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-rw-r--r--arch/powerpc/lib/checksum_64.S482
1 files changed, 355 insertions, 127 deletions
diff --git a/arch/powerpc/lib/checksum_64.S b/arch/powerpc/lib/checksum_64.S
index ef96c6c58efc..18245af38aea 100644
--- a/arch/powerpc/lib/checksum_64.S
+++ b/arch/powerpc/lib/checksum_64.S
@@ -65,165 +65,393 @@ _GLOBAL(csum_tcpudp_magic)
srwi r3,r3,16
blr
+#define STACKFRAMESIZE 256
+#define STK_REG(i) (112 + ((i)-14)*8)
+
/*
* Computes the checksum of a memory block at buff, length len,
* and adds in "sum" (32-bit).
*
- * This code assumes at least halfword alignment, though the length
- * can be any number of bytes. The sum is accumulated in r5.
- *
* csum_partial(r3=buff, r4=len, r5=sum)
*/
_GLOBAL(csum_partial)
- subi r3,r3,8 /* we'll offset by 8 for the loads */
- srdi. r6,r4,3 /* divide by 8 for doubleword count */
- addic r5,r5,0 /* clear carry */
- beq 3f /* if we're doing < 8 bytes */
- andi. r0,r3,2 /* aligned on a word boundary already? */
- beq+ 1f
- lhz r6,8(r3) /* do 2 bytes to get aligned */
- addi r3,r3,2
- subi r4,r4,2
- addc r5,r5,r6
- srdi. r6,r4,3 /* recompute number of doublewords */
- beq 3f /* any left? */
-1: mtctr r6
-2: ldu r6,8(r3) /* main sum loop */
- adde r5,r5,r6
- bdnz 2b
- andi. r4,r4,7 /* compute bytes left to sum after doublewords */
-3: cmpwi 0,r4,4 /* is at least a full word left? */
- blt 4f
- lwz r6,8(r3) /* sum this word */
+ addic r0,r5,0 /* clear carry */
+
+ srdi. r6,r4,3 /* less than 8 bytes? */
+ beq .Lcsum_tail_word
+
+ /*
+ * If only halfword aligned, align to a double word. Since odd
+ * aligned addresses should be rare and they would require more
+ * work to calculate the correct checksum, we ignore that case
+ * and take the potential slowdown of unaligned loads.
+ */
+ rldicl. r6,r3,64-1,64-2 /* r6 = (r3 & 0x3) >> 1 */
+ beq .Lcsum_aligned
+
+ li r7,4
+ sub r6,r7,r6
+ mtctr r6
+
+1:
+ lhz r6,0(r3) /* align to doubleword */
+ subi r4,r4,2
+ addi r3,r3,2
+ adde r0,r0,r6
+ bdnz 1b
+
+.Lcsum_aligned:
+ /*
+ * We unroll the loop such that each iteration is 64 bytes with an
+ * entry and exit limb of 64 bytes, meaning a minimum size of
+ * 128 bytes.
+ */
+ srdi. r6,r4,7
+ beq .Lcsum_tail_doublewords /* len < 128 */
+
+ srdi r6,r4,6
+ subi r6,r6,1
+ mtctr r6
+
+ stdu r1,-STACKFRAMESIZE(r1)
+ std r14,STK_REG(r14)(r1)
+ std r15,STK_REG(r15)(r1)
+ std r16,STK_REG(r16)(r1)
+
+ ld r6,0(r3)
+ ld r9,8(r3)
+
+ ld r10,16(r3)
+ ld r11,24(r3)
+
+ /*
+ * On POWER6 and POWER7 back to back addes take 2 cycles because of
+ * the XER dependency. This means the fastest this loop can go is
+ * 16 cycles per iteration. The scheduling of the loop below has
+ * been shown to hit this on both POWER6 and POWER7.
