xref: /openbmc/qemu/hw/xen/xen-host-pci-device.c (revision 7acafcfa) 
1 /*
2  * Copyright (C) 2011       Citrix Ltd.
3  *
4  * This work is licensed under the terms of the GNU GPL, version 2.  See
5  * the COPYING file in the top-level directory.
6  *
7  */
8 
9 #include "qemu/osdep.h"
10 #include "qapi/error.h"
11 #include "qemu/cutils.h"
12 #include "xen-host-pci-device.h"
13 
14 #define XEN_HOST_PCI_MAX_EXT_CAP \
15     ((PCIE_CONFIG_SPACE_SIZE - PCI_CONFIG_SPACE_SIZE) / (PCI_CAP_SIZEOF + 4))
16 
17 #ifdef XEN_HOST_PCI_DEVICE_DEBUG
18 #  define XEN_HOST_PCI_LOG(f, a...) fprintf(stderr, "%s: " f, __func__, ##a)
19 #else
20 #  define XEN_HOST_PCI_LOG(f, a...) (void)0
21 #endif
22 
23 /*
24  * from linux/ioport.h
25  * IO resources have these defined flags.
26  */
27 #define IORESOURCE_BITS         0x000000ff      /* Bus-specific bits */
28 
29 #define IORESOURCE_TYPE_BITS    0x00000f00      /* Resource type */
30 #define IORESOURCE_IO           0x00000100
31 #define IORESOURCE_MEM          0x00000200
32 
33 #define IORESOURCE_PREFETCH     0x00001000      /* No side effects */
34 #define IORESOURCE_MEM_64       0x00100000
35 
36 static void xen_host_pci_sysfs_path(const XenHostPCIDevice *d,
37                                     const char *name, char *buf, ssize_t size)
38 {
39     int rc;
40 
41     rc = snprintf(buf, size, "/sys/bus/pci/devices/%04x:%02x:%02x.%d/%s",
42                   d->domain, d->bus, d->dev, d->func, name);
43     assert(rc >= 0 && rc < size);
44 }
45 
46 
47 /* This size should be enough to read the first 7 lines of a resource file */
48 #define XEN_HOST_PCI_RESOURCE_BUFFER_SIZE 400
49 static void xen_host_pci_get_resource(XenHostPCIDevice *d, Error **errp)
50 {
51     int i, rc, fd;
52     char path[PATH_MAX];
53     char buf[XEN_HOST_PCI_RESOURCE_BUFFER_SIZE];
54     unsigned long long start, end, flags, size;
55     char *endptr, *s;
56     uint8_t type;
57 
58     xen_host_pci_sysfs_path(d, "resource", path, sizeof(path));
59 
60     fd = open(path, O_RDONLY);
61     if (fd == -1) {
62         error_setg_file_open(errp, errno, path);
63         return;
64     }
65 
66     do {
67         rc = read(fd, &buf, sizeof(buf) - 1);
68         if (rc < 0 && errno != EINTR) {
69             error_setg_errno(errp, errno, "read err");
70             goto out;
71         }
72     } while (rc < 0);
73     buf[rc] = 0;
74 
75     s = buf;
76     for (i = 0; i < PCI_NUM_REGIONS; i++) {
77         type = 0;
78 
79         start = strtoll(s, &endptr, 16);
80         if (*endptr != ' ' || s == endptr) {
81             break;
82         }
83         s = endptr + 1;
84         end = strtoll(s, &endptr, 16);
85         if (*endptr != ' ' || s == endptr) {
86             break;
87         }
88         s = endptr + 1;
89         flags = strtoll(s, &endptr, 16);
90         if (*endptr != '\n' || s == endptr) {
91             break;
92         }
93         s = endptr + 1;
94 
95         if (start) {
96             size = end - start + 1;
97         } else {
98             size = 0;
99         }
100 
101         if (flags & IORESOURCE_IO) {
102             type |= XEN_HOST_PCI_REGION_TYPE_IO;
103         }
104         if (flags & IORESOURCE_MEM) {
105             type |= XEN_HOST_PCI_REGION_TYPE_MEM;
106         }
107         if (flags & IORESOURCE_PREFETCH) {
108             type |= XEN_HOST_PCI_REGION_TYPE_PREFETCH;
109         }
110         if (flags & IORESOURCE_MEM_64) {
111             type |= XEN_HOST_PCI_REGION_TYPE_MEM_64;
112         }
113 
114         if (i < PCI_ROM_SLOT) {
115             d->io_regions[i].base_addr = start;
116             d->io_regions[i].size = size;
117             d->io_regions[i].type = type;
118             d->io_regions[i].bus_flags = flags & IORESOURCE_BITS;
119         } else {
120             d->rom.base_addr = start;
121             d->rom.size = size;
