new file mode 100644
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+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ */
+
+/**
+ * DOC: Nitro Enclaves (NE) PCI device driver.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/nitro_enclaves.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+#include "ne_misc_dev.h"
+#include "ne_pci_dev.h"
+
+/**
+ * NE_DEFAULT_TIMEOUT_MSECS - Default timeout to wait for a reply from
+ * the NE PCI device.
+ */
+#define NE_DEFAULT_TIMEOUT_MSECS (120000) /* 120 sec */
+
+static const struct pci_device_id ne_pci_ids[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_AMAZON, PCI_DEVICE_ID_NE) },
+ { 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, ne_pci_ids);
+
+/**
+ * ne_setup_msix() - Setup MSI-X vectors for the PCI device.
+ * @pdev: PCI device to setup the MSI-X for.
+ *
+ * Context: Process context.
+ * Return:
+ * * 0 on success.
+ * * Negative return value on failure.
+ */
+static int ne_setup_msix(struct pci_dev *pdev)
+{
+ int nr_vecs = 0;
+ int rc = -EINVAL;
+
+ nr_vecs = pci_msix_vec_count(pdev);
+ if (nr_vecs < 0) {
+ rc = nr_vecs;
+
+ dev_err(&pdev->dev, "Error in getting vec count [rc=%d]\n", rc);
+
+ return rc;
+ }
+
+ rc = pci_alloc_irq_vectors(pdev, nr_vecs, nr_vecs, PCI_IRQ_MSIX);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Error in alloc MSI-X vecs [rc=%d]\n", rc);
+
+ return rc;
+ }
+
+ return 0;
+}
+
+/**
+ * ne_teardown_msix() - Teardown MSI-X vectors for the PCI device.
+ * @pdev: PCI device to teardown the MSI-X for.
+ *
+ * Context: Process context.
+ */
+static void ne_teardown_msix(struct pci_dev *pdev)
+{
+ pci_free_irq_vectors(pdev);
+}
+
+/**
+ * ne_pci_dev_enable() - Select the PCI device version and enable it.
+ * @pdev: PCI device to select version for and then enable.
+ *
+ * Context: Process context.
+ * Return:
+ * * 0 on success.
+ * * Negative return value on failure.
+ */
+static int ne_pci_dev_enable(struct pci_dev *pdev)
+{
+ u8 dev_enable_reply = 0;
+ u16 dev_version_reply = 0;
+ struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+ iowrite16(NE_VERSION_MAX, ne_pci_dev->iomem_base + NE_VERSION);
+
+ dev_version_reply = ioread16(ne_pci_dev->iomem_base + NE_VERSION);
+ if (dev_version_reply != NE_VERSION_MAX) {
+ dev_err(&pdev->dev, "Error in pci dev version cmd\n");
+
+ return -EIO;
+ }
+
+ iowrite8(NE_ENABLE_ON, ne_pci_dev->iomem_base + NE_ENABLE);
+
+ dev_enable_reply = ioread8(ne_pci_dev->iomem_base + NE_ENABLE);
+ if (dev_enable_reply != NE_ENABLE_ON) {
+ dev_err(&pdev->dev, "Error in pci dev enable cmd\n");
+
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/**
+ * ne_pci_dev_disable() - Disable the PCI device.
+ * @pdev: PCI device to disable.
+ *
+ * Context: Process context.
+ */
+static void ne_pci_dev_disable(struct pci_dev *pdev)
+{
+ u8 dev_disable_reply = 0;
+ struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+ const unsigned int sleep_time = 10; /* 10 ms */
+ unsigned int sleep_time_count = 0;
+
+ iowrite8(NE_ENABLE_OFF, ne_pci_dev->iomem_base + NE_ENABLE);
+
+ /*
+ * Check for NE_ENABLE_OFF in a loop, to handle cases when the device
+ * state is not immediately set to disabled and going through a
+ * transitory state of disabling.
+ */
+ while (sleep_time_count < NE_DEFAULT_TIMEOUT_MSECS) {
+ dev_disable_reply = ioread8(ne_pci_dev->iomem_base + NE_ENABLE);
+ if (dev_disable_reply == NE_ENABLE_OFF)
+ return;
+
+ msleep_interruptible(sleep_time);
+ sleep_time_count += sleep_time;
+ }
+
+ dev_disable_reply = ioread8(ne_pci_dev->iomem_base + NE_ENABLE);
+ if (dev_disable_reply != NE_ENABLE_OFF)
+ dev_err(&pdev->dev, "Error in pci dev disable cmd\n");
+}
+
+/**
+ * ne_pci_probe() - Probe function for the NE PCI device.
