Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Copyright (C) 2010 Michael Neuling IBM Corporation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Driver for the pseries hardware RNG for POWER7+ and above
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/hw_random.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <asm/vio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) static int pseries_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	u64 buffer[PLPAR_HCALL_BUFSIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	int rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	rc = plpar_hcall(H_RANDOM, (unsigned long *)buffer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	if (rc != H_SUCCESS) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 		pr_err_ratelimited("H_RANDOM call failed %d\n", rc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	memcpy(data, buffer, 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	/* The hypervisor interface returns 64 bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	return 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)  * pseries_rng_get_desired_dma - Return desired DMA allocate for CMO operations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)  * This is a required function for a driver to operate in a CMO environment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)  * but this device does not make use of DMA allocations, return 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)  * Return value:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)  *	Number of bytes of IO data the driver will need to perform well -> 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static unsigned long pseries_rng_get_desired_dma(struct vio_dev *vdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) static struct hwrng pseries_rng = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	.name		= KBUILD_MODNAME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	.read		= pseries_rng_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) static int pseries_rng_probe(struct vio_dev *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		const struct vio_device_id *id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	return hwrng_register(&pseries_rng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) static int pseries_rng_remove(struct vio_dev *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 	hwrng_unregister(&pseries_rng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) static const struct vio_device_id pseries_rng_driver_ids[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 	{ "ibm,random-v1", "ibm,random"},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 	{ "", "" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) MODULE_DEVICE_TABLE(vio, pseries_rng_driver_ids);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) static struct vio_driver pseries_rng_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 	.name = KBUILD_MODNAME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	.probe = pseries_rng_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 	.remove = pseries_rng_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 	.get_desired_dma = pseries_rng_get_desired_dma,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 	.id_table = pseries_rng_driver_ids
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) static int __init rng_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) 	pr_info("Registering IBM pSeries RNG driver\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) 	return vio_register_driver(&pseries_rng_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) module_init(rng_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) static void __exit rng_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) 	vio_unregister_driver(&pseries_rng_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) module_exit(rng_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) MODULE_AUTHOR("Michael Neuling <mikey@neuling.org>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) MODULE_DESCRIPTION("H/W RNG driver for IBM pSeries processors");