On Wed, 8 Apr 2015 15:06:13 -0400
Vladimir Medvedkin <medvedkinv at gmail.com> wrote:
> Software implementation of the Toeplitz hash function used by RSS.
> Can be used either for packet distribution on single queue NIC
> or for simulating of RSS computation on specific NIC (for example
> after GRE header decapsulating).
>
> Signed-off-by: Vladimir Medvedkin <medvedkinv at gmail.com>
> +enum rte_thash_flag {
> + RTE_THASH_L3 = 0, //calculate hash tacking into account only l3
> header
> + RTE_THASH_L4 //calculate hash tacking into account l4 + l4
> headers
> +};
> +
> +/**
> + * Prepare special converted key to use with rte_softrss_be()
> + * @param orig
> + * pointer to original RSS key
> + * @param targ
> + * pointer to target RSS key
> + */
> +
> +static inline void
> +rte_convert_rss_key(uint32_t *orig, uint32_t *targ)
orig should be const
> +{
> + int i;
> + for (i = 0; i < 10; i++) {
> + targ[i] = rte_be_to_cpu_32(orig[i]);
> + }
> +}
> +static inline uint32_t
> +rte_softrss(uint32_t sip, uint32_t dip, uint16_t sp, uint16_t dp, enum
> rte_thash_flag flag, uint32_t *rss_key)
rss_key should be const
> +{
> + uint32_t ret = 0;
> + int i;
> + for (i = 0; i < 32; i++) {
blank line after declaration please
> + if (sip & (1 << (31 - i))) {
> + ret ^= (rte_cpu_to_be_32(*rss_key) <<
> i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
Long expression > 80 characters.
Repeated multiple times (should be inline)
Extra parens ()
Extension to 64 bits is only to avoid compiler warning?
> + }
> + }
> + rss_key++;
> + for (i = 0; i < 32; i++) {
> + if (dip & (1 << (31 - i))) {
> + ret ^= (rte_cpu_to_be_32(*rss_key) <<
> i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
> + }
> + }
> + if (flag == RTE_THASH_L4) {
> + rss_key++;
> + for (i = 0; i < 32; i++) {
> + if (((sp<<16)|dp) & (1 << (31 - i))) {
> + ret ^= (rte_cpu_to_be_32(*rss_key) <<
> i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
> + }
> + }
> + }
> + return ret;
> +}
> +
> +/**
> + * Optimized implementation.
> + * If you want the calculated hash value matches NIC RSS value
> + * you have to use special converted key.
> + * All ip's and ports have to be CPU byte order.
> + * @param sip
> + * Source ip address.
> + * @param dip
> + * Destination ip address.
> + * @param sp
> + * Source TCP|UDP port.
> + * @param dp
> + * Destination TCP|UDP port.
> + * @param flag
> + * RTE_THASH_L3: calculate hash tacking into account only sip and dip
> + * RTE_THASH_L4: calculate hash tacking into account sip, dip, sp and dp
> + * @param *rss_key
> + * Pointer to 40-byte RSS hash key.
> + * @return
> + * Calculated hash value.
> + */
> +
> +static inline uint32_t
> +rte_softrss_be(uint32_t sip, uint32_t dip, uint16_t sp, uint16_t dp, enum
> rte_thash_flag flag, uint32_t *rss_key)
> +{
Same problems as previous code.
Also lots of copy paste (see Do Not Repeat Yourself principle).
