xref: /openbmc/linux/drivers/xen/arm-device.c (revision cfbb9be8)
1 /*
2  * Copyright (c) 2015, Linaro Limited, Shannon Zhao
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include <linux/platform_device.h>
18 #include <linux/acpi.h>
19 #include <xen/xen.h>
20 #include <xen/page.h>
21 #include <xen/interface/memory.h>
22 #include <asm/xen/hypervisor.h>
23 #include <asm/xen/hypercall.h>
24 
25 static int xen_unmap_device_mmio(const struct resource *resources,
26 				 unsigned int count)
27 {
28 	unsigned int i, j, nr;
29 	int rc = 0;
30 	const struct resource *r;
31 	struct xen_remove_from_physmap xrp;
32 
33 	for (i = 0; i < count; i++) {
34 		r = &resources[i];
35 		nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
36 		if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
37 			continue;
38 
39 		for (j = 0; j < nr; j++) {
40 			xrp.domid = DOMID_SELF;
41 			xrp.gpfn = XEN_PFN_DOWN(r->start) + j;
42 			rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap,
43 						  &xrp);
44 			if (rc)
45 				return rc;
46 		}
47 	}
48 
49 	return rc;
50 }
51 
52 static int xen_map_device_mmio(const struct resource *resources,
53 			       unsigned int count)
54 {
55 	unsigned int i, j, nr;
56 	int rc = 0;
57 	const struct resource *r;
58 	xen_pfn_t *gpfns;
59 	xen_ulong_t *idxs;
60 	int *errs;
61 
62 	for (i = 0; i < count; i++) {
63 		struct xen_add_to_physmap_range xatp = {
64 			.domid = DOMID_SELF,
65 			.space = XENMAPSPACE_dev_mmio
66 		};
67 
68 		r = &resources[i];
69 		nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
70 		if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
71 			continue;
72 
73 		gpfns = kzalloc(sizeof(xen_pfn_t) * nr, GFP_KERNEL);
74 		idxs = kzalloc(sizeof(xen_ulong_t) * nr, GFP_KERNEL);
75 		errs = kzalloc(sizeof(int) * nr, GFP_KERNEL);
76 		if (!gpfns || !idxs || !errs) {
77 			kfree(gpfns);
78 			kfree(idxs);
79 			kfree(errs);
80 			rc = -ENOMEM;
81 			goto unmap;
82 		}
83 
84 		for (j = 0; j < nr; j++) {
85 			/*
86 			 * The regions are always mapped 1:1 to DOM0 and this is
87 			 * fine because the memory map for DOM0 is the same as
88 			 * the host (except for the RAM).
89 			 */
90 			gpfns[j] = XEN_PFN_DOWN(r->start) + j;
91 			idxs[j] = XEN_PFN_DOWN(r->start) + j;
92 		}
93 
94 		xatp.size = nr;
95 
96 		set_xen_guest_handle(xatp.gpfns, gpfns);
97 		set_xen_guest_handle(xatp.idxs, idxs);
98 		set_xen_guest_handle(xatp.errs, errs);
99 
100 		rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
101 		kfree(gpfns);
102 		kfree(idxs);
103 		kfree(errs);
104 		if (rc)
105 			goto unmap;
106 	}
107 
108 	return rc;
109 
110 unmap:
111 	xen_unmap_device_mmio(resources, i);
112 	return rc;
113 }
114 
115 static int xen_platform_notifier(struct notifier_block *nb,
116 				 unsigned long action, void *data)
117 {
118 	struct platform_device *pdev = to_platform_device(data);
119 	int r = 0;
120 
121 	if (pdev->num_resources == 0 || pdev->resource == NULL)
122 		return NOTIFY_OK;
123 
124 	switch (action) {
125 	case BUS_NOTIFY_ADD_DEVICE:
126 		r = xen_map_device_mmio(pdev->resource, pdev->num_resources);
127 		break;
128 	case BUS_NOTIFY_DEL_DEVICE:
129 		r = xen_unmap_device_mmio(pdev->resource, pdev->num_resources);
130 		break;
131 	default:
132 		return NOTIFY_DONE;
133 	}
134 	if (r)
135 		dev_err(&pdev->dev, "Platform: Failed to %s device %s MMIO!\n",
136 			action == BUS_NOTIFY_ADD_DEVICE ? "map" :
137 			(action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
138 			pdev->name);
139 
140 	return NOTIFY_OK;
141 }
142 
143 static struct notifier_block platform_device_nb = {
144 	.notifier_call = xen_platform_notifier,
145 };
146 
147 static int __init register_xen_platform_notifier(void)
148 {
149 	if (!xen_initial_domain() || acpi_disabled)
150 		return 0;
151 
152 	return bus_register_notifier(&platform_bus_type, &platform_device_nb);
153 }
154 
155 arch_initcall(register_xen_platform_notifier);
156 
157 #ifdef CONFIG_ARM_AMBA
158 #include <linux/amba/bus.h>
159 
160 static int xen_amba_notifier(struct notifier_block *nb,
161 			     unsigned long action, void *data)
162 {
163 	struct amba_device *adev = to_amba_device(data);
164 	int r = 0;
165 
166 	switch (action) {
167 	case BUS_NOTIFY_ADD_DEVICE:
168 		r = xen_map_device_mmio(&adev->res, 1);
169 		break;
170 	case BUS_NOTIFY_DEL_DEVICE:
171 		r = xen_unmap_device_mmio(&adev->res, 1);
172 		break;
173 	default:
174 		return NOTIFY_DONE;
175 	}
176 	if (r)
177 		dev_err(&adev->dev, "AMBA: Failed to %s device %s MMIO!\n",
178 			action == BUS_NOTIFY_ADD_DEVICE ? "map" :
179 			(action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
180 			adev->dev.init_name);
181 
182 	return NOTIFY_OK;
183 }
184 
185 static struct notifier_block amba_device_nb = {
186 	.notifier_call = xen_amba_notifier,
187 };
188 
189 static int __init register_xen_amba_notifier(void)
190 {
191 	if (!xen_initial_domain() || acpi_disabled)
192 		return 0;
193 
194 	return bus_register_notifier(&amba_bustype, &amba_device_nb);
195 }
196 
197 arch_initcall(register_xen_amba_notifier);
198 #endif
199