diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/Kconfig | 3 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/archrandom.h | 32 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/machdep.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/Makefile | 2 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/rng.c | 122 |
6 files changed, 163 insertions, 1 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index c5a868bc7aa4..875d815a8e7f 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -1012,6 +1012,9 @@ config PHYSICAL_START default "0x00000000" endif +config ARCH_RANDOM + def_bool n + source "net/Kconfig" source "drivers/Kconfig" diff --git a/arch/powerpc/include/asm/archrandom.h b/arch/powerpc/include/asm/archrandom.h new file mode 100644 index 000000000000..d853d163ba47 --- /dev/null +++ b/arch/powerpc/include/asm/archrandom.h @@ -0,0 +1,32 @@ +#ifndef _ASM_POWERPC_ARCHRANDOM_H +#define _ASM_POWERPC_ARCHRANDOM_H + +#ifdef CONFIG_ARCH_RANDOM + +#include <asm/machdep.h> + +static inline int arch_get_random_long(unsigned long *v) +{ + if (ppc_md.get_random_long) + return ppc_md.get_random_long(v); + + return 0; +} + +static inline int arch_get_random_int(unsigned int *v) +{ + unsigned long val; + int rc; + + rc = arch_get_random_long(&val); + if (rc) + *v = val; + + return rc; +} + +int powernv_get_random_long(unsigned long *v); + +#endif /* CONFIG_ARCH_RANDOM */ + +#endif /* _ASM_POWERPC_ARCHRANDOM_H */ diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h index 8b480901165a..ce6cc2a7b8b9 100644 --- a/arch/powerpc/include/asm/machdep.h +++ b/arch/powerpc/include/asm/machdep.h @@ -263,6 +263,10 @@ struct machdep_calls { ssize_t (*cpu_probe)(const char *, size_t); ssize_t (*cpu_release)(const char *, size_t); #endif + +#ifdef CONFIG_ARCH_RANDOM + int (*get_random_long)(unsigned long *v); +#endif }; extern void e500_idle(void); diff --git a/arch/powerpc/platforms/powernv/Kconfig b/arch/powerpc/platforms/powernv/Kconfig index 6fae5eb99ea6..21084645c70a 100644 --- a/arch/powerpc/platforms/powernv/Kconfig +++ b/arch/powerpc/platforms/powernv/Kconfig @@ -9,6 +9,7 @@ config PPC_POWERNV select EPAPR_BOOT select PPC_INDIRECT_PIO select PPC_UDBG_16550 + select ARCH_RANDOM default y config POWERNV_MSI diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile index 300c437d713c..6760a86d5bd0 100644 --- a/arch/powerpc/platforms/powernv/Makefile +++ b/arch/powerpc/platforms/powernv/Makefile @@ -1,5 +1,5 @@ obj-y += setup.o opal-takeover.o opal-wrappers.o opal.o -obj-y += opal-rtc.o opal-nvram.o opal-lpc.o +obj-y += opal-rtc.o opal-nvram.o opal-lpc.o rng.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_PCI) += pci.o pci-p5ioc2.o pci-ioda.o diff --git a/arch/powerpc/platforms/powernv/rng.c b/arch/powerpc/platforms/powernv/rng.c new file mode 100644 index 000000000000..02db7d73cf8b --- /dev/null +++ b/arch/powerpc/platforms/powernv/rng.c @@ -0,0 +1,122 @@ +/* + * 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) "powernv-rng: " fmt + +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/slab.h> +#include <asm/archrandom.h> +#include <asm/io.h> +#include <asm/machdep.h> + + +struct powernv_rng { + void __iomem *regs; + unsigned long mask; +}; + +static DEFINE_PER_CPU(struct powernv_rng *, powernv_rng); + + +static unsigned long rng_whiten(struct powernv_rng *rng, unsigned long val) +{ + unsigned long parity; + + /* Calculate the parity of the value */ + asm ("popcntd %0,%1" : "=r" (parity) : "r" (val)); + + /* xor our value with the previous mask */ + val ^= rng->mask; + + /* update the mask based on the parity of this value */ + rng->mask = (rng->mask << 1) | (parity & 1); + + return val; +} + +int powernv_get_random_long(unsigned long *v) +{ + struct powernv_rng *rng; + + rng = get_cpu_var(powernv_rng); + + *v = rng_whiten(rng, in_be64(rng->regs)); + + put_cpu_var(rng); + + return 1; +} +EXPORT_SYMBOL_GPL(powernv_get_random_long); + +static __init void rng_init_per_cpu(struct powernv_rng *rng, + struct device_node *dn) +{ + int chip_id, cpu; + + chip_id = of_get_ibm_chip_id(dn); + if (chip_id == -1) + pr_warn("No ibm,chip-id found for %s.\n", dn->full_name); + + for_each_possible_cpu(cpu) { + if (per_cpu(powernv_rng, cpu) == NULL || + cpu_to_chip_id(cpu) == chip_id) { + per_cpu(powernv_rng, cpu) = rng; + } + } +} + +static __init int rng_create(struct device_node *dn) +{ + struct powernv_rng *rng; + unsigned long val; + + rng = kzalloc(sizeof(*rng), GFP_KERNEL); + if (!rng) + return -ENOMEM; + + rng->regs = of_iomap(dn, 0); + if (!rng->regs) { + kfree(rng); + return -ENXIO; + } + + val = in_be64(rng->regs); + rng->mask = val; + + rng_init_per_cpu(rng, dn); + + pr_info_once("Registering arch random hook.\n"); + + ppc_md.get_random_long = powernv_get_random_long; + + return 0; +} + +static __init int rng_init(void) +{ + struct device_node *dn; + int rc; + + for_each_compatible_node(dn, NULL, "ibm,power-rng") { + rc = rng_create(dn); + if (rc) { + pr_err("Failed creating rng for %s (%d).\n", + dn->full_name, rc); + continue; + } + + /* Create devices for hwrng driver */ + of_platform_device_create(dn, NULL, NULL); + } + + return 0; +} +subsys_initcall(rng_init); |