.h
@@ -11,7 +11,6 @@
 #include <asm/system.h>
 #include <asm/machvec.h>
 
-
 /*
  * Force a context reload. This is needed when we change the page
  * table pointer or when we update the ASN of the current process.
@@ -93,12 +92,7 @@ extern unsigned long last_asn;
 #endif /* CONFIG_SMP */
 
 #define WIDTH_HARDWARE_ASN	8
-#ifdef CONFIG_SMP
-#define WIDTH_THIS_PROCESSOR	5
-#else
-#define WIDTH_THIS_PROCESSOR	0
-#endif
-#define ASN_FIRST_VERSION (1UL << (WIDTH_THIS_PROCESSOR + WIDTH_HARDWARE_ASN))
+#define ASN_FIRST_VERSION (1UL << WIDTH_HARDWARE_ASN)
 #define HARDWARE_ASN_MASK ((1UL << WIDTH_HARDWARE_ASN) - 1)
 
 /*
@@ -137,19 +131,24 @@ __EXTERN_INLINE void
 ev5_switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm,
 	      struct task_struct *next, long cpu)
 {
-	/* Check if our ASN is of an older version, or on a different CPU,
-	   and thus invalid.  */
-	/* ??? If we have two threads on different cpus, we'll continually
-	   fight over the context.  Find a way to record a per-mm, per-cpu
-	   value for the asn.  */
+	/* Check if our ASN is of an older version, and thus invalid. */
+	unsigned long asn;
+	unsigned long mmc;
 
-	unsigned long asn = cpu_last_asn(cpu);
-	unsigned long mmc = next_mm->context;
-	
+#ifdef CONFIG_SMP
+	cpu_data[cpu].asn_lock = 1;
+	barrier();
+#endif
+	asn = cpu_last_asn(cpu);
+	mmc = next_mm->context[cpu];
 	if ((mmc ^ asn) & ~HARDWARE_ASN_MASK) {
 		mmc = __get_new_mm_context(next_mm, cpu);
-		next_mm->context = mmc;
+		next_mm->context[cpu] = mmc;
 	}
+#ifdef CONFIG_SMP
+	else
+		cpu_data[cpu].need_new_asn = 1;
+#endif
 
 	/* Always update the PCB ASN.  Another thread may have allocated
 	   a new mm->context (via flush_tlb_mm) without the ASN serial
@@ -179,6 +178,23 @@ ev4_switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm,
 
 extern void __load_new_mm_context(struct mm_struct *);
 
+#ifdef CONFIG_SMP
+#define check_mmu_context()					\
+do {								\
+	int cpu = smp_processor_id();				\
+	cpu_data[cpu].asn_lock = 0;				\
+	barrier();						\
+	if (cpu_data[cpu].need_new_asn) {			\
+		struct mm_struct * mm = current->active_mm;	\
+		cpu_data[cpu].need_new_asn = 0;			\
+		if (!mm->context[cpu])			\
+			__load_new_mm_context(mm);		\
+	}							\
+} while(0)
+#else
+#define check_mmu_context()  do { } while(0)
+#endif
+
 __EXTERN_INLINE void
 ev5_activate_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm)
 {
@@ -208,7 +224,10 @@ ev4_activate_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm)
 extern inline int
 init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 {
-	mm->context = 0;
+	int i;
+
+	for (i = 0; i < smp_num_cpus; i++)
+		mm->context[cpu_logical_map(i)] = 0;
         tsk->thread.ptbr = ((unsigned long)mm->pgd - IDENT_ADDR) >> PAGE_SHIFT;
 	return 0;
 }
diff --git a/include/asm-alpha/pgalloc.h b/include/asm-alpha/pgalloc.h
index dd09a2eec..7e377bdfd 100644
--- a/include/asm-alpha/pgalloc.h
+++ b/include/asm-alpha/pgalloc.h
@@ -38,29 +38,6 @@ extern void __load_new_mm_context(struct mm_struct *);
 extern void smp_imb(void);
 #endif
 
-/* We need to flush the userspace icache after setting breakpoints in
-   ptrace.  I don't think it's needed in do_swap_page, or do_no_page,
-   but I don't know how to get rid of it either.
-
-   Instead of indiscriminately using imb, take advantage of the fact
-   that icache entries are tagged with the ASN and load a new mm context.  */
-/* ??? Ought to use this in arch/alpha/kernel/signal.c too.  */
-
-#ifndef CONFIG_SMP
-static inline void
-flush_icache_page(struct vm_area_struct *vma, struct page *page)
-{
-	if (vma->vm_flags & VM_EXEC) {
-		struct mm_struct *mm = vma->vm_mm;
-		mm->context = 0;
-		if (current->active_mm == mm)
-			__load_new_mm_context(mm);
-	}
-}
-#else
-extern void flush_icache_page(struct vm_area_struct *vma, struct page *page);
-#endif
-
 
