xref: /freebsd-src/sys/i386/i386/k6_mem.c (revision 17ed18fef3ee30b72f8f88ef7b43d082ae8d8bf1)
1 /*-
2  * Copyright (c) 1999 Brian Fundakowski Feldman
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
33 #include <sys/malloc.h>
34 #include <sys/memrange.h>
35 
36 #include <machine/md_var.h>
37 #include <machine/specialreg.h>
38 
39 /*
40  * A K6-2 MTRR is defined as the highest 15 bits having the address, the next
41  * 15 having the mask, the 1st bit being "write-combining" and the 0th bit
42  * being "uncacheable".
43  *
44  *	Address		    Mask	WC  UC
45  * | XXXXXXXXXXXXXXX | XXXXXXXXXXXXXXX | X | X |
46  *
47  * There are two of these in the 64-bit UWCCR.
48  */
49 
50 #define UWCCR 0xc0000085
51 
52 #define K6_REG_GET(reg, addr, mask, wc, uc)	do {			\
53 		addr = (reg) & 0xfffe0000;				\
54 		mask = ((reg) & 0x1fffc) >> 2;				\
55 		wc = ((reg) & 0x2) >> 1;				\
56 		uc = (reg) & 0x1;					\
57 	} while (0)
58 
59 #define K6_REG_MAKE(addr, mask, wc, uc) 				\
60 		((addr) | ((mask) << 2) | ((wc) << 1) | uc)
61 
62 static void k6_mrinit(struct mem_range_softc *sc);
63 static int k6_mrset(struct mem_range_softc *, struct mem_range_desc *, int *);
64 static __inline int k6_mrmake(struct mem_range_desc *, u_int32_t *);
65 static void k6_mem_drvinit(void *);
66 
67 static struct mem_range_ops k6_mrops = {
68 	k6_mrinit,
69 	k6_mrset,
70 	NULL
71 };
72 
73 static __inline int
74 k6_mrmake(struct mem_range_desc *desc, u_int32_t *mtrr) {
75 	u_int32_t len = 0, wc, uc;
76 	register int bit;
77 
78 	if (desc->mr_base &~ 0xfffe0000)
79 		return EINVAL;
80 	if (desc->mr_len < 131072 || !powerof2(desc->mr_len))
81 		return EINVAL;
82 	if (desc->mr_flags &~ (MDF_WRITECOMBINE|MDF_UNCACHEABLE|MDF_FORCE))
83 		return EOPNOTSUPP;
84 
85 	for (bit = ffs(desc->mr_len >> 17) - 1; bit < 15; bit++)
86 		len |= 1 << bit;
87 	wc = (desc->mr_flags & MDF_WRITECOMBINE) ? 1 : 0;
88 	uc = (desc->mr_flags & MDF_UNCACHEABLE) ? 1 : 0;
89 
90 	*mtrr = K6_REG_MAKE(desc->mr_base, len, wc, uc);
91 	return 0;
92 }
93 
94 static void
95 k6_mrinit(struct mem_range_softc *sc) {
96 	u_int64_t reg;
97 	u_int32_t addr, mask, wc, uc;
98 	int d;
99 
100 	sc->mr_cap = 0;
101 	sc->mr_ndesc = 2; /* XXX (BFF) For now, we only have one msr for this */
102 	sc->mr_desc = malloc(sc->mr_ndesc * sizeof(struct mem_range_desc),
103 			     M_MEMDESC, M_NOWAIT | M_ZERO);
104 	if (sc->mr_desc == NULL)
105 		panic("k6_mrinit: malloc returns NULL");
106 
107 	reg = rdmsr(UWCCR);
108 	for (d = 0; d < sc->mr_ndesc; d++) {
109 		u_int32_t one = (reg & (0xffffffff << (32 * d))) >> (32 * d);
110 
111 		K6_REG_GET(one, addr, mask, wc, uc);
112 		sc->mr_desc[d].mr_base = addr;
113 		sc->mr_desc[d].mr_len = ffs(mask) << 17;
114 		if (wc)
115 			sc->mr_desc[d].mr_flags |= MDF_WRITECOMBINE;
116 		if (uc)
117 			sc->mr_desc[d].mr_flags |= MDF_UNCACHEABLE;
118 	}
119 
120 	printf("K6-family MTRR support enabled (%d registers)\n", sc->mr_ndesc);
121 }
122 
123 static int
124 k6_mrset(struct mem_range_softc *sc, struct mem_range_desc *desc, int *arg) {
125 	u_int64_t reg;
126 	u_int32_t mtrr;
127 	int error, d;
128 
129 	switch (*arg) {
130 	case MEMRANGE_SET_UPDATE:
131 		error = k6_mrmake(desc, &mtrr);
132 		if (error)
133 			return error;
134 		for (d = 0; d < sc->mr_ndesc; d++) {
135 			if (!sc->mr_desc[d].mr_len) {
136 				sc->mr_desc[d] = *desc;
137 				goto out;
138 			}
139 			if (sc->mr_desc[d].mr_base == desc->mr_base &&
140 			    sc->mr_desc[d].mr_len == desc->mr_len)
141 				return EEXIST;
142 		}
143 
144 		return ENOSPC;
145 	case MEMRANGE_SET_REMOVE:
146 		mtrr = 0;
147 		for (d = 0; d < sc->mr_ndesc; d++)
148 			if (sc->mr_desc[d].mr_base == desc->mr_base &&
149 			    sc->mr_desc[d].mr_len == desc->mr_len) {
150 				bzero(&sc->mr_desc[d], sizeof(sc->mr_desc[d]));
151 				goto out;
152 			}
153 
154 		return ENOENT;
155 	default:
156 		return EOPNOTSUPP;
157 	}
158 
159 out:
160 
161 	disable_intr();
162 	wbinvd();
163 	reg = rdmsr(UWCCR);
164 	reg &= ~(0xffffffff << (32 * d));
165 	reg |= mtrr << (32 * d);
166 	wrmsr(UWCCR, reg);
167 	wbinvd();
168 	enable_intr();
169 
170 	return 0;
171 }
172 
173 static void
174 k6_mem_drvinit(void *unused) {
175 	if (!strcmp(cpu_vendor, "AuthenticAMD") &&
176 	    (cpu_id & 0xf00) == 0x500 &&
177 	    	((cpu_id & 0xf0) > 0x80 ||
178 		    ((cpu_id & 0xf0) == 0x80 &&
179 		     (cpu_id & 0xf) > 0x7))
180 	    )
181 		mem_range_softc.mr_op = &k6_mrops;
182 }
183 
184 SYSINIT(k6memdev, SI_SUB_DRIVERS, SI_ORDER_FIRST, k6_mem_drvinit, NULL)
185