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path: root/drivers/char/hw_random/cavium-rng.c
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-rw-r--r--drivers/char/hw_random/cavium-rng.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/char/hw_random/cavium-rng.c b/drivers/char/hw_random/cavium-rng.c
new file mode 100644
index 000000000..b96579222
--- /dev/null
+++ b/drivers/char/hw_random/cavium-rng.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hardware Random Number Generator support.
+ * Cavium Thunder, Marvell OcteonTx/Tx2 processor families.
+ *
+ * Copyright (C) 2016 Cavium, Inc.
+ */
+
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+
+#define THUNDERX_RNM_ENT_EN 0x1
+#define THUNDERX_RNM_RNG_EN 0x2
+
+struct cavium_rng_pf {
+ void __iomem *control_status;
+};
+
+/* Enable the RNG hardware and activate the VF */
+static int cavium_rng_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ struct cavium_rng_pf *rng;
+ int iov_err;
+
+ rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
+ if (!rng)
+ return -ENOMEM;
+
+ /*Map the RNG control */
+ rng->control_status = pcim_iomap(pdev, 0, 0);
+ if (!rng->control_status) {
+ dev_err(&pdev->dev,
+ "Error iomap failed retrieving control_status.\n");
+ return -ENOMEM;
+ }
+
+ /* Enable the RNG hardware and entropy source */
+ writeq(THUNDERX_RNM_RNG_EN | THUNDERX_RNM_ENT_EN,
+ rng->control_status);
+
+ pci_set_drvdata(pdev, rng);
+
+ /* Enable the Cavium RNG as a VF */
+ iov_err = pci_enable_sriov(pdev, 1);
+ if (iov_err != 0) {
+ /* Disable the RNG hardware and entropy source */
+ writeq(0, rng->control_status);
+ dev_err(&pdev->dev,
+ "Error initializing RNG virtual function,(%i).\n",
+ iov_err);
+ return iov_err;
+ }
+
+ return 0;
+}
+
+/* Disable VF and RNG Hardware */
+static void cavium_rng_remove(struct pci_dev *pdev)
+{
+ struct cavium_rng_pf *rng;
+
+ rng = pci_get_drvdata(pdev);
+
+ /* Remove the VF */
+ pci_disable_sriov(pdev);
+
+ /* Disable the RNG hardware and entropy source */
+ writeq(0, rng->control_status);
+}
+
+static const struct pci_device_id cavium_rng_pf_id_table[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa018), 0, 0, 0}, /* Thunder RNM */
+ {0,},
+};
+
+MODULE_DEVICE_TABLE(pci, cavium_rng_pf_id_table);
+
+static struct pci_driver cavium_rng_pf_driver = {
+ .name = "cavium_rng_pf",
+ .id_table = cavium_rng_pf_id_table,
+ .probe = cavium_rng_probe,
+ .remove = cavium_rng_remove,
+};
+
+module_pci_driver(cavium_rng_pf_driver);
+MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
+MODULE_LICENSE("GPL v2");