k6_mem.c revision 1.3 
1/* $OpenBSD: k6_mem.c,v 1.3 1999/11/24 01:43:32 deraadt Exp $ */
2/*-
3 * Copyright (c) 1999 Brian Fundakowski Feldman
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: src/sys/i386/i386/k6_mem.c,v 1.4 1999/09/05 15:45:57 green Exp $
28 *
29 */
30
31#include <sys/param.h>
32#include <sys/kernel.h>
33#include <sys/systm.h>
34#include <sys/ioccom.h>
35#include <sys/malloc.h>
36#include <sys/memrange.h>
37
38#include <machine/cpufunc.h>
39#include <machine/specialreg.h>
40
41/*
42 * A K6-2 MTRR is defined as the highest 15 bits having the address, the next
43 * 15 having the mask, the 1st bit being "write-combining" and the 0th bit
44 * being "uncacheable".
45 *
46 *	Address		    Mask	WC  UC
47 * | XXXXXXXXXXXXXXX | XXXXXXXXXXXXXXX | X | X |
48 *
49 * There are two of these in the 64-bit UWCCR.
50 */
51
52/*
53 * NOTE: I do _not_ comment my code unless it's truly necessary. Don't
54 * 	 expect anything frivolous here, and do NOT touch my bit-shifts
55 *	 unless you want to break this.
56 */
57
58#define UWCCR 0xc0000085
59
60#define k6_reg_get(reg, addr, mask, wc, uc)	do {			\
61		addr = (reg) & 0xfffe0000;				\
62		mask = ((reg) & 0x1fffc) >> 2;				\
63		wc = ((reg) & 0x2) >> 1;				\
64		uc = (reg) & 0x1;					\
65	} while (0)
66
67#define k6_reg_make(addr, mask, wc, uc) 				\
68		((addr) | ((mask) << 2) | ((wc) << 1) | uc)
69
70void k6_mrinit __P((struct mem_range_softc *sc));
71int k6_mrset __P((struct mem_range_softc *, struct mem_range_desc *, int *));
72__inline int k6_mrmake __P((struct mem_range_desc *, u_int32_t *));
73
74struct mem_range_ops k6_mrops = {
75	k6_mrinit,
76	k6_mrset,
77	NULL
78};
79
80__inline int
81k6_mrmake(desc, mtrr)
82	struct mem_range_desc 	*desc;
83	u_int32_t 		*mtrr;
84{
85	u_int32_t len = 0, wc, uc;
86	register int bit;
87
88	if (desc->mr_base &~ 0xfffe0000)
89		return EINVAL;
90	if (desc->mr_len < 131072 || !powerof2(desc->mr_len))
91		return EINVAL;
92	if (desc->mr_flags &~ (MDF_WRITECOMBINE|MDF_UNCACHEABLE))
93		return EOPNOTSUPP;
94
95	for (bit = ffs(desc->mr_len >> 17) - 1; bit < 15; bit++)
96		len |= 1 << (14 - bit);
97	wc = (desc->mr_flags & MDF_WRITECOMBINE) ? 1 : 0;
98	uc = (desc->mr_flags & MDF_UNCACHEABLE) ? 1 : 0;
99
100	*mtrr = k6_reg_make(desc->mr_base, len, wc, uc);
101	return 0;
102}
103
104void
105k6_mrinit(sc)
106	struct mem_range_softc *sc;
107{
108	u_int64_t reg;
109	u_int32_t addr, mask, wc, uc;
110	int d;
111
112	sc->mr_cap = 0;
113	sc->mr_ndesc = 2; /* XXX (BFF) For now, we only have one msr for this */
114	sc->mr_desc = malloc(sc->mr_ndesc * sizeof(struct mem_range_desc),
115			     M_MEMDESC, M_NOWAIT);
116	if (sc->mr_desc == NULL)
117		panic("k6_mrinit: malloc returns NULL");
118
119	bzero(sc->mr_desc, sc->mr_ndesc * sizeof(struct mem_range_desc));
120
121	reg = rdmsr(UWCCR);
122	for (d = 0; d < sc->mr_ndesc; d++) {
123		u_int32_t one = (reg & (0xffffffff << (32 * d))) >> (32 * d);
124
125		k6_reg_get(one, addr, mask, wc, uc);
126		sc->mr_desc[d].mr_base = addr;
127		sc->mr_desc[d].mr_len = ffs(mask) << 17;
128		if (wc)
129			sc->mr_desc[d].mr_flags |= MDF_WRITECOMBINE;
130		if (uc)
131			sc->mr_desc[d].mr_flags |= MDF_UNCACHEABLE;
132	}
133
134	printf("mtrr: K6-family MTRR support (%d registers)\n", sc->mr_ndesc);
135}
136
137int
138k6_mrset(sc, desc, arg)
139	struct mem_range_softc 	*sc;
140	struct mem_range_desc 	*desc;
141	int 			*arg;
142{
143	u_int64_t reg;
144	u_int32_t mtrr;
145	int error, d;
146
147	switch (*arg) {
148	case MEMRANGE_SET_UPDATE:
149		error = k6_mrmake(desc, &mtrr);
150		if (error)
151			return error;
152		for (d = 0; d < sc->mr_ndesc; d++) {
153			if (!sc->mr_desc[d].mr_len) {
154				sc->mr_desc[d] = *desc;
155				goto out;
156			}
157			if (sc->mr_desc[d].mr_base == desc->mr_base &&
158			    sc->mr_desc[d].mr_len == desc->mr_len)
159				return EEXIST;
160		}
161
162		return ENOSPC;
163	case MEMRANGE_SET_REMOVE:
164		mtrr = 0;
165		for (d = 0; d < sc->mr_ndesc; d++)
166			if (sc->mr_desc[d].mr_base == desc->mr_base &&
167			    sc->mr_desc[d].mr_len == desc->mr_len) {
168				bzero(&sc->mr_desc[d], sizeof(sc->mr_desc[d]));
169				goto out;
170			}
171
172		return ENOENT;
173	default:
174		return EOPNOTSUPP;
175	}
176
177out:
178
179	disable_intr();
180	wbinvd();
181	reg = rdmsr(UWCCR);
182	reg &= ~(0xffffffff << (32 * d));
183	reg |= mtrr << (32 * d);
184	wrmsr(UWCCR, reg);
185	wbinvd();
186	enable_intr();
187
188	return 0;
189}
190
191