xref: /openbmc/qemu/hw/cxl/cxl-cdat.c (revision f0dbe427ec7c0dd81fc95c1d0d7174b79b6e6587)
1  /*
2   * CXL CDAT Structure
3   *
4   * Copyright (C) 2021 Avery Design Systems, Inc.
5   *
6   * This work is licensed under the terms of the GNU GPL, version 2 or later.
7   * See the COPYING file in the top-level directory.
8   */
9  
10  #include "qemu/osdep.h"
11  #include "hw/pci/pci.h"
12  #include "hw/cxl/cxl.h"
13  #include "qapi/error.h"
14  #include "qemu/error-report.h"
15  
16  static void cdat_len_check(CDATSubHeader *hdr, Error **errp)
17  {
18      assert(hdr->length);
19      assert(hdr->reserved == 0);
20  
21      switch (hdr->type) {
22      case CDAT_TYPE_DSMAS:
23          assert(hdr->length == sizeof(CDATDsmas));
24          break;
25      case CDAT_TYPE_DSLBIS:
26          assert(hdr->length == sizeof(CDATDslbis));
27          break;
28      case CDAT_TYPE_DSMSCIS:
29          assert(hdr->length == sizeof(CDATDsmscis));
30          break;
31      case CDAT_TYPE_DSIS:
32          assert(hdr->length == sizeof(CDATDsis));
33          break;
34      case CDAT_TYPE_DSEMTS:
35          assert(hdr->length == sizeof(CDATDsemts));
36          break;
37      case CDAT_TYPE_SSLBIS:
38          assert(hdr->length >= sizeof(CDATSslbisHeader));
39          assert((hdr->length - sizeof(CDATSslbisHeader)) %
40                 sizeof(CDATSslbe) == 0);
41          break;
42      default:
43          error_setg(errp, "Type %d is reserved", hdr->type);
44      }
45  }
46  
47  static void ct3_build_cdat(CDATObject *cdat, Error **errp)
48  {
49      g_autofree CDATTableHeader *cdat_header = NULL;
50      g_autofree CDATEntry *cdat_st = NULL;
51      uint8_t sum = 0;
52      int ent, i;
53  
54      /* Use default table if fopen == NULL */
55      assert(cdat->build_cdat_table);
56  
57      cdat_header = g_malloc0(sizeof(*cdat_header));
58      if (!cdat_header) {
59          error_setg(errp, "Failed to allocate CDAT header");
60          return;
61      }
62  
63      cdat->built_buf_len = cdat->build_cdat_table(&cdat->built_buf,
64                                                   cdat->private);
65  
66      if (!cdat->built_buf_len) {
67          /* Build later as not all data available yet */
68          cdat->to_update = true;
69          return;
70      }
71      cdat->to_update = false;
72  
73      cdat_st = g_malloc0(sizeof(*cdat_st) * (cdat->built_buf_len + 1));
74      if (!cdat_st) {
75          error_setg(errp, "Failed to allocate CDAT entry array");
76          return;
77      }
78  
79      /* Entry 0 for CDAT header, starts with Entry 1 */
80      for (ent = 1; ent < cdat->built_buf_len + 1; ent++) {
81          CDATSubHeader *hdr = cdat->built_buf[ent - 1];
82          uint8_t *buf = (uint8_t *)cdat->built_buf[ent - 1];
83  
84          cdat_st[ent].base = hdr;
85          cdat_st[ent].length = hdr->length;
86  
87          cdat_header->length += hdr->length;
88          for (i = 0; i < hdr->length; i++) {
89              sum += buf[i];
90          }
91      }
92  
93      /* CDAT header */
94      cdat_header->revision = CXL_CDAT_REV;
95      /* For now, no runtime updates */
96      cdat_header->sequence = 0;
97      cdat_header->length += sizeof(CDATTableHeader);
98      sum += cdat_header->revision + cdat_header->sequence +
99          cdat_header->length;
100      /* Sum of all bytes including checksum must be 0 */
101      cdat_header->checksum = ~sum + 1;
102  
103      cdat_st[0].base = g_steal_pointer(&cdat_header);