+ */
+ .align 5
+2:
+ adde r0,r0,r6
+ ld r12,32(r3)
+ ld r14,40(r3)
+
+ adde r0,r0,r9
+ ld r15,48(r3)
+ ld r16,56(r3)
+ addi r3,r3,64
+
+ adde r0,r0,r10
+
+ adde r0,r0,r11
+
+ adde r0,r0,r12
+
+ adde r0,r0,r14
+
+ adde r0,r0,r15
+ ld r6,0(r3)
+ ld r9,8(r3)
+
+ adde r0,r0,r16
+ ld r10,16(r3)
+ ld r11,24(r3)
+ bdnz 2b
+
+
+ adde r0,r0,r6
+ ld r12,32(r3)
+ ld r14,40(r3)
+
+ adde r0,r0,r9
+ ld r15,48(r3)
+ ld r16,56(r3)
+ addi r3,r3,64
+
+ adde r0,r0,r10
+ adde r0,r0,r11
+ adde r0,r0,r12
+ adde r0,r0,r14
+ adde r0,r0,r15
+ adde r0,r0,r16
+
+ ld r14,STK_REG(r14)(r1)
+ ld r15,STK_REG(r15)(r1)
+ ld r16,STK_REG(r16)(r1)
+ addi r1,r1,STACKFRAMESIZE
+
+ andi. r4,r4,63
+
+.Lcsum_tail_doublewords: /* Up to 127 bytes to go */
+ srdi. r6,r4,3
+ beq .Lcsum_tail_word
+
+ mtctr r6
+3:
+ ld r6,0(r3)
+ addi r3,r3,8
+ adde r0,r0,r6
+ bdnz 3b
+
+ andi. r4,r4,7
+
+.Lcsum_tail_word: /* Up to 7 bytes to go */
+ srdi. r6,r4,2
+ beq .Lcsum_tail_halfword
+
+ lwz r6,0(r3)
addi r3,r3,4
+ adde r0,r0,r6
subi r4,r4,4
- adde r5,r5,r6
-4: cmpwi 0,r4,2 /* is at least a halfword left? */
- blt+ 5f
- lhz r6,8(r3) /* sum this halfword */
- addi r3,r3,2
- subi r4,r4,2
- adde r5,r5,r6
-5: cmpwi 0,r4,1 /* is at least a byte left? */
- bne+ 6f
- lbz r6,8(r3) /* sum this byte */
- slwi r6,r6,8 /* this byte is assumed to be the upper byte of a halfword */
- adde r5,r5,r6
-6: addze r5,r5 /* add in final carry */
- rldicl r4,r5,32,0 /* fold two 32-bit halves together */
- add r3,r4,r5
- srdi r3,r3,32
- blr
+
+.Lcsum_tail_halfword: /* Up to 3 bytes to go */
+ srdi. r6,r4,1
+ beq .Lcsum_tail_byte
+
+ lhz r6,0(r3)
+ addi r3,r3,2
+ adde r0,r0,r6
+ subi r4,r4,2
+
+.Lcsum_tail_byte: /* Up to 1 byte to go */
+ andi. r6,r4,1
+ beq .Lcsum_finish
+
+ lbz r6,0(r3)
+ sldi r9,r6,8 /* Pad the byte out to 16 bits */
+ adde r0,r0,r9
+
+.Lcsum_finish:
+ addze r0,r0 /* add in final carry */
+ rldicl r4,r0,32,0 /* fold two 32 bit halves together */
+ add r3,r4,r0
+ srdi r3,r3,32
+ blr
+
+
+ .macro source
+100:
+ .section __ex_table,"a"
+ .align 3
+ .llong 100b,.Lsrc_error
+ .previous
+ .endm
+
+ .macro dest
+200:
+ .section __ex_table,"a"
+ .align 3
+ .llong 200b,.Ldest_error
+ .previous
+ .endm
/*
* Computes the checksum of a memory block at src, length len,
* and adds in "sum" (32-bit), while copying the block to dst.
* If an access exception occurs on src or dst, it stores -EFAULT
- * to *src_err or *dst_err respectively, and (for an error on
- * src) zeroes the rest of dst.
- *
- * This code needs to be reworked to take advantage of 64 bit sum+copy.
- * However, due to tokenring halfword alignment problems this will be very
- * tricky. For now we'll leave it until we instrument it somehow.
+ * to *src_err or *dst_err respectively. The caller must take any action
+ * required in this case (zeroing memory, recalculating partial checksum etc).
