xref: /openbmc/qemu/hw/cxl/cxl-host.c (revision c4b8ffcb)
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/pci/pci_bus.h"
19 #include "hw/pci/pci_bridge.h"
20 #include "hw/pci/pci_host.h"
21 #include "hw/pci/pcie_port.h"
22 
23 void cxl_fixed_memory_window_config(MachineState *ms,
24                                     CXLFixedMemoryWindowOptions *object,
25                                     Error **errp)
26 {
27     CXLFixedWindow *fw = g_malloc0(sizeof(*fw));
28     strList *target;
29     int i;
30 
31     for (target = object->targets; target; target = target->next) {
32         fw->num_targets++;
33     }
34 
35     fw->enc_int_ways = cxl_interleave_ways_enc(fw->num_targets, errp);
36     if (*errp) {
37         return;
38     }
39 
40     fw->targets = g_malloc0_n(fw->num_targets, sizeof(*fw->targets));
41     for (i = 0, target = object->targets; target; i++, target = target->next) {
42         /* This link cannot be resolved yet, so stash the name for now */
43         fw->targets[i] = g_strdup(target->value);
44     }
45 
46     if (object->size % (256 * MiB)) {
47         error_setg(errp,
48                    "Size of a CXL fixed memory window must my a multiple of 256MiB");
49         return;
50     }
51     fw->size = object->size;
52 
53     if (object->has_interleave_granularity) {
54         fw->enc_int_gran =
55             cxl_interleave_granularity_enc(object->interleave_granularity,
56                                            errp);
57         if (*errp) {
58             return;
59         }
60     } else {
61         /* Default to 256 byte interleave */
62         fw->enc_int_gran = 0;
63     }
64 
65     ms->cxl_devices_state->fixed_windows =
66         g_list_append(ms->cxl_devices_state->fixed_windows, fw);
67 
68     return;
69 }
70 
71 void cxl_fixed_memory_window_link_targets(Error **errp)
72 {
73     MachineState *ms = MACHINE(qdev_get_machine());
74 
75     if (ms->cxl_devices_state && ms->cxl_devices_state->fixed_windows) {
76         GList *it;
77 
78         for (it = ms->cxl_devices_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_reg;
108     uint32_t target_idx;
109 
110     ctrl = cache_mem[R_CXL_HDM_DECODER0_CTRL];
111     if (!FIELD_EX32(ctrl, CXL_HDM_DECODER0_CTRL, COMMITTED)) {
112         return false;
113     }
114 
115     ig_enc = FIELD_EX32(ctrl, CXL_HDM_DECODER0_CTRL, IG);
116     iw_enc = FIELD_EX32(ctrl, CXL_HDM_DECODER0_CTRL, IW);
117     target_idx = (addr / cxl_decode_ig(ig_enc)) % (1 << iw_enc);
118 
119     if (target_idx > 4) {
120         target_reg = cache_mem[R_CXL_HDM_DECODER0_TARGET_LIST_LO];
121         target_reg >>= target_idx * 8;
122     } else {
123         target_reg = cache_mem[R_CXL_HDM_DECODER0_TARGET_LIST_LO];
124         target_reg >>= (target_idx - 4) * 8;
125     }
126     *target = target_reg & 0xff;
127 
128     return true;
129 }
130 
131 static PCIDevice *cxl_cfmws_find_device(CXLFixedWindow *fw, hwaddr addr)
132 {
133     CXLComponentState *hb_cstate;
134     PCIHostState *hb;
135     int rb_index;
136     uint32_t *cache_mem;
137     uint8_t target;
138     bool target_found;
139     PCIDevice *rp, *d;
140 
141     /* Address is relative to memory region. Convert to HPA */
142     addr += fw->base;
143 
144     rb_index = (addr / cxl_decode_ig(fw->enc_int_gran)) % fw->num_targets;
145     hb = PCI_HOST_BRIDGE(fw->target_hbs[rb_index]->cxl.cxl_host_bridge);
146     if (!hb || !hb->bus || !pci_bus_is_cxl(hb->bus)) {
147         return NULL;
148     }
149 
150     hb_cstate = cxl_get_hb_cstate(hb);
151     if (!hb_cstate) {
152         return NULL;
153     }
154 
155     cache_mem = hb_cstate->crb.cache_mem_registers;
156 
157     target_found = cxl_hdm_find_target(cache_mem, addr, &target);
158     if (!target_found) {
159         return NULL;
160     }
161 
162     rp = pcie_find_port_by_pn(hb->bus, target);
163     if (!rp) {
164         return NULL;
165     }
166 
167     d = pci_bridge_get_sec_bus(PCI_BRIDGE(rp))->devices[0];
168 
169     if (!d || !object_dynamic_cast(OBJECT(d), TYPE_CXL_TYPE3)) {
170         return NULL;
171     }
172 
173     return d;
174 }
175 
176 static MemTxResult cxl_read_cfmws(void *opaque, hwaddr addr, uint64_t *data,
177                                   unsigned size, MemTxAttrs attrs)
178 {
179     CXLFixedWindow *fw = opaque;
180     PCIDevice *d;
181 
182     d = cxl_cfmws_find_device(fw, addr);
183     if (d == NULL) {
184         *data = 0;
185         /* Reads to invalid address return poison */
186         return MEMTX_ERROR;
187     }
188 
189     return cxl_type3_read(d, addr + fw->base, data, size, attrs);
190 }
191 
192 static MemTxResult cxl_write_cfmws(void *opaque, hwaddr addr,
193                                    uint64_t data, unsigned size,
194                                    MemTxAttrs attrs)
195 {
196     CXLFixedWindow *fw = opaque;
197     PCIDevice *d;
198 
199     d = cxl_cfmws_find_device(fw, addr);
200     if (d == NULL) {
201         /* Writes to invalid address are silent */
202         return MEMTX_OK;
203     }
204 
205     return cxl_type3_write(d, addr + fw->base, data, size, attrs);
206 }
207 
208 const MemoryRegionOps cfmws_ops = {
209     .read_with_attrs = cxl_read_cfmws,
210     .write_with_attrs = cxl_write_cfmws,
211     .endianness = DEVICE_LITTLE_ENDIAN,
212     .valid = {
213         .min_access_size = 1,
214         .max_access_size = 8,
215         .unaligned = true,
216     },
217     .impl = {
218         .min_access_size = 1,
219         .max_access_size = 8,
220         .unaligned = true,
221     },
222 };
223