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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;
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,
};
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