tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Modifications by Kumar Gala (galak@kernel.crashing.org) to support
3 * E500 Book E processors.
4 *
5 * Copyright 2004 Freescale Semiconductor, Inc
6 *
7 * This file contains the routines for initializing the MMU
8 * on the 4xx series of chips.
9 * -- paulus
10 *
11 * Derived from arch/ppc/mm/init.c:
12 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
13 *
14 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
15 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
16 * Copyright (C) 1996 Paul Mackerras
17 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
18 *
19 * Derived from "arch/i386/mm/init.c"
20 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
21 *
22 * This program is free software; you can redistribute it and/or
23 * modify it under the terms of the GNU General Public License
24 * as published by the Free Software Foundation; either version
25 * 2 of the License, or (at your option) any later version.
26 *
27 */
28
29#include <linux/config.h>
30#include <linux/signal.h>
31#include <linux/sched.h>
32#include <linux/kernel.h>
33#include <linux/errno.h>
34#include <linux/string.h>
35#include <linux/types.h>
36#include <linux/ptrace.h>
37#include <linux/mman.h>
38#include <linux/mm.h>
39#include <linux/swap.h>
40#include <linux/stddef.h>
41#include <linux/vmalloc.h>
42#include <linux/init.h>
43#include <linux/delay.h>
44#include <linux/highmem.h>
45
46#include <asm/pgalloc.h>
47#include <asm/prom.h>
48#include <asm/io.h>
49#include <asm/mmu_context.h>
50#include <asm/pgtable.h>
51#include <asm/mmu.h>
52#include <asm/uaccess.h>
53#include <asm/smp.h>
54#include <asm/bootx.h>
55#include <asm/machdep.h>
56#include <asm/setup.h>
57
58extern void loadcam_entry(unsigned int index);
59unsigned int tlbcam_index;
60unsigned int num_tlbcam_entries;
61static unsigned long __cam0, __cam1, __cam2;
62extern unsigned long total_lowmem;
63extern unsigned long __max_low_memory;
64#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
65
66#define NUM_TLBCAMS (16)
67
68struct tlbcam {
69 u32 MAS0;
70 u32 MAS1;
71 u32 MAS2;
72 u32 MAS3;
73 u32 MAS7;
74} TLBCAM[NUM_TLBCAMS];
75
76struct tlbcamrange {
77 unsigned long start;
78 unsigned long limit;
79 phys_addr_t phys;
80} tlbcam_addrs[NUM_TLBCAMS];
81
82extern unsigned int tlbcam_index;
83
84/*
85 * Return PA for this VA if it is mapped by a CAM, or 0
86 */
87unsigned long v_mapped_by_tlbcam(unsigned long va)
88{
89 int b;
90 for (b = 0; b < tlbcam_index; ++b)
91 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
92 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
93 return 0;
94}
95
96/*
97 * Return VA for a given PA or 0 if not mapped
98 */
99unsigned long p_mapped_by_tlbcam(unsigned long pa)
100{
101 int b;
102 for (b = 0; b < tlbcam_index; ++b)
103 if (pa >= tlbcam_addrs[b].phys
104 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
105 +tlbcam_addrs[b].phys)
106 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
107 return 0;
108}
109
110/*
111 * Set up one of the I/D BAT (block address translation) register pairs.
112 * The parameters are not checked; in particular size must be a power
113 * of 4 between 4k and 256M.
114 */
115void settlbcam(int index, unsigned long virt, phys_addr_t phys,
116 unsigned int size, int flags, unsigned int pid)
117{
118 unsigned int tsize, lz;
119
120 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size));
121 tsize = (21 - lz) / 2;
122
123#ifdef CONFIG_SMP
124 if ((flags & _PAGE_NO_CACHE) == 0)
125 flags |= _PAGE_COHERENT;
126#endif
127
128 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
129 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
130 TLBCAM[index].MAS2 = virt & PAGE_MASK;
131
132 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
133 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
134 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
135 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
136 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
137
138 TLBCAM[index].MAS3 = (phys & PAGE_MASK) | MAS3_SX | MAS3_SR;
139 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
140
141#ifndef CONFIG_KGDB /* want user access for breakpoints */
142 if (flags & _PAGE_USER) {
143 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
144 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
145 }
146#else
147 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
148 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
149#endif
150
151 tlbcam_addrs[index].start = virt;
152 tlbcam_addrs[index].limit = virt + size - 1;
153 tlbcam_addrs[index].phys = phys;
154
155 loadcam_entry(index);
156}
157
158void invalidate_tlbcam_entry(int index)
159{
160 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index);
161 TLBCAM[index].MAS1 = ~MAS1_VALID;
162
163 loadcam_entry(index);
164}
165
166void __init cam_mapin_ram(unsigned long cam0, unsigned long cam1,
167 unsigned long cam2)
168{
169 settlbcam(0, KERNELBASE, PPC_MEMSTART, cam0, _PAGE_KERNEL, 0);
170 tlbcam_index++;
171 if (cam1) {
172 tlbcam_index++;
173 settlbcam(1, KERNELBASE+cam0, PPC_MEMSTART+cam0, cam1, _PAGE_KERNEL, 0);
174 }
175 if (cam2) {
176 tlbcam_index++;
177 settlbcam(2, KERNELBASE+cam0+cam1, PPC_MEMSTART+cam0+cam1, cam2, _PAGE_KERNEL, 0);
178 }
179}
180
181/*
182 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
183 */
184void __init MMU_init_hw(void)
185{
186 flush_instruction_cache();
187}
188
189unsigned long __init mmu_mapin_ram(void)
190{
191 cam_mapin_ram(__cam0, __cam1, __cam2);
192
193 return __cam0 + __cam1 + __cam2;
194}
195
196
197void __init
198adjust_total_lowmem(void)
199{
200 unsigned long max_low_mem = MAX_LOW_MEM;
201 unsigned long cam_max = 0x10000000;
202 unsigned long ram;
203
204 /* adjust CAM size to max_low_mem */
205 if (max_low_mem < cam_max)
206 cam_max = max_low_mem;
207
208 /* adjust lowmem size to max_low_mem */
209 if (max_low_mem < total_lowmem)
210 ram = max_low_mem;
211 else
212 ram = total_lowmem;
213
214 /* Calculate CAM values */
215 __cam0 = 1UL << 2 * (__ilog2(ram) / 2);
216 if (__cam0 > cam_max)
217 __cam0 = cam_max;
218 ram -= __cam0;
219 if (ram) {
220 __cam1 = 1UL << 2 * (__ilog2(ram) / 2);
221 if (__cam1 > cam_max)
222 __cam1 = cam_max;
223 ram -= __cam1;
224 }
225 if (ram) {
226 __cam2 = 1UL << 2 * (__ilog2(ram) / 2);
227 if (__cam2 > cam_max)
228 __cam2 = cam_max;
229 ram -= __cam2;
230 }
231
232 printk(KERN_INFO "Memory CAM mapping: CAM0=%ldMb, CAM1=%ldMb,"
233 " CAM2=%ldMb residual: %ldMb\n",
234 __cam0 >> 20, __cam1 >> 20, __cam2 >> 20,
235 (total_lowmem - __cam0 - __cam1 - __cam2) >> 20);
236 __max_low_memory = max_low_mem = __cam0 + __cam1 + __cam2;
237}