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(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
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(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
99unmap:
100	xen_unmap_device_mmio(resources, 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(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
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(&platform_bus_type, &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