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[PATCH] rename net_random to random32

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Make net_random() more widely available by calling it random32

akpm: hopefully this will permit the removal of carta_random32.  That needs
confirmation from Stephane - this code looks somewhat more computationally
expensive, and has a different (ie: callee-stateful) interface.

[akpm@osdl.org: lots of build fixes, cleanups]
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Stephen Hemminger 2006-10-17 00:09:42 -07:00 • committed by Linus Torvalds
parent 0187f879ee
commit aaa248f6c9
6 changed files with 150 additions and 122 deletions
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116
net/core/utils.c
View file

@ -30,119 +30,6 @@
#include <asm/system.h>
#include <asm/uaccess.h>
/*
This is a maximally equidistributed combined Tausworthe generator
based on code from GNU Scientific Library 1.5 (30 Jun 2004)
x_n = (s1_n ^ s2_n ^ s3_n)
s1_{n+1} = (((s1_n & 4294967294) <<12) ^ (((s1_n <<13) ^ s1_n) >>19))
s2_{n+1} = (((s2_n & 4294967288) << 4) ^ (((s2_n << 2) ^ s2_n) >>25))
s3_{n+1} = (((s3_n & 4294967280) <<17) ^ (((s3_n << 3) ^ s3_n) >>11))
The period of this generator is about 2^88.
From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe
Generators", Mathematics of Computation, 65, 213 (1996), 203--213.
This is available on the net from L'Ecuyer's home page,
http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps
There is an erratum in the paper "Tables of Maximally
Equidistributed Combined LFSR Generators", Mathematics of
Computation, 68, 225 (1999), 261--269:
http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
... the k_j most significant bits of z_j must be non-
zero, for each j. (Note: this restriction also applies to the
computer code given in [4], but was mistakenly not mentioned in
that paper.)
This affects the seeding procedure by imposing the requirement
s1 > 1, s2 > 7, s3 > 15.
*/
struct nrnd_state {
u32 s1, s2, s3;
};
static DEFINE_PER_CPU(struct nrnd_state, net_rand_state);
static u32 __net_random(struct nrnd_state *state)
{
#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12);
state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4);
state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17);
return (state->s1 ^ state->s2 ^ state->s3);
}
static void __net_srandom(struct nrnd_state *state, unsigned long s)
{
if (s == 0)
s = 1; /* default seed is 1 */
#define LCG(n) (69069 * n)
state->s1 = LCG(s);
state->s2 = LCG(state->s1);
state->s3 = LCG(state->s2);
/* "warm it up" */
__net_random(state);
__net_random(state);
__net_random(state);
__net_random(state);
__net_random(state);
__net_random(state);
}
unsigned long net_random(void)
{
unsigned long r;
struct nrnd_state *state = &get_cpu_var(net_rand_state);
r = __net_random(state);
put_cpu_var(state);
return r;
}
void net_srandom(unsigned long entropy)
{
struct nrnd_state *state = &get_cpu_var(net_rand_state);
__net_srandom(state, state->s1^entropy);
put_cpu_var(state);
}
void __init net_random_init(void)
{
int i;
for_each_possible_cpu(i) {
struct nrnd_state *state = &per_cpu(net_rand_state,i);
__net_srandom(state, i+jiffies);
}
}
static int net_random_reseed(void)
{
int i;
unsigned long seed;
for_each_possible_cpu(i) {
struct nrnd_state *state = &per_cpu(net_rand_state,i);
get_random_bytes(&seed, sizeof(seed));
__net_srandom(state, seed);
}
return 0;
}
late_initcall(net_random_reseed);
int net_msg_cost = 5*HZ;
int net_msg_burst = 10;
@ -153,10 +40,7 @@ int net_ratelimit(void)
{
return __printk_ratelimit(net_msg_cost, net_msg_burst);
}
EXPORT_SYMBOL(net_random);
EXPORT_SYMBOL(net_ratelimit);
EXPORT_SYMBOL(net_srandom);
/*
* Convert an ASCII string to binary IP.