1 files changed, 304 insertions, 0 deletions
diff --git a/drivers/virt/nitro_enclaves/ne_pci_dev.c b/drivers/virt/nitro_enclaves/ne_pci_dev.c
new file mode 100644
index 000000000000..32f07345c3b5
--- /dev/null
+++ b/drivers/virt/nitro_enclaves/ne_pci_dev.c
@@ -0,0 +1,304 @@
+// 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;
+
+	ne_devs.ne_pci_dev = ne_pci_dev;
+
+	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_devs.ne_pci_dev = NULL;
+
+	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_devs.ne_pci_dev = NULL;
+
+	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,
+};