[PATCH 4.19 42/49] powerpc/pseries: wire up rng during setup_arch()

Greg Kroah-Hartman
2022-06-30T14:02:10Z

From: Jason A. Donenfeld <Jason@zx2c4.com>

commit e561e472a3d441753bd012333b057f48fef1045b upstream.

The platform's RNG must be available before random_init() in order to be
useful for initial seeding, which in turn means that it needs to be
called from setup_arch(), rather than from an init call. Fortunately,
each platform already has a setup_arch function pointer, which means
it's easy to wire this up. This commit also removes some noisy log
messages that don't add much.

Fixes: a489043f4626 ("powerpc/pseries: Implement arch_get_random_long() based on H_RANDOM")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220611151015.548325-4-Jason@zx2c4.com
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/platforms/pseries/pseries.h | 2 ++
arch/powerpc/platforms/pseries/rng.c | 11 +++--------
arch/powerpc/platforms/pseries/setup.c | 1 +
3 files changed, 6 insertions(+), 8 deletions(-)

--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -110,4 +110,6 @@ int dlpar_workqueue_init(void);

void pseries_setup_rfi_flush(void);

+void pseries_rng_init(void);
+
#endif /* _PSERIES_PSERIES_H */
--- a/arch/powerpc/platforms/pseries/rng.c
+++ b/arch/powerpc/platforms/pseries/rng.c
@@ -14,6 +14,7 @@
#include <asm/archrandom.h>
#include <asm/machdep.h>
#include <asm/plpar_wrappers.h>
+#include "pseries.h"

static int pseries_get_random_long(unsigned long *v)
@@ -28,19 +29,13 @@ static int pseries_get_random_long(unsig
return 0;
}

-static __init int rng_init(void)
+void __init pseries_rng_init(void)
{
struct device_node *dn;

dn = of_find_compatible_node(NULL, NULL, "ibm,random");
if (!dn)
- return -ENODEV;
-
- pr_info("Registering arch random hook.\n");
-
+ return;
ppc_md.get_random_seed = pseries_get_random_long;
-
of_node_put(dn);
- return 0;
}
-machine_subsys_initcall(pseries, rng_init);
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -792,6 +792,7 @@ static void __init pSeries_setup_arch(vo
}

ppc_md.pcibios_root_bridge_prepare = pseries_root_bridge_prepare;
+ pseries_rng_init();
}

static void pseries_panic(char *str)