xref: /openbmc/qemu/hw/cxl/cxl-events.c (revision ed75658a) 
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 CXLRetCode cxl_event_get_records(CXLDeviceState *cxlds, CXLGetEventPayload *pl,
143                                  uint8_t log_type, int max_recs,
144                                  size_t *len)
145 {
146     CXLEventLog *log;
147     CXLEvent *entry;
148     uint16_t nr;
149 
150     if (log_type >= CXL_EVENT_TYPE_MAX) {
151         return CXL_MBOX_INVALID_INPUT;
152     }
153 
154     log = &cxlds->event_logs[log_type];
155 
156     QEMU_LOCK_GUARD(&log->lock);
157 
158     entry = cxl_event_get_head(log);
159     for (nr = 0; entry && nr < max_recs; nr++) {
160         memcpy(&pl->records[nr], &entry->data, CXL_EVENT_RECORD_SIZE);
161         entry = cxl_event_get_next(entry);
162     }
163 
164     if (!cxl_event_empty(log)) {
165         pl->flags |= CXL_GET_EVENT_FLAG_MORE_RECORDS;
166     }
167 
168     if (log->overflow_err_count) {
169         pl->flags |= CXL_GET_EVENT_FLAG_OVERFLOW;
170         pl->overflow_err_count = cpu_to_le16(log->overflow_err_count);
171         pl->first_overflow_timestamp =
172             cpu_to_le64(log->first_overflow_timestamp);
173         pl->last_overflow_timestamp =
174             cpu_to_le64(log->last_overflow_timestamp);
175     }
176 
177     pl->record_count = cpu_to_le16(nr);
178     *len = CXL_EVENT_PAYLOAD_HDR_SIZE + (CXL_EVENT_RECORD_SIZE * nr);
179 
180     return CXL_MBOX_SUCCESS;
181 }
182 
183 CXLRetCode cxl_event_clear_records(CXLDeviceState *cxlds,
184                                    CXLClearEventPayload *pl)
185 {
186     CXLEventLog *log;
187     uint8_t log_type;
188     CXLEvent *entry;
189     int nr;
190 
191     log_type = pl->event_log;
192 
193     if (log_type >= CXL_EVENT_TYPE_MAX) {
194         return CXL_MBOX_INVALID_INPUT;
195     }
196 
197     log = &cxlds->event_logs[log_type];
198 
199     QEMU_LOCK_GUARD(&log->lock);
200     /*
201      * Must iterate the queue twice.
202      * "The device shall verify the event record handles specified in the input
203      * payload are in temporal order. If the device detects an older event
204      * record that will not be cleared when Clear Event Records is executed,
205      * the device shall return the Invalid Handle return code and shall not
206      * clear any of the specified event records."
207      *   -- CXL r3.1 Section 8.2.9.2.3: Clear Event Records (0101h)
208      */
209     entry = cxl_event_get_head(log);
210     for (nr = 0; entry && nr < pl->nr_recs; nr++) {
211         uint16_t handle = pl->handle[nr];
212 
213         /* NOTE: Both handles are little endian. */
214         if (handle == 0 || entry->data.hdr.handle != handle) {
215             return CXL_MBOX_INVALID_INPUT;
216         }
217         entry = cxl_event_get_next(entry);
218     }
219 
220     entry = cxl_event_get_head(log);
221     for (nr = 0; entry && nr < pl->nr_recs; nr++) {
222         cxl_event_delete_head(cxlds, log_type, log);
223         entry = cxl_event_get_head(log);
224     }
225 
226     return CXL_MBOX_SUCCESS;
227 }
228 
229 void cxl_event_irq_assert(CXLType3Dev *ct3d)
230 {
231     CXLDeviceState *cxlds = &ct3d->cxl_dstate;
232     PCIDevice *pdev = &ct3d->parent_obj;
233     int i;
234 
235     for (i = 0; i < CXL_EVENT_TYPE_MAX; i++) {
236         CXLEventLog *log = &cxlds->event_logs[i];
237 
238         if (!log->irq_enabled || cxl_event_empty(log)) {
239             continue;
240         }
241 
242         /*  Notifies interrupt, legacy IRQ is not supported */
243         if (msix_enabled(pdev)) {
244             msix_notify(pdev, log->irq_vec);
245         } else if (msi_enabled(pdev)) {
246             msi_notify(pdev, log->irq_vec);
247         }
248     }
249 }
250