 /*
  * Use a few helper functions to hide the ugly broken ASN
@@ -83,8 +60,38 @@ ev5_flush_tlb_current(struct mm_struct *mm)
 static inline void
 flush_tlb_other(struct mm_struct *mm)
 {
-	mm->context = 0;
+	long * mmc = &mm->context[smp_processor_id()];
+	/*
+	 * Check it's not zero first to avoid cacheline ping pong when
+	 * possible.
+	 */
+	if (*mmc)
+		*mmc = 0;
+}
+
+/* We need to flush the userspace icache after setting breakpoints in
+   ptrace.  I don't think it's needed in do_swap_page, or do_no_page,
+   but I don't know how to get rid of it either.
+
+   Instead of indiscriminately using imb, take advantage of the fact
+   that icache entries are tagged with the ASN and load a new mm context.  */
+/* ??? Ought to use this in arch/alpha/kernel/signal.c too.  */
+
+#ifndef CONFIG_SMP
+static inline void
+flush_icache_page(struct vm_area_struct *vma, struct page *page)
+{
+	if (vma->vm_flags & VM_EXEC) {
+		struct mm_struct *mm = vma->vm_mm;
+		if (current->active_mm == mm)
+			__load_new_mm_context(mm);
+		else
+			mm->context[smp_processor_id()] = 0;
+	}
 }
+#else
+extern void flush_icache_page(struct vm_area_struct *vma, struct page *page);
+#endif
 
 /*
  * Flush just one page in the current TLB set.
@@ -140,7 +147,7 @@ ev5_flush_tlb_current_page(struct mm_struct * mm,
  */
 static inline void flush_tlb(void)
 {
-	flush_tlb_current(current->mm);
+	flush_tlb_current(current->active_mm);
 }
 
 /*
@@ -170,10 +177,10 @@ static inline void flush_tlb_all(void)
  */
 static inline void flush_tlb_mm(struct mm_struct *mm)
 {
-	if (mm != current->mm)
-		flush_tlb_other(mm);
-	else
+	if (mm == current->active_mm)
 		flush_tlb_current(mm);
+	else
+		flush_tlb_other(mm);
 }
 
 /*
@@ -189,10 +196,10 @@ static inline void flush_tlb_page(struct vm_area_struct *vma,
 {
 	struct mm_struct * mm = vma->vm_mm;
 
-	if (mm != current->mm)
-		flush_tlb_other(mm);
-	else
+	if (mm == current->active_mm)
 		flush_tlb_current_page(mm, vma, addr);
+	else
+		flush_tlb_other(mm);
 }
 
 /*
diff --git a/include/asm-alpha/processor.h b/include/asm-alpha/processor.h
index 81427025c..49f228f3f 100644
--- a/include/asm-alpha/processor.h
+++ b/include/asm-alpha/processor.h
@@ -124,7 +124,6 @@ extern long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
 
 #define copy_segments(tsk, mm)		do { } while (0)
 #define release_segments(mm)		do { } while (0)
-#define forget_segments()		do { } while (0)
 
 unsigned long get_wchan(struct task_struct *p);
 
diff --git a/include/asm-alpha/smp.h b/include/asm-alpha/smp.h
index 44ec5e8ea..6331af6f2 100644
--- a/include/asm-alpha/smp.h
+++ b/include/asm-alpha/smp.h
@@ -26,6 +26,8 @@ __hard_smp_processor_id(void)
 struct cpuinfo_alpha {
 	unsigned long loops_per_sec;
 	unsigned long last_asn;
+	int need_new_asn;
+	int asn_lock;
 	unsigned long *pgd_cache;
 	unsigned long *pte_cache;
 	unsigned long pgtable_cache_sz;
diff --git a/include/asm-alpha/system.h b/include/asm-alpha/system.h
index 6d34c5472..3a8c9385d 100644
--- a/include/asm-alpha/system.h
+++ b/include/asm-alpha/system.h
@@ -125,6 +125,7 @@ do {							\
 	current = (next);				\
 	pcbb = virt_to_phys(&current->thread);		\
 	(last) = alpha_switch_to(pcbb, (prev));		\
+	check_mmu_context();				\
 } while (0)
 
 extern struct task_struct* alpha_switch_to(unsigned long, struct task_struct*);