sys/mips/rmi/xlr_csum_nocopy.S

   1 #include <machine/asm.h>
   2
   3
   4 /*
   5  * a0: source address
   6  * a1: length of the area to checksum
   7  * a2: partial checksum
   8  * a3: dst
   9  */
  10
  11 #define src a0
  12 #define dst a3
  13 #define sum v0
  14
  15         .text
  16         .set    noreorder
  17
  18         .macro CSUM_BIGCHUNK_AND_COPY offset
  19         pref                    0,  (\offset+0x0)(a0)
  20         ld                      t0, (\offset+0x00)(a0)
  21         ld                      t1, (\offset+0x08)(a0)
  22         .word                   0x70481038  /*daddwc v0, v0, t0 */
  23         .word                   0x70491038 /*daddwc v0, v0, t1 */
  24         ld                      t0, (\offset + 0x10)(a0)
  25         ld                      t1, (\offset + 0x18)(a0)
  26         .word                   0x70481038 /* daddwc v0, v0, t0 */
  27         .word                   0x70491038 /*daddwc v0, v0, t1 */
  28         .endm
  29
  30 small_csumcpy:                                          /* unknown src alignment and < 8 bytes to go  */
  31         move            a1, t2
  32
  33         andi            t0, a1, 4
  34         beqz            t0, 1f
  35         andi            t0, a1, 2
  36
  37         ulw                     t1, (src)                       /* Still a full word to go  */
  38         daddiu          src, 4
  39         .word                   0x70491038 /*daddwc v0, v0, t1 */
  40
  41 1:      move            t1, zero
  42         beqz            t0, 1f
  43         andi            t0, a1, 1
  44
  45         ulhu            t1, (src)                       /* Still a halfword to go  */
  46         daddiu          src, 2
  47
  48 1:      beqz            t0, 1f
  49         sll                     t1, t1, 16
  50
  51         lbu                     t2, (src)
  52         nop
  53
  54 #ifdef __MIPSEB__
  55         sll             t2, t2, 8
  56 #endif
  57         or              t1, t2
  58
  59 1:      .word                   0x70491038 /*daddwc v0, v0, t1 */
  60
  61         .word                   0x70461038 /*daddwc v0, v0, a2 */
  62         .word                   0x70401038 /*daddwc v0, v0, $0 */
  63
  64         /* Ideally at this point of time the status flag must be cleared */
  65
  66         dsll32      v1, sum, 0
  67         .word                   0x70431038 /*daddwc v0, v0, v1 */
  68         dsrl32          sum, sum, 0
  69         .word                   0x70401038 /*daddwc v0, v0, zero */
  70
  71         /* fold the checksum */
  72         sll             v1, sum, 16
  73         addu            sum, v1
  74         sltu            v1, sum, v1
  75         srl             sum, sum, 16
  76         addu            sum, v1
  77 1:
  78         .set            reorder
  79         jr                      ra
  80         .set            noreorder
  81
  82 /* ------------------------------------------------------------------ */
  83
  84         .align  5
  85 LEAF(xlr_csum_partial_nocopy)
  86         move            sum, zero
  87         move            t7, zero
  88
  89         sltiu           t8, a1, 0x8
  90         bnez            t8, small_csumcpy               /* < 8 bytes to copy */
  91         move            t2, a1
  92
  93         beqz            a1, out
  94         andi            t7, src, 0x1                    /* odd buffer? */
  95
  96 hword_align:
  97         beqz            t7, word_align
  98         andi            t8, src, 0x2
  99
 100         lbu                     t0, (src)
 101         dsubu           a1, a1, 0x1
 102         .word                   0x70481038 /*daddwc v0, v0, t0 */
 103         daddu           src, src, 0x1
 104         andi            t8, src, 0x2
 105
 106 word_align:
