1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015, Linaro Limited, Shannon Zhao
4 */
5
6#include <linux/platform_device.h>
7#include <linux/acpi.h>
8#include <xen/xen.h>
9#include <xen/page.h>
10#include <xen/interface/memory.h>
11#include <asm/xen/hypervisor.h>
12#include <asm/xen/hypercall.h>
13
14static int xen_unmap_device_mmio(const struct resource *resources,
15 unsigned int count)
16{
17 unsigned int i, j, nr;
18 int rc = 0;
19 const struct resource *r;
20 struct xen_remove_from_physmap xrp;
21
22 for (i = 0; i < count; i++) {
23 r = &resources[i];
24 nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
25 if ((resource_type(res: r) != IORESOURCE_MEM) || (nr == 0))
26 continue;
27
28 for (j = 0; j < nr; j++) {
29 xrp.domid = DOMID_SELF;
30 xrp.gpfn = XEN_PFN_DOWN(r->start) + j;
31 rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap,
32 arg: &xrp);
33 if (rc)
34 return rc;
35 }
36 }
37
38 return rc;
39}
40
41static int xen_map_device_mmio(const struct resource *resources,
42 unsigned int count)
43{
44 unsigned int i, j, nr;
45 int rc = 0;
46 const struct resource *r;
47 xen_pfn_t *gpfns;
48 xen_ulong_t *idxs;
49 int *errs;
50
51 for (i = 0; i < count; i++) {
52 struct xen_add_to_physmap_range xatp = {
53 .domid = DOMID_SELF,
54 .space = XENMAPSPACE_dev_mmio
55 };
56
57 r = &resources[i];
58 nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
59 if ((resource_type(res: r) != IORESOURCE_MEM) || (nr == 0))
60 continue;
61
62 gpfns = kcalloc(n: nr, size: sizeof(xen_pfn_t), GFP_KERNEL);
63 idxs = kcalloc(n: nr, size: sizeof(xen_ulong_t), GFP_KERNEL);
64 errs = kcalloc(n: nr, size: sizeof(int), GFP_KERNEL);
65 if (!gpfns || !idxs || !errs) {
66 kfree(objp: gpfns);
67 kfree(objp: idxs);
68 kfree(objp: errs);
69 rc = -ENOMEM;
70 goto unmap;
71 }
72
73 for (j = 0; j < nr; j++) {
74 /*
75 * The regions are always mapped 1:1 to DOM0 and this is
76 * fine because the memory map for DOM0 is the same as
77 * the host (except for the RAM).
78 */
79 gpfns[j] = XEN_PFN_DOWN(r->start) + j;
80 idxs[j] = XEN_PFN_DOWN(r->start) + j;
81 }
82
83 xatp.size = nr;
84
85 set_xen_guest_handle(xatp.gpfns, gpfns);
86 set_xen_guest_handle(xatp.idxs, idxs);
87 set_xen_guest_handle(xatp.errs, errs);
88
89 rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, arg: &xatp);
90 kfree(objp: gpfns);
91 kfree(objp: idxs);
92 kfree(objp: errs);
93 if (rc)
94 goto unmap;
95 }
96
97 return rc;
98
99unmap:
100 xen_unmap_device_mmio(resources, count: i);
101 return rc;
102}
103
104static int xen_platform_notifier(struct notifier_block *nb,
105 unsigned long action, void *data)
106{
107 struct platform_device *pdev = to_platform_device(data);
108 int r = 0;
109
110 if (pdev->num_resources == 0 || pdev->resource == NULL)
111 return NOTIFY_OK;
112
113 switch (action) {
114 case BUS_NOTIFY_ADD_DEVICE:
115 r = xen_map_device_mmio(resources: pdev->resource, count: pdev->num_resources);
116 break;
117 case BUS_NOTIFY_DEL_DEVICE:
118 r = xen_unmap_device_mmio(resources: pdev->resource, count: pdev->num_resources);
119 break;
120 default:
121 return NOTIFY_DONE;
122 }
123 if (r)
124 dev_err(&pdev->dev, "Platform: Failed to %s device %s MMIO!\n",
125 action == BUS_NOTIFY_ADD_DEVICE ? "map" :
126 (action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
127 pdev->name);
128
129 return NOTIFY_OK;
130}
131
132static struct notifier_block platform_device_nb = {
133 .notifier_call = xen_platform_notifier,
134};
135
136static int __init register_xen_platform_notifier(void)
137{
138 if (!xen_initial_domain() || acpi_disabled)
139 return 0;
140
141 return bus_register_notifier(bus: &platform_bus_type, nb: &platform_device_nb);
142}
143
144arch_initcall(register_xen_platform_notifier);
145
146#ifdef CONFIG_ARM_AMBA
147#include <linux/amba/bus.h>
148
149static int xen_amba_notifier(struct notifier_block *nb,
150 unsigned long action, void *data)
151{
152 struct amba_device *adev = to_amba_device(data);
153 int r = 0;
154
155 switch (action) {
156 case BUS_NOTIFY_ADD_DEVICE:
157 r = xen_map_device_mmio(&adev->res, 1);
158 break;
159 case BUS_NOTIFY_DEL_DEVICE:
160 r = xen_unmap_device_mmio(&adev->res, 1);
161 break;
162 default:
163 return NOTIFY_DONE;
164 }
165 if (r)
166 dev_err(&adev->dev, "AMBA: Failed to %s device %s MMIO!\n",
167 action == BUS_NOTIFY_ADD_DEVICE ? "map" :
168 (action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
169 adev->dev.init_name);
170
171 return NOTIFY_OK;
172}
173
174static struct notifier_block amba_device_nb = {
175 .notifier_call = xen_amba_notifier,
176};
177
178static int __init register_xen_amba_notifier(void)
179{
180 if (!xen_initial_domain() || acpi_disabled)
181 return 0;
182
183 return bus_register_notifier(&amba_bustype, &amba_device_nb);
184}
185
186arch_initcall(register_xen_amba_notifier);
187#endif
188

source code of linux/drivers/xen/arm-device.c