xref: /openbmc/qemu/hw/nvram/spapr_nvram.c (revision 650d103d)
1 /*
2  * QEMU sPAPR NVRAM emulation
3  *
4  * Copyright (C) 2012 David Gibson, IBM Corporation.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qemu/module.h"
27 #include "qemu/units.h"
28 #include "qapi/error.h"
29 #include "cpu.h"
30 #include <libfdt.h>
31 
32 #include "sysemu/block-backend.h"
33 #include "sysemu/device_tree.h"
34 #include "hw/sysbus.h"
35 #include "migration/vmstate.h"
36 #include "hw/nvram/chrp_nvram.h"
37 #include "hw/ppc/spapr.h"
38 #include "hw/ppc/spapr_vio.h"
39 
40 typedef struct SpaprNvram {
41     SpaprVioDevice sdev;
42     uint32_t size;
43     uint8_t *buf;
44     BlockBackend *blk;
45     VMChangeStateEntry *vmstate;
46 } SpaprNvram;
47 
48 #define TYPE_VIO_SPAPR_NVRAM "spapr-nvram"
49 #define VIO_SPAPR_NVRAM(obj) \
50      OBJECT_CHECK(SpaprNvram, (obj), TYPE_VIO_SPAPR_NVRAM)
51 
52 #define MIN_NVRAM_SIZE      (8 * KiB)
53 #define DEFAULT_NVRAM_SIZE  (64 * KiB)
54 #define MAX_NVRAM_SIZE      (1 * MiB)
55 
56 static void rtas_nvram_fetch(PowerPCCPU *cpu, SpaprMachineState *spapr,
57                              uint32_t token, uint32_t nargs,
58                              target_ulong args,
59                              uint32_t nret, target_ulong rets)
60 {
61     SpaprNvram *nvram = spapr->nvram;
62     hwaddr offset, buffer, len;
63     void *membuf;
64 
65     if ((nargs != 3) || (nret != 2)) {
66         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
67         return;
68     }
69 
70     if (!nvram) {
71         rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
72         rtas_st(rets, 1, 0);
73         return;
74     }
75 
76     offset = rtas_ld(args, 0);
77     buffer = rtas_ld(args, 1);
78     len = rtas_ld(args, 2);
79 
80     if (((offset + len) < offset)
81         || ((offset + len) > nvram->size)) {
82         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
83         rtas_st(rets, 1, 0);
84         return;
85     }
86 
87     assert(nvram->buf);
88 
89     membuf = cpu_physical_memory_map(buffer, &len, 1);
90     memcpy(membuf, nvram->buf + offset, len);
91     cpu_physical_memory_unmap(membuf, len, 1, len);
92 
93     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
94     rtas_st(rets, 1, len);
95 }
96 
97 static void rtas_nvram_store(PowerPCCPU *cpu, SpaprMachineState *spapr,
98                              uint32_t token, uint32_t nargs,
99                              target_ulong args,
100                              uint32_t nret, target_ulong rets)
101 {
102     SpaprNvram *nvram = spapr->nvram;
103     hwaddr offset, buffer, len;
104     int alen;
105     void *membuf;
106 
107     if ((nargs != 3) || (nret != 2)) {
108         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
109         return;
110     }
111 
112     if (!nvram) {
113         rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
114         return;
115     }
116 
117     offset = rtas_ld(args, 0);
118     buffer = rtas_ld(args, 1);
119     len = rtas_ld(args, 2);
120 
121     if (((offset + len) < offset)
122         || ((offset + len) > nvram->size)) {
123         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
124         return;
125     }
126 
127     membuf = cpu_physical_memory_map(buffer, &len, 0);
128 
129     alen = len;
130     if (nvram->blk) {
131         alen = blk_pwrite(nvram->blk, offset, membuf, len, 0);
132     }
133 
134     assert(nvram->buf);
135     memcpy(nvram->buf + offset, membuf, len);
136 
137     cpu_physical_memory_unmap(membuf, len, 0, len);
138 
139     rtas_st(rets, 0, (alen < len) ? RTAS_OUT_HW_ERROR : RTAS_OUT_SUCCESS);
140     rtas_st(rets, 1, (alen < 0) ? 0 : alen);
141 }
142 
143 static void spapr_nvram_realize(SpaprVioDevice *dev, Error **errp)
144 {
145     SpaprNvram *nvram = VIO_SPAPR_NVRAM(dev);
146     int ret;
147 
148     if (nvram->blk) {
149         int64_t len = blk_getlength(nvram->blk);
150 
151         if (len < 0) {
152             error_setg_errno(errp, -len,
153                              "could not get length of backing image");
154             return;
155         }
156 
157         nvram->size = len;
158 
159         ret = blk_set_perm(nvram->blk,
160                            BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE,
