/*
 * Poly1305 authenticator algorithm, RFC7539, x64 SSE2 functions
 *
 * Copyright (C) 2015 Martin Willi
 *
 * 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.
 */

#include <linux/linkage.h>

.section        .rodata.cst16.ANMASK, "aM", @progbits, 16
.align 16
ANMASK: .octa 0x0000000003ffffff0000000003ffffff

.section        .rodata.cst16.ORMASK, "aM", @progbits, 16
.align 16
ORMASK: .octa 0x00000000010000000000000001000000

.text

#define h0 0x00(%rdi)
#define h1 0x04(%rdi)
#define h2 0x08(%rdi)
#define h3 0x0c(%rdi)
#define h4 0x10(%rdi)
#define r0 0x00(%rdx)
#define r1 0x04(%rdx)
#define r2 0x08(%rdx)
#define r3 0x0c(%rdx)
#define r4 0x10(%rdx)
#define s1 0x00(%rsp)
#define s2 0x04(%rsp)
#define s3 0x08(%rsp)
#define s4 0x0c(%rsp)
#define m %rsi
#define h01 %xmm0
#define h23 %xmm1
#define h44 %xmm2
#define t1 %xmm3
#define t2 %xmm4
#define t3 %xmm5
#define t4 %xmm6
#define mask %xmm7
#define d0 %r8
#define d1 %r9
#define d2 %r10
#define d3 %r11
#define d4 %r12

ENTRY(poly1305_block_sse2)
        # %rdi: Accumulator h[5]
        # %rsi: 16 byte input block m
        # %rdx: Poly1305 key r[5]
        # %rcx: Block count

        # This single block variant tries to improve performance by doing two
        # multiplications in parallel using SSE instructions. There is quite
        # some quardword packing involved, hence the speedup is marginal.

        push            %rbx
        push            %r12
        sub             $0x10,%rsp

        # s1..s4 = r1..r4 * 5
        mov             r1,%eax
        lea             (%eax,%eax,4),%eax
        mov             %eax,s1
        mov             r2,%eax
        lea             (%eax,%eax,4),%eax
        mov             %eax,s2
        mov             r3,%eax
        lea             (%eax,%eax,4),%eax
        mov             %eax,s3
        mov             r4,%eax
        lea             (%eax,%eax,4),%eax
        mov             %eax,s4

        movdqa          ANMASK(%rip),mask

.Ldoblock:
        # h01 = [0, h1, 0, h0]
        # h23 = [0, h3, 0, h2]
        # h44 = [0, h4, 0, h4]
        movd            h0,h01
        movd            h1,t1
        movd            h2,h23
        movd            h3,t2
        movd            h4,h44
        punpcklqdq      t1,h01
        punpcklqdq      t2,h23
        punpcklqdq      h44,h44

        # h01 += [ (m[3-6] >> 2) & 0x3ffffff, m[0-3] & 0x3ffffff ]
        movd            0x00(m),t1
        movd            0x03(m),t2
        psrld           $2,t2
        punpcklqdq      t2,t1
        pand            mask,t1
        paddd           t1,h01
        # h23 += [ (m[9-12] >> 6) & 0x3ffffff, (m[6-9] >> 4) & 0x3ffffff ]
        movd            0x06(m),t1
        movd            0x09(m),t2
        psrld           $4,t1
        psrld           $6,t2
        punpcklqdq      t2,t1
        pand            mask,t1
        paddd           t1,h23
        # h44 += [ (m[12-15] >> 8) | (1 << 24), (m[12-15] >> 8) | (1 << 24) ]
        mov             0x0c(m),%eax
        shr             $8,%eax
        or              $0x01000000,%eax
        movd            %eax,t1
        pshufd          $0xc4,t1,t1
        paddd           t1,h44

