From 8055eb245481474d30b1ceaaff1b52555e06c327 Mon Sep 17 00:00:00 2001 From: kib Date: Fri, 7 Nov 2014 20:10:09 +0000 Subject: [PATCH] Simplify assembler in ivy.c. Move the copying of the random bits into 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 --- sys/dev/random/ivy.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/sys/dev/random/ivy.c b/sys/dev/random/ivy.c index 724e7aacf937..c098b872f7af 100644 --- a/sys/dev/random/ivy.c +++ b/sys/dev/random/ivy.c @@ -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); }