powerpc: Support for relocatable kdump kernel
[linux-2.6] / arch / powerpc / sysdev / dcr.c
1 /*
2  * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
3  *                    <benh@kernel.crashing.org>
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19
20 #undef DEBUG
21
22 #include <linux/kernel.h>
23 #include <asm/prom.h>
24 #include <asm/dcr.h>
25
26 #ifdef CONFIG_PPC_DCR_MMIO
27 static struct device_node *find_dcr_parent(struct device_node *node)
28 {
29         struct device_node *par, *tmp;
30         const u32 *p;
31
32         for (par = of_node_get(node); par;) {
33                 if (of_get_property(par, "dcr-controller", NULL))
34                         break;
35                 p = of_get_property(par, "dcr-parent", NULL);
36                 tmp = par;
37                 if (p == NULL)
38                         par = of_get_parent(par);
39                 else
40                         par = of_find_node_by_phandle(*p);
41                 of_node_put(tmp);
42         }
43         return par;
44 }
45 #endif
46
47 #if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
48
49 bool dcr_map_ok_generic(dcr_host_t host)
50 {
51         if (host.type == DCR_HOST_NATIVE)
52                 return dcr_map_ok_native(host.host.native);
53         else if (host.type == DCR_HOST_MMIO)
54                 return dcr_map_ok_mmio(host.host.mmio);
55         else
56                 return 0;
57 }
58 EXPORT_SYMBOL_GPL(dcr_map_ok_generic);
59
60 dcr_host_t dcr_map_generic(struct device_node *dev,
61                            unsigned int dcr_n,
62                            unsigned int dcr_c)
63 {
64         dcr_host_t host;
65         struct device_node *dp;
66         const char *prop;
67
68         host.type = DCR_HOST_INVALID;
69
70         dp = find_dcr_parent(dev);
71         if (dp == NULL)
72                 return host;
73
74         prop = of_get_property(dp, "dcr-access-method", NULL);
75
76         pr_debug("dcr_map_generic(dcr-access-method = %s)\n", prop);
77
78         if (!strcmp(prop, "native")) {
79                 host.type = DCR_HOST_NATIVE;
80                 host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
81         } else if (!strcmp(prop, "mmio")) {
82                 host.type = DCR_HOST_MMIO;
83                 host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
84         }
85
86         of_node_put(dp);
87         return host;
88 }
89 EXPORT_SYMBOL_GPL(dcr_map_generic);
90
91 void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
92 {
93         if (host.type == DCR_HOST_NATIVE)
94                 dcr_unmap_native(host.host.native, dcr_c);
95         else if (host.type == DCR_HOST_MMIO)
96                 dcr_unmap_mmio(host.host.mmio, dcr_c);
97         else /* host.type == DCR_HOST_INVALID */
98                 WARN_ON(true);
99 }
100 EXPORT_SYMBOL_GPL(dcr_unmap_generic);
101
102 u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n)
103 {
104         if (host.type == DCR_HOST_NATIVE)
105                 return dcr_read_native(host.host.native, dcr_n);
106         else if (host.type == DCR_HOST_MMIO)
107                 return dcr_read_mmio(host.host.mmio, dcr_n);
108         else /* host.type == DCR_HOST_INVALID */
109                 WARN_ON(true);
110         return 0;
111 }
112 EXPORT_SYMBOL_GPL(dcr_read_generic);
113
114 void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value)
115 {
116         if (host.type == DCR_HOST_NATIVE)
117                 dcr_write_native(host.host.native, dcr_n, value);
118         else if (host.type == DCR_HOST_MMIO)
119                 dcr_write_mmio(host.host.mmio, dcr_n, value);
120         else /* host.type == DCR_HOST_INVALID */
121                 WARN_ON(true);
122 }
123 EXPORT_SYMBOL_GPL(dcr_write_generic);
124
125 #endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */
126
127 unsigned int dcr_resource_start(struct device_node *np, unsigned int index)
128 {
129         unsigned int ds;
130         const u32 *dr = of_get_property(np, "dcr-reg", &ds);
131
132         if (dr == NULL || ds & 1 || index >= (ds / 8))
133                 return 0;
134
135         return dr[index * 2];
136 }
137 EXPORT_SYMBOL_GPL(dcr_resource_start);
138
139 unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
140 {
141         unsigned int ds;
142         const u32 *dr = of_get_property(np, "dcr-reg", &ds);
143
144         if (dr == NULL || ds & 1 || index >= (ds / 8))
145                 return 0;
146
147         return dr[index * 2 + 1];
148 }
149 EXPORT_SYMBOL_GPL(dcr_resource_len);
150
151 #ifdef CONFIG_PPC_DCR_MMIO
152
153 u64 of_translate_dcr_address(struct device_node *dev,
154                              unsigned int dcr_n,
155                              unsigned int *out_stride)
156 {
157         struct device_node *dp;
158         const u32 *p;
159         unsigned int stride;
160         u64 ret = OF_BAD_ADDR;
161
162         dp = find_dcr_parent(dev);
163         if (dp == NULL)
164                 return OF_BAD_ADDR;
165
166         /* Stride is not properly defined yet, default to 0x10 for Axon */
167         p = of_get_property(dp, "dcr-mmio-stride", NULL);
168         stride = (p == NULL) ? 0x10 : *p;
169
170         /* XXX FIXME: Which property name is to use of the 2 following ? */
171         p = of_get_property(dp, "dcr-mmio-range", NULL);
172         if (p == NULL)
173                 p = of_get_property(dp, "dcr-mmio-space", NULL);
174         if (p == NULL)
175                 goto done;
176
177         /* Maybe could do some better range checking here */
178         ret = of_translate_address(dp, p);
179         if (ret != OF_BAD_ADDR)
180                 ret += (u64)(stride) * (u64)dcr_n;
181         if (out_stride)
182                 *out_stride = stride;
183
184  done:
185         of_node_put(dp);
186         return ret;
187 }
188
189 dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
190                              unsigned int dcr_n,
191                              unsigned int dcr_c)
192 {
193         dcr_host_mmio_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
194         u64 addr;
195
196         pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
197                  dev->full_name, dcr_n, dcr_c);
198
199         addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
200         pr_debug("translates to addr: 0x%llx, stride: 0x%x\n",
201                  (unsigned long long) addr, ret.stride);
202         if (addr == OF_BAD_ADDR)
203                 return ret;
204         pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
205         ret.token = ioremap(addr, dcr_c * ret.stride);
206         if (ret.token == NULL)
207                 return ret;
208         pr_debug("mapped at 0x%p -> base is 0x%p\n",
209                  ret.token, ret.token - dcr_n * ret.stride);
210         ret.token -= dcr_n * ret.stride;
211         return ret;
212 }
213 EXPORT_SYMBOL_GPL(dcr_map_mmio);
214
215 void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c)
216 {
217         dcr_host_mmio_t h = host;
218
219         if (h.token == NULL)
220                 return;
221         h.token += host.base * h.stride;
222         iounmap(h.token);
223         h.token = NULL;
224 }
225 EXPORT_SYMBOL_GPL(dcr_unmap_mmio);
226
227 #endif /* defined(CONFIG_PPC_DCR_MMIO) */
228
229 #ifdef CONFIG_PPC_DCR_NATIVE
230 DEFINE_SPINLOCK(dcr_ind_lock);
231 #endif  /* defined(CONFIG_PPC_DCR_NATIVE) */
232