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Diffstat (limited to 'arch/powerpc/platforms/powernv/rng.c')
-rw-r--r--arch/powerpc/platforms/powernv/rng.c52
1 files changed, 36 insertions, 16 deletions
diff --git a/arch/powerpc/platforms/powernv/rng.c b/arch/powerpc/platforms/powernv/rng.c
index e3d44b36ae98..463c78c52cc5 100644
--- a/arch/powerpc/platforms/powernv/rng.c
+++ b/arch/powerpc/platforms/powernv/rng.c
@@ -17,6 +17,7 @@
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/smp.h>
+#include "powernv.h"
#define DARN_ERR 0xFFFFFFFFFFFFFFFFul
@@ -28,7 +29,6 @@ struct powernv_rng {
static DEFINE_PER_CPU(struct powernv_rng *, powernv_rng);
-
int powernv_hwrng_present(void)
{
struct powernv_rng *rng;
@@ -98,9 +98,6 @@ static int __init initialise_darn(void)
return 0;
}
}
-
- pr_warn("Unable to use DARN for get_random_seed()\n");
-
return -EIO;
}
@@ -163,32 +160,55 @@ static __init int rng_create(struct device_node *dn)
rng_init_per_cpu(rng, dn);
- pr_info_once("Registering arch random hook.\n");
-
ppc_md.get_random_seed = powernv_get_random_long;
return 0;
}
-static __init int rng_init(void)
+static int __init pnv_get_random_long_early(unsigned long *v)
{
struct device_node *dn;
- int rc;
+
+ if (!slab_is_available())
+ return 0;
+
+ if (cmpxchg(&ppc_md.get_random_seed, pnv_get_random_long_early,
+ NULL) != pnv_get_random_long_early)
+ return 0;
for_each_compatible_node(dn, NULL, "ibm,power-rng") {
- rc = rng_create(dn);
- if (rc) {
- pr_err("Failed creating rng for %pOF (%d).\n",
- dn, rc);
+ if (rng_create(dn))
continue;
- }
-
/* Create devices for hwrng driver */
of_platform_device_create(dn, NULL, NULL);
}
- initialise_darn();
+ if (!ppc_md.get_random_seed)
+ return 0;
+ return ppc_md.get_random_seed(v);
+}
+
+void __init pnv_rng_init(void)
+{
+ struct device_node *dn;
+ /* Prefer darn over the rest. */
+ if (!initialise_darn())
+ return;
+
+ dn = of_find_compatible_node(NULL, NULL, "ibm,power-rng");
+ if (dn)
+ ppc_md.get_random_seed = pnv_get_random_long_early;
+
+ of_node_put(dn);
+}
+
+static int __init pnv_rng_late_init(void)
+{
+ unsigned long v;
+ /* In case it wasn't called during init for some other reason. */
+ if (ppc_md.get_random_seed == pnv_get_random_long_early)
+ pnv_get_random_long_early(&v);
return 0;
}
-machine_subsys_initcall(powernv, rng_init);
+machine_subsys_initcall(powernv, pnv_rng_late_init);