xref: /openbmc/qemu/hw/cxl/cxl-cdat.c (revision d02eb5bcdeb3d3890404c1cc688cbcfcbd3ca65b)
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, cdat->private);
64  
65      if (!cdat->built_buf_len) {
66          /* Build later as not all data available yet */
67          cdat->to_update = true;
68          return;
69      }
70      cdat->to_update = false;
71  
72      cdat_st = g_malloc0(sizeof(*cdat_st) * (cdat->built_buf_len + 1));
73      if (!cdat_st) {
74          error_setg(errp, "Failed to allocate CDAT entry array");
75          return;
76      }
77  
78      /* Entry 0 for CDAT header, starts with Entry 1 */
79      for (ent = 1; ent < cdat->built_buf_len + 1; ent++) {
80          CDATSubHeader *hdr = cdat->built_buf[ent - 1];
81          uint8_t *buf = (uint8_t *)cdat->built_buf[ent - 1];
82  
83          cdat_st[ent].base = hdr;
84          cdat_st[ent].length = hdr->length;
85  
86          cdat_header->length += hdr->length;
87          for (i = 0; i < hdr->length; i++) {
88              sum += buf[i];
89          }
90      }
91  
92      /* CDAT header */
93      cdat_header->revision = CXL_CDAT_REV;
94      /* For now, no runtime updates */
95      cdat_header->sequence = 0;
96      cdat_header->length += sizeof(CDATTableHeader);
97      sum += cdat_header->revision + cdat_header->sequence +
98          cdat_header->length;
99      /* Sum of all bytes including checksum must be 0 */
100      cdat_header->checksum = ~sum + 1;
101  
102      cdat_st[0].base = g_steal_pointer(&cdat_header);
103      cdat_st[0].length = sizeof(*cdat_header);
104      cdat->entry_len = 1 + cdat->built_buf_len;
105      cdat->entry = g_steal_pointer(&cdat_st);
106  }
107  
108  static void ct3_load_cdat(CDATObject *cdat, Error **errp)
109  {
110      g_autofree CDATEntry *cdat_st = NULL;
111      g_autofree char *buf = NULL;
112      uint8_t sum = 0;
113      int num_ent;
114      int i = 0, ent = 1;
115      gsize file_size = 0;
116      CDATSubHeader *hdr;
117      GError *error = NULL;
118  
119      /* Read CDAT file and create its cache */
120      if (!g_file_get_contents(cdat->filename, (gchar **)&buf,
121                               &file_size, &error)) {
122          error_setg(errp, "CDAT: File read failed: %s", error->message);
123          g_error_free(error);
124          return;
125      }
126      if (file_size < sizeof(CDATTableHeader)) {
127          error_setg(errp, "CDAT: File too short");
128          return;
129      }
130      i = sizeof(CDATTableHeader);
131      num_ent = 1;
132      while (i < file_size) {
133          hdr = (CDATSubHeader *)(buf + i);
134          if (i + sizeof(CDATSubHeader) > file_size) {
135              error_setg(errp, "CDAT: Truncated table");
136              return;
137          }
138          cdat_len_check(hdr, errp);
139          i += hdr->length;
140          if (i > file_size) {
141              error_setg(errp, "CDAT: Truncated table");
142              return;
143          }
144          num_ent++;
145      }
146      if (i != file_size) {
147          error_setg(errp, "CDAT: File length mismatch");
148          return;
149      }
150  
151      cdat_st = g_new0(CDATEntry, num_ent);
152  
153      /* Set CDAT header, Entry = 0 */
154      cdat_st[0].base = buf;
155      cdat_st[0].length = sizeof(CDATTableHeader);
156      i = 0;
157  
158      while (i < cdat_st[0].length) {
159          sum += buf[i++];
160      }
161  
162      /* Read CDAT structures */
163      while (i < file_size) {
164          hdr = (CDATSubHeader *)(buf + i);
165          cdat_st[ent].base = hdr;
166          cdat_st[ent].length = hdr->length;
167  
168          while (buf + i < (char *)cdat_st[ent].base + cdat_st[ent].length) {
169              assert(i < file_size);
170              sum += buf[i++];
171          }
172  
173          ent++;
174      }
175  
176      if (sum != 0) {
177          warn_report("CDAT: Found checksum mismatch in %s", cdat->filename);
178      }
179      cdat->entry_len = num_ent;
180      cdat->entry = g_steal_pointer(&cdat_st);
181      cdat->buf = g_steal_pointer(&buf);
182  }
183  
184  void cxl_doe_cdat_init(CXLComponentState *cxl_cstate, Error **errp)
185  {
186      CDATObject *cdat = &cxl_cstate->cdat;
187  
188      if (cdat->filename) {
189          ct3_load_cdat(cdat, errp);
190      } else {
191          ct3_build_cdat(cdat, errp);
192      }
193  }
194  
195  void cxl_doe_cdat_update(CXLComponentState *cxl_cstate, Error **errp)
196  {
197      CDATObject *cdat = &cxl_cstate->cdat;
198  
199      if (cdat->to_update) {
200          ct3_build_cdat(cdat, errp);
201      }
202  }
203  
204  void cxl_doe_cdat_release(CXLComponentState *cxl_cstate)
205  {
206      CDATObject *cdat = &cxl_cstate->cdat;
207  
208      free(cdat->entry);
209      if (cdat->built_buf) {
210          cdat->free_cdat_table(cdat->built_buf, cdat->built_buf_len,
211                                cdat->private);
212      }
213      g_free(cdat->buf);
214  }
215