xref: /openbmc/qemu/hw/cxl/cxl-events.c (revision 5551449b) 
1 /*
2  * CXL Event processing
3  *
4  * Copyright(C) 2023 Intel Corporation.
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2. See the
7  * COPYING file in the top-level directory.
8  */
9 
10 #include "qemu/osdep.h"
11 
12 #include "qemu/bswap.h"
13 #include "qemu/error-report.h"
14 #include "hw/pci/msi.h"
15 #include "hw/pci/msix.h"
16 #include "hw/cxl/cxl.h"
17 #include "hw/cxl/cxl_events.h"
18 
19 /* Artificial limit on the number of events a log can hold */
20 #define CXL_TEST_EVENT_OVERFLOW 8
21 
22 static void reset_overflow(CXLEventLog *log)
23 {
24     log->overflow_err_count = 0;
25     log->first_overflow_timestamp = 0;
26     log->last_overflow_timestamp = 0;
27 }
28 
29 void cxl_event_init(CXLDeviceState *cxlds, int start_msg_num)
30 {
31     CXLEventLog *log;
32     int i;
33 
34     for (i = 0; i < CXL_EVENT_TYPE_MAX; i++) {
35         log = &cxlds->event_logs[i];
36         log->next_handle = 1;
37         log->overflow_err_count = 0;
38         log->first_overflow_timestamp = 0;
39         log->last_overflow_timestamp = 0;
40         log->irq_enabled = false;
41         log->irq_vec = start_msg_num++;
42         qemu_mutex_init(&log->lock);
43         QSIMPLEQ_INIT(&log->events);
44     }
45 
46     /* Override -- Dynamic Capacity uses the same vector as info */
47     cxlds->event_logs[CXL_EVENT_TYPE_DYNAMIC_CAP].irq_vec =
48                       cxlds->event_logs[CXL_EVENT_TYPE_INFO].irq_vec;
49 
50 }
51 
52 static CXLEvent *cxl_event_get_head(CXLEventLog *log)
53 {
54     return QSIMPLEQ_FIRST(&log->events);
55 }
56 
57 static CXLEvent *cxl_event_get_next(CXLEvent *entry)
58 {
59     return QSIMPLEQ_NEXT(entry, node);
60 }
61 
62 static int cxl_event_count(CXLEventLog *log)
63 {
64     CXLEvent *event;
65     int rc = 0;
66 
67     QSIMPLEQ_FOREACH(event, &log->events, node) {
68         rc++;
69     }
70 
71     return rc;
72 }
73 
74 static bool cxl_event_empty(CXLEventLog *log)
75 {
76     return QSIMPLEQ_EMPTY(&log->events);
77 }
78 
79 static void cxl_event_delete_head(CXLDeviceState *cxlds,
80                                   CXLEventLogType log_type,
81                                   CXLEventLog *log)
82 {
83     CXLEvent *entry = cxl_event_get_head(log);
84 
85     reset_overflow(log);
86     QSIMPLEQ_REMOVE_HEAD(&log->events, node);
87     if (cxl_event_empty(log)) {
88         cxl_event_set_status(cxlds, log_type, false);
89     }
90     g_free(entry);
91 }
92 
93 /*
94  * return true if an interrupt should be generated as a result
95  * of inserting this event.
96  */
97 bool cxl_event_insert(CXLDeviceState *cxlds, CXLEventLogType log_type,
98                       CXLEventRecordRaw *event)
99 {
100     uint64_t time;
101     CXLEventLog *log;
102     CXLEvent *entry;
103 
104     if (log_type >= CXL_EVENT_TYPE_MAX) {
105         return false;
106     }
107 
108     time = cxl_device_get_timestamp(cxlds);
109 
110     log = &cxlds->event_logs[log_type];
111 
112     QEMU_LOCK_GUARD(&log->lock);
113 
114     if (cxl_event_count(log) >= CXL_TEST_EVENT_OVERFLOW) {
115         if (log->overflow_err_count == 0) {
116             log->first_overflow_timestamp = time;
117         }
118         log->overflow_err_count++;
119         log->last_overflow_timestamp = time;
120         return false;
121     }
122 
123     entry = g_new0(CXLEvent, 1);
124 
125     memcpy(&entry->data, event, sizeof(*event));
126 
127     entry->data.hdr.handle = cpu_to_le16(log->next_handle);
128     log->next_handle++;
129     /* 0 handle is never valid */
130     if (log->next_handle == 0) {
131         log->next_handle++;
132     }
133     entry->data.hdr.timestamp = cpu_to_le64(time);
134 
135     QSIMPLEQ_INSERT_TAIL(&log->events, entry, node);
136     cxl_event_set_status(cxlds, log_type, true);
137 
138     /* Count went from 0 to 1 */
139     return cxl_event_count(log) == 1;
140 }
141 
142 void cxl_discard_all_event_records(CXLDeviceState *cxlds)
