diff -urN 2.3.41/arch/alpha/kernel/alpha_ksyms.c smp-imb/arch/alpha/kernel/alpha_ksyms.c
--- 2.3.41/arch/alpha/kernel/alpha_ksyms.c	Fri Dec 17 18:17:06 1999
+++ smp-imb/arch/alpha/kernel/alpha_ksyms.c	Wed Feb  2 13:43:09 2000
@@ -160,6 +160,7 @@
 EXPORT_SYMBOL(flush_tlb_mm);
 EXPORT_SYMBOL(flush_tlb_page);
 EXPORT_SYMBOL(flush_tlb_range);
+EXPORT_SYMBOL(smp_imb);
 EXPORT_SYMBOL(cpu_data);
 EXPORT_SYMBOL(cpu_number_map);
 EXPORT_SYMBOL(global_bh_lock);
diff -urN 2.3.41/arch/alpha/kernel/smp.c smp-imb/arch/alpha/kernel/smp.c
--- 2.3.41/arch/alpha/kernel/smp.c	Wed Dec  8 00:05:25 1999
+++ smp-imb/arch/alpha/kernel/smp.c	Wed Feb  2 13:42:27 2000
@@ -868,6 +868,22 @@
 }
 
 static void
+ipi_imb(void)
+{
+	imb();
+}
+
+void
+smp_imb(void)
+{
+	/* Must wait other processors to flush their icache before continue. */
+	if (smp_call_function(ipi_imb, NULL, 1, 1))
+		printk(KERN_CRIT "smp_imb: timed out\n");
+
+	imb();
+}
+
+static void
 ipi_flush_tlb_all(void *ignored)
 {
 	tbia();
diff -urN 2.3.41/include/asm-alpha/pgalloc.h smp-imb/include/asm-alpha/pgalloc.h
--- 2.3.41/include/asm-alpha/pgalloc.h	Tue Jan 18 01:11:25 2000
+++ smp-imb/include/asm-alpha/pgalloc.h	Wed Feb  2 13:42:27 2000
@@ -3,13 +3,27 @@
 
 #include <linux/config.h>
 
-/* Caches aren't brain-dead on the Alpha. */
-#define flush_cache_all()			do { } while (0)
+/* The icache is not coherent with the dcache on alpha, thus before
+   running self modified code we must always run an imb().
+   Actually flush_cache_all() is real overkill as it's recalled from
+   vmalloc() before accessing pagetables and on the Alpha we are not required
+   to flush the icache before doing that, but the semantic of flush_cache_all()
+   requires us to flush _all_ the caches and so we must be correct here. It's
+   instead vmalloc that should be changed to use a more finegrined cache
+   flush operation (I suspect that also other archs doesn't need an icache
+   flush while handling pagetables). OTOH vmalloc is not a performance critical
+   path so after all we can live with it for now. */
+#define flush_cache_all()			flush_icache_range(0, 0)
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(mm, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
 #define flush_page_to_ram(page)			do { } while (0)
-#define flush_icache_range(start, end)		do { } while (0)
+#ifndef __SMP__
+#define flush_icache_range(start, end)		imb()
+#else
+#define flush_icache_range(start, end)		smp_imb()
+extern void smp_imb(void);
+#endif
 
 /*
  * Use a few helper functions to hide the ugly broken ASN