1 /*
2  * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
3  *                    <benh@kernel.crashing.org>
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #ifndef _ASM_POWERPC_DCR_NATIVE_H
21 #define _ASM_POWERPC_DCR_NATIVE_H
22 #ifdef __KERNEL__
23 #ifndef __ASSEMBLY__
24 
25 #include <linux/spinlock.h>
26 #include <asm/cputable.h>
27 #include <asm/cpu_has_feature.h>
28 
29 typedef struct {
30 	unsigned int base;
31 } dcr_host_native_t;
32 
33 static inline bool dcr_map_ok_native(dcr_host_native_t host)
34 {
35 	return true;
36 }
37 
38 #define dcr_map_native(dev, dcr_n, dcr_c) \
39 	((dcr_host_native_t){ .base = (dcr_n) })
40 #define dcr_unmap_native(host, dcr_c)		do {} while (0)
41 #define dcr_read_native(host, dcr_n)		mfdcr(dcr_n + host.base)
42 #define dcr_write_native(host, dcr_n, value)	mtdcr(dcr_n + host.base, value)
43 
44 /* Table based DCR accessors */
45 extern void __mtdcr(unsigned int reg, unsigned int val);
46 extern unsigned int __mfdcr(unsigned int reg);
47 
48 /* mfdcrx/mtdcrx instruction based accessors. We hand code
49  * the opcodes in order not to depend on newer binutils
50  */
51 static inline unsigned int mfdcrx(unsigned int reg)
52 {
53 	unsigned int ret;
54 	asm volatile(".long 0x7c000206 | (%0 << 21) | (%1 << 16)"
55 		     : "=r" (ret) : "r" (reg));
56 	return ret;
57 }
58 
59 static inline void mtdcrx(unsigned int reg, unsigned int val)
60 {
61 	asm volatile(".long 0x7c000306 | (%0 << 21) | (%1 << 16)"
62 		     : : "r" (val), "r" (reg));
63 }
64 
65 #define mfdcr(rn)						\
66 	({unsigned int rval;					\
67 	if (__builtin_constant_p(rn) && rn < 1024)		\
68 		asm volatile("mfdcr %0," __stringify(rn)	\
69 		              : "=r" (rval));			\
70 	else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR)))	\
71 		rval = mfdcrx(rn);				\
72 	else							\
73 		rval = __mfdcr(rn);				\
74 	rval;})
75 
76 #define mtdcr(rn, v)						\
77 do {								\
78 	if (__builtin_constant_p(rn) && rn < 1024)		\
79 		asm volatile("mtdcr " __stringify(rn) ",%0"	\
80 			      : : "r" (v)); 			\
81 	else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR)))	\
82 		mtdcrx(rn, v);					\
83 	else							\
84 		__mtdcr(rn, v);					\
85 } while (0)
86 
87 /* R/W of indirect DCRs make use of standard naming conventions for DCRs */
88 extern spinlock_t dcr_ind_lock;
89 
90 static inline unsigned __mfdcri(int base_addr, int base_data, int reg)
91 {
92 	unsigned long flags;
93 	unsigned int val;
94 
95 	spin_lock_irqsave(&dcr_ind_lock, flags);
96 	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
97 		mtdcrx(base_addr, reg);
98 		val = mfdcrx(base_data);
99 	} else {
100 		__mtdcr(base_addr, reg);
101 		val = __mfdcr(base_data);
102 	}
103 	spin_unlock_irqrestore(&dcr_ind_lock, flags);
104 	return val;
105 }
106 
107 static inline void __mtdcri(int base_addr, int base_data, int reg,
108 			    unsigned val)
109 {
110 	unsigned long flags;
111 
112 	spin_lock_irqsave(&dcr_ind_lock, flags);
113 	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
114 		mtdcrx(base_addr, reg);
115 		mtdcrx(base_data, val);
116 	} else {
117 		__mtdcr(base_addr, reg);
118 		__mtdcr(base_data, val);
119 	}
120 	spin_unlock_irqrestore(&dcr_ind_lock, flags);
121 }
122 
123 static inline void __dcri_clrset(int base_addr, int base_data, int reg,
124 				 unsigned clr, unsigned set)
125 {
126 	unsigned long flags;
127 	unsigned int val;
128 
129 	spin_lock_irqsave(&dcr_ind_lock, flags);
130 	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
131 		mtdcrx(base_addr, reg);
132 		val = (mfdcrx(base_data) & ~clr) | set;
133 		mtdcrx(base_data, val);
134 	} else {
135 		__mtdcr(base_addr, reg);
136 		val = (__mfdcr(base_data) & ~clr) | set;
137 		__mtdcr(base_data, val);
138 	}
139 	spin_unlock_irqrestore(&dcr_ind_lock, flags);
140 }
141 
142 #define mfdcri(base, reg)	__mfdcri(DCRN_ ## base ## _CONFIG_ADDR,	\
143 					 DCRN_ ## base ## _CONFIG_DATA,	\
144 					 reg)
145 
146 #define mtdcri(base, reg, data)	__mtdcri(DCRN_ ## base ## _CONFIG_ADDR,	\
147 					 DCRN_ ## base ## _CONFIG_DATA,	\
148 					 reg, data)
149 
150 #define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ## _CONFIG_ADDR,	\
151 							      DCRN_ ## base ## _CONFIG_DATA,	\
152 							      reg, clr, set)
153 
154 #endif /* __ASSEMBLY__ */
155 #endif /* __KERNEL__ */
156 #endif /* _ASM_POWERPC_DCR_NATIVE_H */
157