122             d->rom.type = type;
123             d->rom.bus_flags = flags & IORESOURCE_BITS;
124         }
125     }
126 
127     if (i != PCI_NUM_REGIONS) {
128         error_setg(errp, "Invalid format or input too short: %s", buf);
129     }
130 
131 out:
132     close(fd);
133 }
134 
135 /* This size should be enough to read a long from a file */
136 #define XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE 22
137 static void xen_host_pci_get_value(XenHostPCIDevice *d, const char *name,
138                                    unsigned int *pvalue, int base, Error **errp)
139 {
140     char path[PATH_MAX];
141     char buf[XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE];
142     int fd, rc;
143     unsigned long value;
144     const char *endptr;
145 
146     xen_host_pci_sysfs_path(d, name, path, sizeof(path));
147 
148     fd = open(path, O_RDONLY);
149     if (fd == -1) {
150         error_setg_file_open(errp, errno, path);
151         return;
152     }
153 
154     do {
155         rc = read(fd, &buf, sizeof(buf) - 1);
156         if (rc < 0 && errno != EINTR) {
157             error_setg_errno(errp, errno, "read err");
158             goto out;
159         }
160     } while (rc < 0);
161 
162     buf[rc] = 0;
163     rc = qemu_strtoul(buf, &endptr, base, &value);
164     if (!rc) {
165         assert(value <= UINT_MAX);
166         *pvalue = value;
167     } else {
168         error_setg_errno(errp, -rc, "failed to parse value '%s'", buf);
169     }
170 
171 out:
172     close(fd);
173 }
174 
175 static inline void xen_host_pci_get_hex_value(XenHostPCIDevice *d,
176                                               const char *name,
177                                               unsigned int *pvalue,
178                                               Error **errp)
179 {
180     xen_host_pci_get_value(d, name, pvalue, 16, errp);
181 }
182 
183 static inline void xen_host_pci_get_dec_value(XenHostPCIDevice *d,
184                                               const char *name,
185                                               unsigned int *pvalue,
186                                               Error **errp)
187 {
188     xen_host_pci_get_value(d, name, pvalue, 10, errp);
189 }
190 
191 static bool xen_host_pci_dev_is_virtfn(XenHostPCIDevice *d)
192 {
193     char path[PATH_MAX];
194     struct stat buf;
195 
196     xen_host_pci_sysfs_path(d, "physfn", path, sizeof(path));
197 
198     return !stat(path, &buf);
199 }
200 
201 static void xen_host_pci_config_open(XenHostPCIDevice *d, Error **errp)
202 {
203     char path[PATH_MAX];
204 
205     xen_host_pci_sysfs_path(d, "config", path, sizeof(path));
206 
207     d->config_fd = open(path, O_RDWR);
208     if (d->config_fd == -1) {
209         error_setg_file_open(errp, errno, path);
210     }
211 }
212 
213 static int xen_host_pci_config_read(XenHostPCIDevice *d,
214                                     int pos, void *buf, int len)
215 {
216     int rc;
217 
218     do {
219         rc = pread(d->config_fd, buf, len, pos);
220     } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
221     if (rc != len) {
222         return -errno;
223     }
224     return 0;
225 }
226 
227 static int xen_host_pci_config_write(XenHostPCIDevice *d,
228                                      int pos, const void *buf, int len)
229 {
230     int rc;
231 
232     do {
233         rc = pwrite(d->config_fd, buf, len, pos);
234     } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
235     if (rc != len) {
236         return -errno;
237     }
238     return 0;
239 }
240 
241 
242 int xen_host_pci_get_byte(XenHostPCIDevice *d, int pos, uint8_t *p)
243 {
244     uint8_t buf;
245     int rc = xen_host_pci_config_read(d, pos, &buf, 1);
246     if (!rc) {
247         *p = buf;
248     }
249     return rc;
250 }
251 
