Hi Kim, >On Fri, 1 Mar 2013 11:16:22 -0500 >Akshay Saraswat <aksha...@samsung.com> wrote: > >> SHA-256 and SHA-1 accelerated using ACE hardware. > >curious about the rationale: how much faster is this than software? >
Time taken by s/w and h/w sha256 are as given below: Size: 0x1000 s/w - 11 ticks h/w - 10 ticks Size: 0x2000 s/w - 11 ticks h/w - 10 ticks Size: 0x4000 s/w - 13 ticks h/w - 10 ticks Size: 0x8000 s/w - 16 ticks h/w - 10 ticks Size: 0x800000 s/w - 1775 ticks h/w - 45 ticks Size: 0x400000 s/w - 893 ticks h/w - 27 ticks Size: 0x200000 s/w - 451 ticks h/w - 18 ticks Size: 0x8000000 s/w - 28270 ticks h/w - 110 ticks Size: 0x40000000 s/w - 225896 ticks h/w - 110 ticks >> --- >> Changes since v2: >> - Added falling back to software sha256 in case length exceeds buffer >> limit. >> - Reduced one tab at lines 533, 559 and 571 in this patch. >> - Removed space after a cast at line 506 in this patch. >> - Removed blank line at line 561 in this patch. >> - Removed space before semicolon at line 576 in this patch. > >you should retain the list of changes since v1 here. Read: > >http://www.denx.de/wiki/view/U-Boot/Patches#Sending_updated_patch_versions > >> +/* Hash status */ >> +#define ACE_HASH_BUFRDY_MASK (1 << 0) >> +#define ACE_HASH_BUFRDY_OFF (0 << 0) >> +#define ACE_HASH_BUFRDY_ON (1 << 0) >> +#define ACE_HASH_SEEDSETTING_MASK (1 << 1) >> +#define ACE_HASH_SEEDSETTING_OFF (0 << 1) >> +#define ACE_HASH_SEEDSETTING_ON (1 << 1) >> +#define ACE_HASH_PRNGBUSY_MASK (1 << 2) >> +#define ACE_HASH_PRNGBUSY_OFF (0 << 2) >> +#define ACE_HASH_PRNGBUSY_ON (1 << 2) >> +#define ACE_HASH_PARTIALDONE_MASK (1 << 4) >> +#define ACE_HASH_PARTIALDONE_OFF (0 << 4) >> +#define ACE_HASH_PARTIALDONE_ON (1 << 4) > >based on the nomenclature of the above definitions, this hardware >obviously has support for breaking up hash requests into multiple >buffer submissions, so do that, and not this: > >> + } else if (buf_len > BUF_LIMIT) { >> + /* >> + * ACE H/W cannot compute hash value for buffer > 8 MB. >> + * Falling back to software. >> + */ >> + if (hash_type == ACE_SHA_TYPE_SHA1) >> + sha1_csum_wd(pbuf, buf_len, pout, CHUNKSZ_SHA1); >> + else >> + sha256_csum_wd(pbuf, buf_len, pout, CHUNKSZ_SHA256); >> + return 0; >> + } > >Kim > Regards, Akshay Saraswat _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
