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authorThomas Bushnell <thomas@gnu.org>1999-04-26 05:58:44 +0000
committerThomas Bushnell <thomas@gnu.org>1999-04-26 05:58:44 +0000
commit86297c41a26f18d924e64fc93321c59cbc4c48dd (patch)
tree376954c6b95b735d361875319a1a2a9db6a27527 /linux/src/include/asm-i386/bitops.h
parent851137902d3e7ad87af177487df3eea53e940a1c (diff)
1998-11-30 OKUJI Yoshinori <okuji@kuicr.kyoto-u.ac.jp>
Clean up linux emulation code to make it architecture-independent as much as possible. * linux: Renamed from linuxdev. * Makefile.in (objfiles): Add linux.o instead of linuxdev.o. (MAKE): New variable. Used for the linux.o target. * configure.in: Add AC_CHECK_TOOL(MAKE, make). * i386/i386/spl.h: Include <i386/ipl.h>, for compatibility with OSF Mach 3.0. Suggested by Elgin Lee <ehl@funghi.com>. * linux/src: Renamed from linux/linux. * linux/dev: Renamed from linux/mach. * linux/Drivers.in (AC_INIT): Use dev/include/linux/autoconf.h, instead of mach/include/linux/autoconf.h. * Makefile.in (all): Target ../linux.o instead of ../linuxdev.o. * linux/dev/drivers/block/genhd.c: Include <machine/spl.h> instead of <i386/ipl.h>. * linux/dev/drivers/net/auto_irq.c: Remove unneeded header files, <i386/ipl.h> and <i386/pic.h>. * linux/dev/init/main.c: Many i386-dependent codes moved to ... * linux/dev/arch/i386/irq.c: ... here. * linux/dev/arch/i386/setup.c: New file. * linux/dev/arch/i386/linux_emul.h: Likewise. * linux/dev/arch/i386/glue/timer.c: Merged into sched.c. * linux/dev/arch/i386/glue/sched.c: Include <machine/spl.h> instead of <i386/ipl.h>, and moved to ... * linux/dev/kernel/sched.c: ... here. * linux/dev/arch/i386/glue/block.c: Include <machine/spl.h> and <linux_emul.h>, instead of i386-dependent header files, and moved to ... * linux/dev/glue/blocl.c: ... here. * linux/dev/arch/i386/glue/net.c: Include <machine/spl.h> and <linux_emul.h>, instead of i386-dependent header files, and moved to ... * linux/dev/glue/net.c: ... here. * linux/dev/arch/i386/glue/misc.c: Remove `x86' and moved to ... * linux/dev/glue/misc.c: ... here. * linux/dev/arch/i386/glue/kmem.c: Moved to ... * linux/dev/glue/kmem.c: ... here.
Diffstat (limited to 'linux/src/include/asm-i386/bitops.h')
-rw-r--r--linux/src/include/asm-i386/bitops.h137
1 files changed, 137 insertions, 0 deletions
diff --git a/linux/src/include/asm-i386/bitops.h b/linux/src/include/asm-i386/bitops.h
new file mode 100644
index 0000000..e3ea8f5
--- /dev/null
+++ b/linux/src/include/asm-i386/bitops.h
@@ -0,0 +1,137 @@
+#ifndef _I386_BITOPS_H
+#define _I386_BITOPS_H
+
+/*
+ * Copyright 1992, Linus Torvalds.
+ */
+
+/*
+ * These have to be done with inline assembly: that way the bit-setting
+ * is guaranteed to be atomic. All bit operations return 0 if the bit
+ * was cleared before the operation and != 0 if it was not.
+ *
+ * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
+ */
+
+#ifdef __SMP__
+#define LOCK_PREFIX "lock ; "
+#define SMPVOL volatile
+#else
+#define LOCK_PREFIX ""
+#define SMPVOL
+#endif
+
+/*
+ * Some hacks to defeat gcc over-optimizations..
+ */
+struct __dummy { unsigned long a[100]; };
+#define ADDR (*(struct __dummy *) addr)
+#define CONST_ADDR (*(const struct __dummy *) addr)
+
+extern __inline__ int set_bit(int nr, SMPVOL void * addr)
+{
+ int oldbit;
+
+ __asm__ __volatile__(LOCK_PREFIX
+ "btsl %2,%1\n\tsbbl %0,%0"
+ :"=r" (oldbit),"=m" (ADDR)
+ :"ir" (nr));
+ return oldbit;
+}
+
+extern __inline__ int clear_bit(int nr, SMPVOL void * addr)
+{
+ int oldbit;
+
+ __asm__ __volatile__(LOCK_PREFIX
+ "btrl %2,%1\n\tsbbl %0,%0"
+ :"=r" (oldbit),"=m" (ADDR)
+ :"ir" (nr));
+ return oldbit;
+}
+
+extern __inline__ int change_bit(int nr, SMPVOL void * addr)
+{
+ int oldbit;
+
+ __asm__ __volatile__(LOCK_PREFIX
+ "btcl %2,%1\n\tsbbl %0,%0"
+ :"=r" (oldbit),"=m" (ADDR)
+ :"ir" (nr));
+ return oldbit;
+}
+
+/*
+ * This routine doesn't need to be atomic.
+ */
+extern __inline__ int test_bit(int nr, const SMPVOL void * addr)
+{
+ return ((1UL << (nr & 31)) & (((const unsigned int *) addr)[nr >> 5])) != 0;
+}
+
+/*
+ * Find-bit routines..
+ */
+extern __inline__ int find_first_zero_bit(void * addr, unsigned size)
+{
+ int res;
+
+ if (!size)
+ return 0;
+ __asm__("cld\n\t"
+ "movl $-1,%%eax\n\t"
+ "xorl %%edx,%%edx\n\t"
+ "repe; scasl\n\t"
+ "je 1f\n\t"
+ "xorl -4(%%edi),%%eax\n\t"
+ "subl $4,%%edi\n\t"
+ "bsfl %%eax,%%edx\n"
+ "1:\tsubl %%ebx,%%edi\n\t"
+ "shll $3,%%edi\n\t"
+ "addl %%edi,%%edx"
+ :"=d" (res)
+ :"c" ((size + 31) >> 5), "D" (addr), "b" (addr)
+ :"ax", "cx", "di");
+ return res;
+}
+
+extern __inline__ int find_next_zero_bit (void * addr, int size, int offset)
+{
+ unsigned long * p = ((unsigned long *) addr) + (offset >> 5);
+ int set = 0, bit = offset & 31, res;
+
+ if (bit) {
+ /*
+ * Look for zero in first byte
+ */
+ __asm__("bsfl %1,%0\n\t"
+ "jne 1f\n\t"
+ "movl $32, %0\n"
+ "1:"
+ : "=r" (set)
+ : "r" (~(*p >> bit)));
+ if (set < (32 - bit))
+ return set + offset;
+ set = 32 - bit;
+ p++;
+ }
+ /*
+ * No zero yet, search remaining full bytes for a zero
+ */
+ res = find_first_zero_bit (p, size - 32 * (p - (unsigned long *) addr));
+ return (offset + set + res);
+}
+
+/*
+ * ffz = Find First Zero in word. Undefined if no zero exists,
+ * so code should check against ~0UL first..
+ */
+extern __inline__ unsigned long ffz(unsigned long word)
+{
+ __asm__("bsfl %1,%0"
+ :"=r" (word)
+ :"r" (~word));
+ return word;
+}
+
+#endif /* _I386_BITOPS_H */