xref: /openbmc/qemu/hw/xen/xen-host-pci-device.c (revision 520e210c) 
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-common.h"
12 #include "qemu/cutils.h"
13 #include "xen-host-pci-device.h"
14 
15 #define XEN_HOST_PCI_MAX_EXT_CAP \
16     ((PCIE_CONFIG_SPACE_SIZE - PCI_CONFIG_SPACE_SIZE) / (PCI_CAP_SIZEOF + 4))
17 
18 #ifdef XEN_HOST_PCI_DEVICE_DEBUG
19 #  define XEN_HOST_PCI_LOG(f, a...) fprintf(stderr, "%s: " f, __func__, ##a)
20 #else
21 #  define XEN_HOST_PCI_LOG(f, a...) (void)0
22 #endif
23 
24 /*
25  * from linux/ioport.h
26  * IO resources have these defined flags.
27  */
28 #define IORESOURCE_BITS         0x000000ff      /* Bus-specific bits */
29 
30 #define IORESOURCE_TYPE_BITS    0x00000f00      /* Resource type */
31 #define IORESOURCE_IO           0x00000100
32 #define IORESOURCE_MEM          0x00000200
33 
34 #define IORESOURCE_PREFETCH     0x00001000      /* No side effects */
35 #define IORESOURCE_MEM_64       0x00100000
36 
37 static void xen_host_pci_sysfs_path(const XenHostPCIDevice *d,
38                                     const char *name, char *buf, ssize_t size)
39 {
40     int rc;
41 
42     rc = snprintf(buf, size, "/sys/bus/pci/devices/%04x:%02x:%02x.%d/%s",
43                   d->domain, d->bus, d->dev, d->func, name);
44     assert(rc >= 0 && rc < size);
45 }
46 
47 
48 /* This size should be enough to read the first 7 lines of a resource file */
49 #define XEN_HOST_PCI_RESOURCE_BUFFER_SIZE 400
50 static void xen_host_pci_get_resource(XenHostPCIDevice *d, Error **errp)
51 {
52     int i, rc, fd;
53     char path[PATH_MAX];
54     char buf[XEN_HOST_PCI_RESOURCE_BUFFER_SIZE];
55     unsigned long long start, end, flags, size;
56     char *endptr, *s;
57     uint8_t type;
58 
59     xen_host_pci_sysfs_path(d, "resource", path, sizeof(path));
60 
61     fd = open(path, O_RDONLY);
62     if (fd == -1) {
63         error_setg_file_open(errp, errno, path);
64         return;
65     }
66 
67     do {
68         rc = read(fd, &buf, sizeof(buf) - 1);
69         if (rc < 0 && errno != EINTR) {
70             error_setg_errno(errp, errno, "read err");
71             goto out;
72         }
73     } while (rc < 0);
74     buf[rc] = 0;
75 
76     s = buf;
77     for (i = 0; i < PCI_NUM_REGIONS; i++) {
78         type = 0;
79 
80         start = strtoll(s, &endptr, 16);
81         if (*endptr != ' ' || s == endptr) {
82             break;
83         }
84         s = endptr + 1;
85         end = strtoll(s, &endptr, 16);
86         if (*endptr != ' ' || s == endptr) {
87             break;
88         }
89         s = endptr + 1;
90         flags = strtoll(s, &endptr, 16);
91         if (*endptr != '\n' || s == endptr) {
92             break;
93         }
94         s = endptr + 1;
95 
96         if (start) {
97             size = end - start + 1;
98         } else {
99             size = 0;
100         }
101 
102         if (flags & IORESOURCE_IO) {
103             type |= XEN_HOST_PCI_REGION_TYPE_IO;
104         }
105         if (flags & IORESOURCE_MEM) {
106             type |= XEN_HOST_PCI_REGION_TYPE_MEM;
107         }
108         if (flags & IORESOURCE_PREFETCH) {
109             type |= XEN_HOST_PCI_REGION_TYPE_PREFETCH;
110         }
111         if (flags & IORESOURCE_MEM_64) {
112             type |= XEN_HOST_PCI_REGION_TYPE_MEM_64;
113         }
114 
115         if (i < PCI_ROM_SLOT) {
116             d->io_regions[i].base_addr = start;
117             d->io_regions[i].size = size;
118             d->io_regions[i].type = type;
119             d->io_regions[i].bus_flags = flags & IORESOURCE_BITS;
120         } else {
121             d->rom.base_addr = start;
122             d->rom.size = size;
123             d->rom.type = type;
124             d->rom.bus_flags = flags & IORESOURCE_BITS;
125         }
126     }
