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)HVM_PARAM_CALLBACK_TYPE_PCI_INTX <<
58			  HVM_CALLBACK_VIA_TYPE_SHIFT) |
59		((uint64_t)pci_domain_nr(pdev->bus) << 32) |
60		((uint64_t)pdev->bus->number << 16) |
61		((uint64_t)(pdev->devfn & 0xff) << 8) |
62		((uint64_t)(pin - 1) & 3);
63}
64
65static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
66{
67	return xen_evtchn_do_upcall();
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_SHARED,
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 irq_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 irq_out;
156	ret = gnttab_init();
157	if (ret)
158		goto grant_out;
159	return 0;
160grant_out:
161	gnttab_free_auto_xlat_frames();
162irq_out:
163	if (!xen_have_vector_callback)
164		free_irq(pdev->irq, pdev);
165out:
166	pci_release_region(pdev, 0);
167mem_out:
168	pci_release_region(pdev, 1);
169pci_out:
170	pci_disable_device(pdev);
171	return ret;
172}
173
174static const struct pci_device_id platform_pci_tbl[] = {
175	{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
176		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
177	{0,}
178};
179
180static const struct dev_pm_ops platform_pm_ops = {
181	.resume_noirq =   platform_pci_resume,
182};
183
184static struct pci_driver platform_driver = {
185	.name =           DRV_NAME,
186	.probe =          platform_pci_probe,
187	.id_table =       platform_pci_tbl,
188	.driver = {
189		.pm =     &platform_pm_ops,
190	},
191};
192
193builtin_pci_driver(platform_driver);
194