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| author | Al Viro <viro@zeniv.linux.org.uk> | 2020-07-20 10:09:24 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-08-20 15:45:22 -0400 |
| commit | 70d65cd555c5e43c613700f604a47f7ebcf7b6f1 (patch) | |
| tree | 5c0494b0c4bec1c753e158cf7b25e9f1ead37088 /arch/powerpc/lib/checksum_64.S | |
| parent | daf52375c19feb4397cfd883302a7c907de2d6ad (diff) | |
| download | lwn-70d65cd555c5e43c613700f604a47f7ebcf7b6f1.tar.gz lwn-70d65cd555c5e43c613700f604a47f7ebcf7b6f1.zip | |
ppc: propagate the calling conventions change down to csum_partial_copy_generic()
... and get rid of the pointless fallback in the wrappers. On error it used
to zero the unwritten area and calculate the csum of the entire thing. Not
wanting to do it in assembler part had been very reasonable; doing that in
the first place, OTOH... In case of an error the caller discards the data
we'd copied, along with whatever checksum it might've had.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/powerpc/lib/checksum_64.S')
| -rw-r--r-- | arch/powerpc/lib/checksum_64.S | 37 |
1 files changed, 11 insertions, 26 deletions
diff --git a/arch/powerpc/lib/checksum_64.S b/arch/powerpc/lib/checksum_64.S index 514978f908d4..98ff51bd2f7d 100644 --- a/arch/powerpc/lib/checksum_64.S +++ b/arch/powerpc/lib/checksum_64.S @@ -182,34 +182,33 @@ EXPORT_SYMBOL(__csum_partial) .macro srcnr 100: - EX_TABLE(100b,.Lsrc_error_nr) + EX_TABLE(100b,.Lerror_nr) .endm .macro source 150: - EX_TABLE(150b,.Lsrc_error) + EX_TABLE(150b,.Lerror) .endm .macro dstnr 200: - EX_TABLE(200b,.Ldest_error_nr) + EX_TABLE(200b,.Lerror_nr) .endm .macro dest 250: - EX_TABLE(250b,.Ldest_error) + EX_TABLE(250b,.Lerror) .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. The caller must take any action - * required in this case (zeroing memory, recalculating partial checksum etc). + * and adds in 0xffffffff (32-bit), while copying the block to dst. + * If an access exception occurs, it returns 0. * - * csum_partial_copy_generic(r3=src, r4=dst, r5=len, r6=sum, r7=src_err, r8=dst_err) + * csum_partial_copy_generic(r3=src, r4=dst, r5=len) */ _GLOBAL(csum_partial_copy_generic) + li r6,-1 addic r0,r6,0 /* clear carry */ srdi. r6,r5,3 /* less than 8 bytes? */ @@ -401,29 +400,15 @@ dstnr; stb r6,0(r4) srdi r3,r3,32 blr -.Lsrc_error: +.Lerror: ld r14,STK_REG(R14)(r1) ld r15,STK_REG(R15)(r1) ld r16,STK_REG(R16)(r1) addi r1,r1,STACKFRAMESIZE -.Lsrc_error_nr: - cmpdi 0,r7,0 - beqlr - li r6,-EFAULT - stw r6,0(r7) +.Lerror_nr: + li r3,0 blr -.Ldest_error: - ld r14,STK_REG(R14)(r1) - ld r15,STK_REG(R15)(r1) - ld r16,STK_REG(R16)(r1) - addi r1,r1,STACKFRAMESIZE -.Ldest_error_nr: - cmpdi 0,r8,0 - beqlr - li r6,-EFAULT - stw r6,0(r8) - blr EXPORT_SYMBOL(csum_partial_copy_generic) /* |