127 
128     if (i != PCI_NUM_REGIONS) {
129         error_setg(errp, "Invalid format or input too short: %s", buf);
130     }
131 
132 out:
133     close(fd);
134 }
135 
136 /* This size should be enough to read a long from a file */
137 #define XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE 22
138 static void xen_host_pci_get_value(XenHostPCIDevice *d, const char *name,
139                                    unsigned int *pvalue, int base, Error **errp)
140 {
141     char path[PATH_MAX];
142     char buf[XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE];
143     int fd, rc;
144     unsigned long value;
145     const char *endptr;
146 
147     xen_host_pci_sysfs_path(d, name, path, sizeof(path));
148 
149     fd = open(path, O_RDONLY);
150     if (fd == -1) {
151         error_setg_file_open(errp, errno, path);
152         return;
153     }
154 
155     do {
156         rc = read(fd, &buf, sizeof(buf) - 1);
157         if (rc < 0 && errno != EINTR) {
158             error_setg_errno(errp, errno, "read err");
159             goto out;
160         }
161     } while (rc < 0);
162 
163     buf[rc] = 0;
164     rc = qemu_strtoul(buf, &endptr, base, &value);
165     if (!rc) {
166         assert(value <= UINT_MAX);
167         *pvalue = value;
168     } else {
169         error_setg_errno(errp, -rc, "failed to parse value '%s'", buf);
170     }
171 
172 out:
173     close(fd);
174 }
175 
176 static inline void xen_host_pci_get_hex_value(XenHostPCIDevice *d,
177                                               const char *name,
178                                               unsigned int *pvalue,
179                                               Error **errp)
180 {
181     xen_host_pci_get_value(d, name, pvalue, 16, errp);
182 }
183 
184 static inline void xen_host_pci_get_dec_value(XenHostPCIDevice *d,
185                                               const char *name,
186                                               unsigned int *pvalue,
187                                               Error **errp)
188 {
189     xen_host_pci_get_value(d, name, pvalue, 10, errp);
190 }
191 
192 static bool xen_host_pci_dev_is_virtfn(XenHostPCIDevice *d)
193 {
194     char path[PATH_MAX];
195     struct stat buf;
196 
197     xen_host_pci_sysfs_path(d, "physfn", path, sizeof(path));
198 
199     return !stat(path, &buf);
200 }
201 
202 static void xen_host_pci_config_open(XenHostPCIDevice *d, Error **errp)
203 {
204     char path[PATH_MAX];
205 
206     xen_host_pci_sysfs_path(d, "config", path, sizeof(path));
207 
208     d->config_fd = open(path, O_RDWR);
209     if (d->config_fd == -1) {
210         error_setg_file_open(errp, errno, path);
211     }
212 }
213 
214 static int xen_host_pci_config_read(XenHostPCIDevice *d,
215                                     int pos, void *buf, int len)
216 {
217     int rc;
218 
219     do {
220         rc = pread(d->config_fd, buf, len, pos);
221     } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
222     if (rc != len) {
223         return -errno;
224     }
225     return 0;
226 }
227 
228 static int xen_host_pci_config_write(XenHostPCIDevice *d,
229                                      int pos, const void *buf, int len)
230 {
231     int rc;
232 
233     do {
234         rc = pwrite(d->config_fd, buf, len, pos);
235     } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
236     if (rc != len) {
237         return -errno;
238     }
239     return 0;
240 }
241 
242 
243 int xen_host_pci_get_byte(XenHostPCIDevice *d, int pos, uint8_t *p)
244 {
245     uint8_t buf;
246     int rc = xen_host_pci_config_read(d, pos, &buf, 1);
247     if (!rc) {
248         *p = buf;
249     }
250     return rc;
251 }
252 
253 int xen_host_pci_get_word(XenHostPCIDevice *d, int pos, uint16_t *p)
254 {
