xref: /openbmc/qemu/hw/cxl/cxl-host.c (revision df1f50c3) 
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     g_autofree CXLFixedWindow *fw = g_malloc0(sizeof(*fw));
30     strList *target;
31     int i;
32 
33     for (target = object->targets; target; target = target->next) {
34         fw->num_targets++;
35     }
36 
37     fw->enc_int_ways = cxl_interleave_ways_enc(fw->num_targets, errp);
38     if (*errp) {
39         return;
40     }
41 
42     fw->targets = g_malloc0_n(fw->num_targets, sizeof(*fw->targets));
43     for (i = 0, target = object->targets; target; i++, target = target->next) {
44         /* This link cannot be resolved yet, so stash the name for now */
45         fw->targets[i] = g_strdup(target->value);
46     }
47 
48     if (object->size % (256 * MiB)) {
49         error_setg(errp,
50                    "Size of a CXL fixed memory window must be a multiple of 256MiB");
51         return;
52     }
53     fw->size = object->size;
54 
55     if (object->has_interleave_granularity) {
56         fw->enc_int_gran =
57             cxl_interleave_granularity_enc(object->interleave_granularity,
58                                            errp);
59         if (*errp) {
60             return;
61         }
62     } else {
63         /* Default to 256 byte interleave */
64         fw->enc_int_gran = 0;
65     }
66 
67     cxl_state->fixed_windows = g_list_append(cxl_state->fixed_windows,
68                                              g_steal_pointer(&fw));
69 
70     return;
71 }
72 
73 void cxl_fmws_link_targets(CXLState *cxl_state, Error **errp)
74 {
75     if (cxl_state && cxl_state->fixed_windows) {
76         GList *it;
77 
78         for (it = cxl_state->fixed_windows; it; it = it->next) {
79             CXLFixedWindow *fw = it->data;
80             int i;
81 
82             for (i = 0; i < fw->num_targets; i++) {
83                 Object *o;
84                 bool ambig;
85 
86                 o = object_resolve_path_type(fw->targets[i],
87                                              TYPE_PXB_CXL_DEV,
88                                              &ambig);
89                 if (!o) {
90                     error_setg(errp, "Could not resolve CXLFM target %s",
91                                fw->targets[i]);
92                     return;
93                 }
94                 fw->target_hbs[i] = PXB_CXL_DEV(o);
95             }
96         }
97     }
98 }
99 
100 /* TODO: support, multiple hdm decoders */
101 static bool cxl_hdm_find_target(uint32_t *cache_mem, hwaddr addr,
102                                 uint8_t *target)
103 {
104     uint32_t ctrl;
105     uint32_t ig_enc;
106     uint32_t iw_enc;
107     uint32_t target_idx;
108 
109     ctrl = cache_mem[R_CXL_HDM_DECODER0_CTRL];
110     if (!FIELD_EX32(ctrl, CXL_HDM_DECODER0_CTRL, COMMITTED)) {
111         return false;
112     }
113 
114     ig_enc = FIELD_EX32(ctrl, CXL_HDM_DECODER0_CTRL, IG);
115     iw_enc = FIELD_EX32(ctrl, CXL_HDM_DECODER0_CTRL, IW);
116     target_idx = (addr / cxl_decode_ig(ig_enc)) % (1 << iw_enc);
117 
118     if (target_idx < 4) {
119         *target = extract32(cache_mem[R_CXL_HDM_DECODER0_TARGET_LIST_LO],
120                             target_idx * 8, 8);
121     } else {
122         *target = extract32(cache_mem[R_CXL_HDM_DECODER0_TARGET_LIST_HI],
123                             (target_idx - 4) * 8, 8);
124     }
125 
126     return true;
127 }
128 
129 static PCIDevice *cxl_cfmws_find_device(CXLFixedWindow *fw, hwaddr addr)
130 {
131     CXLComponentState *hb_cstate, *usp_cstate;
132     PCIHostState *hb;
133     CXLUpstreamPort *usp;
134     int rb_index;
135     uint32_t *cache_mem;
136     uint8_t target;
137     bool target_found;
138     PCIDevice *rp, *d;
139 
140     /* Address is relative to memory region. Convert to HPA */
141     addr += fw->base;
142 
143     rb_index = (addr / cxl_decode_ig(fw->enc_int_gran)) % fw->num_targets;
144     hb = PCI_HOST_BRIDGE(fw->target_hbs[rb_index]->cxl_host_bridge);
145     if (!hb || !hb->bus || !pci_bus_is_cxl(hb->bus)) {
146         return NULL;
147     }
148 
149     if (cxl_get_hb_passthrough(hb)) {
150         rp = pcie_find_port_first(hb->bus);
151         if (!rp) {
152             return NULL;
153         }
154     } else {
155         hb_cstate = cxl_get_hb_cstate(hb);
156         if (!hb_cstate) {
157             return NULL;
158         }
159 
160         cache_mem = hb_cstate->crb.cache_mem_registers;
161 
162         target_found = cxl_hdm_find_target(cache_mem, addr, &target);
163         if (!target_found) {
164             return NULL;
165         }
166 
167         rp = pcie_find_port_by_pn(hb->bus, target);
168         if (!rp) {
169             return NULL;
170         }
171     }
172 
173     d = pci_bridge_get_sec_bus(PCI_BRIDGE(rp))->devices[0];
174     if (!d) {
175         return NULL;
176     }
177 
178     if (object_dynamic_cast(OBJECT(d), TYPE_CXL_TYPE3)) {
179         return d;
180     }
181 
182     /*
183      * Could also be a switch.  Note only one level of switching currently
184      * supported.
