hwrng: cavium - Add Cavium HWRNG driver for ThunderX SoC.

The Cavium ThunderX SoC has a hardware random number generator.
This driver provides support using the HWRNG framework.

Signed-off-by: Omer Khaliq <okhaliq@caviumnetworks.com>
Signed-off-by: Ananth Jasty <Ananth.Jasty@cavium.com>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 56ad5a5..fb9c7ad 100644 (file)
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -410,6 +410,19 @@ config HW_RANDOM_MESON
 
          If unsure, say Y.
 
+config HW_RANDOM_CAVIUM
+       tristate "Cavium ThunderX Random Number Generator support"
+       depends on HW_RANDOM && PCI && (ARM64 || (COMPILE_TEST && 64BIT))
+       default HW_RANDOM
+       ---help---
+         This driver provides kernel-side support for the Random Number
+         Generator hardware found on Cavium SoCs.
+
+         To compile this driver as a module, choose M here: the
+         module will be called cavium_rng.
+
+         If unsure, say Y.
+
 endif # HW_RANDOM
 
 config UML_RANDOM

diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 04bb0b0..5f52b1e 100644 (file)
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -35,3 +35,4 @@ obj-$(CONFIG_HW_RANDOM_XGENE) += xgene-rng.o
 obj-$(CONFIG_HW_RANDOM_STM32) += stm32-rng.o
 obj-$(CONFIG_HW_RANDOM_PIC32) += pic32-rng.o
 obj-$(CONFIG_HW_RANDOM_MESON) += meson-rng.o
+obj-$(CONFIG_HW_RANDOM_CAVIUM) += cavium-rng.o cavium-rng-vf.o

diff --git a/drivers/char/hw_random/cavium-rng-vf.c b/drivers/char/hw_random/cavium-rng-vf.c
new file mode 100644 (file)
index 0000000..066ae0e
--- /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");

diff --git a/drivers/char/hw_random/cavium-rng.c b/drivers/char/hw_random/cavium-rng.c
new file mode 100644 (file)
index 0000000..a944e0a
--- /dev/null
+++ b/drivers/char/hw_random/cavium-rng.c
@@ -0,0 +1,94 @@
+/*
+ * 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>
+
+#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 */
+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");