platform-pci.c

  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
 29#define PCI_DEVICE_ID_XEN_PLATFORM_XS61	0x0002
 30
 31static unsigned long platform_mmio;
 32static unsigned long platform_mmio_alloc;
 33static unsigned long platform_mmiolen;
 34static uint64_t callback_via;
 35
 36static unsigned long alloc_xen_mmio(unsigned long len)
 37{
 38	unsigned long addr;
 39
 40	addr = platform_mmio + platform_mmio_alloc;
 41	platform_mmio_alloc += len;
 42	BUG_ON(platform_mmio_alloc > platform_mmiolen);
 43
 44	return addr;
 45}
 46
 47static uint64_t get_callback_via(struct pci_dev *pdev)
 48{
 49	u8 pin;
 50	int irq;
 51
 52	irq = pdev->irq;
 53	if (irq < 16)
 54		return irq; /* ISA IRQ */
 55
 56	pin = pdev->pin;
 57
 58	/* We don't know the GSI. Specify the PCI INTx line instead. */
 59	return ((uint64_t)HVM_PARAM_CALLBACK_TYPE_PCI_INTX <<
 60			  HVM_CALLBACK_VIA_TYPE_SHIFT) |
 61		((uint64_t)pci_domain_nr(pdev->bus) << 32) |
 62		((uint64_t)pdev->bus->number << 16) |
 63		((uint64_t)(pdev->devfn & 0xff) << 8) |
 64		((uint64_t)(pin - 1) & 3);
 65}
 66
 67static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
 68{
 69	return xen_evtchn_do_upcall();
 70}
 71
 72static int xen_allocate_irq(struct pci_dev *pdev)
 73{
 74	return request_irq(pdev->irq, do_hvm_evtchn_intr,
 75			IRQF_NOBALANCING | IRQF_SHARED,
 76			"xen-platform-pci", pdev);
 77}
 78
 79static int platform_pci_resume(struct device *dev)
 80{
 81	int err;
 82
 83	if (xen_have_vector_callback)
 84		return 0;
 85
 86	err = xen_set_callback_via(callback_via);
 87	if (err) {
 88		dev_err(dev, "platform_pci_resume failure!\n");
 89		return err;
 90	}
 91	return 0;
 92}
 93
 94static int platform_pci_probe(struct pci_dev *pdev,
 95			      const struct pci_device_id *ent)
 96{
 97	int i, ret;
 98	long ioaddr;
 99	long mmio_addr, mmio_len;
100	unsigned int max_nr_gframes;
101	unsigned long grant_frames;
102
103	if (!xen_domain())
104		return -ENODEV;
105
106	i = pci_enable_device(pdev);
107	if (i)
108		return i;
109
110	ioaddr = pci_resource_start(pdev, 0);
111
112	mmio_addr = pci_resource_start(pdev, 1);
113	mmio_len = pci_resource_len(pdev, 1);
114
115	if (mmio_addr == 0 || ioaddr == 0) {
116		dev_err(&pdev->dev, "no resources found\n");
117		ret = -ENOENT;
118		goto pci_out;
119	}
120
121	ret = pci_request_region(pdev, 1, DRV_NAME);
122	if (ret < 0)
123		goto pci_out;
124
125	ret = pci_request_region(pdev, 0, DRV_NAME);
126	if (ret < 0)
127		goto mem_out;
128
129	platform_mmio = mmio_addr;
130	platform_mmiolen = mmio_len;
131	if (!xen_have_vector_callback) {
132		ret = xen_allocate_irq(pdev);
133		if (ret) {
134			dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
135			goto out;
136		}
137		/*
138		 * It doesn't strictly *have* to run on CPU0 but it sure
139		 * as hell better process the event channel ports delivered
140		 * to CPU0.
141		 */
142		irq_set_affinity(pdev->irq, cpumask_of(0));
143
144		callback_via = get_callback_via(pdev);
145		ret = xen_set_callback_via(callback_via);
146		if (ret) {
147			dev_warn(&pdev->dev, "Unable to set the evtchn callback "
148					 "err=%d\n", ret);
149			goto irq_out;
150		}
151	}
152
153	max_nr_gframes = gnttab_max_grant_frames();
154	grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
155	ret = gnttab_setup_auto_xlat_frames(grant_frames);
156	if (ret)
157		goto irq_out;
158	ret = gnttab_init();
159	if (ret)
160		goto grant_out;
161	return 0;
162grant_out:
163	gnttab_free_auto_xlat_frames();
164irq_out:
165	if (!xen_have_vector_callback)
166		free_irq(pdev->irq, pdev);
167out:
168	pci_release_region(pdev, 0);
169mem_out:
170	pci_release_region(pdev, 1);
171pci_out:
172	pci_disable_device(pdev);
173	return ret;
174}
175
176static const struct pci_device_id platform_pci_tbl[] = {
177	{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
178		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
179	{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM_XS61,
180		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
181	{0,}
182};
183
184static const struct dev_pm_ops platform_pm_ops = {
185	.resume_noirq =   platform_pci_resume,
186};
187
188static struct pci_driver platform_driver = {
189	.name =           DRV_NAME,
190	.probe =          platform_pci_probe,
191	.id_table =       platform_pci_tbl,
192	.driver = {
193		.pm =     &platform_pm_ops,
194	},
195};
196
197builtin_pci_driver(platform_driver);