xref: /openbmc/qemu/hw/ppc/pnv_adu.c (revision 700784bf)
1 /*
2  * QEMU PowerPC PowerNV ADU unit
3  *
4  * The ADU unit actually implements XSCOM, which is the bridge between MMIO
5  * and PIB. However it also includes control and status registers and other
6  * functions that are exposed as PIB (xscom) registers.
7  *
8  * To keep things simple, pnv_xscom.c remains the XSCOM bridge
9  * implementation, and pnv_adu.c implements the ADU registers and other
10  * functions.
11  *
12  * Copyright (c) 2024, IBM Corporation.
13  *
14  * SPDX-License-Identifier: GPL-2.0-or-later
15  */
16 
17 #include "qemu/osdep.h"
18 #include "qemu/log.h"
19 
20 #include "hw/qdev-properties.h"
21 #include "hw/ppc/pnv.h"
22 #include "hw/ppc/pnv_adu.h"
23 #include "hw/ppc/pnv_chip.h"
24 #include "hw/ppc/pnv_lpc.h"
25 #include "hw/ppc/pnv_xscom.h"
26 #include "trace.h"
27 
28 #define ADU_LPC_BASE_REG     0x40
29 #define ADU_LPC_CMD_REG      0x41
30 #define ADU_LPC_DATA_REG     0x42
31 #define ADU_LPC_STATUS_REG   0x43
32 
33 static uint64_t pnv_adu_xscom_read(void *opaque, hwaddr addr, unsigned width)
34 {
35     PnvADU *adu = PNV_ADU(opaque);
36     uint32_t offset = addr >> 3;
37     uint64_t val = 0;
38 
39     switch (offset) {
40     case 0x18:     /* Receive status reg */
41     case 0x12:     /* log register */
42     case 0x13:     /* error register */
43         break;
44     case ADU_LPC_BASE_REG:
45         /*
46          * LPC Address Map in Pervasive ADU Workbook
47          *
48          * return PNV10_LPCM_BASE(chip) & PPC_BITMASK(8, 31);
49          * XXX: implement as class property, or get from LPC?
50          */
51         qemu_log_mask(LOG_UNIMP, "ADU: LPC_BASE_REG is not implemented\n");
52         break;
53     case ADU_LPC_CMD_REG:
54         val = adu->lpc_cmd_reg;
55         break;
56     case ADU_LPC_DATA_REG:
57         val = adu->lpc_data_reg;
58         break;
59     case ADU_LPC_STATUS_REG:
60         val = PPC_BIT(0); /* ack / done */
61         break;
62 
63     default:
64         qemu_log_mask(LOG_UNIMP, "ADU Unimplemented read register: Ox%08x\n",
65                                                                      offset);
66     }
67 
68     trace_pnv_adu_xscom_read(addr, val);
69 
70     return val;
71 }
72 
73 static bool lpc_cmd_read(PnvADU *adu)
74 {
75     return !!(adu->lpc_cmd_reg & PPC_BIT(0));
76 }
77 
78 static bool lpc_cmd_write(PnvADU *adu)
79 {
80     return !lpc_cmd_read(adu);
81 }
82 
83 static uint32_t lpc_cmd_addr(PnvADU *adu)
84 {
85     return (adu->lpc_cmd_reg & PPC_BITMASK(32, 63)) >> PPC_BIT_NR(63);
86 }
87 
88 static uint32_t lpc_cmd_size(PnvADU *adu)
89 {
90     return (adu->lpc_cmd_reg & PPC_BITMASK(5, 11)) >> PPC_BIT_NR(11);
91 }
92 
93 static void pnv_adu_xscom_write(void *opaque, hwaddr addr, uint64_t val,
94                                 unsigned width)
95 {
96     PnvADU *adu = PNV_ADU(opaque);
97     uint32_t offset = addr >> 3;
98 
99     trace_pnv_adu_xscom_write(addr, val);
100 
101     switch (offset) {
102     case 0x18:     /* Receive status reg */
103     case 0x12:     /* log register */
104     case 0x13:     /* error register */
105         break;
106 
107     case ADU_LPC_BASE_REG:
108         qemu_log_mask(LOG_UNIMP,
109                       "ADU: Changing LPC_BASE_REG is not implemented\n");
110         break;
111 
112     case ADU_LPC_CMD_REG:
113         adu->lpc_cmd_reg = val;
114         if (lpc_cmd_read(adu)) {
115             uint32_t lpc_addr = lpc_cmd_addr(adu);
116             uint32_t lpc_size = lpc_cmd_size(adu);
117             uint64_t data = 0;
118 
119             if (!is_power_of_2(lpc_size) || lpc_size > sizeof(data)) {
120                 qemu_log_mask(LOG_GUEST_ERROR, "ADU: Unsupported LPC access "
121                                                "size:%" PRId32 "\n", lpc_size);
122                 break;
123             }
124 
125             pnv_lpc_opb_read(adu->lpc, lpc_addr, (void *)&data, lpc_size);
126 
127             /*
128              * ADU access is performed within 8-byte aligned sectors. Smaller
129              * access sizes don't get formatted to the least significant byte,
130              * but rather appear in the data reg at the same offset as the
131              * address in memory. This shifts them into that position.
