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/*
 * This module contains the PowerPC interrupt fielders
 * set of code at specific locations, based on function
 */

#include <linux/sys.h>
#include "../kernel/ppc_asm.tmpl"

_TEXT()

/*
 * Compute IP checksums
 *   _ip_fast_csum(buf, len) -- Optimized for IP header
 *   _ip_compute_csum(buf, len)
 */

_GLOBAL(_ip_fast_csum)
        li      r0,0
        addic   r0,r0,0         /* Clear initial carry */
        lwz     r4,0(r3)
        lwz     r5,4(r3)
        adde    r0,r0,r4
        lwz     r4,8(r3)
        adde    r0,r0,r5
        lwz     r5,12(r3)
        adde    r0,r0,r4
        lwz     r4,16(r3)
        adde    r0,r0,r5
        adde    r0,r0,r4
        mr      r3,r0
        andi.   r3,r3,0xFFFF
        srwi    r0,r0,16
        adde    r3,r3,r0
        andis.  r0,r3,1
        beq     10f
        addi    r3,r3,1
10:     not     r3,r3
        andi.   r3,r3,0xFFFF
        blr

_GLOBAL(_ip_compute_csum)
        li      r0,0
        addic   r0,r0,0
finish_ip_csum: 
        subi    r3,r3,4
        andi.   r5,r3,2         /* Align buffer to longword boundary */
        beq     10f
        lhz     r5,4(r3)
        adde    r0,r0,r5
        addi    r3,r3,2
        subi    r4,r4,2
10:     cmpi    0,r4,16         /* unrolled loop - 16 bytes at a time */
        blt     20f
        lwz     r5,4(r3)
        lwz     r6,8(r3)
        adde    r0,r0,r5
        lwz     r5,12(r3)
        adde    r0,r0,r6
        lwzu    r6,16(r3)
        adde    r0,r0,r5
        adde    r0,r0,r6
        subi    r4,r4,16
        b       10b
20:     cmpi    0,r4,4
        blt     30f
        lwzu    r5,4(r3)
        adde    r0,r0,r5
        subi    r4,r4,4
        b       20b
30:     cmpi    0,r4,2
        blt     40f
        lhz     r5,4(r3)
        addi    r3,r3,2
        adde    r0,r0,r5
        subi    r4,r4,2
40:     cmpi    0,r4,1
        bne     50f
        lbz     r5,4(r3)
        slwi    r5,r5,8         /* Upper byte of word */
        adde    r0,r0,r5
50:     mr      r3,r0
        andi.   r3,r3,0xFFFF
        srwi    r0,r0,16
        adde    r3,r3,r0
        andis.  r0,r3,1
        beq     60f
        addi    r3,r3,1
60:     not     r3,r3
        andi.   r3,r3,0xFFFF
        blr

_GLOBAL(_udp_check)
        addc    r0,r5,r6        /* Add in header fields */
        adde    r0,r0,r7
        b       finish_ip_csum  

_GLOBAL(_tcp_check)
        addc    r0,r5,r6        /* Add in header fields */
        adde    r0,r0,r7
        b       finish_ip_csum  

_GLOBAL(_csum_partial)
        li      r0,0
        addc    r0,r5,r0
        b       finish_ip_csum  

/*
 * Compute 16 bit sum:
 *   _csum_tcpudp_magic(int saddr, int daddr, int sum, int proto)
 */     
_GLOBAL(_csum_tcpudp_magic)
        addc    r0,r3,r4
        adde    r0,r0,r5
        adde    r0,r0,r6
        mr      r3,r0
        andi.   r3,r3,0xFFFF
        srwi    r0,r0,16
        adde    r3,r3,r0
        andis.  r0,r3,1                 /* Carry out of 16 bits? */
        beq     10f
        addi    r3,r3,1
10:     not     r3,r3
        andi.   r3,r3,0xFFFF
        blr