143 {
144     CXLEventLogType log_type;
145     CXLEventLog *log;
146 
147     for (log_type = 0; log_type < CXL_EVENT_TYPE_MAX; log_type++) {
148         log = &cxlds->event_logs[log_type];
149         while (!cxl_event_empty(log)) {
150             cxl_event_delete_head(cxlds, log_type, log);
151         }
152     }
153 }
154 
155 CXLRetCode cxl_event_get_records(CXLDeviceState *cxlds, CXLGetEventPayload *pl,
156                                  uint8_t log_type, int max_recs,
157                                  size_t *len)
158 {
159     CXLEventLog *log;
160     CXLEvent *entry;
161     uint16_t nr;
162 
163     if (log_type >= CXL_EVENT_TYPE_MAX) {
164         return CXL_MBOX_INVALID_INPUT;
165     }
166 
167     log = &cxlds->event_logs[log_type];
168 
169     QEMU_LOCK_GUARD(&log->lock);
170 
171     entry = cxl_event_get_head(log);
172     for (nr = 0; entry && nr < max_recs; nr++) {
173         memcpy(&pl->records[nr], &entry->data, CXL_EVENT_RECORD_SIZE);
174         entry = cxl_event_get_next(entry);
175     }
176 
177     if (!cxl_event_empty(log)) {
178         pl->flags |= CXL_GET_EVENT_FLAG_MORE_RECORDS;
179     }
180 
181     if (log->overflow_err_count) {
182         pl->flags |= CXL_GET_EVENT_FLAG_OVERFLOW;
183         pl->overflow_err_count = cpu_to_le16(log->overflow_err_count);
184         pl->first_overflow_timestamp =
185             cpu_to_le64(log->first_overflow_timestamp);
186         pl->last_overflow_timestamp =
187             cpu_to_le64(log->last_overflow_timestamp);
188     }
189 
190     pl->record_count = cpu_to_le16(nr);
191     *len = CXL_EVENT_PAYLOAD_HDR_SIZE + (CXL_EVENT_RECORD_SIZE * nr);
192 
193     return CXL_MBOX_SUCCESS;
194 }
195 
196 CXLRetCode cxl_event_clear_records(CXLDeviceState *cxlds,
197                                    CXLClearEventPayload *pl)
198 {
199     CXLEventLog *log;
200     uint8_t log_type;
201     CXLEvent *entry;
202     int nr;
203 
204     log_type = pl->event_log;
205 
206     if (log_type >= CXL_EVENT_TYPE_MAX) {
207         return CXL_MBOX_INVALID_INPUT;
208     }
209 
210     log = &cxlds->event_logs[log_type];
211 
212     QEMU_LOCK_GUARD(&log->lock);
213     /*
214      * Must iterate the queue twice.
215      * "The device shall verify the event record handles specified in the input
216      * payload are in temporal order. If the device detects an older event
217      * record that will not be cleared when Clear Event Records is executed,
218      * the device shall return the Invalid Handle return code and shall not
219      * clear any of the specified event records."
220      *   -- CXL r3.1 Section 8.2.9.2.3: Clear Event Records (0101h)
221      */
222     entry = cxl_event_get_head(log);
223     for (nr = 0; entry && nr < pl->nr_recs; nr++) {
224         uint16_t handle = pl->handle[nr];
225 
226         /* NOTE: Both handles are little endian. */
227         if (handle == 0 || entry->data.hdr.handle != handle) {
228             return CXL_MBOX_INVALID_INPUT;
229         }
230         entry = cxl_event_get_next(entry);
231     }
232 
233     entry = cxl_event_get_head(log);
234     for (nr = 0; entry && nr < pl->nr_recs; nr++) {
235         cxl_event_delete_head(cxlds, log_type, log);
236         entry = cxl_event_get_head(log);
237     }
238 
239     return CXL_MBOX_SUCCESS;
240 }
241 
242 void cxl_event_irq_assert(CXLType3Dev *ct3d)
243 {
244     CXLDeviceState *cxlds = &ct3d->cxl_dstate;
245     PCIDevice *pdev = &ct3d->parent_obj;
246     int i;
247 
248     for (i = 0; i < CXL_EVENT_TYPE_MAX; i++) {
249         CXLEventLog *log = &cxlds->event_logs[i];
250 
251         if (!log->irq_enabled || cxl_event_empty(log)) {
252             continue;
253         }
254 
255         /*  Notifies interrupt, legacy IRQ is not supported */
256         if (msix_enabled(pdev)) {
257             msix_notify(pdev, log->irq_vec);
258         } else if (msi_enabled(pdev)) {
259             msi_notify(pdev, log->irq_vec);
260         }
261     }
262 }
263