xref: /openbmc/linux/arch/sparc/include/asm/viking.h (revision 0b26ca68)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * viking.h:  Defines specific to the GNU/Viking MBUS module.
4  *            This is SRMMU stuff.
5  *
6  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
7  */
8 #ifndef _SPARC_VIKING_H
9 #define _SPARC_VIKING_H
10 
11 #include <asm/asi.h>
12 #include <asm/mxcc.h>
13 #include <asm/pgtable.h>
14 #include <asm/pgtsrmmu.h>
15 
16 /* Bits in the SRMMU control register for GNU/Viking modules.
17  *
18  * -----------------------------------------------------------
19  * |impl-vers| RSV |TC|AC|SP|BM|PC|MBM|SB|IC|DC|PSO|RSV|NF|ME|
20  * -----------------------------------------------------------
21  *  31     24 23-17 16 15 14 13 12 11  10  9  8  7  6-2  1  0
22  *
23  * TC: Tablewalk Cacheable -- 0 = Twalks are not cacheable in E-cache
24  *                            1 = Twalks are cacheable in E-cache
25  *
26  * GNU/Viking will only cache tablewalks in the E-cache (mxcc) if present
27  * and never caches them internally (or so states the docs).  Therefore
28  * for machines lacking an E-cache (ie. in MBUS mode) this bit must
29  * remain cleared.
30  *
31  * AC: Alternate Cacheable -- 0 = Passthru physical accesses not cacheable
32  *                            1 = Passthru physical accesses cacheable
33  *
34  * This indicates whether accesses are cacheable when no cachable bit
35  * is present in the pte when the processor is in boot-mode or the
36  * access does not need pte's for translation (ie. pass-thru ASI's).
37  * "Cachable" is only referring to E-cache (if present) and not the
38  * on chip split I/D caches of the GNU/Viking.
39  *
40  * SP: SnooP Enable -- 0 = bus snooping off, 1 = bus snooping on
41  *
42  * This enables snooping on the GNU/Viking bus.  This must be on
43  * for the hardware cache consistency mechanisms of the GNU/Viking
44  * to work at all.  On non-mxcc GNU/Viking modules the split I/D
45  * caches will snoop regardless of whether they are enabled, this
46  * takes care of the case where the I or D or both caches are turned
47  * off yet still contain valid data.  Note also that this bit does
48  * not affect GNU/Viking store-buffer snoops, those happen if the
49  * store-buffer is enabled no matter what.
50  *
51  * BM: Boot Mode -- 0 = not in boot mode, 1 = in boot mode
52  *
53  * This indicates whether the GNU/Viking is in boot-mode or not,
54  * if it is then all instruction fetch physical addresses are
55  * computed as 0xff0000000 + low 28 bits of requested address.
56  * GNU/Viking boot-mode does not affect data accesses.  Also,
57  * in boot mode instruction accesses bypass the split on chip I/D
58  * caches, they may be cached by the GNU/MXCC if present and enabled.
59  *
60  * MBM: MBus Mode -- 0 = not in MBus mode, 1 = in MBus mode
61  *
62  * This indicated the GNU/Viking configuration present.  If in
63  * MBUS mode, the GNU/Viking lacks a GNU/MXCC E-cache.  If it is
64  * not then the GNU/Viking is on a module VBUS connected directly
65  * to a GNU/MXCC cache controller.  The GNU/MXCC can be thus connected
66  * to either an GNU/MBUS (sun4m) or the packet-switched GNU/XBus (sun4d).
67  *
68  * SB: StoreBuffer enable -- 0 = store buffer off, 1 = store buffer on
69  *
70  * The GNU/Viking store buffer allows the chip to continue execution
71  * after a store even if the data cannot be placed in one of the
72  * caches during that cycle.  If disabled, all stores operations
73  * occur synchronously.
