aad887f664
Device number (the character device index) is not a stable identifier for a TPM chip. That is the reason why every call site passes TPM_ANY_NUM to tpm_chip_find_get(). This commit changes the API in a way that instead a struct tpm_chip instance is given and NULL means the default chip. In addition, this commit refines the documentation to be up to date with the implementation. Suggested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> (@chip_num -> @chip part) Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@ziepe.ca> Tested-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
51 lines
1.4 KiB
C
51 lines
1.4 KiB
C
/*
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* Copyright (C) 2012 Kent Yoder IBM Corporation
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*
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* HWRNG interfaces to pull RNG data from a TPM
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/module.h>
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#include <linux/hw_random.h>
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#include <linux/tpm.h>
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#define MODULE_NAME "tpm-rng"
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static int tpm_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
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{
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return tpm_get_random(NULL, data, max);
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}
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static struct hwrng tpm_rng = {
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.name = MODULE_NAME,
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.read = tpm_rng_read,
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};
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static int __init rng_init(void)
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{
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return hwrng_register(&tpm_rng);
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}
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module_init(rng_init);
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static void __exit rng_exit(void)
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{
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hwrng_unregister(&tpm_rng);
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}
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module_exit(rng_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Kent Yoder <key@linux.vnet.ibm.com>");
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MODULE_DESCRIPTION("RNG driver for TPM devices");
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