kbuild: Add support for alpha asm offset generation

Now we have three archs and three different prefixes in front of
numbers: #,$,none. We'll see what the others bring...

Makefile

@@ -447,7 +447,7 @@ define generate-asm-offsets.h
 	 echo " *"; \
 	 echo " */"; \
 	 echo ""; \
-	 sed -ne "/^->/{s:^->\([^ ]*\) [\$$#]\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; s:->::; p;}"; \
+	 sed -ne "/^->/{s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; s:->::; p;}"; \
 	 echo ""; \
 	 echo "#endif" )
 endef

arch/alpha/Makefile

@@ -128,8 +128,6 @@ archmrproper:
 	rm -f include/asm-alpha/asm_offsets.h
 
 archdep:
-	$(MAKE) -C arch/alpha/kernel asm_offsets
-	@$(MAKEBOOT) dep
 
 vmlinux: arch/alpha/vmlinux.lds
 
@@ -138,3 +136,19 @@ arch/alpha/vmlinux.lds: arch/alpha/vmlinux.lds.in
 
 bootpfile:
 	@$(MAKEBOOT) bootpfile
+
+
+prepare: include/asm-$(ARCH)/asm_offsets.h
+
+arch/$(ARCH)/kernel/asm-offsets.s: include/asm include/linux/version.h \
+				   include/config/MARKER
+
+include/asm-$(ARCH)/asm_offsets.h.tmp: arch/$(ARCH)/kernel/asm-offsets.s
+	@$(generate-asm-offsets.h) < $< > $@
+
+include/asm-$(ARCH)/asm_offsets.h: include/asm-$(ARCH)/asm_offsets.h.tmp
+	@echo -n '  Generating $@'
+	@$(update-if-changed)
+
+CLEAN_FILES += include/asm-$(ARCH)/offset.h.tmp \
+	       include/asm-$(ARCH)/offset.h

arch/alpha/boot/Makefile

@@ -96,6 +96,4 @@ clean:
 	rm -f tools/mkbb tools/bootlx tools/lxboot tools/bootph
 	rm -f vmlinux.nh ksize.h
 
-dep:
-
 FORCE:

arch/alpha/kernel/Makefile

@@ -94,17 +94,3 @@ endif
 endif # GENERIC
 
 include $(TOPDIR)/Rules.make
-
-ASM_OFFSETS_H = $(TOPDIR)/include/asm-alpha/asm_offsets.h
-asm_offsets:
-	$(CC) $(CFLAGS) -S -o - check_asm.c | \
-	sed -e '/xyzzy/ { s/xyzzy //; p; }; d;' > asm_offsets.tmp
-	@if cmp -s asm_offsets.tmp $(ASM_OFFSETS_H); then \
-	  set -x; rm asm_offsets.tmp; \
-	else \
-	  set -x; mv asm_offsets.tmp $(ASM_OFFSETS_H); \
-	fi
-
-clean::
-	rm -f check_asm
-

arch/alpha/kernel/asm-offsets.c

+/*
+ * Generate definitions needed by assembly language modules.
+ * This code generates raw asm output which is post-processed to extract
+ * and format the required data.
+ */
+
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <asm/io.h>
+
+#define DEFINE(sym, val) \
+        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+
+#define BLANK() asm volatile("\n->" : : )
+
+void foo(void)
+{
+	DEFINE(TI_TASK, offsetof(struct thread_info, task));
+	DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
+	DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
+	BLANK();
+	DEFINE(PT_PTRACED, PT_PTRACED);
+	DEFINE(CLONE_VM, CLONE_VM);
+	DEFINE(SIGCHLD, SIGCHLD);
+	BLANK();
+	DEFINE(HAE_CACHE, offsetof(struct alpha_machine_vector, hae_cache));
+	DEFINE(HAE_REG, offsetof(struct alpha_machine_vector, hae_register));
+}

arch/alpha/kernel/check_asm.c

-#include <linux/types.h>
-#include <linux/stddef.h>
-#include <linux/sched.h>
-#include <asm/io.h>
-
-#define OUT(x) \
-  asm ("\nxyzzy " x)
-#define DEF(name, val) \
-  asm volatile ("\nxyzzy #define " name " %0" : : "i"(val))
-
-void foo(void)
-{
-	OUT("#ifndef __ASM_OFFSETS_H__");
-	OUT("#define __ASM_OFFSETS_H__");
-	OUT("");
-
-	DEF("TI_TASK", offsetof(struct thread_info, task));
-	DEF("TI_FLAGS", offsetof(struct thread_info, flags));
-	DEF("TI_CPU", offsetof(struct thread_info, cpu));
-
-	DEF("PT_PTRACED", PT_PTRACED);
-	DEF("CLONE_VM", CLONE_VM);
-	DEF("SIGCHLD", SIGCHLD);
-
-	DEF("HAE_CACHE", offsetof(struct alpha_machine_vector, hae_cache));
-	DEF("HAE_REG", offsetof(struct alpha_machine_vector, hae_register));
-
-	OUT("");
-	OUT("#endif /* __ASM_OFFSETS_H__ */");
-}