2 * Modifications by Kumar Gala (galak@kernel.crashing.org) to support
3 * E500 Book E processors.
5 * Copyright 2004 Freescale Semiconductor, Inc
7 * This file contains the routines for initializing the MMU
8 * on the 4xx series of chips.
11 * Derived from arch/ppc/mm/init.c:
12 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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
18 * Derived from "arch/i386/mm/init.c"
19 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
21 * This program is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU General Public License
23 * as published by the Free Software Foundation; either version
24 * 2 of the License, or (at your option) any later version.
28 #include <linux/signal.h>
29 #include <linux/sched.h>
30 #include <linux/kernel.h>
31 #include <linux/errno.h>
32 #include <linux/string.h>
33 #include <linux/types.h>
34 #include <linux/ptrace.h>
35 #include <linux/mman.h>
37 #include <linux/swap.h>
38 #include <linux/stddef.h>
39 #include <linux/vmalloc.h>
40 #include <linux/init.h>
41 #include <linux/delay.h>
42 #include <linux/highmem.h>
44 #include <asm/pgalloc.h>
47 #include <asm/mmu_context.h>
48 #include <asm/pgtable.h>
50 #include <asm/uaccess.h>
52 #include <asm/bootx.h>
53 #include <asm/machdep.h>
54 #include <asm/setup.h>
56 extern void loadcam_entry(unsigned int index);
57 unsigned int tlbcam_index;
58 unsigned int num_tlbcam_entries;
59 static unsigned long __cam0, __cam1, __cam2;
60 extern unsigned long total_lowmem;
61 extern unsigned long __max_low_memory;
62 #define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
64 #define NUM_TLBCAMS (16)
72 } TLBCAM[NUM_TLBCAMS];
78 } tlbcam_addrs[NUM_TLBCAMS];
80 extern unsigned int tlbcam_index;
83 * Return PA for this VA if it is mapped by a CAM, or 0
85 unsigned long v_mapped_by_tlbcam(unsigned long va)
88 for (b = 0; b < tlbcam_index; ++b)
89 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
90 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
95 * Return VA for a given PA or 0 if not mapped
97 unsigned long p_mapped_by_tlbcam(unsigned long pa)
100 for (b = 0; b < tlbcam_index; ++b)
101 if (pa >= tlbcam_addrs[b].phys
102 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
103 +tlbcam_addrs[b].phys)
104 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
109 * Set up one of the I/D BAT (block address translation) register pairs.
110 * The parameters are not checked; in particular size must be a power
111 * of 4 between 4k and 256M.
113 void settlbcam(int index, unsigned long virt, phys_addr_t phys,
114 unsigned int size, int flags, unsigned int pid)
116 unsigned int tsize, lz;
118 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size));
119 tsize = (21 - lz) / 2;
122 if ((flags & _PAGE_NO_CACHE) == 0)
123 flags |= _PAGE_COHERENT;
126 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
127 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
128 TLBCAM[index].MAS2 = virt & PAGE_MASK;
130 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
131 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
132 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
133 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
134 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
136 TLBCAM[index].MAS3 = (phys & PAGE_MASK) | MAS3_SX | MAS3_SR;
137 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
139 #ifndef CONFIG_KGDB /* want user access for breakpoints */
140 if (flags & _PAGE_USER) {
141 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
142 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
145 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
146 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
149 tlbcam_addrs[index].start = virt;
150 tlbcam_addrs[index].limit = virt + size - 1;
151 tlbcam_addrs[index].phys = phys;
153 loadcam_entry(index);
156 void invalidate_tlbcam_entry(int index)
158 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index);
159 TLBCAM[index].MAS1 = ~MAS1_VALID;
161 loadcam_entry(index);
164 void __init cam_mapin_ram(unsigned long cam0, unsigned long cam1,
167 settlbcam(0, KERNELBASE, PPC_MEMSTART, cam0, _PAGE_KERNEL, 0);
171 settlbcam(1, KERNELBASE+cam0, PPC_MEMSTART+cam0, cam1, _PAGE_KERNEL, 0);
175 settlbcam(2, KERNELBASE+cam0+cam1, PPC_MEMSTART+cam0+cam1, cam2, _PAGE_KERNEL, 0);
180 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
182 void __init MMU_init_hw(void)
184 flush_instruction_cache();
187 unsigned long __init mmu_mapin_ram(void)
189 cam_mapin_ram(__cam0, __cam1, __cam2);
191 return __cam0 + __cam1 + __cam2;
196 adjust_total_lowmem(void)
198 unsigned long max_low_mem = MAX_LOW_MEM;
199 unsigned long cam_max = 0x10000000;
202 /* adjust CAM size to max_low_mem */
203 if (max_low_mem < cam_max)
204 cam_max = max_low_mem;
206 /* adjust lowmem size to max_low_mem */
207 if (max_low_mem < total_lowmem)
212 /* Calculate CAM values */
213 __cam0 = 1UL << 2 * (__ilog2(ram) / 2);
214 if (__cam0 > cam_max)
218 __cam1 = 1UL << 2 * (__ilog2(ram) / 2);
219 if (__cam1 > cam_max)
224 __cam2 = 1UL << 2 * (__ilog2(ram) / 2);
225 if (__cam2 > cam_max)
230 printk(KERN_INFO "Memory CAM mapping: CAM0=%ldMb, CAM1=%ldMb,"
231 " CAM2=%ldMb residual: %ldMb\n",
232 __cam0 >> 20, __cam1 >> 20, __cam2 >> 20,
233 (total_lowmem - __cam0 - __cam1 - __cam2) >> 20);
234 __max_low_memory = max_low_mem = __cam0 + __cam1 + __cam2;