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 
xen_unmap_device_mmio(const struct resource * resources,unsigned int count)14 static 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(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 						  &xrp);
33 			if (rc)
34 				return rc;
35 		}
36 	}
37 
38 	return rc;
39 }
40 
xen_map_device_mmio(const struct resource * resources,unsigned int count)41 static 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(r) != IORESOURCE_MEM) || (nr == 0))
60 			continue;
61 
62 		gpfns = kcalloc(nr, sizeof(xen_pfn_t), GFP_KERNEL);
63 		idxs = kcalloc(nr, sizeof(xen_ulong_t), GFP_KERNEL);
64 		errs = kcalloc(nr, sizeof(int), GFP_KERNEL);
65 		if (!gpfns || !idxs || !errs) {
66 			kfree(gpfns);
67 			kfree(idxs);
68 			kfree(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, &xatp);
90 		kfree(gpfns);
91 		kfree(idxs);
92 		kfree(errs);
93 		if (rc)
94 			goto unmap;
95 	}
96 
97 	return rc;
98 
99 unmap:
100 	xen_unmap_device_mmio(resources, i);
101 	return rc;
102 }
103 
xen_platform_notifier(struct notifier_block * nb,unsigned long action,void * data)104 static 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(pdev->resource, pdev->num_resources);
116 		break;
117 	case BUS_NOTIFY_DEL_DEVICE:
118 		r = xen_unmap_device_mmio(pdev->resource, 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 
132 static struct notifier_block platform_device_nb = {
133 	.notifier_call = xen_platform_notifier,
134 };
135 
register_xen_platform_notifier(void)136 static int __init register_xen_platform_notifier(void)
137 {
138 	if (!xen_initial_domain() || acpi_disabled)
139 		return 0;
140 
141 	return bus_register_notifier(&platform_bus_type, &platform_device_nb);
142 }
143 
144 arch_initcall(register_xen_platform_notifier);
145 
146 #ifdef CONFIG_ARM_AMBA
147 #include <linux/amba/bus.h>
148 
xen_amba_notifier(struct notifier_block * nb,unsigned long action,void * data)149 static 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 
174 static struct notifier_block amba_device_nb = {
175 	.notifier_call = xen_amba_notifier,
176 };
177 
register_xen_amba_notifier(void)178 static 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 
186 arch_initcall(register_xen_amba_notifier);
187 #endif
188