74  *
75  * IC: Instruction Cache -- 0 = off, 1 = on
76  * DC: Data Cache -- 0 = off, 1 = 0n
77  *
78  * These bits enable the on-cpu GNU/Viking split I/D caches.  Note,
79  * as mentioned above, these caches will snoop the bus in GNU/MBUS
80  * configurations even when disabled to avoid data corruption.
81  *
82  * NF: No Fault -- 0 = faults generate traps, 1 = faults don't trap
83  * ME: MMU enable -- 0 = mmu not translating, 1 = mmu translating
84  *
85  */
86 
87 #define VIKING_MMUENABLE    0x00000001
88 #define VIKING_NOFAULT      0x00000002
89 #define VIKING_PSO          0x00000080
90 #define VIKING_DCENABLE     0x00000100   /* Enable data cache */
91 #define VIKING_ICENABLE     0x00000200   /* Enable instruction cache */
92 #define VIKING_SBENABLE     0x00000400   /* Enable store buffer */
93 #define VIKING_MMODE        0x00000800   /* MBUS mode */
94 #define VIKING_PCENABLE     0x00001000   /* Enable parity checking */
95 #define VIKING_BMODE        0x00002000
96 #define VIKING_SPENABLE     0x00004000   /* Enable bus cache snooping */
97 #define VIKING_ACENABLE     0x00008000   /* Enable alternate caching */
98 #define VIKING_TCENABLE     0x00010000   /* Enable table-walks to be cached */
99 #define VIKING_DPENABLE     0x00040000   /* Enable the data prefetcher */
100 
101 /*
102  * GNU/Viking Breakpoint Action Register fields.
103  */
104 #define VIKING_ACTION_MIX   0x00001000   /* Enable multiple instructions */
105 
106 /*
107  * GNU/Viking Cache Tags.
108  */
109 #define VIKING_PTAG_VALID   0x01000000   /* Cache block is valid */
110 #define VIKING_PTAG_DIRTY   0x00010000   /* Block has been modified */
111 #define VIKING_PTAG_SHARED  0x00000100   /* Shared with some other cache */
112 
113 #ifndef __ASSEMBLY__
114 
115 static inline void viking_flush_icache(void)
116 {
117 	__asm__ __volatile__("sta %%g0, [%%g0] %0\n\t"
118 			     : /* no outputs */
119 			     : "i" (ASI_M_IC_FLCLEAR)
120 			     : "memory");
121 }
122 
123 static inline void viking_flush_dcache(void)
124 {
125 	__asm__ __volatile__("sta %%g0, [%%g0] %0\n\t"
126 			     : /* no outputs */
127 			     : "i" (ASI_M_DC_FLCLEAR)
128 			     : "memory");
129 }
130 
131 static inline void viking_unlock_icache(void)
132 {
133 	__asm__ __volatile__("sta %%g0, [%0] %1\n\t"
134 			     : /* no outputs */
135 			     : "r" (0x80000000), "i" (ASI_M_IC_FLCLEAR)
136 			     : "memory");
137 }
138 
139 static inline void viking_unlock_dcache(void)
140 {
141 	__asm__ __volatile__("sta %%g0, [%0] %1\n\t"
142 			     : /* no outputs */
143 			     : "r" (0x80000000), "i" (ASI_M_DC_FLCLEAR)
144 			     : "memory");
145 }
146 
147 static inline void viking_set_bpreg(unsigned long regval)
148 {
149 	__asm__ __volatile__("sta %0, [%%g0] %1\n\t"
150 			     : /* no outputs */
151 			     : "r" (regval), "i" (ASI_M_ACTION)
152 			     : "memory");
153 }
154 
