xref: /openbmc/qemu/hw/cxl/cxl-cdat.c (revision 64c6e744)
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     uint8_t *hdr_buf;
53     int ent, i;
54 
55     /* Use default table if fopen == NULL */
56     assert(cdat->build_cdat_table);
57 
58     cdat_header = g_malloc0(sizeof(*cdat_header));
59     if (!cdat_header) {
60         error_setg(errp, "Failed to allocate CDAT header");
61         return;
62     }
63 
64     cdat->built_buf_len = cdat->build_cdat_table(&cdat->built_buf,
65                                                  cdat->private);
66 
67     if (cdat->built_buf_len <= 0) {
68         /* Build later as not all data available yet */
69         cdat->to_update = true;
70         return;
71     }
72     cdat->to_update = false;
73 
74     cdat_st = g_malloc0(sizeof(*cdat_st) * (cdat->built_buf_len + 1));
75     if (!cdat_st) {
76         error_setg(errp, "Failed to allocate CDAT entry array");
77         return;
78     }
79 
80     /* Entry 0 for CDAT header, starts with Entry 1 */
81     for (ent = 1; ent < cdat->built_buf_len + 1; ent++) {
82         CDATSubHeader *hdr = cdat->built_buf[ent - 1];
83         uint8_t *buf = (uint8_t *)cdat->built_buf[ent - 1];
84 
85         cdat_st[ent].base = hdr;
86         cdat_st[ent].length = hdr->length;
87 
88         cdat_header->length += hdr->length;
89         for (i = 0; i < hdr->length; i++) {
90             sum += buf[i];
91         }
92     }
93 
94     /* CDAT header */
95     cdat_header->revision = CXL_CDAT_REV;
96     /* For now, no runtime updates */
97     cdat_header->sequence = 0;
98     cdat_header->length += sizeof(CDATTableHeader);
99 
100     hdr_buf = (uint8_t *)cdat_header;
101     for (i = 0; i < sizeof(*cdat_header); i++) {
102         sum += hdr_buf[i];
103     }
104 
105     /* Sum of all bytes including checksum must be 0 */
106     cdat_header->checksum = ~sum + 1;
107 
108     cdat_st[0].base = g_steal_pointer(&cdat_header);
109     cdat_st[0].length = sizeof(*cdat_header);
110     cdat->entry_len = 1 + cdat->built_buf_len;
111     cdat->entry = g_steal_pointer(&cdat_st);
112 }
113 
114 static void ct3_load_cdat(CDATObject *cdat, Error **errp)
115 {
116     g_autofree CDATEntry *cdat_st = NULL;
117     g_autofree char *buf = NULL;
118     uint8_t sum = 0;
119     int num_ent;
120     int i = 0, ent = 1;
121     gsize file_size = 0;
122     CDATSubHeader *hdr;
123     GError *error = NULL;
124 
125     /* Read CDAT file and create its cache */
126     if (!g_file_get_contents(cdat->filename, (gchar **)&buf,
127                              &file_size, &error)) {
128         error_setg(errp, "CDAT: File read failed: %s", error->message);
129         g_error_free(error);
130         return;
131     }
132     if (file_size < sizeof(CDATTableHeader)) {
133         error_setg(errp, "CDAT: File too short");
134         return;
135     }
136     i = sizeof(CDATTableHeader);
137     num_ent = 1;
138     while (i < file_size) {
139         hdr = (CDATSubHeader *)(buf + i);
140         if (i + sizeof(CDATSubHeader) > file_size) {
141             error_setg(errp, "CDAT: Truncated table");
142             return;
143         }
144         cdat_len_check(hdr, errp);
145         i += hdr->length;
146         if (i > file_size) {
147             error_setg(errp, "CDAT: Truncated table");
148             return;
149         }
150         num_ent++;
151     }
152     if (i != file_size) {
153         error_setg(errp, "CDAT: File length mismatch");
154         return;
155     }
156 
157     cdat_st = g_new0(CDATEntry, num_ent);
158 
159     /* Set CDAT header, Entry = 0 */
160     cdat_st[0].base = buf;
161     cdat_st[0].length = sizeof(CDATTableHeader);
162     i = 0;
163 
164     while (i < cdat_st[0].length) {
165         sum += buf[i++];
166     }
167 
168     /* Read CDAT structures */
169     while (i < file_size) {
170         hdr = (CDATSubHeader *)(buf + i);
171         cdat_st[ent].base = hdr;
172         cdat_st[ent].length = hdr->length;
173 
174         while (buf + i < (char *)cdat_st[ent].base + cdat_st[ent].length) {
175             assert(i < file_size);
176             sum += buf[i++];
177         }
178 
179         ent++;
180     }
181 
182     if (sum != 0) {
183         warn_report("CDAT: Found checksum mismatch in %s", cdat->filename);
184     }
185     cdat->entry_len = num_ent;
186     cdat->entry = g_steal_pointer(&cdat_st);
187     cdat->buf = g_steal_pointer(&buf);
188 }
189 
190 void cxl_doe_cdat_init(CXLComponentState *cxl_cstate, Error **errp)
191 {
192     CDATObject *cdat = &cxl_cstate->cdat;
193 
194     if (cdat->filename) {
195         ct3_load_cdat(cdat, errp);
196     } else {
197         ct3_build_cdat(cdat, errp);
198     }
199 }
200 
201 void cxl_doe_cdat_update(CXLComponentState *cxl_cstate, Error **errp)
202 {
203     CDATObject *cdat = &cxl_cstate->cdat;
204 
205     if (cdat->to_update) {
206         ct3_build_cdat(cdat, errp);
207     }
208 }
209 
210 void cxl_doe_cdat_release(CXLComponentState *cxl_cstate)
211 {
212     CDATObject *cdat = &cxl_cstate->cdat;
213 
214     free(cdat->entry);
215     if (cdat->built_buf) {
216         cdat->free_cdat_table(cdat->built_buf, cdat->built_buf_len,
217                               cdat->private);
218     }
219     g_free(cdat->buf);
220 }
221