104      cdat_st[0].length = sizeof(*cdat_header);
105      cdat->entry_len = 1 + cdat->built_buf_len;
106      cdat->entry = g_steal_pointer(&cdat_st);
107  }
108  
109  static void ct3_load_cdat(CDATObject *cdat, Error **errp)
110  {
111      g_autofree CDATEntry *cdat_st = NULL;
112      g_autofree char *buf = NULL;
113      uint8_t sum = 0;
114      int num_ent;
115      int i = 0, ent = 1;
116      gsize file_size = 0;
117      CDATSubHeader *hdr;
118      GError *error = NULL;
119  
120      /* Read CDAT file and create its cache */
121      if (!g_file_get_contents(cdat->filename, (gchar **)&buf,
122                               &file_size, &error)) {
123          error_setg(errp, "CDAT: File read failed: %s", error->message);
124          g_error_free(error);
125          return;
126      }
127      if (file_size < sizeof(CDATTableHeader)) {
128          error_setg(errp, "CDAT: File too short");
129          return;
130      }
131      i = sizeof(CDATTableHeader);
132      num_ent = 1;
133      while (i < file_size) {
134          hdr = (CDATSubHeader *)(buf + i);
135          if (i + sizeof(CDATSubHeader) > file_size) {
136              error_setg(errp, "CDAT: Truncated table");
137              return;
138          }
139          cdat_len_check(hdr, errp);
140          i += hdr->length;
141          if (i > file_size) {
142              error_setg(errp, "CDAT: Truncated table");
143              return;
144          }
145          num_ent++;
146      }
147      if (i != file_size) {
148          error_setg(errp, "CDAT: File length mismatch");
149          return;
150      }
151  
152      cdat_st = g_new0(CDATEntry, num_ent);
153  
154      /* Set CDAT header, Entry = 0 */
155      cdat_st[0].base = buf;
156      cdat_st[0].length = sizeof(CDATTableHeader);
157      i = 0;
158  
159      while (i < cdat_st[0].length) {
160          sum += buf[i++];
161      }
162  
163      /* Read CDAT structures */
164      while (i < file_size) {
165          hdr = (CDATSubHeader *)(buf + i);
166          cdat_st[ent].base = hdr;
167          cdat_st[ent].length = hdr->length;
168  
169          while (buf + i < (char *)cdat_st[ent].base + cdat_st[ent].length) {
170              assert(i < file_size);
171              sum += buf[i++];
172          }
173  
174          ent++;
175      }
176  
177      if (sum != 0) {
178          warn_report("CDAT: Found checksum mismatch in %s", cdat->filename);
179      }
180      cdat->entry_len = num_ent;
181      cdat->entry = g_steal_pointer(&cdat_st);
182      cdat->buf = g_steal_pointer(&buf);
183  }
184  
185  void cxl_doe_cdat_init(CXLComponentState *cxl_cstate, Error **errp)
186  {
187      CDATObject *cdat = &cxl_cstate->cdat;
188  
189      if (cdat->filename) {
190          ct3_load_cdat(cdat, errp);
191      } else {
192          ct3_build_cdat(cdat, errp);
193      }
194  }
195  
196  void cxl_doe_cdat_update(CXLComponentState *cxl_cstate, Error **errp)
197  {
198      CDATObject *cdat = &cxl_cstate->cdat;
199  
200      if (cdat->to_update) {
201          ct3_build_cdat(cdat, errp);
202      }
203  }
204  
205  void cxl_doe_cdat_release(CXLComponentState *cxl_cstate)
206  {
207      CDATObject *cdat = &cxl_cstate->cdat;
208  
209      free(cdat->entry);
210      if (cdat->built_buf) {
211          cdat->free_cdat_table(cdat->built_buf, cdat->built_buf_len,
212                                cdat->private);
213      }
214      g_free(cdat->buf);
215  }
216