252 int xen_host_pci_get_word(XenHostPCIDevice *d, int pos, uint16_t *p)
253 {
254     uint16_t buf;
255     int rc = xen_host_pci_config_read(d, pos, &buf, 2);
256     if (!rc) {
257         *p = le16_to_cpu(buf);
258     }
259     return rc;
260 }
261 
262 int xen_host_pci_get_long(XenHostPCIDevice *d, int pos, uint32_t *p)
263 {
264     uint32_t buf;
265     int rc = xen_host_pci_config_read(d, pos, &buf, 4);
266     if (!rc) {
267         *p = le32_to_cpu(buf);
268     }
269     return rc;
270 }
271 
272 int xen_host_pci_get_block(XenHostPCIDevice *d, int pos, uint8_t *buf, int len)
273 {
274     return xen_host_pci_config_read(d, pos, buf, len);
275 }
276 
277 int xen_host_pci_set_byte(XenHostPCIDevice *d, int pos, uint8_t data)
278 {
279     return xen_host_pci_config_write(d, pos, &data, 1);
280 }
281 
282 int xen_host_pci_set_word(XenHostPCIDevice *d, int pos, uint16_t data)
283 {
284     data = cpu_to_le16(data);
285     return xen_host_pci_config_write(d, pos, &data, 2);
286 }
287 
288 int xen_host_pci_set_long(XenHostPCIDevice *d, int pos, uint32_t data)
289 {
290     data = cpu_to_le32(data);
291     return xen_host_pci_config_write(d, pos, &data, 4);
292 }
293 
294 int xen_host_pci_set_block(XenHostPCIDevice *d, int pos, uint8_t *buf, int len)
295 {
296     return xen_host_pci_config_write(d, pos, buf, len);
297 }
298 
299 int xen_host_pci_find_ext_cap_offset(XenHostPCIDevice *d, uint32_t cap)
300 {
301     uint32_t header = 0;
302     int max_cap = XEN_HOST_PCI_MAX_EXT_CAP;
303     int pos = PCI_CONFIG_SPACE_SIZE;
304 
305     do {
306         if (xen_host_pci_get_long(d, pos, &header)) {
307             break;
308         }
309         /*
310          * If we have no capabilities, this is indicated by cap ID,
311          * cap version and next pointer all being 0.
312          */
313         if (header == 0) {
314             break;
315         }
316 
317         if (PCI_EXT_CAP_ID(header) == cap) {
318             return pos;
319         }
320 
321         pos = PCI_EXT_CAP_NEXT(header);
322         if (pos < PCI_CONFIG_SPACE_SIZE) {
323             break;
324         }
325 
326         max_cap--;
327     } while (max_cap > 0);
328 
329     return -1;
330 }
331 
332 void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
333                              uint8_t bus, uint8_t dev, uint8_t func,
334                              Error **errp)
335 {
336     ERRP_GUARD();
337     unsigned int v;
338 
339     d->config_fd = -1;
340     d->domain = domain;
341     d->bus = bus;
342     d->dev = dev;
343     d->func = func;
344 
345     xen_host_pci_config_open(d, errp);
346     if (*errp) {
347         goto error;
348     }
349 
350     xen_host_pci_get_resource(d, errp);
351     if (*errp) {
352         goto error;
353     }
354 
355     xen_host_pci_get_hex_value(d, "vendor", &v, errp);
356     if (*errp) {
357         goto error;
358     }
359     d->vendor_id = v;
360 
361     xen_host_pci_get_hex_value(d, "device", &v, errp);
362     if (*errp) {
363         goto error;
364     }
365     d->device_id = v;
366 
367     xen_host_pci_get_dec_value(d, "irq", &v, errp);
368     if (*errp) {
369         goto error;
370     }
371     d->irq = v;
372 
373     xen_host_pci_get_hex_value(d, "class", &v, errp);
374     if (*errp) {
375         goto error;
376     }
377     d->class_code = v;
378 
379     d->is_virtfn = xen_host_pci_dev_is_virtfn(d);
380 
381     return;
382 
383 error:
384 
385     if (d->config_fd >= 0) {
386         close(d->config_fd);
387         d->config_fd = -1;
388     }
389 }
390 
391 bool xen_host_pci_device_closed(XenHostPCIDevice *d)
392 {
393     return d->config_fd == -1;
394 }
395 
396 void xen_host_pci_device_put(XenHostPCIDevice *d)
397 {
398     if (d->config_fd >= 0) {
399         close(d->config_fd);
400         d->config_fd = -1;
401     }
402 }
403