+ * @pdev: PCI device to match with the NE PCI driver.
+ * @id : PCI device id table associated with the NE PCI driver.
+ *
+ * Context: Process context.
+ * Return:
+ * * 0 on success.
+ * * Negative return value on failure.
+ */
+static int ne_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+ struct ne_pci_dev *ne_pci_dev = NULL;
+ int rc = -EINVAL;
+
+ ne_pci_dev = kzalloc(sizeof(*ne_pci_dev), GFP_KERNEL);
+ if (!ne_pci_dev)
+ return -ENOMEM;
+
+ rc = pci_enable_device(pdev);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Error in pci dev enable [rc=%d]\n", rc);
+
+ goto free_ne_pci_dev;
+ }
+
+ rc = pci_request_regions_exclusive(pdev, "nitro_enclaves");
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Error in pci request regions [rc=%d]\n", rc);
+
+ goto disable_pci_dev;
+ }
+
+ ne_pci_dev->iomem_base = pci_iomap(pdev, PCI_BAR_NE, 0);
+ if (!ne_pci_dev->iomem_base) {
+ rc = -ENOMEM;
+
+ dev_err(&pdev->dev, "Error in pci iomap [rc=%d]\n", rc);
+
+ goto release_pci_regions;
+ }
+
+ pci_set_drvdata(pdev, ne_pci_dev);
+
+ rc = ne_setup_msix(pdev);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Error in pci dev msix setup [rc=%d]\n", rc);
+
+ goto iounmap_pci_bar;
+ }
+
+ ne_pci_dev_disable(pdev);
+
+ rc = ne_pci_dev_enable(pdev);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Error in ne_pci_dev enable [rc=%d]\n", rc);
+
+ goto teardown_msix;
+ }
+
+ atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
+ init_waitqueue_head(&ne_pci_dev->cmd_reply_wait_q);
+ INIT_LIST_HEAD(&ne_pci_dev->enclaves_list);
+ mutex_init(&ne_pci_dev->enclaves_list_mutex);
+ mutex_init(&ne_pci_dev->pci_dev_mutex);
+ ne_pci_dev->pdev = pdev;
+
+ return 0;
+
+teardown_msix:
+ ne_teardown_msix(pdev);
+iounmap_pci_bar:
+ pci_set_drvdata(pdev, NULL);
+ pci_iounmap(pdev, ne_pci_dev->iomem_base);
+release_pci_regions:
+ pci_release_regions(pdev);
+disable_pci_dev:
+ pci_disable_device(pdev);
+free_ne_pci_dev:
+ kfree(ne_pci_dev);
+
+ return rc;
+}
+
+/**
+ * ne_pci_remove() - Remove function for the NE PCI device.
+ * @pdev: PCI device associated with the NE PCI driver.
+ *
+ * Context: Process context.
+ */
+static void ne_pci_remove(struct pci_dev *pdev)
+{
+ struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+ ne_pci_dev_disable(pdev);
+
+ ne_teardown_msix(pdev);
+
+ pci_set_drvdata(pdev, NULL);
+
+ pci_iounmap(pdev, ne_pci_dev->iomem_base);
+
+ pci_release_regions(pdev);
+
+ pci_disable_device(pdev);
+
+ kfree(ne_pci_dev);
+}
+
+/**
+ * ne_pci_shutdown() - Shutdown function for the NE PCI device.
+ * @pdev: PCI device associated with the NE PCI driver.
+ *
+ * Context: Process context.
+ */
+static void ne_pci_shutdown(struct pci_dev *pdev)
+{
+ struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+ if (!ne_pci_dev)
+ return;
+
+ ne_pci_dev_disable(pdev);
+
+ ne_teardown_msix(pdev);
+
+ pci_set_drvdata(pdev, NULL);
+
+ pci_iounmap(pdev, ne_pci_dev->iomem_base);
+
+ pci_release_regions(pdev);
+
+ pci_disable_device(pdev);
+
+ kfree(ne_pci_dev);
+}
+
+/*
+ * TODO: Add suspend / resume functions for power management w/ CONFIG_PM, if
+ * needed.
+ */
+/* NE PCI device driver. */
+struct pci_driver ne_pci_driver = {
+ .name = "nitro_enclaves",
+ .id_table = ne_pci_ids,
+ .probe = ne_pci_probe,
+ .remove = ne_pci_remove,
+ .shutdown = ne_pci_shutdown,
+};