*
* csum_partial_copy_generic(r3=src, r4=dst, r5=len, r6=sum, r7=src_err, r8=dst_err)
*/
_GLOBAL(csum_partial_copy_generic)
- addic r0,r6,0
- subi r3,r3,4
- subi r4,r4,4
- srwi. r6,r5,2
- beq 3f /* if we're doing < 4 bytes */
- andi. r9,r4,2 /* Align dst to longword boundary */
- beq+ 1f
-81: lhz r6,4(r3) /* do 2 bytes to get aligned */
- addi r3,r3,2
+ addic r0,r6,0 /* clear carry */
+
+ srdi. r6,r5,3 /* less than 8 bytes? */
+ beq .Lcopy_tail_word
+
+ /*
+ * If only halfword aligned, align to a double word. Since odd
+ * aligned addresses should be rare and they would require more
+ * work to calculate the correct checksum, we ignore that case
+ * and take the potential slowdown of unaligned loads.
+ *
+ * If the source and destination are relatively unaligned we only
+ * align the source. This keeps things simple.
+ */
+ rldicl. r6,r3,64-1,64-2 /* r6 = (r3 & 0x3) >> 1 */
+ beq .Lcopy_aligned
+
+ li r7,4
+ sub r6,r7,r6
+ mtctr r6
+
+1:
+source; lhz r6,0(r3) /* align to doubleword */
subi r5,r5,2
-91: sth r6,4(r4)
- addi r4,r4,2
- addc r0,r0,r6
- srwi. r6,r5,2 /* # words to do */
- beq 3f
-1: mtctr r6
-82: lwzu r6,4(r3) /* the bdnz has zero overhead, so it should */
-92: stwu r6,4(r4) /* be unnecessary to unroll this loop */
- adde r0,r0,r6
- bdnz 82b
- andi. r5,r5,3
-3: cmpwi 0,r5,2
- blt+ 4f
-83: lhz r6,4(r3)
addi r3,r3,2
- subi r5,r5,2
-93: sth r6,4(r4)
+ adde r0,r0,r6
+dest; sth r6,0(r4)
addi r4,r4,2
+ bdnz 1b
+
+.Lcopy_aligned:
+ /*
+ * We unroll the loop such that each iteration is 64 bytes with an
+ * entry and exit limb of 64 bytes, meaning a minimum size of
+ * 128 bytes.
+ */
+ srdi. r6,r5,7
+ beq .Lcopy_tail_doublewords /* len < 128 */
+
+ srdi r6,r5,6
+ subi r6,r6,1
+ mtctr r6
+
+ stdu r1,-STACKFRAMESIZE(r1)
+ std r14,STK_REG(r14)(r1)
+ std r15,STK_REG(r15)(r1)
+ std r16,STK_REG(r16)(r1)
+
+source; ld r6,0(r3)
+source; ld r9,8(r3)
+
+source; ld r10,16(r3)
+source; ld r11,24(r3)
+
+ /*
+ * On POWER6 and POWER7 back to back addes take 2 cycles because of
+ * the XER dependency. This means the fastest this loop can go is
+ * 16 cycles per iteration. The scheduling of the loop below has
+ * been shown to hit this on both POWER6 and POWER7.
+ */
+ .align 5
+2:
adde r0,r0,r6
-4: cmpwi 0,r5,1
- bne+ 5f
-84: lbz r6,4(r3)
-94: stb r6,4(r4)
- slwi r6,r6,8 /* Upper byte of word */
+source; ld r12,32(r3)
+source; ld r14,40(r3)
+
+ adde r0,r0,r9
+source; ld r15,48(r3)
+source; ld r16,56(r3)
+ addi r3,r3,64
+
+ adde r0,r0,r10
+dest; std r6,0(r4)
+dest; std r9,8(r4)
+
+ adde r0,r0,r11
+dest; std r10,16(r4)
+dest; std r11,24(r4)
+
+ adde r0,r0,r12
+dest; std r12,32(r4)
+dest; std r14,40(r4)
+
+ adde r0,r0,r14
+dest; std r15,48(r4)
+dest; std r16,56(r4)
+ addi r4,r4,64
+
+ adde r0,r0,r15
+source; ld r6,0(r3)
+source; ld r9,8(r3)
+
