xref: /openbmc/qemu/hw/cxl/cxl-cdat.c (revision bad5cfcd)
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