xref: /openbmc/qemu/hw/cxl/cxl-host.c (revision ab0c7fb2)
1 /*
2  * CXL host parameter parsing routines
3  *
4  * Copyright (c) 2022 Huawei
5  * Modeled loosely on the NUMA options handling in hw/core/numa.c
6  */
7 
8 #include "qemu/osdep.h"
9 #include "qemu/units.h"
10 #include "qemu/bitmap.h"
11 #include "qemu/error-report.h"
12 #include "qapi/error.h"
13 #include "sysemu/qtest.h"
14 #include "hw/boards.h"
15 
16 #include "qapi/qapi-visit-machine.h"
17 #include "hw/cxl/cxl.h"
18 #include "hw/cxl/cxl_host.h"
19 #include "hw/pci/pci_bus.h"
20 #include "hw/pci/pci_bridge.h"
21 #include "hw/pci/pci_host.h"
22 #include "hw/pci/pcie_port.h"
23 #include "hw/pci-bridge/pci_expander_bridge.h"
24 
25 static void cxl_fixed_memory_window_config(CXLState *cxl_state,
26                                            CXLFixedMemoryWindowOptions *object,
27                                            Error **errp)
28 {
29     ERRP_GUARD();
30     g_autofree CXLFixedWindow *fw = g_malloc0(sizeof(*fw));
31     strList *target;
32     int i;
33 
34     for (target = object->targets; target; target = target->next) {
35         fw->num_targets++;
36     }
37 
38     fw->enc_int_ways = cxl_interleave_ways_enc(fw->num_targets, errp);
39     if (*errp) {
40         return;
41     }
42 
43     if (object->size % (256 * MiB)) {
44         error_setg(errp,
45                    "Size of a CXL fixed memory window must be a multiple of 256MiB");
46         return;
47     }
48     fw->size = object->size;
49 
50     if (object->has_interleave_granularity) {
51         fw->enc_int_gran =
52             cxl_interleave_granularity_enc(object->interleave_granularity,
53                                            errp);
54         if (*errp) {
55             return;
56         }
57     } else {
58         /* Default to 256 byte interleave */
59         fw->enc_int_gran = 0;
60     }
61 
62     fw->targets = g_malloc0_n(fw->num_targets, sizeof(*fw->targets));
63     for (i = 0, target = object->targets; target; i++, target = target->next) {
64         /* This link cannot be resolved yet, so stash the name for now */
65         fw->targets[i] = g_strdup(target->value);
66     }
67 
68     cxl_state->fixed_windows = g_list_append(cxl_state->fixed_windows,
69                                              g_steal_pointer(&fw));
70 
71     return;
72 }
73 
74 void cxl_fmws_link_targets(CXLState *cxl_state, Error **errp)
75 {
76     if (cxl_state && cxl_state->fixed_windows) {
77         GList *it;
78 
79         for (it = cxl_state->fixed_windows; it; it = it->next) {
80             CXLFixedWindow *fw = it->data;
81             int i;
82 
83             for (i = 0; i < fw->num_targets; i++) {
84                 Object *o;
85                 bool ambig;
86 
87                 o = object_resolve_path_type(fw->targets[i],
88                                              TYPE_PXB_CXL_DEV,
89                                              &ambig);
90                 if (!o) {
91                     error_setg(errp, "Could not resolve CXLFM target %s",
92                                fw->targets[i]);
93                     return;
94                 }
95                 fw->target_hbs[i] = PXB_CXL_DEV(o);
96             }
97         }
98     }
99 }
100 
101 static bool cxl_hdm_find_target(uint32_t *cache_mem, hwaddr addr,
102                                 uint8_t *target)
103 {
104     int hdm_inc = R_CXL_HDM_DECODER1_BASE_LO - R_CXL_HDM_DECODER0_BASE_LO;
105     unsigned int hdm_count;
106     bool found = false;
107     int i;
108     uint32_t cap;
109 
110     cap = ldl_le_p(cache_mem + R_CXL_HDM_DECODER_CAPABILITY);
