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Simplify assembler in ivy.c. Move the copying of the random bits into

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buffer from asm to C, which reduces amount of arguments for inline asm
and simplifies constraints.  Use unsigned types consistently.

Submitted by:	bde
Approved by:	secteam (delphij)
Reviewed by:	markm
MFC after:	1 week
This commit is contained in:
Konstantin Belousov 2014-11-07 20:10:09 +00:00
parent 76a8ef267d
commit 76c16ab94f
1 changed files with 11 additions and 12 deletions
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23
sys/dev/random/ivy.c
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@ -61,42 +61,41 @@ static struct live_entropy_source random_ivy = {
};
static inline int
ivy_rng_store(long *buf)
ivy_rng_store(u_long *buf)
{
#ifdef __GNUCLIKE_ASM
long tmp;
u_long rndval;
int retry;
retry = RETRY_COUNT;
__asm __volatile(
"1:\n\t"
"rdrand %2\n\t" /* read randomness into tmp */
"jb 2f\n\t" /* CF is set on success, exit retry loop */
"rdrand %1\n\t" /* read randomness into tmp */
"jc 2f\n\t" /* CF is set on success, exit retry loop */
"dec %0\n\t" /* otherwise, retry-- */
"jne 1b\n\t" /* and loop if retries are not exhausted */
"jmp 3f\n" /* failure, retry is 0, used as return value */
"2:\n\t"
"mov %2,%1\n\t" /* *buf = tmp */
"3:"
: "+q" (retry), "=m" (*buf), "+q" (tmp) : : "cc");
"2:"
: "+r" (retry), "=r" (rndval) : : "cc");
*buf = rndval;
return (retry);
#else /* __GNUCLIKE_ASM */
return (0);
#endif
}
/* It is specifically allowed that buf is a multiple of sizeof(long) */
/* It is required that buf length is a multiple of sizeof(u_long). */
static u_int
random_ivy_read(void *buf, u_int c)
{
long *b;
u_long *b, rndval;
u_int count;
KASSERT(c % sizeof(*b) == 0, ("partial read %d", c));
b = buf;
for (count = c; count > 0; count -= sizeof(*b)) {
if (ivy_rng_store(b++) == 0)
if (ivy_rng_store(&rndval) == 0)
break;
*b++ = rndval;
}
return (c - count);
}