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Commit 7b878d4b authored by H. Peter Anvin's avatar H. Peter Anvin Committed by Theodore Ts'o
Browse files

random: Add arch_has_random[_seed]() 



Add predicate functions for having arch_get_random[_seed]*().  The
only current use is to avoid the loop in arch_random_refill() when
arch_get_random_seed_long() is unavailable.

Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 331c6490

arch/powerpc/include/asm/archrandom.h

+9 −0
Original line number Diff line number Diff line
@@ -25,6 +25,11 @@ static inline int arch_get_random_int(unsigned int *v) 
	return rc;

}



static inline int arch_has_random(void)

{

	return !!ppc_md.get_random_long;

}



int powernv_get_random_long(unsigned long *v);



static inline int arch_get_random_seed_long(unsigned long *v)
@@ -35,6 +40,10 @@ static inline int arch_get_random_seed_int(unsigned int *v) 
{

	return 0;

}

static inline int arch_has_random_seed(void)

{

	return 0;

}



#endif /* CONFIG_ARCH_RANDOM */

arch/x86/include/asm/archrandom.h

+3 −0
Original line number Diff line number Diff line
@@ -114,6 +114,9 @@ GET_SEED(arch_get_random_seed_int, unsigned int, RDSEED_INT, ASM_NOP4); 


#endif /* CONFIG_X86_64 */



#define arch_has_random()	static_cpu_has(X86_FEATURE_RDRAND)

#define arch_has_random_seed()	static_cpu_has(X86_FEATURE_RDSEED)



#else



static inline int rdrand_long(unsigned long *v)

drivers/char/random.c

+3 −0
Original line number Diff line number Diff line
@@ -1307,6 +1307,9 @@ static int arch_random_refill(void) 
	unsigned int i;

	unsigned long buf[nlongs];



	if (!arch_has_random_seed())

		return 0;



	for (i = 0; i < nlongs; i++) {

		if (arch_get_random_seed_long(&buf[n]))

			n++;

include/linux/random.h

+8 −0
Original line number Diff line number Diff line
@@ -88,6 +88,10 @@ static inline int arch_get_random_int(unsigned int *v) 
{

	return 0;

}

static inline int arch_has_random(void)

{

	return 0;

}

static inline int arch_get_random_seed_long(unsigned long *v)

{

	return 0;
@@ -96,6 +100,10 @@ static inline int arch_get_random_seed_int(unsigned int *v) 
{

	return 0;

}

static inline int arch_has_random_seed(void)

{

	return 0;

}

#endif



/* Pseudo random number generator from numerical recipes. */