111     hdm_count = cxl_decoder_count_dec(FIELD_EX32(cap,
112                                                  CXL_HDM_DECODER_CAPABILITY,
113                                                  DECODER_COUNT));
114     for (i = 0; i < hdm_count; i++) {
115         uint32_t ctrl, ig_enc, iw_enc, target_idx;
116         uint32_t low, high;
117         uint64_t base, size;
118 
119         low = ldl_le_p(cache_mem + R_CXL_HDM_DECODER0_BASE_LO + i * hdm_inc);
120         high = ldl_le_p(cache_mem + R_CXL_HDM_DECODER0_BASE_HI + i * hdm_inc);
121         base = (low & 0xf0000000) | ((uint64_t)high << 32);
122         low = ldl_le_p(cache_mem + R_CXL_HDM_DECODER0_SIZE_LO + i * hdm_inc);
123         high = ldl_le_p(cache_mem + R_CXL_HDM_DECODER0_SIZE_HI + i * hdm_inc);
124         size = (low & 0xf0000000) | ((uint64_t)high << 32);
125         if (addr < base || addr >= base + size) {
126             continue;
127         }
128 
129         ctrl = ldl_le_p(cache_mem + R_CXL_HDM_DECODER0_CTRL + i * hdm_inc);
130         if (!FIELD_EX32(ctrl, CXL_HDM_DECODER0_CTRL, COMMITTED)) {
131             return false;
132         }
133         found = true;
134         ig_enc = FIELD_EX32(ctrl, CXL_HDM_DECODER0_CTRL, IG);
135         iw_enc = FIELD_EX32(ctrl, CXL_HDM_DECODER0_CTRL, IW);
136         target_idx = (addr / cxl_decode_ig(ig_enc)) % (1 << iw_enc);
137 
138         if (target_idx < 4) {
139             uint32_t val = ldl_le_p(cache_mem +
140                                     R_CXL_HDM_DECODER0_TARGET_LIST_LO +
141                                     i * hdm_inc);
142             *target = extract32(val, target_idx * 8, 8);
143         } else {
144             uint32_t val = ldl_le_p(cache_mem +
145                                     R_CXL_HDM_DECODER0_TARGET_LIST_HI +
146                                     i * hdm_inc);
147             *target = extract32(val, (target_idx - 4) * 8, 8);
148         }
149         break;
150     }
151 
152     return found;
153 }
154 
155 static PCIDevice *cxl_cfmws_find_device(CXLFixedWindow *fw, hwaddr addr)
156 {
157     CXLComponentState *hb_cstate, *usp_cstate;
158     PCIHostState *hb;
159     CXLUpstreamPort *usp;
160     int rb_index;
161     uint32_t *cache_mem;
162     uint8_t target;
163     bool target_found;
164     PCIDevice *rp, *d;
165 
166     /* Address is relative to memory region. Convert to HPA */
167     addr += fw->base;
168 
169     rb_index = (addr / cxl_decode_ig(fw->enc_int_gran)) % fw->num_targets;
170     hb = PCI_HOST_BRIDGE(fw->target_hbs[rb_index]->cxl_host_bridge);
171     if (!hb || !hb->bus || !pci_bus_is_cxl(hb->bus)) {
172         return NULL;
173     }
174 
175     if (cxl_get_hb_passthrough(hb)) {
176         rp = pcie_find_port_first(hb->bus);
177         if (!rp) {
178             return NULL;
179         }
180     } else {
181         hb_cstate = cxl_get_hb_cstate(hb);
182         if (!hb_cstate) {
183             return NULL;
184         }
185 
186         cache_mem = hb_cstate->crb.cache_mem_registers;
187 
188         target_found = cxl_hdm_find_target(cache_mem, addr, &target);
189         if (!target_found) {
190             return NULL;
191         }
192 
193         rp = pcie_find_port_by_pn(hb->bus, target);
194         if (!rp) {
195             return NULL;
196         }
197     }
198 
199     d = pci_bridge_get_sec_bus(PCI_BRIDGE(rp))->devices[0];
200     if (!d) {
201         return NULL;
202     }
203 
204     if (object_dynamic_cast(OBJECT(d), TYPE_CXL_TYPE3)) {
205         return d;
206     }
207 
208     /*
209      * Could also be a switch.  Note only one level of switching currently
210      * supported.