+ adde r0,r0,r16
+source; ld r10,16(r3)
+source; ld r11,24(r3)
+ bdnz 2b
+
+
adde r0,r0,r6
-5: addze r3,r0 /* add in final carry (unlikely with 64-bit regs) */
- rldicl r4,r3,32,0 /* fold 64 bit value */
- add r3,r4,r3
- srdi r3,r3,32
- blr
+source; ld r12,32(r3)
+source; ld r14,40(r3)
-/* These shouldn't go in the fixup section, since that would
- cause the ex_table addresses to get out of order. */
+ adde r0,r0,r9
+source; ld r15,48(r3)
+source; ld r16,56(r3)
+ addi r3,r3,64
+
+ adde r0,r0,r10
+dest; std r6,0(r4)
+dest; std r9,8(r4)
+
+ adde r0,r0,r11
+dest; std r10,16(r4)
+dest; std r11,24(r4)
+
+ adde r0,r0,r12
+dest; std r12,32(r4)
+dest; std r14,40(r4)
+
+ adde r0,r0,r14
+dest; std r15,48(r4)
+dest; std r16,56(r4)
+ addi r4,r4,64
+
+ adde r0,r0,r15
+ adde r0,r0,r16
+
+ ld r14,STK_REG(r14)(r1)
+ ld r15,STK_REG(r15)(r1)
+ ld r16,STK_REG(r16)(r1)
+ addi r1,r1,STACKFRAMESIZE
+
+ andi. r5,r5,63
+
+.Lcopy_tail_doublewords: /* Up to 127 bytes to go */
+ srdi. r6,r5,3
+ beq .Lcopy_tail_word
- .globl src_error_1
-src_error_1:
- li r6,0
- subi r5,r5,2
-95: sth r6,4(r4)
- addi r4,r4,2
- srwi. r6,r5,2
- beq 3f
mtctr r6
- .globl src_error_2
-src_error_2:
- li r6,0
-96: stwu r6,4(r4)
- bdnz 96b
-3: andi. r5,r5,3
- beq src_error
- .globl src_error_3
-src_error_3:
- li r6,0
- mtctr r5
- addi r4,r4,3
-97: stbu r6,1(r4)
- bdnz 97b
- .globl src_error
-src_error:
+3:
+source; ld r6,0(r3)
+ addi r3,r3,8
+ adde r0,r0,r6
+dest; std r6,0(r4)
+ addi r4,r4,8
+ bdnz 3b
+
+ andi. r5,r5,7
+
+.Lcopy_tail_word: /* Up to 7 bytes to go */
+ srdi. r6,r5,2
+ beq .Lcopy_tail_halfword
+
+source; lwz r6,0(r3)
+ addi r3,r3,4
+ adde r0,r0,r6
+dest; stw r6,0(r4)
+ addi r4,r4,4
+ subi r5,r5,4
+
+.Lcopy_tail_halfword: /* Up to 3 bytes to go */
+ srdi. r6,r5,1
+ beq .Lcopy_tail_byte
+
+source; lhz r6,0(r3)
+ addi r3,r3,2
+ adde r0,r0,r6
+dest; sth r6,0(r4)
+ addi r4,r4,2
+ subi r5,r5,2
+
+.Lcopy_tail_byte: /* Up to 1 byte to go */
+ andi. r6,r5,1
+ beq .Lcopy_finish
+
+source; lbz r6,0(r3)
+ sldi r9,r6,8 /* Pad the byte out to 16 bits */
+ adde r0,r0,r9
+dest; stb r6,0(r4)
+
+.Lcopy_finish:
+ addze r0,r0 /* add in final carry */
+ rldicl r4,r0,32,0 /* fold two 32 bit halves together */
+ add r3,r4,r0
+ srdi r3,r3,32
+ blr
+
+.Lsrc_error:
cmpdi 0,r7,0
- beq 1f
+ beqlr
li r6,-EFAULT
stw r6,0(r7)
-1: addze r3,r0
blr
- .globl dst_error
-dst_error:
+.Ldest_error:
cmpdi 0,r8,0
- beq 1f
+ beqlr
li r6,-EFAULT
stw r6,0(r8)
-1: addze r3,r0
blr
-
-.section __ex_table,"a"
- .align 3
- .llong 81b,src_error_1
- .llong 91b,dst_error
- .llong 82b,src_error_2
- .llong 92b,dst_error
- .llong 83b,src_error_3
- .llong 93b,dst_error
- .llong 84b,src_error_3
- .llong 94b,dst_error
- .llong 95b,dst_error
- .llong 96b,dst_error
- .llong 97b,dst_error
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