s390/facilities: add helper tool to generate facility lists

Modifying the architecture level set facility lists was always very
error prone. Given the numbering of the facility bits within the
Principles of Operation, where the most significant bit number is 0,
it happened a lot of times that wrong bits were set or cleared.

Therefore this patch adds a tool "gen_facilities" which generates
include/generated/facilites.h.  The definition of the bits to be set
is contained within arch/s390/include/asm/facilities_src.h and can be
easily extended to e.g. also generate such lists for the KVM module.

The generated file looks like this:

 #define FACILITIES_ALS _AC(0xc1006450f0040000,UL)
 #define FACILITIES_ALS_DWORDS 1

The facility bits defined in this patch match 1:1 to the current masks
that can be found in head.S.

That is if the tool gets executed with -march=z990 then the generated
masks will equal the masks in head.S for CONFIG_MARCH_Z990.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 83 insertions, 0 deletions

diff --git a/arch/s390/tools/.gitignore b/arch/s390/tools/.gitignore
new file mode 100644
index 000000000000..72a4b2cf1365
--- /dev/null
+++ b/arch/s390/tools/.gitignore
@@ -0,0 +1 @@
+gen_facilities
diff --git a/arch/s390/tools/Makefile b/arch/s390/tools/Makefile
new file mode 100644
index 000000000000..6d9814c9df2b
--- /dev/null
+++ b/arch/s390/tools/Makefile
@@ -0,0 +1,15 @@
+#
+# Makefile for s390 specific build tools
+#
+
+hostprogs-y		    += gen_facilities
+HOSTCFLAGS_gen_facilities.o += -Wall $(LINUXINCLUDE)
+
+define filechk_facilities.h
+	$(obj)/gen_facilities
+endef
+
+$(obj)/gen_facilities.o: $(srctree)/arch/s390/tools/gen_facilities.c
+
+include/generated/facilities.h: $(obj)/gen_facilities FORCE
+	$(call filechk,facilities.h)
diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c
new file mode 100644
index 000000000000..e2660d27889b
--- /dev/null
+++ b/arch/s390/tools/gen_facilities.c
@@ -0,0 +1,67 @@
+/*
+ * Simple program to generate defines out of facility lists that use the bit
+ * numbering scheme from the Princples of Operations: most significant bit
+ * has bit number 0.
+ *
+ *    Copyright IBM Corp. 2015
+ *
+ */
+
+#define S390_GEN_FACILITIES_C
+
+#include <strings.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <asm/facilities_src.h>
+
+static void print_facility_list(struct facility_def *def)
+{
+	unsigned int high, bit, dword, i;
+	unsigned long long *array;
+
+	array = calloc(1, 8);
+	if (!array)
+		exit(EXIT_FAILURE);
+	high = 0;
+	for (i = 0; def->bits[i] != -1; i++) {
+		bit = 63 - (def->bits[i] & 63);
+		dword = def->bits[i] / 64;
+		if (dword > high) {
+			array = realloc(array, (dword + 1) * 8);
+			if (!array)
+				exit(EXIT_FAILURE);
+			memset(array + high + 1, 0, (dword - high) * 8);
+			high = dword;
+		}
+		array[dword] |= 1ULL << bit;
+	}
+	printf("#define %s ", def->name);
+	for (i = 0; i <= high; i++)
+		printf("_AC(0x%016llx,UL)%c", array[i], i < high ? ',' : '\n');
+	printf("#define %s_DWORDS %d\n", def->name, high + 1);
+	free(array);
+}
+
+static void print_facility_lists(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(facility_defs) / sizeof(facility_defs[0]); i++)
+		print_facility_list(&facility_defs[i]);
+}
+
+int main(int argc, char **argv)
+{
+	printf("#ifndef __ASM_S390_FACILITIES__\n");
+	printf("#define __ASM_S390_FACILITIES__\n");
+	printf("/*\n");
+	printf(" * DO NOT MODIFY.\n");
+	printf(" *\n");
+	printf(" * This file was generated by %s\n", __FILE__);
+	printf(" */\n\n");
+	printf("#include <linux/const.h>\n\n");
+	print_facility_lists();
+	printf("\n#endif\n");
+	return 0;
+}