Scalable CPU bitmasks

diff -Nru a/include/linux/cpumap.h b/include/linux/cpumap.h
@@ -0,0 +1,110 @@
+/*
+ * cpumap_t data type and supporting functions
+ *
+ * Copyright (c) 2002 IBM Corp.
+ *
+ *	01/25/02 Initial Version 	Russ Weight <[email protected]>
+ *	03/20/02 Move larger functions to cpumap.c	Russ Weight
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+#ifndef __LINUX_CPUMAP_H
+#define __LINUX_CPUMAP_H
+
+#include <linux/config.h>
+#include <linux/threads.h>
+#include <asm/types.h>
+
+#define CPUMAP_SIZE       ((NR_CPUS + BITS_PER_LONG - 1) / BITS_PER_LONG)
+
+#ifndef __ASSEMBLY__
+#include <linux/bitops.h>
+typedef unsigned long cpumap_t[CPUMAP_SIZE];
+
+/*
+ * The following interfaces are the same regardless of CPUMAP_SIZE
+ */
+#define cpumap_clear_bit	clear_bit
+#define cpumap_set_bit		set_bit
+#define cpumap_test_and_set_bit	test_and_set_bit
+#define cpumap_test_bit		test_bit
+
+#if (NR_CPUS % BITS_PER_LONG)
+#define CPUMAP_FILLMASK	((1 << (NR_CPUS % BITS_PER_LONG)) -1)
+#else
+#define CPUMAP_FILLMASK	(~0UL)
+#endif
+
+/*
+ * The following macros and prototype are used to format
+ * a cpumap_t object for display. This function knows the 
+ * minimum size required, which is provided as CPUMAP_BUFSIZE.
+ *
+ * The CPUMAP_BUFSIZE is an exact calcuation of the byte count
+ * required to display a cpumap_t object.
+ */
+
+#define CPUMAP_BUFSIZE (((sizeof(long) * 2) + 1) * CPUMAP_SIZE + 2)
+
+#if BITS_PER_LONG > 32
+#define CPUMAP_FORMAT_STR	"%016lx"
+#else
+#define CPUMAP_FORMAT_STR	"%08lx"
+#endif
+extern char *cpumap_format(cpumap_t map, char *buf, int size);
+
+#if CPUMAP_SIZE == 1
+/*
+ * The following interfaces are optimized for the case where
+ * CPUMAP_SIZE==1 (i.e. a single unsigned long). The single
+ * CPU case falls into the CPUMAP_SIZE==1 case.
+ */
+#define cpumap_to_ulong(cpumap)			(cpumap[0])
+#define cpumap_ulong_to_cpumap(bitmap, cpumap)	(cpumap[0] = bitmap)
+#define cpumap_is_empty(cpumap) 		(cpumap[0] == 0)
+#define cpumap_cmp_mask(map1, map2)		(map1[0] ==  map2[0])
+#define cpumap_clear_mask(cpumap)		(cpumap[0] = 0)
+#define cpumap_fill(cpumap)			(cpumap[0] = CPUMAP_FILLMASK)
+#define cpumap_copy_mask(srcmap, destmap) 	(destmap[0] = srcmap[0])
+#define cpumap_and_mask(map1, map2, result)	(result[0] = map1[0] & map2[0])
+
+#else
+
+/*
+ * The cpumap_to_ulong() and cpumap_ulong_to_cpumap() functions
+ * are provided to facilitate migration to the cpumap_t datatype.
+ * As currently defined, they are only valid for CPUMAP_SIZE==1.
+ * If they are referenced when CPUMAP_SIZE > 1, then we call a
+ * bogus function name in order to trigger a link-time error.
+ */
+extern unsigned long __bad_cpumap_to_ulong(void);
+extern void __bad_cpumap_ulong_to_cpumap(void);
+#define cpumap_to_ulong(cpumap)			__bad_cpumap_to_ulong()
+#define cpumap_ulong_to_cpumap(bitmap, cpumap)	__bad_cpumap_ulong_to_cpumap()
+
+extern int cpumap_is_empty(cpumap_t map);
+extern int cpumap_cmp_mask(cpumap_t map1, cpumap_t map2);
+extern void cpumap_clear_mask(cpumap_t cpumap);
+extern void cpumap_fill(cpumap_t cpumap);
+extern void cpumap_copy_mask(cpumap_t srcmap, cpumap_t destmap);
+extern void cpumap_and_mask(cpumap_t map1, cpumap_t map2, cpumap_t result);
+
+#endif
+#endif
+#endif

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