155 static inline unsigned long viking_get_bpreg(void)
156 {
157 	unsigned long regval;
158 
159 	__asm__ __volatile__("lda [%%g0] %1, %0\n\t"
160 			     : "=r" (regval)
161 			     : "i" (ASI_M_ACTION));
162 	return regval;
163 }
164 
165 static inline void viking_get_dcache_ptag(int set, int block,
166 					      unsigned long *data)
167 {
168 	unsigned long ptag = ((set & 0x7f) << 5) | ((block & 0x3) << 26) |
169 			     0x80000000;
170 	unsigned long info, page;
171 
172 	__asm__ __volatile__ ("ldda [%2] %3, %%g2\n\t"
173 			      "or %%g0, %%g2, %0\n\t"
174 			      "or %%g0, %%g3, %1\n\t"
175 			      : "=r" (info), "=r" (page)
176 			      : "r" (ptag), "i" (ASI_M_DATAC_TAG)
177 			      : "g2", "g3");
178 	data[0] = info;
179 	data[1] = page;
180 }
181 
182 static inline void viking_mxcc_turn_off_parity(unsigned long *mregp,
183 						   unsigned long *mxcc_cregp)
184 {
185 	unsigned long mreg = *mregp;
186 	unsigned long mxcc_creg = *mxcc_cregp;
187 
188 	mreg &= ~(VIKING_PCENABLE);
189 	mxcc_creg &= ~(MXCC_CTL_PARE);
190 
191 	__asm__ __volatile__ ("set 1f, %%g2\n\t"
192 			      "andcc %%g2, 4, %%g0\n\t"
193 			      "bne 2f\n\t"
194 			      " nop\n"
195 			      "1:\n\t"
196 			      "sta %0, [%%g0] %3\n\t"
197 			      "sta %1, [%2] %4\n\t"
198 			      "b 1f\n\t"
199 			      " nop\n\t"
200 			      "nop\n"
201 			      "2:\n\t"
202 			      "sta %0, [%%g0] %3\n\t"
203 			      "sta %1, [%2] %4\n"
204 			      "1:\n\t"
205 			      : /* no output */
206 			      : "r" (mreg), "r" (mxcc_creg),
207 			        "r" (MXCC_CREG), "i" (ASI_M_MMUREGS),
208 			        "i" (ASI_M_MXCC)
209 			      : "g2", "memory", "cc");
210 	*mregp = mreg;
211 	*mxcc_cregp = mxcc_creg;
212 }
213 
214 static inline unsigned long viking_hwprobe(unsigned long vaddr)
215 {
216 	unsigned long val;
217 
218 	vaddr &= PAGE_MASK;
219 	/* Probe all MMU entries. */
220 	__asm__ __volatile__("lda [%1] %2, %0\n\t"
221 			     : "=r" (val)
222 			     : "r" (vaddr | 0x400), "i" (ASI_M_FLUSH_PROBE));
223 	if (!val)
224 		return 0;
225 
226 	/* Probe region. */
227 	__asm__ __volatile__("lda [%1] %2, %0\n\t"
228 			     : "=r" (val)
229 			     : "r" (vaddr | 0x200), "i" (ASI_M_FLUSH_PROBE));
230 	if ((val & SRMMU_ET_MASK) == SRMMU_ET_PTE) {
231 		vaddr &= ~PGDIR_MASK;
232 		vaddr >>= PAGE_SHIFT;
233 		return val | (vaddr << 8);
234 	}
235 
236 	/* Probe segment. */
237 	__asm__ __volatile__("lda [%1] %2, %0\n\t"
238 			     : "=r" (val)
239 			     : "r" (vaddr | 0x100), "i" (ASI_M_FLUSH_PROBE));
240 	if ((val & SRMMU_ET_MASK) == SRMMU_ET_PTE) {
241 		vaddr &= ~PMD_MASK;
242 		vaddr >>= PAGE_SHIFT;
243 		return val | (vaddr << 8);
244 	}
245 
246 	/* Probe page. */
247 	__asm__ __volatile__("lda [%1] %2, %0\n\t"
248 			     : "=r" (val)
249 			     : "r" (vaddr), "i" (ASI_M_FLUSH_PROBE));
250 	return val;
251 }
252 
253 #endif /* !__ASSEMBLY__ */
254 
255 #endif /* !(_SPARC_VIKING_H) */
256