cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cavium-rng.c (2164B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Hardware Random Number Generator support.
      4 * Cavium Thunder, Marvell OcteonTx/Tx2 processor families.
      5 *
      6 * Copyright (C) 2016 Cavium, Inc.
      7 */
      8
      9#include <linux/hw_random.h>
     10#include <linux/io.h>
     11#include <linux/module.h>
     12#include <linux/pci.h>
     13#include <linux/pci_ids.h>
     14
     15#define THUNDERX_RNM_ENT_EN     0x1
     16#define THUNDERX_RNM_RNG_EN     0x2
     17
     18struct cavium_rng_pf {
     19	void __iomem *control_status;
     20};
     21
     22/* Enable the RNG hardware and activate the VF */
     23static int cavium_rng_probe(struct pci_dev *pdev,
     24			const struct pci_device_id *id)
     25{
     26	struct	cavium_rng_pf *rng;
     27	int	iov_err;
     28
     29	rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
     30	if (!rng)
     31		return -ENOMEM;
     32
     33	/*Map the RNG control */
     34	rng->control_status = pcim_iomap(pdev, 0, 0);
     35	if (!rng->control_status) {
     36		dev_err(&pdev->dev,
     37			"Error iomap failed retrieving control_status.\n");
     38		return -ENOMEM;
     39	}
     40
     41	/* Enable the RNG hardware and entropy source */
     42	writeq(THUNDERX_RNM_RNG_EN | THUNDERX_RNM_ENT_EN,
     43		rng->control_status);
     44
     45	pci_set_drvdata(pdev, rng);
     46
     47	/* Enable the Cavium RNG as a VF */
     48	iov_err = pci_enable_sriov(pdev, 1);
     49	if (iov_err != 0) {
     50		/* Disable the RNG hardware and entropy source */
     51		writeq(0, rng->control_status);
     52		dev_err(&pdev->dev,
     53			"Error initializing RNG virtual function,(%i).\n",
     54			iov_err);
     55		return iov_err;
     56	}
     57
     58	return 0;
     59}
     60
     61/* Disable VF and RNG Hardware */
     62static void cavium_rng_remove(struct pci_dev *pdev)
     63{
     64	struct cavium_rng_pf *rng;
     65
     66	rng = pci_get_drvdata(pdev);
     67
     68	/* Remove the VF */
     69	pci_disable_sriov(pdev);
     70
     71	/* Disable the RNG hardware and entropy source */
     72	writeq(0, rng->control_status);
     73}
     74
     75static const struct pci_device_id cavium_rng_pf_id_table[] = {
     76	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa018), 0, 0, 0}, /* Thunder RNM */
     77	{0,},
     78};
     79
     80MODULE_DEVICE_TABLE(pci, cavium_rng_pf_id_table);
     81
     82static struct pci_driver cavium_rng_pf_driver = {
     83	.name		= "cavium_rng_pf",
     84	.id_table	= cavium_rng_pf_id_table,
     85	.probe		= cavium_rng_probe,
     86	.remove		= cavium_rng_remove,
     87};
     88
     89module_pci_driver(cavium_rng_pf_driver);
     90MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
     91MODULE_LICENSE("GPL v2");