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path: root/drivers/char/hw_random/cavium-rng-vf.c
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Diffstat (limited to 'drivers/char/hw_random/cavium-rng-vf.c')
-rw-r--r--drivers/char/hw_random/cavium-rng-vf.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/drivers/char/hw_random/cavium-rng-vf.c b/drivers/char/hw_random/cavium-rng-vf.c
new file mode 100644
index 000000000000..066ae0e78d63
--- /dev/null
+++ b/drivers/char/hw_random/cavium-rng-vf.c
@@ -0,0 +1,99 @@
+/*
+ * Hardware Random Number Generator support for Cavium, Inc.
+ * Thunder processor family.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * 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>
+
+struct cavium_rng {
+ struct hwrng ops;
+ void __iomem *result;
+};
+
+/* Read data from the RNG unit */
+static int cavium_rng_read(struct hwrng *rng, void *dat, size_t max, bool wait)
+{
+ struct cavium_rng *p = container_of(rng, struct cavium_rng, ops);
+ unsigned int size = max;
+
+ while (size >= 8) {
+ *((u64 *)dat) = readq(p->result);
+ size -= 8;
+ dat += 8;
+ }
+ while (size > 0) {
+ *((u8 *)dat) = readb(p->result);
+ size--;
+ dat++;
+ }
+ return max;
+}
+
+/* Map Cavium RNG to an HWRNG object */
+static int cavium_rng_probe_vf(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ struct cavium_rng *rng;
+ int ret;
+
+ rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
+ if (!rng)
+ return -ENOMEM;
+
+ /* Map the RNG result */
+ rng->result = pcim_iomap(pdev, 0, 0);
+ if (!rng->result) {
+ dev_err(&pdev->dev, "Error iomap failed retrieving result.\n");
+ return -ENOMEM;
+ }
+
+ rng->ops.name = "cavium rng";
+ rng->ops.read = cavium_rng_read;
+ rng->ops.quality = 1000;
+
+ pci_set_drvdata(pdev, rng);
+
+ ret = hwrng_register(&rng->ops);
+ if (ret) {
+ dev_err(&pdev->dev, "Error registering device as HWRNG.\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+/* Remove the VF */
+void cavium_rng_remove_vf(struct pci_dev *pdev)
+{
+ struct cavium_rng *rng;
+
+ rng = pci_get_drvdata(pdev);
+ hwrng_unregister(&rng->ops);
+}
+
+static const struct pci_device_id cavium_rng_vf_id_table[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa033), 0, 0, 0},
+ {0,},
+};
+MODULE_DEVICE_TABLE(pci, cavium_rng_vf_id_table);
+
+static struct pci_driver cavium_rng_vf_driver = {
+ .name = "cavium_rng_vf",
+ .id_table = cavium_rng_vf_id_table,
+ .probe = cavium_rng_probe_vf,
+ .remove = cavium_rng_remove_vf,
+};
+module_pci_driver(cavium_rng_vf_driver);
+
+MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
+MODULE_LICENSE("GPL");