xref: /openbmc/qemu/include/hw/misc/mips_itu.h (revision 48e06b64)
1 /*
2  * Inter-Thread Communication Unit emulation.
3  *
4  * Copyright (c) 2016 Imagination Technologies
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #ifndef MIPS_ITU_H
21 #define MIPS_ITU_H
22 
23 #include "hw/sysbus.h"
24 #include "qom/object.h"
25 
26 #define TYPE_MIPS_ITU "mips-itu"
27 OBJECT_DECLARE_SIMPLE_TYPE(MIPSITUState, MIPS_ITU)
28 
29 #define ITC_CELL_DEPTH_SHIFT 2
30 #define ITC_CELL_DEPTH (1u << ITC_CELL_DEPTH_SHIFT)
31 
32 typedef struct ITCStorageCell {
33     struct {
34         uint8_t FIFODepth; /* Log2 of the cell depth */
35         uint8_t FIFOPtr; /* Number of elements in a FIFO cell */
36         uint8_t FIFO; /* 1 - FIFO cell, 0 - Semaphore cell */
37         uint8_t T; /* Trap Bit */
38         uint8_t F; /* Full Bit */
39         uint8_t E; /* Empty Bit */
40     } tag;
41 
42     /* Index of the oldest element in the queue */
43     uint8_t fifo_out;
44 
45     /* Circular buffer for FIFO. Semaphore cells use index 0 only */
46     uint64_t data[ITC_CELL_DEPTH];
47 
48     /* Bitmap tracking blocked threads on the cell.
49        TODO: support >64 threads ? */
50     uint64_t blocked_threads;
51 } ITCStorageCell;
52 
53 #define ITC_ADDRESSMAP_NUM 2
54 
55 struct MIPSITUState {
56     /*< private >*/
57     SysBusDevice parent_obj;
58     /*< public >*/
59 
60     uint32_t num_fifo;
61     uint32_t num_semaphores;
62 
63     /* ITC Storage */
64     ITCStorageCell *cell;
65     MemoryRegion storage_io;
66 
67     /* ITC Configuration Tags */
68     uint64_t ITCAddressMap[ITC_ADDRESSMAP_NUM];
69     MemoryRegion tag_io;
70 
71     /* ITU Control Register */
72     uint64_t icr0;
73 };
74 
75 /* Get ITC Configuration Tag memory region. */
76 MemoryRegion *mips_itu_get_tag_region(MIPSITUState *itu);
77 
78 #endif /* MIPS_ITU_H */
79