        # t1[0] = h0 * r0 + h2 * s3
        # t1[1] = h1 * s4 + h3 * s2
        movd            r0,t1
        movd            s4,t2
        punpcklqdq      t2,t1
        pmuludq         h01,t1
        movd            s3,t2
        movd            s2,t3
        punpcklqdq      t3,t2
        pmuludq         h23,t2
        paddq           t2,t1
        # t2[0] = h0 * r1 + h2 * s4
        # t2[1] = h1 * r0 + h3 * s3
        movd            r1,t2
        movd            r0,t3
        punpcklqdq      t3,t2
        pmuludq         h01,t2
        movd            s4,t3
        movd            s3,t4
        punpcklqdq      t4,t3
        pmuludq         h23,t3
        paddq           t3,t2
        # t3[0] = h4 * s1
        # t3[1] = h4 * s2
        movd            s1,t3
        movd            s2,t4
        punpcklqdq      t4,t3
        pmuludq         h44,t3
        # d0 = t1[0] + t1[1] + t3[0]
        # d1 = t2[0] + t2[1] + t3[1]
        movdqa          t1,t4
        punpcklqdq      t2,t4
        punpckhqdq      t2,t1
        paddq           t4,t1
        paddq           t3,t1
        movq            t1,d0
        psrldq          $8,t1
        movq            t1,d1

        # t1[0] = h0 * r2 + h2 * r0
        # t1[1] = h1 * r1 + h3 * s4
        movd            r2,t1
        movd            r1,t2
        punpcklqdq      t2,t1
        pmuludq         h01,t1
        movd            r0,t2
        movd            s4,t3
        punpcklqdq      t3,t2
        pmuludq         h23,t2
        paddq           t2,t1
        # t2[0] = h0 * r3 + h2 * r1
        # t2[1] = h1 * r2 + h3 * r0
        movd            r3,t2
        movd            r2,t3
        punpcklqdq      t3,t2
        pmuludq         h01,t2
        movd            r1,t3
        movd            r0,t4
        punpcklqdq      t4,t3
        pmuludq         h23,t3
        paddq           t3,t2
        # t3[0] = h4 * s3
        # t3[1] = h4 * s4
        movd            s3,t3
        movd            s4,t4
        punpcklqdq      t4,t3
        pmuludq         h44,t3
        # d2 = t1[0] + t1[1] + t3[0]
        # d3 = t2[0] + t2[1] + t3[1]
        movdqa          t1,t4
        punpcklqdq      t2,t4
        punpckhqdq      t2,t1
        paddq           t4,t1
        paddq           t3,t1
        movq            t1,d2
        psrldq          $8,t1
        movq            t1,d3

        # t1[0] = h0 * r4 + h2 * r2
        # t1[1] = h1 * r3 + h3 * r1
        movd            r4,t1
        movd            r3,t2
        punpcklqdq      t2,t1
        pmuludq         h01,t1
        movd            r2,t2
        movd            r1,t3
        punpcklqdq      t3,t2
        pmuludq         h23,t2
        paddq           t2,t1
        # t3[0] = h4 * r0
        movd            r0,t3
        pmuludq         h44,t3
        # d4 = t1[0] + t1[1] + t3[0]
        movdqa          t1,t4
        psrldq          $8,t4
        paddq           t4,t1
        paddq           t3,t1
        movq            t1,d4

        # d1 += d0 >> 26
        mov             d0,%rax
        shr             $26,%rax
        add             %rax,d1
        # h0 = d0 & 0x3ffffff
        mov             d0,%rbx
        and             $0x3ffffff,%ebx

        # d2 += d1 >> 26
        mov             d1,%rax
        shr             $26,%rax
        add             %rax,d2
        # h1 = d1 & 0x3ffffff
        mov             d1,%rax
        and             $0x3ffffff,%eax
        mov             %eax,h1

        # d3 += d2 >> 26
        mov             d2,%rax
        shr             $26,%rax
        add             %rax,d3
        # h2 = d2 & 0x3ffffff
        mov             d2,%rax
        and             $0x3ffffff,%eax
        mov             %eax,h2

