xref: /openbmc/qemu/hw/cxl/cxl-cdat.c (revision 7200fb21)
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