 107         beqz            t8, dword_align
 108         sltiu           t8, a1, 56
 109
 110         lhu                     t0, (src)
 111         dsubu           a1, a1, 0x2
 112         .word                   0x70481038 /*daddwc v0, v0, t0 */
 113         sltiu           t8, a1, 56
 114         daddu           src, src, 0x2
 115
 116 dword_align:
 117         bnez            t8, do_end_words
 118         move            t8, a1
 119
 120         andi            t8, src, 0x4
 121         beqz            t8, qword_align
 122         andi            t8, src, 0x8
 123
 124         lw                      t0, 0x00(src)
 125         dsubu           a1, a1, 0x4
 126         .word                   0x70481038 /*daddwc v0, v0, t0 */
 127         daddu           src, src, 0x4
 128         andi            t8, src, 0x8
 129
 130 qword_align:
 131         beqz            t8, oword_align
 132         andi            t8, src, 0x10
 133
 134         ld                      t0, 0x00(src)
 135         dsubu           a1, a1, 0x8
 136         .word                   0x70481038 /*daddwc v0, v0, t0 */
 137         daddu           src, src, 0x8
 138         andi            t8, src, 0x10
 139
 140 oword_align:
 141         beqz            t8, begin_movement
 142         dsrl            t8, a1, 0x7
 143
 144         ld                      t3, 0x08(src)
 145         ld                      t0, 0x00(src)
 146         .word                   0x704b1038 /*daddwc v0, v0, t3 */
 147         .word                   0x70481038 /*daddwc v0, v0, t0 */
 148         dsubu           a1, a1, 0x10
 149         daddu           src, src, 0x10
 150         dsrl            t8, a1, 0x7
 151
 152 begin_movement:
 153         beqz            t8, 1f
 154         andi            t2, a1, 0x40
 155
 156 move_128bytes:
 157         pref            0, 0x20(a0)
 158         pref            0, 0x40(a0)
 159         pref            0, 0x60(a0)
 160         CSUM_BIGCHUNK_AND_COPY(0x00)
 161         CSUM_BIGCHUNK_AND_COPY(0x20)
 162         CSUM_BIGCHUNK_AND_COPY(0x40)
 163         CSUM_BIGCHUNK_AND_COPY(0x60)
 164         dsubu           t8, t8, 0x01
 165         bnez            t8, move_128bytes       /* flag */
 166         daddu           src, src, 0x80
 167
 168 1:
 169         beqz            t2, 1f
 170         andi            t2, a1, 0x20
 171
 172 move_64bytes:
 173         pref            0, 0x20(a0)
 174         pref            0, 0x40(a0)
 175         CSUM_BIGCHUNK_AND_COPY(0x00)
 176         CSUM_BIGCHUNK_AND_COPY(0x20)
 177         daddu   src, src, 0x40
 178
 179 1:
 180         beqz            t2, do_end_words
 181         andi            t8, a1, 0x1c
 182
 183 move_32bytes:
 184         pref            0, 0x20(a0)
 185         CSUM_BIGCHUNK_AND_COPY(0x00)
 186         andi            t8, a1, 0x1c
 187         daddu           src, src, 0x20
 188
 189 do_end_words:
 190         beqz            t8, maybe_end_cruft
 191         dsrl            t8, t8, 0x2
 192
 193 end_words:
 194         lw                      t0, (src)
 195         dsubu           t8, t8, 0x1
 196         .word                   0x70481038 /*daddwc v0, v0, t0 */
 197         bnez            t8, end_words
 198         daddu           src, src, 0x4
 199
 200 maybe_end_cruft:
 201         andi            t2, a1, 0x3
 202
 203 small_memcpy:
 204  j small_csumcpy; move a1, t2
 205         beqz            t2, out
 206         move            a1, t2
 207
 208 end_bytes:
 209         lb                      t0, (src)
 210         dsubu           a1, a1, 0x1
 211         bnez            a2, end_bytes
 212         daddu           src, src, 0x1
 213
 214 out:
 215         jr                      ra
 216         move            v0, sum
 217         END(xlr_csum_partial_nocopy)