xref: /openbmc/qemu/hw/cxl/cxl-device-utils.c (revision 9c255cb5)
1 /*
2  * CXL Utility library for devices
3  *
4  * Copyright(C) 2020 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 #include "qemu/log.h"
12 #include "hw/cxl/cxl.h"
13 
14 /*
15  * Device registers have no restrictions per the spec, and so fall back to the
16  * default memory mapped register rules in 8.2:
17  *   Software shall use CXL.io Memory Read and Write to access memory mapped
18  *   register defined in this section. Unless otherwise specified, software
19  *   shall restrict the accesses width based on the following:
20  *   • A 32 bit register shall be accessed as a 1 Byte, 2 Bytes or 4 Bytes
21  *     quantity.
22  *   • A 64 bit register shall be accessed as a 1 Byte, 2 Bytes, 4 Bytes or 8
23  *     Bytes
24  *   • The address shall be a multiple of the access width, e.g. when
25  *     accessing a register as a 4 Byte quantity, the address shall be
26  *     multiple of 4.
27  *   • The accesses shall map to contiguous bytes.If these rules are not
28  *     followed, the behavior is undefined
29  */
30 
31 static uint64_t caps_reg_read(void *opaque, hwaddr offset, unsigned size)
32 {
33     CXLDeviceState *cxl_dstate = opaque;
34 
35     if (size == 4) {
36         return cxl_dstate->caps_reg_state32[offset / sizeof(*cxl_dstate->caps_reg_state32)];
37     } else {
38         return cxl_dstate->caps_reg_state64[offset / sizeof(*cxl_dstate->caps_reg_state64)];
39     }
40 }
41 
42 static uint64_t dev_reg_read(void *opaque, hwaddr offset, unsigned size)
43 {
44     CXLDeviceState *cxl_dstate = opaque;
45 
46     switch (size) {
47     case 1:
48         return cxl_dstate->dev_reg_state[offset];
49     case 2:
50         return cxl_dstate->dev_reg_state16[offset / size];
51     case 4:
52         return cxl_dstate->dev_reg_state32[offset / size];
53     case 8:
54         return cxl_dstate->dev_reg_state64[offset / size];
55     default:
56         g_assert_not_reached();
57     }
58 }
59 
60 static uint64_t mailbox_reg_read(void *opaque, hwaddr offset, unsigned size)
61 {
62     CXLDeviceState *cxl_dstate = opaque;
63 
64     switch (size) {
65     case 1:
66         return cxl_dstate->mbox_reg_state[offset];
67     case 2:
68         return cxl_dstate->mbox_reg_state16[offset / size];
69     case 4:
70         return cxl_dstate->mbox_reg_state32[offset / size];
71     case 8:
72         return cxl_dstate->mbox_reg_state64[offset / size];
73     default:
74         g_assert_not_reached();
75     }
76 }
77 
78 static void mailbox_mem_writel(uint32_t *reg_state, hwaddr offset,
79                                uint64_t value)
80 {
81     switch (offset) {
82     case A_CXL_DEV_MAILBOX_CTRL:
83         /* fallthrough */
84     case A_CXL_DEV_MAILBOX_CAP:
85         /* RO register */
86         break;
87     default:
88         qemu_log_mask(LOG_UNIMP,
89                       "%s Unexpected 32-bit access to 0x%" PRIx64 " (WI)\n",
90                       __func__, offset);
91         return;
92     }
93 
94     reg_state[offset / sizeof(*reg_state)] = value;
95 }
96 
97 static void mailbox_mem_writeq(uint64_t *reg_state, hwaddr offset,
98                                uint64_t value)
99 {
100     switch (offset) {
101     case A_CXL_DEV_MAILBOX_CMD:
102         break;
103     case A_CXL_DEV_BG_CMD_STS:
104         /* BG not supported */
105         /* fallthrough */
106     case A_CXL_DEV_MAILBOX_STS:
107         /* Read only register, will get updated by the state machine */
108         return;
109     default:
110         qemu_log_mask(LOG_UNIMP,