        # d4 += d3 >> 26
        mov             d3,%rax
        shr             $26,%rax
        add             %rax,d4
        # h3 = d3 & 0x3ffffff
        mov             d3,%rax
        and             $0x3ffffff,%eax
        mov             %eax,h3

        # h0 += (d4 >> 26) * 5
        mov             d4,%rax
        shr             $26,%rax
        lea             (%eax,%eax,4),%eax
        add             %eax,%ebx
        # h4 = d4 & 0x3ffffff
        mov             d4,%rax
        and             $0x3ffffff,%eax
        mov             %eax,h4

        # h1 += h0 >> 26
        mov             %ebx,%eax
        shr             $26,%eax
        add             %eax,h1
        # h0 = h0 & 0x3ffffff
        andl            $0x3ffffff,%ebx
        mov             %ebx,h0

        add             $0x10,m
        dec             %rcx
        jnz             .Ldoblock

        add             $0x10,%rsp
        pop             %r12
        pop             %rbx
        ret
ENDPROC(poly1305_block_sse2)


#define u0 0x00(%r8)
#define u1 0x04(%r8)
#define u2 0x08(%r8)
#define u3 0x0c(%r8)
#define u4 0x10(%r8)
#define hc0 %xmm0
#define hc1 %xmm1
#define hc2 %xmm2
#define hc3 %xmm5
#define hc4 %xmm6
#define ru0 %xmm7
#define ru1 %xmm8
#define ru2 %xmm9
#define ru3 %xmm10
#define ru4 %xmm11
#define sv1 %xmm12
#define sv2 %xmm13
#define sv3 %xmm14
#define sv4 %xmm15
#undef d0
#define d0 %r13

ENTRY(poly1305_2block_sse2)
        # %rdi: Accumulator h[5]
        # %rsi: 16 byte input block m
        # %rdx: Poly1305 key r[5]
        # %rcx: Doubleblock count
        # %r8:  Poly1305 derived key r^2 u[5]

        # This two-block variant further improves performance by using loop
        # unrolled block processing. This is more straight forward and does
        # less byte shuffling, but requires a second Poly1305 key r^2:
        # h = (h + m) * r    =>    h = (h + m1) * r^2 + m2 * r

        push            %rbx
        push            %r12
        push            %r13

        # combine r0,u0
        movd            u0,ru0
        movd            r0,t1
        punpcklqdq      t1,ru0

        # combine r1,u1 and s1=r1*5,v1=u1*5
        movd            u1,ru1
        movd            r1,t1
        punpcklqdq      t1,ru1
        movdqa          ru1,sv1
        pslld           $2,sv1
        paddd           ru1,sv1

        # combine r2,u2 and s2=r2*5,v2=u2*5
        movd            u2,ru2
        movd            r2,t1
        punpcklqdq      t1,ru2
        movdqa          ru2,sv2
        pslld           $2,sv2
        paddd           ru2,sv2

        # combine r3,u3 and s3=r3*5,v3=u3*5
        movd            u3,ru3
        movd            r3,t1
        punpcklqdq      t1,ru3
        movdqa          ru3,sv3
        pslld           $2,sv3
        paddd           ru3,sv3

        # combine r4,u4 and s4=r4*5,v4=u4*5
        movd            u4,ru4
        movd            r4,t1
        punpcklqdq      t1,ru4
        movdqa          ru4,sv4
        pslld           $2,sv4
        paddd           ru4,sv4

