cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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platform-pci.c (4241B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/******************************************************************************
      3 * platform-pci.c
      4 *
      5 * Xen platform PCI device driver
      6 *
      7 * Authors: ssmith@xensource.com and stefano.stabellini@eu.citrix.com
      8 *
      9 * Copyright (c) 2005, Intel Corporation.
     10 * Copyright (c) 2007, XenSource Inc.
     11 * Copyright (c) 2010, Citrix
     12 */
     13
     14
     15#include <linux/interrupt.h>
     16#include <linux/io.h>
     17#include <linux/init.h>
     18#include <linux/pci.h>
     19
     20#include <xen/platform_pci.h>
     21#include <xen/grant_table.h>
     22#include <xen/xenbus.h>
     23#include <xen/events.h>
     24#include <xen/hvm.h>
     25#include <xen/xen-ops.h>
     26
     27#define DRV_NAME    "xen-platform-pci"
     28
     29static unsigned long platform_mmio;
     30static unsigned long platform_mmio_alloc;
     31static unsigned long platform_mmiolen;
     32static uint64_t callback_via;
     33
     34static unsigned long alloc_xen_mmio(unsigned long len)
     35{
     36	unsigned long addr;
     37
     38	addr = platform_mmio + platform_mmio_alloc;
     39	platform_mmio_alloc += len;
     40	BUG_ON(platform_mmio_alloc > platform_mmiolen);
     41
     42	return addr;
     43}
     44
     45static uint64_t get_callback_via(struct pci_dev *pdev)
     46{
     47	u8 pin;
     48	int irq;
     49
     50	irq = pdev->irq;
     51	if (irq < 16)
     52		return irq; /* ISA IRQ */
     53
     54	pin = pdev->pin;
     55
     56	/* We don't know the GSI. Specify the PCI INTx line instead. */
     57	return ((uint64_t)0x01 << HVM_CALLBACK_VIA_TYPE_SHIFT) | /* PCI INTx identifier */
     58		((uint64_t)pci_domain_nr(pdev->bus) << 32) |
     59		((uint64_t)pdev->bus->number << 16) |
     60		((uint64_t)(pdev->devfn & 0xff) << 8) |
     61		((uint64_t)(pin - 1) & 3);
     62}
     63
     64static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
     65{
     66	xen_hvm_evtchn_do_upcall();
     67	return IRQ_HANDLED;
     68}
     69
     70static int xen_allocate_irq(struct pci_dev *pdev)
     71{
     72	return request_irq(pdev->irq, do_hvm_evtchn_intr,
     73			IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
     74			"xen-platform-pci", pdev);
     75}
     76
     77static int platform_pci_resume(struct device *dev)
     78{
     79	int err;
     80
     81	if (xen_have_vector_callback)
     82		return 0;
     83
     84	err = xen_set_callback_via(callback_via);
     85	if (err) {
     86		dev_err(dev, "platform_pci_resume failure!\n");
     87		return err;
     88	}
     89	return 0;
     90}
     91
     92static int platform_pci_probe(struct pci_dev *pdev,
     93			      const struct pci_device_id *ent)
     94{
     95	int i, ret;
     96	long ioaddr;
     97	long mmio_addr, mmio_len;
     98	unsigned int max_nr_gframes;
     99	unsigned long grant_frames;
    100
    101	if (!xen_domain())
    102		return -ENODEV;
    103
    104	i = pci_enable_device(pdev);
    105	if (i)
    106		return i;
    107
    108	ioaddr = pci_resource_start(pdev, 0);
    109
    110	mmio_addr = pci_resource_start(pdev, 1);
    111	mmio_len = pci_resource_len(pdev, 1);
    112
    113	if (mmio_addr == 0 || ioaddr == 0) {
    114		dev_err(&pdev->dev, "no resources found\n");
    115		ret = -ENOENT;
    116		goto pci_out;
    117	}
    118
    119	ret = pci_request_region(pdev, 1, DRV_NAME);
    120	if (ret < 0)
    121		goto pci_out;
    122
    123	ret = pci_request_region(pdev, 0, DRV_NAME);
    124	if (ret < 0)
    125		goto mem_out;
    126
    127	platform_mmio = mmio_addr;
    128	platform_mmiolen = mmio_len;
    129	if (!xen_have_vector_callback) {
    130		ret = xen_allocate_irq(pdev);
    131		if (ret) {
    132			dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
    133			goto out;
    134		}
    135		/*
    136		 * It doesn't strictly *have* to run on CPU0 but it sure
    137		 * as hell better process the event channel ports delivered
    138		 * to CPU0.
    139		 */
    140		irq_set_affinity(pdev->irq, cpumask_of(0));
    141
    142		callback_via = get_callback_via(pdev);
    143		ret = xen_set_callback_via(callback_via);
    144		if (ret) {
    145			dev_warn(&pdev->dev, "Unable to set the evtchn callback "
    146					 "err=%d\n", ret);
    147			goto out;
    148		}
    149	}
    150
    151	max_nr_gframes = gnttab_max_grant_frames();
    152	grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
    153	ret = gnttab_setup_auto_xlat_frames(grant_frames);
    154	if (ret)
    155		goto out;
    156	ret = gnttab_init();
    157	if (ret)
    158		goto grant_out;
    159	return 0;
    160grant_out:
    161	gnttab_free_auto_xlat_frames();
    162out:
    163	pci_release_region(pdev, 0);
    164mem_out:
    165	pci_release_region(pdev, 1);
    166pci_out:
    167	pci_disable_device(pdev);
    168	return ret;
    169}
    170
    171static const struct pci_device_id platform_pci_tbl[] = {
    172	{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
    173		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
    174	{0,}
    175};
    176
    177static const struct dev_pm_ops platform_pm_ops = {
    178	.resume_noirq =   platform_pci_resume,
    179};
    180
    181static struct pci_driver platform_driver = {
    182	.name =           DRV_NAME,
    183	.probe =          platform_pci_probe,
    184	.id_table =       platform_pci_tbl,
    185	.driver = {
    186		.pm =     &platform_pm_ops,
    187	},
    188};
    189
    190builtin_pci_driver(platform_driver);