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 static unsigned long platform_mmio; 30 static unsigned long platform_mmio_alloc; 31 static unsigned long platform_mmiolen; 32 static uint64_t callback_via; 33 34 static 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 45 static 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 64 static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id) 65 { 66 xen_hvm_evtchn_do_upcall(); 67 return IRQ_HANDLED; 68 } 69 70 static 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 77 static 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 92 static 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; 160 grant_out: 161 gnttab_free_auto_xlat_frames(); 162 out: 163 pci_release_region(pdev, 0); 164 mem_out: 165 pci_release_region(pdev, 1); 166 pci_out: 167 pci_disable_device(pdev); 168 return ret; 169 } 170 171 static 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 }; 176 177 static const struct dev_pm_ops platform_pm_ops = { 178 .resume_noirq = platform_pci_resume, 179 }; 180 181 static 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 }; 189 190 builtin_pci_driver(platform_driver); 191