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| author | Michael Ellerman | 2013-10-11 05:07:59 +0200 |
|---|---|---|
| committer | Benjamin Herrenschmidt | 2013-10-11 07:50:21 +0200 |
| commit | a489043f462639988f86c1cf49475580e9dba965 (patch) | |
| tree | bbd0a84b5755f096962aab9b3a36662bc3294846 | |
| parent | hwrng: Add a driver for the hwrng found in power7+ systems (diff) | |
| download | kernel-qcow2-linux-a489043f462639988f86c1cf49475580e9dba965.tar.gz kernel-qcow2-linux-a489043f462639988f86c1cf49475580e9dba965.tar.xz kernel-qcow2-linux-a489043f462639988f86c1cf49475580e9dba965.zip | |
powerpc/pseries: Implement arch_get_random_long() based on H_RANDOM
Add support for the arch_get_random_long() hook based on the H_RANDOM
hypervisor call. We trust the hypervisor to provide us with random data,
ie. we don't whiten it in anyway.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| -rw-r--r-- | arch/powerpc/platforms/pseries/Makefile | 2 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/rng.c | 44 |
2 files changed, 45 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile index 6c61ec5ee914..fbccac9cd2dc 100644 --- a/arch/powerpc/platforms/pseries/Makefile +++ b/arch/powerpc/platforms/pseries/Makefile @@ -3,7 +3,7 @@ ccflags-$(CONFIG_PPC_PSERIES_DEBUG) += -DDEBUG obj-y := lpar.o hvCall.o nvram.o reconfig.o \ setup.o iommu.o event_sources.o ras.o \ - firmware.o power.o dlpar.o mobility.o + firmware.o power.o dlpar.o mobility.o rng.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_SCANLOG) += scanlog.o obj-$(CONFIG_EEH) += eeh_pseries.o diff --git a/arch/powerpc/platforms/pseries/rng.c b/arch/powerpc/platforms/pseries/rng.c new file mode 100644 index 000000000000..a702f1c08242 --- /dev/null +++ b/arch/powerpc/platforms/pseries/rng.c @@ -0,0 +1,44 @@ +/* + * Copyright 2013, Michael Ellerman, IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#define pr_fmt(fmt) "pseries-rng: " fmt + +#include <linux/kernel.h> +#include <linux/of.h> +#include <asm/archrandom.h> +#include <asm/machdep.h> + + +static int pseries_get_random_long(unsigned long *v) +{ + unsigned long retbuf[PLPAR_HCALL_BUFSIZE]; + + if (plpar_hcall(H_RANDOM, retbuf) == H_SUCCESS) { + *v = retbuf[0]; + return 1; + } + + return 0; +} + +static __init int 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"); + + ppc_md.get_random_long = pseries_get_random_long; + + return 0; +} +subsys_initcall(rng_init); |