185      */
186     if (!object_dynamic_cast(OBJECT(d), TYPE_CXL_USP)) {
187         return NULL;
188     }
189     usp = CXL_USP(d);
190 
191     usp_cstate = cxl_usp_to_cstate(usp);
192     if (!usp_cstate) {
193         return NULL;
194     }
195 
196     cache_mem = usp_cstate->crb.cache_mem_registers;
197 
198     target_found = cxl_hdm_find_target(cache_mem, addr, &target);
199     if (!target_found) {
200         return NULL;
201     }
202 
203     d = pcie_find_port_by_pn(&PCI_BRIDGE(d)->sec_bus, target);
204     if (!d) {
205         return NULL;
206     }
207 
208     d = pci_bridge_get_sec_bus(PCI_BRIDGE(d))->devices[0];
209     if (!d) {
210         return NULL;
211     }
212 
213     if (!object_dynamic_cast(OBJECT(d), TYPE_CXL_TYPE3)) {
214         return NULL;
215     }
216 
217     return d;
218 }
219 
220 static MemTxResult cxl_read_cfmws(void *opaque, hwaddr addr, uint64_t *data,
221                                   unsigned size, MemTxAttrs attrs)
222 {
223     CXLFixedWindow *fw = opaque;
224     PCIDevice *d;
225 
226     d = cxl_cfmws_find_device(fw, addr);
227     if (d == NULL) {
228         *data = 0;
229         /* Reads to invalid address return poison */
230         return MEMTX_ERROR;
231     }
232 
233     return cxl_type3_read(d, addr + fw->base, data, size, attrs);
234 }
235 
236 static MemTxResult cxl_write_cfmws(void *opaque, hwaddr addr,
237                                    uint64_t data, unsigned size,
238                                    MemTxAttrs attrs)
239 {
240     CXLFixedWindow *fw = opaque;
241     PCIDevice *d;
242 
243     d = cxl_cfmws_find_device(fw, addr);
244     if (d == NULL) {
245         /* Writes to invalid address are silent */
246         return MEMTX_OK;
247     }
248 
249     return cxl_type3_write(d, addr + fw->base, data, size, attrs);
250 }
251 
252 const MemoryRegionOps cfmws_ops = {
253     .read_with_attrs = cxl_read_cfmws,
254     .write_with_attrs = cxl_write_cfmws,
255     .endianness = DEVICE_LITTLE_ENDIAN,
256     .valid = {
257         .min_access_size = 1,
258         .max_access_size = 8,
259         .unaligned = true,
260     },
261     .impl = {
262         .min_access_size = 1,
263         .max_access_size = 8,
264         .unaligned = true,
265     },
266 };
267 
268 static void machine_get_cxl(Object *obj, Visitor *v, const char *name,
269                             void *opaque, Error **errp)
270 {
271     CXLState *cxl_state = opaque;
272     bool value = cxl_state->is_enabled;
273 
274     visit_type_bool(v, name, &value, errp);
275 }
276 
277 static void machine_set_cxl(Object *obj, Visitor *v, const char *name,
278                             void *opaque, Error **errp)
279 {
280     CXLState *cxl_state = opaque;
281     bool value;
282 
283     if (!visit_type_bool(v, name, &value, errp)) {
284         return;
285     }
286     cxl_state->is_enabled = value;
287 }
288 
289 static void machine_get_cfmw(Object *obj, Visitor *v, const char *name,
290                              void *opaque, Error **errp)
291 {
292     CXLFixedMemoryWindowOptionsList **list = opaque;
293 
294     visit_type_CXLFixedMemoryWindowOptionsList(v, name, list, errp);
295 }
296 
297 static void machine_set_cfmw(Object *obj, Visitor *v, const char *name,
298                              void *opaque, Error **errp)
299 {
300     CXLState *state = opaque;
301     CXLFixedMemoryWindowOptionsList *cfmw_list = NULL;
302     CXLFixedMemoryWindowOptionsList *it;
303 
304     visit_type_CXLFixedMemoryWindowOptionsList(v, name, &cfmw_list, errp);
305     if (!cfmw_list) {
306         return;
307     }
308 
309     for (it = cfmw_list; it; it = it->next) {
310         cxl_fixed_memory_window_config(state, it->value, errp);
311     }
312     state->cfmw_list = cfmw_list;
313 }
314 
315 void cxl_machine_init(Object *obj, CXLState *state)
316 {
317     object_property_add(obj, "cxl", "bool", machine_get_cxl,
318                         machine_set_cxl, NULL, state);
319     object_property_set_description(obj, "cxl",
320                                     "Set on/off to enable/disable "
321                                     "CXL instantiation");
322 
323     object_property_add(obj, "cxl-fmw", "CXLFixedMemoryWindow",
324                         machine_get_cfmw, machine_set_cfmw,
325                         NULL, state);
326     object_property_set_description(obj, "cxl-fmw",
327                                     "CXL Fixed Memory Windows (array)");
328 }
329 
330 void cxl_hook_up_pxb_registers(PCIBus *bus, CXLState *state, Error **errp)
331 {
332     /* Walk the pci busses looking for pxb busses to hook up */
333     if (bus) {
334         QLIST_FOREACH(bus, &bus->child, sibling) {
335             if (!pci_bus_is_root(bus)) {
336                 continue;
337             }
338             if (pci_bus_is_cxl(bus)) {
339                 if (!state->is_enabled) {
340                     error_setg(errp, "CXL host bridges present, but cxl=off");
341                     return;
342                 }
343                 pxb_cxl_hook_up_registers(state, bus, errp);
344             }
345         }
346     }
347 }
348