211      */
212     if (!object_dynamic_cast(OBJECT(d), TYPE_CXL_USP)) {
213         return NULL;
214     }
215     usp = CXL_USP(d);
216 
217     usp_cstate = cxl_usp_to_cstate(usp);
218     if (!usp_cstate) {
219         return NULL;
220     }
221 
222     cache_mem = usp_cstate->crb.cache_mem_registers;
223 
224     target_found = cxl_hdm_find_target(cache_mem, addr, &target);
225     if (!target_found) {
226         return NULL;
227     }
228 
229     d = pcie_find_port_by_pn(&PCI_BRIDGE(d)->sec_bus, target);
230     if (!d) {
231         return NULL;
232     }
233 
234     d = pci_bridge_get_sec_bus(PCI_BRIDGE(d))->devices[0];
235     if (!d) {
236         return NULL;
237     }
238 
239     if (!object_dynamic_cast(OBJECT(d), TYPE_CXL_TYPE3)) {
240         return NULL;
241     }
242 
243     return d;
244 }
245 
246 static MemTxResult cxl_read_cfmws(void *opaque, hwaddr addr, uint64_t *data,
247                                   unsigned size, MemTxAttrs attrs)
248 {
249     CXLFixedWindow *fw = opaque;
250     PCIDevice *d;
251 
252     d = cxl_cfmws_find_device(fw, addr);
253     if (d == NULL) {
254         *data = 0;
255         /* Reads to invalid address return poison */
256         return MEMTX_ERROR;
257     }
258 
259     return cxl_type3_read(d, addr + fw->base, data, size, attrs);
260 }
261 
262 static MemTxResult cxl_write_cfmws(void *opaque, hwaddr addr,
263                                    uint64_t data, unsigned size,
264                                    MemTxAttrs attrs)
265 {
266     CXLFixedWindow *fw = opaque;
267     PCIDevice *d;
268 
269     d = cxl_cfmws_find_device(fw, addr);
270     if (d == NULL) {
271         /* Writes to invalid address are silent */
272         return MEMTX_OK;
273     }
274 
275     return cxl_type3_write(d, addr + fw->base, data, size, attrs);
276 }
277 
278 const MemoryRegionOps cfmws_ops = {
279     .read_with_attrs = cxl_read_cfmws,
280     .write_with_attrs = cxl_write_cfmws,
281     .endianness = DEVICE_LITTLE_ENDIAN,
282     .valid = {
283         .min_access_size = 1,
284         .max_access_size = 8,
285         .unaligned = true,
286     },
287     .impl = {
288         .min_access_size = 1,
289         .max_access_size = 8,
290         .unaligned = true,
291     },
292 };
293 
294 static void machine_get_cxl(Object *obj, Visitor *v, const char *name,
295                             void *opaque, Error **errp)
296 {
297     CXLState *cxl_state = opaque;
298     bool value = cxl_state->is_enabled;
299 
300     visit_type_bool(v, name, &value, errp);
301 }
302 
303 static void machine_set_cxl(Object *obj, Visitor *v, const char *name,
304                             void *opaque, Error **errp)
305 {
306     CXLState *cxl_state = opaque;
307     bool value;
308 
309     if (!visit_type_bool(v, name, &value, errp)) {
310         return;
311     }
312     cxl_state->is_enabled = value;
313 }
314 
315 static void machine_get_cfmw(Object *obj, Visitor *v, const char *name,
316                              void *opaque, Error **errp)
317 {
318     CXLFixedMemoryWindowOptionsList **list = opaque;
319 
320     visit_type_CXLFixedMemoryWindowOptionsList(v, name, list, errp);
321 }
322 
323 static void machine_set_cfmw(Object *obj, Visitor *v, const char *name,
324                              void *opaque, Error **errp)
325 {
326     CXLState *state = opaque;
327     CXLFixedMemoryWindowOptionsList *cfmw_list = NULL;
328     CXLFixedMemoryWindowOptionsList *it;
329 
330     visit_type_CXLFixedMemoryWindowOptionsList(v, name, &cfmw_list, errp);
331     if (!cfmw_list) {
332         return;
333     }
334 
335     for (it = cfmw_list; it; it = it->next) {
336         cxl_fixed_memory_window_config(state, it->value, errp);
337     }
338     state->cfmw_list = cfmw_list;
339 }
340 
341 void cxl_machine_init(Object *obj, CXLState *state)
342 {
343     object_property_add(obj, "cxl", "bool", machine_get_cxl,
344                         machine_set_cxl, NULL, state);
345     object_property_set_description(obj, "cxl",
346                                     "Set on/off to enable/disable "
347                                     "CXL instantiation");
348 
349     object_property_add(obj, "cxl-fmw", "CXLFixedMemoryWindow",
350                         machine_get_cfmw, machine_set_cfmw,
351                         NULL, state);
352     object_property_set_description(obj, "cxl-fmw",
353                                     "CXL Fixed Memory Windows (array)");
354 }
355 
356 void cxl_hook_up_pxb_registers(PCIBus *bus, CXLState *state, Error **errp)
357 {
358     /* Walk the pci busses looking for pxb busses to hook up */
359     if (bus) {
360         QLIST_FOREACH(bus, &bus->child, sibling) {
361             if (!pci_bus_is_root(bus)) {
362                 continue;
363             }
364             if (pci_bus_is_cxl(bus)) {
365                 if (!state->is_enabled) {
366                     error_setg(errp, "CXL host bridges present, but cxl=off");
367                     return;
368                 }
369                 pxb_cxl_hook_up_registers(state, bus, errp);
370             }
371         }
372     }
373 }
374