.Ldoblock2:
        # hc0 = [ m[16-19] & 0x3ffffff, h0 + m[0-3] & 0x3ffffff ]
        movd            0x00(m),hc0
        movd            0x10(m),t1
        punpcklqdq      t1,hc0
        pand            ANMASK(%rip),hc0
        movd            h0,t1
        paddd           t1,hc0
        # hc1 = [ (m[19-22] >> 2) & 0x3ffffff, h1 + (m[3-6] >> 2) & 0x3ffffff ]
        movd            0x03(m),hc1
        movd            0x13(m),t1
        punpcklqdq      t1,hc1
        psrld           $2,hc1
        pand            ANMASK(%rip),hc1
        movd            h1,t1
        paddd           t1,hc1
        # hc2 = [ (m[22-25] >> 4) & 0x3ffffff, h2 + (m[6-9] >> 4) & 0x3ffffff ]
        movd            0x06(m),hc2
        movd            0x16(m),t1
        punpcklqdq      t1,hc2
        psrld           $4,hc2
        pand            ANMASK(%rip),hc2
        movd            h2,t1
        paddd           t1,hc2
        # hc3 = [ (m[25-28] >> 6) & 0x3ffffff, h3 + (m[9-12] >> 6) & 0x3ffffff ]
        movd            0x09(m),hc3
        movd            0x19(m),t1
        punpcklqdq      t1,hc3
        psrld           $6,hc3
        pand            ANMASK(%rip),hc3
        movd            h3,t1
        paddd           t1,hc3
        # hc4 = [ (m[28-31] >> 8) | (1<<24), h4 + (m[12-15] >> 8) | (1<<24) ]
        movd            0x0c(m),hc4
        movd            0x1c(m),t1
        punpcklqdq      t1,hc4
        psrld           $8,hc4
        por             ORMASK(%rip),hc4
        movd            h4,t1
        paddd           t1,hc4

        # t1 = [ hc0[1] * r0, hc0[0] * u0 ]
        movdqa          ru0,t1
        pmuludq         hc0,t1
        # t1 += [ hc1[1] * s4, hc1[0] * v4 ]
        movdqa          sv4,t2
        pmuludq         hc1,t2
        paddq           t2,t1
        # t1 += [ hc2[1] * s3, hc2[0] * v3 ]
        movdqa          sv3,t2
        pmuludq         hc2,t2
        paddq           t2,t1
        # t1 += [ hc3[1] * s2, hc3[0] * v2 ]
        movdqa          sv2,t2
        pmuludq         hc3,t2
        paddq           t2,t1
        # t1 += [ hc4[1] * s1, hc4[0] * v1 ]
        movdqa          sv1,t2
        pmuludq         hc4,t2
        paddq           t2,t1
        # d0 = t1[0] + t1[1]
        movdqa          t1,t2
        psrldq          $8,t2
        paddq           t2,t1
        movq            t1,d0

        # t1 = [ hc0[1] * r1, hc0[0] * u1 ]
        movdqa          ru1,t1
        pmuludq         hc0,t1
        # t1 += [ hc1[1] * r0, hc1[0] * u0 ]
        movdqa          ru0,t2
        pmuludq         hc1,t2
        paddq           t2,t1
        # t1 += [ hc2[1] * s4, hc2[0] * v4 ]
        movdqa          sv4,t2
        pmuludq         hc2,t2
        paddq           t2,t1
        # t1 += [ hc3[1] * s3, hc3[0] * v3 ]
        movdqa          sv3,t2
        pmuludq         hc3,t2
        paddq           t2,t1
        # t1 += [ hc4[1] * s2, hc4[0] * v2 ]
        movdqa          sv2,t2
        pmuludq         hc4,t2
        paddq           t2,t1
        # d1 = t1[0] + t1[1]
        movdqa          t1,t2
        psrldq          $8,t2
        paddq           t2,t1
        movq            t1,d1

        # t1 = [ hc0[1] * r2, hc0[0] * u2 ]
        movdqa          ru2,t1
        pmuludq         hc0,t1
        # t1 += [ hc1[1] * r1, hc1[0] * u1 ]
        movdqa          ru1,t2
        pmuludq         hc1,t2
        paddq           t2,t1
        # t1 += [ hc2[1] * r0, hc2[0] * u0 ]
        movdqa          ru0,t2
        pmuludq         hc2,t2
        paddq           t2,t1
        # t1 += [ hc3[1] * s4, hc3[0] * v4 ]
        movdqa          sv4,t2
        pmuludq         hc3,t2
        paddq           t2,t1
        # t1 += [ hc4[1] * s3, hc4[0] * v3 ]
        movdqa          sv3,t2
        pmuludq         hc4,t2
        paddq           t2,t1
        # d2 = t1[0] + t1[1]
        movdqa          t1,t2
        psrldq          $8,t2
        paddq           t2,t1
        movq            t1,d2