111                       "%s Unexpected 64-bit access to 0x%" PRIx64 " (WI)\n",
112                       __func__, offset);
113         return;
114     }
115 
116 
117     reg_state[offset / sizeof(*reg_state)] = value;
118 }
119 
120 static void mailbox_reg_write(void *opaque, hwaddr offset, uint64_t value,
121                               unsigned size)
122 {
123     CXLDeviceState *cxl_dstate = opaque;
124 
125     if (offset >= A_CXL_DEV_CMD_PAYLOAD) {
126         memcpy(cxl_dstate->mbox_reg_state + offset, &value, size);
127         return;
128     }
129 
130     switch (size) {
131     case 4:
132         mailbox_mem_writel(cxl_dstate->mbox_reg_state32, offset, value);
133         break;
134     case 8:
135         mailbox_mem_writeq(cxl_dstate->mbox_reg_state64, offset, value);
136         break;
137     default:
138         g_assert_not_reached();
139     }
140 
141     if (ARRAY_FIELD_EX32(cxl_dstate->mbox_reg_state32, CXL_DEV_MAILBOX_CTRL,
142                          DOORBELL)) {
143         cxl_process_mailbox(cxl_dstate);
144     }
145 }
146 
147 static uint64_t mdev_reg_read(void *opaque, hwaddr offset, unsigned size)
148 {
149     uint64_t retval = 0;
150 
151     retval = FIELD_DP64(retval, CXL_MEM_DEV_STS, MEDIA_STATUS, 1);
152     retval = FIELD_DP64(retval, CXL_MEM_DEV_STS, MBOX_READY, 1);
153 
154     return retval;
155 }
156 
157 static void ro_reg_write(void *opaque, hwaddr offset, uint64_t value,
158                            unsigned size)
159 {
160     /* Many register sets are read only */
161 }
162 
163 static const MemoryRegionOps mdev_ops = {
164     .read = mdev_reg_read,
165     .write = ro_reg_write,
166     .endianness = DEVICE_LITTLE_ENDIAN,
167     .valid = {
168         .min_access_size = 1,
169         .max_access_size = 8,
170         .unaligned = false,
171     },
172     .impl = {
173         .min_access_size = 8,
174         .max_access_size = 8,
175     },
176 };
177 
178 static const MemoryRegionOps mailbox_ops = {
179     .read = mailbox_reg_read,
180     .write = mailbox_reg_write,
181     .endianness = DEVICE_LITTLE_ENDIAN,
182     .valid = {
183         .min_access_size = 1,
184         .max_access_size = 8,
185         .unaligned = false,
186     },
187     .impl = {
188         .min_access_size = 1,
189         .max_access_size = 8,
190     },
191 };
192 
193 static const MemoryRegionOps dev_ops = {
194     .read = dev_reg_read,
195     .write = ro_reg_write,
196     .endianness = DEVICE_LITTLE_ENDIAN,
197     .valid = {
198         .min_access_size = 1,
199         .max_access_size = 8,
200         .unaligned = false,
201     },
202     .impl = {
203         .min_access_size = 1,
204         .max_access_size = 8,
205     },
206 };
207 
208 static const MemoryRegionOps caps_ops = {
209     .read = caps_reg_read,
210     .write = ro_reg_write,
211     .endianness = DEVICE_LITTLE_ENDIAN,
212     .valid = {
213         .min_access_size = 1,
214         .max_access_size = 8,
215         .unaligned = false,
216     },
217     .impl = {
218         .min_access_size = 4,
219         .max_access_size = 8,
220     },
221 };
222 
223 void cxl_device_register_block_init(Object *obj, CXLDeviceState *cxl_dstate)
224 {
225     /* This will be a BAR, so needs to be rounded up to pow2 for PCI spec */
226     memory_region_init(&cxl_dstate->device_registers, obj, "device-registers",
227                        pow2ceil(CXL_MMIO_SIZE));
228 
229     memory_region_init_io(&cxl_dstate->caps, obj, &caps_ops, cxl_dstate,
230                           "cap-array", CXL_CAPS_SIZE);
231     memory_region_init_io(&cxl_dstate->device, obj, &dev_ops, cxl_dstate,