132              */
133             adu->lpc_data_reg = be64_to_cpu(data) >> ((lpc_addr & 7) * 8);
134         }
135         break;
136 
137     case ADU_LPC_DATA_REG:
138         adu->lpc_data_reg = val;
139         if (lpc_cmd_write(adu)) {
140             uint32_t lpc_addr = lpc_cmd_addr(adu);
141             uint32_t lpc_size = lpc_cmd_size(adu);
142             uint64_t data;
143 
144             if (!is_power_of_2(lpc_size) || lpc_size > sizeof(data)) {
145                 qemu_log_mask(LOG_GUEST_ERROR, "ADU: Unsupported LPC access "
146                                                "size:%" PRId32 "\n", lpc_size);
147                 break;
148             }
149 
150             data = cpu_to_be64(val) >> ((lpc_addr & 7) * 8); /* See above */
151             pnv_lpc_opb_write(adu->lpc, lpc_addr, (void *)&data, lpc_size);
152         }
153         break;
154 
155     case ADU_LPC_STATUS_REG:
156         qemu_log_mask(LOG_UNIMP,
157                       "ADU: Changing LPC_STATUS_REG is not implemented\n");
158         break;
159 
160     default:
161         qemu_log_mask(LOG_UNIMP, "ADU Unimplemented write register: Ox%08x\n",
162                                                                      offset);
163     }
164 }
165 
166 const MemoryRegionOps pnv_adu_xscom_ops = {
167     .read = pnv_adu_xscom_read,
168     .write = pnv_adu_xscom_write,
169     .valid.min_access_size = 8,
170     .valid.max_access_size = 8,
171     .impl.min_access_size = 8,
172     .impl.max_access_size = 8,
173     .endianness = DEVICE_BIG_ENDIAN,
174 };
175 
176 static void pnv_adu_realize(DeviceState *dev, Error **errp)
177 {
178     PnvADU *adu = PNV_ADU(dev);
179 
180     assert(adu->lpc);
181 
182     /* XScom regions for ADU registers */
183     pnv_xscom_region_init(&adu->xscom_regs, OBJECT(dev),
184                           &pnv_adu_xscom_ops, adu, "xscom-adu",
185                           PNV9_XSCOM_ADU_SIZE);
186 }
187 
188 static Property pnv_adu_properties[] = {
189     DEFINE_PROP_LINK("lpc", PnvADU, lpc, TYPE_PNV_LPC, PnvLpcController *),
190     DEFINE_PROP_END_OF_LIST(),
191 };
192 
193 static void pnv_adu_class_init(ObjectClass *klass, void *data)
194 {
195     DeviceClass *dc = DEVICE_CLASS(klass);
196 
197     dc->realize = pnv_adu_realize;
198     dc->desc = "PowerNV ADU";
199     device_class_set_props(dc, pnv_adu_properties);
200     dc->user_creatable = false;
201 }
202 
203 static const TypeInfo pnv_adu_type_info = {
204     .name          = TYPE_PNV_ADU,
205     .parent        = TYPE_DEVICE,
206     .instance_size = sizeof(PnvADU),
207     .class_init    = pnv_adu_class_init,
208     .interfaces    = (InterfaceInfo[]) {
209         { TYPE_PNV_XSCOM_INTERFACE },
210         { } },
211 };
212 
213 static void pnv_adu_register_types(void)
214 {
215     type_register_static(&pnv_adu_type_info);
216 }
217 
218 type_init(pnv_adu_register_types);
219