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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/checksum.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/checksum.h')
-rw-r--r--linux/src/include/asm-i386/checksum.h121
1 files changed, 121 insertions, 0 deletions
diff --git a/linux/src/include/asm-i386/checksum.h b/linux/src/include/asm-i386/checksum.h
new file mode 100644
index 0000000..ac49b14
--- /dev/null
+++ b/linux/src/include/asm-i386/checksum.h
@@ -0,0 +1,121 @@
+#ifndef _I386_CHECKSUM_H
+#define _I386_CHECKSUM_H
+
+/*
+ * computes the checksum of a memory block at buff, length len,
+ * and adds in "sum" (32-bit)
+ *
+ * returns a 32-bit number suitable for feeding into itself
+ * or csum_tcpudp_magic
+ *
+ * this function must be called with even lengths, except
+ * for the last fragment, which may be odd
+ *
+ * it's best to have buff aligned on a 32-bit boundary
+ */
+unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
+
+/*
+ * the same as csum_partial, but copies from src while it
+ * checksums
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+
+unsigned int csum_partial_copy( const char *src, char *dst, int len, int sum);
+
+
+/*
+ * the same as csum_partial_copy, but copies from user space.
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+
+unsigned int csum_partial_copy_fromuser(const char *src, char *dst, int len, int sum);
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ *
+ * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
+ * Arnt Gulbrandsen.
+ */
+static inline unsigned short ip_fast_csum(unsigned char * iph,
+ unsigned int ihl) {
+ unsigned int sum;
+
+ __asm__ __volatile__("
+ movl (%1), %0
+ subl $4, %2
+ jbe 2f
+ addl 4(%1), %0
+ adcl 8(%1), %0
+ adcl 12(%1), %0
+1: adcl 16(%1), %0
+ lea 4(%1), %1
+ decl %2
+ jne 1b
+ adcl $0, %0
+ movl %0, %2
+ shrl $16, %0
+ addw %w2, %w0
+ adcl $0, %0
+ notl %0
+2:
+ "
+ /* Since the input registers which are loaded with iph and ipl
+ are modified, we must also specify them as outputs, or gcc
+ will assume they contain their original values. */
+ : "=r" (sum), "=r" (iph), "=r" (ihl)
+ : "1" (iph), "2" (ihl));
+ return(sum);
+}
+
+/*
+ * Fold a partial checksum
+ */
+
+static inline unsigned int csum_fold(unsigned int sum)
+{
+ __asm__("
+ addl %1, %0
+ adcl $0xffff, %0
+ "
+ : "=r" (sum)
+ : "r" (sum << 16), "0" (sum & 0xffff0000)
+ );
+ return (~sum) >> 16;
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+
+static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
+ unsigned long daddr,
+ unsigned short len,
+ unsigned short proto,
+ unsigned int sum) {
+ __asm__("
+ addl %1, %0
+ adcl %2, %0
+ adcl %3, %0
+ adcl $0, %0
+ "
+ : "=r" (sum)
+ : "g" (daddr), "g"(saddr), "g"((ntohs(len)<<16)+proto*256), "0"(sum));
+ return csum_fold(sum);
+}
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+
+static inline unsigned short ip_compute_csum(unsigned char * buff, int len) {
+ return csum_fold (csum_partial(buff, len, 0));
+}
+
+#endif