projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 649e9ea0 KY |
1 | /* |
| 2 | * Copyright (C) 2010 Michael Neuling IBM Corporation | |
| 3 | * | |
| 4 | * Driver for the pseries hardware RNG for POWER7+ and above | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or modify | |
| 7 | * it under the terms of the GNU General Public License version 2 as | |
| 8 | * published by the Free Software Foundation. | |
| 9 | * | |
| 10 | * This program is distributed in the hope that it will be useful, | |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 13 | * GNU General Public License for more details. | |
| 14 | * | |
| 15 | * You should have received a copy of the GNU General Public License | |
| 16 | * along with this program; if not, write to the Free Software | |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | */ | |
| 19 | ||
| 20 | #include <linux/module.h> | |
| 21 | #include <linux/hw_random.h> | |
| 22 | #include <asm/vio.h> | |
| 23 | ||
| 24 | #define MODULE_NAME "pseries-rng" | |
| 25 | ||
| 26 | static int pseries_rng_data_read(struct hwrng *rng, u32 *data) | |
| 27 | { | |
| 28 | if (plpar_hcall(H_RANDOM, (unsigned long *)data) != H_SUCCESS) { | |
| 29 | printk(KERN_ERR "pseries rng hcall error\n"); | |
| 30 | return 0; | |
| 31 | } | |
| 32 | return 8; | |
| 33 | } | |
| 34 | ||
| 35 | /** | |
| 36 | * pseries_rng_get_desired_dma - Return desired DMA allocate for CMO operations | |
| 37 | * | |
| 38 | * This is a required function for a driver to operate in a CMO environment | |
| 39 | * but this device does not make use of DMA allocations, return 0. | |
| 40 | * | |
| 41 | * Return value: | |
| 42 | * Number of bytes of IO data the driver will need to perform well -> 0 | |
| 43 | */ | |
| 44 | static unsigned long pseries_rng_get_desired_dma(struct vio_dev *vdev) | |
| 45 | { | |
| 46 | return 0; | |
| 47 | }; | |
| 48 | ||
| 49 | static struct hwrng pseries_rng = { | |
| 50 | .name = MODULE_NAME, | |
| 51 | .data_read = pseries_rng_data_read, | |
| 52 | }; | |
| 53 | ||
| 54 | static int __init pseries_rng_probe(struct vio_dev *dev, | |
| 55 | const struct vio_device_id *id) | |
| 56 | { | |
| 57 | return hwrng_register(&pseries_rng); | |
| 58 | } | |
| 59 | ||
| 60 | static int __exit pseries_rng_remove(struct vio_dev *dev) | |
| 61 | { | |
| 62 | hwrng_unregister(&pseries_rng); | |
| 63 | return 0; | |
| 64 | } | |
| 65 | ||
| 66 | static struct vio_device_id pseries_rng_driver_ids[] = { | |
| 67 | { "ibm,random-v1", "ibm,random"}, | |
| 68 | { "", "" } | |
| 69 | }; | |
| 70 | MODULE_DEVICE_TABLE(vio, pseries_rng_driver_ids); | |
| 71 | ||
| 72 | static struct vio_driver pseries_rng_driver = { | |
| 73 | .name = MODULE_NAME, | |
| 74 | .probe = pseries_rng_probe, | |
| 75 | .remove = pseries_rng_remove, | |
| 76 | .get_desired_dma = pseries_rng_get_desired_dma, | |
| 77 | .id_table = pseries_rng_driver_ids | |
| 78 | }; | |
| 79 | ||
| 80 | static int __init rng_init(void) | |
| 81 | { | |
| 82 | printk(KERN_INFO "Registering IBM pSeries RNG driver\n"); | |
| 83 | return vio_register_driver(&pseries_rng_driver); | |
| 84 | } | |
| 85 | ||
| 86 | module_init(rng_init); | |
| 87 | ||
| 88 | static void __exit rng_exit(void) | |
| 89 | { | |
| 90 | vio_unregister_driver(&pseries_rng_driver); | |
| 91 | } | |
| 92 | module_exit(rng_exit); | |
| 93 | ||
| 94 | MODULE_LICENSE("GPL"); | |
| 95 | MODULE_AUTHOR("Michael Neuling <mikey@neuling.org>"); | |
| 96 | MODULE_DESCRIPTION("H/W RNG driver for IBM pSeries processors"); |