diff options
Diffstat (limited to 'drivers/crypto/ccp/ccp-dev.c')
| -rw-r--r-- | drivers/crypto/ccp/ccp-dev.c | 60 |
1 files changed, 56 insertions, 4 deletions
diff --git a/drivers/crypto/ccp/ccp-dev.c b/drivers/crypto/ccp/ccp-dev.c index 87b9f2bfa623..5d36eeff6d26 100644 --- a/drivers/crypto/ccp/ccp-dev.c +++ b/drivers/crypto/ccp/ccp-dev.c @@ -4,6 +4,7 @@ * Copyright (C) 2013,2016 Advanced Micro Devices, Inc. * * Author: Tom Lendacky <thomas.lendacky@amd.com> + * Author: Gary R Hook <gary.hook@amd.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -58,7 +59,7 @@ static struct ccp_device *ccp_rr; /* Ever-increasing value to produce unique unit numbers */ static atomic_t ccp_unit_ordinal; -unsigned int ccp_increment_unit_ordinal(void) +static unsigned int ccp_increment_unit_ordinal(void) { return atomic_inc_return(&ccp_unit_ordinal); } @@ -118,6 +119,29 @@ void ccp_del_device(struct ccp_device *ccp) write_unlock_irqrestore(&ccp_unit_lock, flags); } + + +int ccp_register_rng(struct ccp_device *ccp) +{ + int ret = 0; + + dev_dbg(ccp->dev, "Registering RNG...\n"); + /* Register an RNG */ + ccp->hwrng.name = ccp->rngname; + ccp->hwrng.read = ccp_trng_read; + ret = hwrng_register(&ccp->hwrng); + if (ret) + dev_err(ccp->dev, "error registering hwrng (%d)\n", ret); + + return ret; +} + +void ccp_unregister_rng(struct ccp_device *ccp) +{ + if (ccp->hwrng.name) + hwrng_unregister(&ccp->hwrng); +} + static struct ccp_device *ccp_get_device(void) { unsigned long flags; @@ -397,9 +421,9 @@ struct ccp_device *ccp_alloc_struct(struct device *dev) spin_lock_init(&ccp->cmd_lock); mutex_init(&ccp->req_mutex); - mutex_init(&ccp->ksb_mutex); - ccp->ksb_count = KSB_COUNT; - ccp->ksb_start = 0; + mutex_init(&ccp->sb_mutex); + ccp->sb_count = KSB_COUNT; + ccp->sb_start = 0; ccp->ord = ccp_increment_unit_ordinal(); snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", ccp->ord); @@ -408,6 +432,34 @@ struct ccp_device *ccp_alloc_struct(struct device *dev) return ccp; } +int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait) +{ + struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng); + u32 trng_value; + int len = min_t(int, sizeof(trng_value), max); + + /* Locking is provided by the caller so we can update device + * hwrng-related fields safely + */ + trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG); + if (!trng_value) { + /* Zero is returned if not data is available or if a + * bad-entropy error is present. Assume an error if + * we exceed TRNG_RETRIES reads of zero. + */ + if (ccp->hwrng_retries++ > TRNG_RETRIES) + return -EIO; + + return 0; + } + + /* Reset the counter and save the rng value */ + ccp->hwrng_retries = 0; + memcpy(data, &trng_value, len); + + return len; +} + #ifdef CONFIG_PM bool ccp_queues_suspended(struct ccp_device *ccp) { |