255     uint16_t buf;
256     int rc = xen_host_pci_config_read(d, pos, &buf, 2);
257     if (!rc) {
258         *p = le16_to_cpu(buf);
259     }
260     return rc;
261 }
262 
263 int xen_host_pci_get_long(XenHostPCIDevice *d, int pos, uint32_t *p)
264 {
265     uint32_t buf;
266     int rc = xen_host_pci_config_read(d, pos, &buf, 4);
267     if (!rc) {
268         *p = le32_to_cpu(buf);
269     }
270     return rc;
271 }
272 
273 int xen_host_pci_get_block(XenHostPCIDevice *d, int pos, uint8_t *buf, int len)
274 {
275     return xen_host_pci_config_read(d, pos, buf, len);
276 }
277 
278 int xen_host_pci_set_byte(XenHostPCIDevice *d, int pos, uint8_t data)
279 {
280     return xen_host_pci_config_write(d, pos, &data, 1);
281 }
282 
283 int xen_host_pci_set_word(XenHostPCIDevice *d, int pos, uint16_t data)
284 {
285     data = cpu_to_le16(data);
286     return xen_host_pci_config_write(d, pos, &data, 2);
287 }
288 
289 int xen_host_pci_set_long(XenHostPCIDevice *d, int pos, uint32_t data)
290 {
291     data = cpu_to_le32(data);
292     return xen_host_pci_config_write(d, pos, &data, 4);
293 }
294 
295 int xen_host_pci_set_block(XenHostPCIDevice *d, int pos, uint8_t *buf, int len)
296 {
297     return xen_host_pci_config_write(d, pos, buf, len);
298 }
299 
300 int xen_host_pci_find_ext_cap_offset(XenHostPCIDevice *d, uint32_t cap)
301 {
302     uint32_t header = 0;
303     int max_cap = XEN_HOST_PCI_MAX_EXT_CAP;
304     int pos = PCI_CONFIG_SPACE_SIZE;
305 
306     do {
307         if (xen_host_pci_get_long(d, pos, &header)) {
308             break;
309         }
310         /*
311          * If we have no capabilities, this is indicated by cap ID,
312          * cap version and next pointer all being 0.
313          */
314         if (header == 0) {
315             break;
316         }
317 
318         if (PCI_EXT_CAP_ID(header) == cap) {
319             return pos;
320         }
321 
322         pos = PCI_EXT_CAP_NEXT(header);
323         if (pos < PCI_CONFIG_SPACE_SIZE) {
324             break;
325         }
326 
327         max_cap--;
328     } while (max_cap > 0);
329 
330     return -1;
331 }
332 
333 void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
334                              uint8_t bus, uint8_t dev, uint8_t func,
335                              Error **errp)
336 {
337     unsigned int v;
338     Error *err = NULL;
339 
340     d->config_fd = -1;
341     d->domain = domain;
342     d->bus = bus;
343     d->dev = dev;
344     d->func = func;
345 
346     xen_host_pci_config_open(d, &err);
347     if (err) {
348         goto error;
349     }
350 
351     xen_host_pci_get_resource(d, &err);
352     if (err) {
353         goto error;
354     }
355 
356     xen_host_pci_get_hex_value(d, "vendor", &v, &err);
357     if (err) {
358         goto error;
359     }
360     d->vendor_id = v;
361 
362     xen_host_pci_get_hex_value(d, "device", &v, &err);
363     if (err) {
364         goto error;
365     }
366     d->device_id = v;
367 
368     xen_host_pci_get_dec_value(d, "irq", &v, &err);
369     if (err) {
370         goto error;
371     }
372     d->irq = v;
373 
374     xen_host_pci_get_hex_value(d, "class", &v, &err);
375     if (err) {
376         goto error;
377     }
378     d->class_code = v;
379 
380     d->is_virtfn = xen_host_pci_dev_is_virtfn(d);
381 
382     return;
383 
384 error:
385     error_propagate(errp, err);
386 
387     if (d->config_fd >= 0) {
388         close(d->config_fd);
389         d->config_fd = -1;
390     }
391 }
392 
393 bool xen_host_pci_device_closed(XenHostPCIDevice *d)
394 {
395     return d->config_fd == -1;
396 }
397 
398 void xen_host_pci_device_put(XenHostPCIDevice *d)
399 {
400     if (d->config_fd >= 0) {
401         close(d->config_fd);
402         d->config_fd = -1;
403     }
404 }
405