161                            BLK_PERM_ALL, errp);
162         if (ret < 0) {
163             return;
164         }
165     } else {
166         nvram->size = DEFAULT_NVRAM_SIZE;
167     }
168 
169     nvram->buf = g_malloc0(nvram->size);
170 
171     if ((nvram->size < MIN_NVRAM_SIZE) || (nvram->size > MAX_NVRAM_SIZE)) {
172         error_setg(errp,
173                    "spapr-nvram must be between %" PRId64
174                    " and %" PRId64 " bytes in size",
175                    MIN_NVRAM_SIZE, MAX_NVRAM_SIZE);
176         return;
177     }
178 
179     if (nvram->blk) {
180         int alen = blk_pread(nvram->blk, 0, nvram->buf, nvram->size);
181 
182         if (alen != nvram->size) {
183             error_setg(errp, "can't read spapr-nvram contents");
184             return;
185         }
186     } else if (nb_prom_envs > 0) {
187         /* Create a system partition to pass the -prom-env variables */
188         chrp_nvram_create_system_partition(nvram->buf, MIN_NVRAM_SIZE / 4);
189         chrp_nvram_create_free_partition(&nvram->buf[MIN_NVRAM_SIZE / 4],
190                                          nvram->size - MIN_NVRAM_SIZE / 4);
191     }
192 
193     spapr_rtas_register(RTAS_NVRAM_FETCH, "nvram-fetch", rtas_nvram_fetch);
194     spapr_rtas_register(RTAS_NVRAM_STORE, "nvram-store", rtas_nvram_store);
195 }
196 
197 static int spapr_nvram_devnode(SpaprVioDevice *dev, void *fdt, int node_off)
198 {
199     SpaprNvram *nvram = VIO_SPAPR_NVRAM(dev);
200 
201     return fdt_setprop_cell(fdt, node_off, "#bytes", nvram->size);
202 }
203 
204 static int spapr_nvram_pre_load(void *opaque)
205 {
206     SpaprNvram *nvram = VIO_SPAPR_NVRAM(opaque);
207 
208     g_free(nvram->buf);
209     nvram->buf = NULL;
210     nvram->size = 0;
211 
212     return 0;
213 }
214 
215 static void postload_update_cb(void *opaque, int running, RunState state)
216 {
217     SpaprNvram *nvram = opaque;
218 
219     /* This is called after bdrv_invalidate_cache_all.  */
220 
221     qemu_del_vm_change_state_handler(nvram->vmstate);
222     nvram->vmstate = NULL;
223 
224     blk_pwrite(nvram->blk, 0, nvram->buf, nvram->size, 0);
225 }
226 
227 static int spapr_nvram_post_load(void *opaque, int version_id)
228 {
229     SpaprNvram *nvram = VIO_SPAPR_NVRAM(opaque);
230 
231     if (nvram->blk) {
232         nvram->vmstate = qemu_add_vm_change_state_handler(postload_update_cb,
233                                                           nvram);
234     }
235 
236     return 0;
237 }
238 
239 static const VMStateDescription vmstate_spapr_nvram = {
240     .name = "spapr_nvram",
241     .version_id = 1,
242     .minimum_version_id = 1,
243     .pre_load = spapr_nvram_pre_load,
244     .post_load = spapr_nvram_post_load,
245     .fields = (VMStateField[]) {
246         VMSTATE_UINT32(size, SpaprNvram),
247         VMSTATE_VBUFFER_ALLOC_UINT32(buf, SpaprNvram, 1, NULL, size),
248         VMSTATE_END_OF_LIST()
249     },
250 };
251 
252 static Property spapr_nvram_properties[] = {
253     DEFINE_SPAPR_PROPERTIES(SpaprNvram, sdev),
254     DEFINE_PROP_DRIVE("drive", SpaprNvram, blk),
255     DEFINE_PROP_END_OF_LIST(),
256 };
257 
258 static void spapr_nvram_class_init(ObjectClass *klass, void *data)
259 {
260     DeviceClass *dc = DEVICE_CLASS(klass);
261     SpaprVioDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
262 
263     k->realize = spapr_nvram_realize;
264     k->devnode = spapr_nvram_devnode;
265     k->dt_name = "nvram";
266     k->dt_type = "nvram";
267     k->dt_compatible = "qemu,spapr-nvram";
268     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
269     dc->props = spapr_nvram_properties;
270     dc->vmsd = &vmstate_spapr_nvram;
271     /* Reason: Internal device only, uses spapr_rtas_register() in realize() */
272     dc->user_creatable = false;
273 }
274 
275 static const TypeInfo spapr_nvram_type_info = {
276     .name          = TYPE_VIO_SPAPR_NVRAM,
277     .parent        = TYPE_VIO_SPAPR_DEVICE,
278     .instance_size = sizeof(SpaprNvram),
279     .class_init    = spapr_nvram_class_init,
280 };
281 
282 static void spapr_nvram_register_types(void)
283 {
284     type_register_static(&spapr_nvram_type_info);
285 }
286 
287 type_init(spapr_nvram_register_types)
288