1 /*
2  * utils.h: Utilities for SPU-side of the context switch operation.
3  *
4  * (C) Copyright IBM 2005
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2, or (at your option)
9  * any later version.
10  *
11  * This program 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
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 
21 #ifndef _SPU_CONTEXT_UTILS_H_
22 #define _SPU_CONTEXT_UTILS_H_
23 
24 /*
25  * 64-bit safe EA.
26  */
27 typedef union {
28 	unsigned long long ull;
29 	unsigned int ui[2];
30 } addr64;
31 
32 /*
33  * 128-bit register template.
34  */
35 typedef union {
36 	unsigned int slot[4];
37 	vector unsigned int v;
38 } spu_reg128v;
39 
40 /*
41  * DMA list structure.
42  */
43 struct dma_list_elem {
44 	unsigned int size;
45 	unsigned int ea_low;
46 };
47 
48 /*
49  * Declare storage for 8-byte aligned DMA list.
50  */
51 struct dma_list_elem dma_list[15] __attribute__ ((aligned(8)));
52 
53 /*
54  * External definition for storage
55  * declared in crt0.
56  */
57 extern spu_reg128v regs_spill[NR_SPU_SPILL_REGS];
58 
59 /*
60  * Compute LSCSA byte offset for a given field.
61  */
62 static struct spu_lscsa *dummy = (struct spu_lscsa *)0;
63 #define LSCSA_BYTE_OFFSET(_field)  \
64 	((char *)(&(dummy->_field)) - (char *)(&(dummy->gprs[0].slot[0])))
65 #define LSCSA_QW_OFFSET(_field)  (LSCSA_BYTE_OFFSET(_field) >> 4)
66 
67 static inline void set_event_mask(void)
68 {
69 	unsigned int event_mask = 0;
70 
71 	/* Save, Step 4:
72 	 * Restore, Step 1:
73 	 *    Set the SPU_RdEventMsk channel to zero to mask
74 	 *    all events.
75 	 */
76 	spu_writech(SPU_WrEventMask, event_mask);
77 }
78 
79 static inline void set_tag_mask(void)
80 {
81 	unsigned int tag_mask = 1;
82 
83 	/* Save, Step 5:
84 	 * Restore, Step 2:
85 	 *    Set the SPU_WrTagMsk channel to '01' to unmask
86 	 *    only tag group 0.
87 	 */
88 	spu_writech(MFC_WrTagMask, tag_mask);
89 }
90 
91 static inline void build_dma_list(addr64 lscsa_ea)
92 {
93 	unsigned int ea_low;
94 	int i;
95 
96 	/* Save, Step 6:
97 	 * Restore, Step 3:
98 	 *    Update the effective address for the CSA in the
99 	 *    pre-canned DMA-list in local storage.
100 	 */
101 	ea_low = lscsa_ea.ui[1];
102 	ea_low += LSCSA_BYTE_OFFSET(ls[16384]);
103 
104 	for (i = 0; i < 15; i++, ea_low += 16384) {
105 		dma_list[i].size = 16384;
106 		dma_list[i].ea_low = ea_low;
107 	}
108 }
109 
110 static inline void enqueue_putllc(addr64 lscsa_ea)
111 {
112 	unsigned int ls = 0;
113 	unsigned int size = 128;
114 	unsigned int tag_id = 0;
115 	unsigned int cmd = 0xB4;	/* PUTLLC */
116 
117 	/* Save, Step 12:
118 	 * Restore, Step 7:
119 	 *    Send a PUTLLC (tag 0) command to the MFC using
120 	 *    an effective address in the CSA in order to
121 	 *    remove any possible lock-line reservation.
122 	 */
123 	spu_writech(MFC_LSA, ls);
124 	spu_writech(MFC_EAH, lscsa_ea.ui[0]);
125 	spu_writech(MFC_EAL, lscsa_ea.ui[1]);
126 	spu_writech(MFC_Size, size);
127 	spu_writech(MFC_TagID, tag_id);
128 	spu_writech(MFC_Cmd, cmd);
129 }
130 
131 static inline void set_tag_update(void)
132 {
133 	unsigned int update_any = 1;
134 
135 	/* Save, Step 15:
136 	 * Restore, Step 8:
137 	 *    Write the MFC_TagUpdate channel with '01'.
138 	 */
139 	spu_writech(MFC_WrTagUpdate, update_any);
140 }
141 
142 static inline void read_tag_status(void)
143 {
144 	/* Save, Step 16:
145 	 * Restore, Step 9:
146 	 *    Read the MFC_TagStat channel data.
147 	 */
148 	spu_readch(MFC_RdTagStat);
149 }
150 
151 static inline void read_llar_status(void)
152 {
153 	/* Save, Step 17:
154 	 * Restore, Step 10:
155 	 *    Read the MFC_AtomicStat channel data.
156 	 */
157 	spu_readch(MFC_RdAtomicStat);
158 }
159 
160 #endif				/* _SPU_CONTEXT_UTILS_H_ */
161