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Differential D22454 Diff 64641 head/sys/dev/random/ivy.c

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head/sys/dev/random/ivy.c

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static u_int random_ivy_read(void *, u_int); static u_int random_ivy_read(void *, u_int);
static struct random_source random_ivy = { static struct random_source random_ivy = {
.rs_ident = "Intel Secure Key RNG", .rs_ident = "Intel Secure Key RNG",
.rs_source = RANDOM_PURE_RDRAND, .rs_source = RANDOM_PURE_RDRAND,
.rs_read = random_ivy_read .rs_read = random_ivy_read
}; };
static int static bool
x86_rdrand_store(u_long *buf) x86_rdrand_store(u_long *buf)
{ {
u_long rndval; u_long rndval;
int retry; int retry;
retry = RETRY_COUNT; retry = RETRY_COUNT;
__asm __volatile( __asm __volatile(
"1:\n\t" "1:\n\t"
"rdrand %1\n\t" /* read randomness into rndval */ "rdrand %1\n\t" /* read randomness into rndval */
"jc 2f\n\t" /* CF is set on success, exit retry loop */ "jc 2f\n\t" /* CF is set on success, exit retry loop */
"dec %0\n\t" /* otherwise, retry-- */ "dec %0\n\t" /* otherwise, retry-- */
"jne 1b\n\t" /* and loop if retries are not exhausted */ "jne 1b\n\t" /* and loop if retries are not exhausted */
"2:" "2:"
: "+r" (retry), "=r" (rndval) : : "cc"); : "+r" (retry), "=r" (rndval) : : "cc");
*buf = rndval; *buf = rndval;
return (retry); return (retry != 0);
} }
static int static bool
x86_rdseed_store(u_long *buf) x86_rdseed_store(u_long *buf)
{ {
u_long rndval; u_long rndval;
int retry; int retry;
retry = RETRY_COUNT; retry = RETRY_COUNT;
__asm __volatile( __asm __volatile(
"1:\n\t" "1:\n\t"
"rdseed %1\n\t" /* read randomness into rndval */ "rdseed %1\n\t" /* read randomness into rndval */
"jc 2f\n\t" /* CF is set on success, exit retry loop */ "jc 2f\n\t" /* CF is set on success, exit retry loop */
"dec %0\n\t" /* otherwise, retry-- */ "dec %0\n\t" /* otherwise, retry-- */
"jne 1b\n\t" /* and loop if retries are not exhausted */ "jne 1b\n\t" /* and loop if retries are not exhausted */
"2:" "2:"
: "+r" (retry), "=r" (rndval) : : "cc"); : "+r" (retry), "=r" (rndval) : : "cc");
*buf = rndval; *buf = rndval;
return (retry); return (retry != 0);
} }
static int static bool
x86_unimpl_store(u_long *buf __unused) x86_unimpl_store(u_long *buf __unused)
{ {
panic("%s called", __func__); panic("%s called", __func__);
} }
DEFINE_IFUNC(static, int, x86_rng_store, (u_long *buf)) DEFINE_IFUNC(static, bool, x86_rng_store, (u_long *buf))
{ {
has_rdrand = (cpu_feature2 & CPUID2_RDRAND); has_rdrand = (cpu_feature2 & CPUID2_RDRAND);
has_rdseed = (cpu_stdext_feature & CPUID_STDEXT_RDSEED); has_rdseed = (cpu_stdext_feature & CPUID_STDEXT_RDSEED);
if (has_rdseed) if (has_rdseed)
return (x86_rdseed_store); return (x86_rdseed_store);
else if (has_rdrand) else if (has_rdrand)
return (x86_rdrand_store); return (x86_rdrand_store);
else else
return (x86_unimpl_store); return (x86_unimpl_store);
} }
/* It is required that buf length is a multiple of sizeof(u_long). */ /* It is required that buf length is a multiple of sizeof(u_long). */
static u_int static u_int
random_ivy_read(void *buf, u_int c) random_ivy_read(void *buf, u_int c)
{ {
u_long *b, rndval; u_long *b, rndval;
u_int count; u_int count;
KASSERT(c % sizeof(*b) == 0, ("partial read %d", c)); KASSERT(c % sizeof(*b) == 0, ("partial read %d", c));
b = buf; b = buf;
for (count = c; count > 0; count -= sizeof(*b)) { for (count = c; count > 0; count -= sizeof(*b)) {
if (x86_rng_store(&rndval) == 0) if (!x86_rng_store(&rndval))
break; break;
*b++ = rndval; *b++ = rndval;
} }
return (c - count); return (c - count);
} }
static int static int
rdrand_modevent(module_t mod, int type, void *unused) rdrand_modevent(module_t mod, int type, void *unused)
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