xref: /openbmc/qemu/hw/cxl/cxl-host.c (revision 8c6631e6) 
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_DEVICE,
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.cxl_host_bridge);
145     if (!hb || !hb->bus || !pci_bus_is_cxl(hb->bus)) {
146         return NULL;
147     }
148 
149     hb_cstate = cxl_get_hb_cstate(hb);
150     if (!hb_cstate) {
151         return NULL;
152     }
153 
154     cache_mem = hb_cstate->crb.cache_mem_registers;
155 
156     target_found = cxl_hdm_find_target(cache_mem, addr, &target);
157     if (!target_found) {
158         return NULL;
159     }
160 
161     rp = pcie_find_port_by_pn(hb->bus, target);
162     if (!rp) {
163         return NULL;
164     }
165 
166     d = pci_bridge_get_sec_bus(PCI_BRIDGE(rp))->devices[0];
167     if (!d) {
168         return NULL;
169     }
170 
171     if (object_dynamic_cast(OBJECT(d), TYPE_CXL_TYPE3)) {
172         return d;
173     }
174 
175     /*
176      * Could also be a switch.  Note only one level of switching currently
177      * supported.
178      */
179     if (!object_dynamic_cast(OBJECT(d), TYPE_CXL_USP)) {
180         return NULL;
181     }
182     usp = CXL_USP(d);
183 
184     usp_cstate = cxl_usp_to_cstate(usp);
185     if (!usp_cstate) {
186         return NULL;
187     }
188 
189     cache_mem = usp_cstate->crb.cache_mem_registers;
190 
191     target_found = cxl_hdm_find_target(cache_mem, addr, &target);
192     if (!target_found) {
193         return NULL;
194     }
195 
196     d = pcie_find_port_by_pn(&PCI_BRIDGE(d)->sec_bus, target);
197     if (!d) {
198         return NULL;
199     }
200 
201     d = pci_bridge_get_sec_bus(PCI_BRIDGE(d))->devices[0];
202     if (!d) {
203         return NULL;
204     }
205 
206     if (!object_dynamic_cast(OBJECT(d), TYPE_CXL_TYPE3)) {
207         return NULL;
208     }
209 
210     return d;
211 }
212 
213 static MemTxResult cxl_read_cfmws(void *opaque, hwaddr addr, uint64_t *data,
214                                   unsigned size, MemTxAttrs attrs)
215 {
216     CXLFixedWindow *fw = opaque;
217     PCIDevice *d;
218 
219     d = cxl_cfmws_find_device(fw, addr);
220     if (d == NULL) {
221         *data = 0;
222         /* Reads to invalid address return poison */
223         return MEMTX_ERROR;
224     }
225 
226     return cxl_type3_read(d, addr + fw->base, data, size, attrs);
227 }
228 
229 static MemTxResult cxl_write_cfmws(void *opaque, hwaddr addr,
230                                    uint64_t data, unsigned size,
231                                    MemTxAttrs attrs)
232 {
233     CXLFixedWindow *fw = opaque;
234     PCIDevice *d;
235 
236     d = cxl_cfmws_find_device(fw, addr);
237     if (d == NULL) {
238         /* Writes to invalid address are silent */
239         return MEMTX_OK;
240     }
241 
242     return cxl_type3_write(d, addr + fw->base, data, size, attrs);
243 }
244 
245 const MemoryRegionOps cfmws_ops = {
246     .read_with_attrs = cxl_read_cfmws,
247     .write_with_attrs = cxl_write_cfmws,
248     .endianness = DEVICE_LITTLE_ENDIAN,
249     .valid = {
250         .min_access_size = 1,
251         .max_access_size = 8,
252         .unaligned = true,
253     },
254     .impl = {
255         .min_access_size = 1,
256         .max_access_size = 8,
257         .unaligned = true,
258     },
259 };
260 
261 static void machine_get_cxl(Object *obj, Visitor *v, const char *name,
262                             void *opaque, Error **errp)
263 {
264     CXLState *cxl_state = opaque;
265     bool value = cxl_state->is_enabled;
266 
267     visit_type_bool(v, name, &value, errp);
268 }
269 
270 static void machine_set_cxl(Object *obj, Visitor *v, const char *name,
271                             void *opaque, Error **errp)
272 {
273     CXLState *cxl_state = opaque;
274     bool value;
275 
276     if (!visit_type_bool(v, name, &value, errp)) {
277         return;
278     }
279     cxl_state->is_enabled = value;
280 }
281 
282 static void machine_get_cfmw(Object *obj, Visitor *v, const char *name,
283                              void *opaque, Error **errp)
284 {
285     CXLFixedMemoryWindowOptionsList **list = opaque;
286 
287     visit_type_CXLFixedMemoryWindowOptionsList(v, name, list, errp);
288 }
289 
290 static void machine_set_cfmw(Object *obj, Visitor *v, const char *name,
291                              void *opaque, Error **errp)
292 {
293     CXLState *state = opaque;
294     CXLFixedMemoryWindowOptionsList *cfmw_list = NULL;
295     CXLFixedMemoryWindowOptionsList *it;
296 
297     visit_type_CXLFixedMemoryWindowOptionsList(v, name, &cfmw_list, errp);
298     if (!cfmw_list) {
299         return;
300     }
301 
302     for (it = cfmw_list; it; it = it->next) {
303         cxl_fixed_memory_window_config(state, it->value, errp);
304     }
305     state->cfmw_list = cfmw_list;
306 }
307 
308 void cxl_machine_init(Object *obj, CXLState *state)
309 {
310     object_property_add(obj, "cxl", "bool", machine_get_cxl,
311                         machine_set_cxl, NULL, state);
312     object_property_set_description(obj, "cxl",
313                                     "Set on/off to enable/disable "
314                                     "CXL instantiation");
315 
316     object_property_add(obj, "cxl-fmw", "CXLFixedMemoryWindow",
317                         machine_get_cfmw, machine_set_cfmw,
318                         NULL, state);
319     object_property_set_description(obj, "cxl-fmw",
320                                     "CXL Fixed Memory Windows (array)");
321 }
322 
323 void cxl_hook_up_pxb_registers(PCIBus *bus, CXLState *state, Error **errp)
324 {
325     /* Walk the pci busses looking for pxb busses to hook up */
326     if (bus) {
327         QLIST_FOREACH(bus, &bus->child, sibling) {
328             if (!pci_bus_is_root(bus)) {
329                 continue;
330             }
331             if (pci_bus_is_cxl(bus)) {
332                 if (!state->is_enabled) {
333                     error_setg(errp, "CXL host bridges present, but cxl=off");
334                     return;
335                 }
336                 pxb_cxl_hook_up_registers(state, bus, errp);
337             }
338         }
339     }
340 }
341