/*
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* Hardware Random Number Generator support for Cavium, Inc.
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* Thunder processor family.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2016 Cavium, Inc.
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*/
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#include <linux/hw_random.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/pci_ids.h>
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struct cavium_rng {
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struct hwrng ops;
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void __iomem *result;
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};
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/* Read data from the RNG unit */
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static int cavium_rng_read(struct hwrng *rng, void *dat, size_t max, bool wait)
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{
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struct cavium_rng *p = container_of(rng, struct cavium_rng, ops);
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unsigned int size = max;
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while (size >= 8) {
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*((u64 *)dat) = readq(p->result);
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size -= 8;
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dat += 8;
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}
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while (size > 0) {
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*((u8 *)dat) = readb(p->result);
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size--;
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dat++;
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}
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return max;
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}
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/* Map Cavium RNG to an HWRNG object */
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static int cavium_rng_probe_vf(struct pci_dev *pdev,
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const struct pci_device_id *id)
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{
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struct cavium_rng *rng;
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int ret;
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rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
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if (!rng)
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return -ENOMEM;
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/* Map the RNG result */
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rng->result = pcim_iomap(pdev, 0, 0);
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if (!rng->result) {
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dev_err(&pdev->dev, "Error iomap failed retrieving result.\n");
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return -ENOMEM;
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}
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rng->ops.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
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"cavium-rng-%s", dev_name(&pdev->dev));
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if (!rng->ops.name)
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return -ENOMEM;
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rng->ops.read = cavium_rng_read;
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rng->ops.quality = 1000;
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pci_set_drvdata(pdev, rng);
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ret = hwrng_register(&rng->ops);
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if (ret) {
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dev_err(&pdev->dev, "Error registering device as HWRNG.\n");
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return ret;
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}
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return 0;
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}
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/* Remove the VF */
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static void cavium_rng_remove_vf(struct pci_dev *pdev)
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{
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struct cavium_rng *rng;
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rng = pci_get_drvdata(pdev);
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hwrng_unregister(&rng->ops);
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}
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static const struct pci_device_id cavium_rng_vf_id_table[] = {
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{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa033), 0, 0, 0},
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{0,},
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};
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MODULE_DEVICE_TABLE(pci, cavium_rng_vf_id_table);
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static struct pci_driver cavium_rng_vf_driver = {
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.name = "cavium_rng_vf",
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.id_table = cavium_rng_vf_id_table,
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.probe = cavium_rng_probe_vf,
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.remove = cavium_rng_remove_vf,
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};
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module_pci_driver(cavium_rng_vf_driver);
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MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
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MODULE_LICENSE("GPL");
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