        # t1 = [ hc0[1] * r3, hc0[0] * u3 ]
        movdqa          ru3,t1
        pmuludq         hc0,t1
        # t1 += [ hc1[1] * r2, hc1[0] * u2 ]
        movdqa          ru2,t2
        pmuludq         hc1,t2
        paddq           t2,t1
        # t1 += [ hc2[1] * r1, hc2[0] * u1 ]
        movdqa          ru1,t2
        pmuludq         hc2,t2
        paddq           t2,t1
        # t1 += [ hc3[1] * r0, hc3[0] * u0 ]
        movdqa          ru0,t2
        pmuludq         hc3,t2
        paddq           t2,t1
        # t1 += [ hc4[1] * s4, hc4[0] * v4 ]
        movdqa          sv4,t2
        pmuludq         hc4,t2
        paddq           t2,t1
        # d3 = t1[0] + t1[1]
        movdqa          t1,t2
        psrldq          $8,t2
        paddq           t2,t1
        movq            t1,d3

        # t1 = [ hc0[1] * r4, hc0[0] * u4 ]
        movdqa          ru4,t1
        pmuludq         hc0,t1
        # t1 += [ hc1[1] * r3, hc1[0] * u3 ]
        movdqa          ru3,t2
        pmuludq         hc1,t2
        paddq           t2,t1
        # t1 += [ hc2[1] * r2, hc2[0] * u2 ]
        movdqa          ru2,t2
        pmuludq         hc2,t2
        paddq           t2,t1
        # t1 += [ hc3[1] * r1, hc3[0] * u1 ]
        movdqa          ru1,t2
        pmuludq         hc3,t2
        paddq           t2,t1
        # t1 += [ hc4[1] * r0, hc4[0] * u0 ]
        movdqa          ru0,t2
        pmuludq         hc4,t2
        paddq           t2,t1
        # d4 = t1[0] + t1[1]
        movdqa          t1,t2
        psrldq          $8,t2
        paddq           t2,t1
        movq            t1,d4

        # d1 += d0 >> 26
        mov             d0,%rax
        shr             $26,%rax
        add             %rax,d1
        # h0 = d0 & 0x3ffffff
        mov             d0,%rbx
        and             $0x3ffffff,%ebx

        # d2 += d1 >> 26
        mov             d1,%rax
        shr             $26,%rax
        add             %rax,d2
        # h1 = d1 & 0x3ffffff
        mov             d1,%rax
        and             $0x3ffffff,%eax
        mov             %eax,h1

        # d3 += d2 >> 26
        mov             d2,%rax
        shr             $26,%rax
        add             %rax,d3
        # h2 = d2 & 0x3ffffff
        mov             d2,%rax
        and             $0x3ffffff,%eax
        mov             %eax,h2

        # d4 += d3 >> 26
        mov             d3,%rax
        shr             $26,%rax
        add             %rax,d4
        # h3 = d3 & 0x3ffffff
        mov             d3,%rax
        and             $0x3ffffff,%eax
        mov             %eax,h3

        # h0 += (d4 >> 26) * 5
        mov             d4,%rax
        shr             $26,%rax
        lea             (%eax,%eax,4),%eax
        add             %eax,%ebx
        # h4 = d4 & 0x3ffffff
        mov             d4,%rax
        and             $0x3ffffff,%eax
        mov             %eax,h4

        # h1 += h0 >> 26
        mov             %ebx,%eax
        shr             $26,%eax
        add             %eax,h1
        # h0 = h0 & 0x3ffffff
        andl            $0x3ffffff,%ebx
        mov             %ebx,h0

        add             $0x20,m
        dec             %rcx
        jnz             .Ldoblock2

        pop             %r13
        pop             %r12
        pop             %rbx
        ret
ENDPROC(poly1305_2block_sse2)