232                           "device-status", CXL_DEVICE_STATUS_REGISTERS_LENGTH);
233     memory_region_init_io(&cxl_dstate->mailbox, obj, &mailbox_ops, cxl_dstate,
234                           "mailbox", CXL_MAILBOX_REGISTERS_LENGTH);
235     memory_region_init_io(&cxl_dstate->memory_device, obj, &mdev_ops,
236                           cxl_dstate, "memory device caps",
237                           CXL_MEMORY_DEVICE_REGISTERS_LENGTH);
238 
239     memory_region_add_subregion(&cxl_dstate->device_registers, 0,
240                                 &cxl_dstate->caps);
241     memory_region_add_subregion(&cxl_dstate->device_registers,
242                                 CXL_DEVICE_STATUS_REGISTERS_OFFSET,
243                                 &cxl_dstate->device);
244     memory_region_add_subregion(&cxl_dstate->device_registers,
245                                 CXL_MAILBOX_REGISTERS_OFFSET,
246                                 &cxl_dstate->mailbox);
247     memory_region_add_subregion(&cxl_dstate->device_registers,
248                                 CXL_MEMORY_DEVICE_REGISTERS_OFFSET,
249                                 &cxl_dstate->memory_device);
250 }
251 
252 void cxl_event_set_status(CXLDeviceState *cxl_dstate, CXLEventLogType log_type,
253                           bool available)
254 {
255     if (available) {
256         cxl_dstate->event_status |= (1 << log_type);
257     } else {
258         cxl_dstate->event_status &= ~(1 << log_type);
259     }
260 
261     ARRAY_FIELD_DP64(cxl_dstate->dev_reg_state64, CXL_DEV_EVENT_STATUS,
262                      EVENT_STATUS, cxl_dstate->event_status);
263 }
264 
265 static void device_reg_init_common(CXLDeviceState *cxl_dstate)
266 {
267     CXLEventLogType log;
268 
269     for (log = 0; log < CXL_EVENT_TYPE_MAX; log++) {
270         cxl_event_set_status(cxl_dstate, log, false);
271     }
272 }
273 
274 static void mailbox_reg_init_common(CXLDeviceState *cxl_dstate)
275 {
276     /* 2048 payload size, with no interrupt or background support */
277     ARRAY_FIELD_DP32(cxl_dstate->mbox_reg_state32, CXL_DEV_MAILBOX_CAP,
278                      PAYLOAD_SIZE, CXL_MAILBOX_PAYLOAD_SHIFT);
279     cxl_dstate->payload_size = CXL_MAILBOX_MAX_PAYLOAD_SIZE;
280 }
281 
282 static void memdev_reg_init_common(CXLDeviceState *cxl_dstate) { }
283 
284 void cxl_device_register_init_common(CXLDeviceState *cxl_dstate)
285 {
286     uint64_t *cap_hdrs = cxl_dstate->caps_reg_state64;
287     const int cap_count = 3;
288 
289     /* CXL Device Capabilities Array Register */
290     ARRAY_FIELD_DP64(cap_hdrs, CXL_DEV_CAP_ARRAY, CAP_ID, 0);
291     ARRAY_FIELD_DP64(cap_hdrs, CXL_DEV_CAP_ARRAY, CAP_VERSION, 1);
292     ARRAY_FIELD_DP64(cap_hdrs, CXL_DEV_CAP_ARRAY, CAP_COUNT, cap_count);
293 
294     cxl_device_cap_init(cxl_dstate, DEVICE_STATUS, 1, 2);
295     device_reg_init_common(cxl_dstate);
296 
297     cxl_device_cap_init(cxl_dstate, MAILBOX, 2, 1);
298     mailbox_reg_init_common(cxl_dstate);
299 
300     cxl_device_cap_init(cxl_dstate, MEMORY_DEVICE, 0x4000, 1);
301     memdev_reg_init_common(cxl_dstate);
302 
303     cxl_initialize_mailbox(cxl_dstate);
304 }
305 
306 uint64_t cxl_device_get_timestamp(CXLDeviceState *cxl_dstate)
307 {
308     uint64_t time, delta;
309     uint64_t final_time = 0;
310 
311     if (cxl_dstate->timestamp.set) {
312         /* Find the delta from the last time the host set the time. */
313         time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
314         delta = time - cxl_dstate->timestamp.last_set;
315         final_time = cxl_dstate->timestamp.host_set + delta;
316     }
317 
318     return final_time;
319 }
320