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/machdep.h>
53 #include <asm/setup.h>
57 extern void loadcam_entry(unsigned int index);
58 unsigned int tlbcam_index;
59 static unsigned long cam[3];
61 #define NUM_TLBCAMS (16)
63 struct tlbcam TLBCAM[NUM_TLBCAMS];
69 } tlbcam_addrs[NUM_TLBCAMS];
71 extern unsigned int tlbcam_index;
74 * Return PA for this VA if it is mapped by a CAM, or 0
76 unsigned long v_mapped_by_tlbcam(unsigned long va)
79 for (b = 0; b < tlbcam_index; ++b)
80 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
81 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
86 * Return VA for a given PA or 0 if not mapped
88 unsigned long p_mapped_by_tlbcam(unsigned long pa)
91 for (b = 0; b < tlbcam_index; ++b)
92 if (pa >= tlbcam_addrs[b].phys
93 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
94 +tlbcam_addrs[b].phys)
95 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
100 * Set up one of the I/D BAT (block address translation) register pairs.
101 * The parameters are not checked; in particular size must be a power
102 * of 4 between 4k and 256M.
104 void settlbcam(int index, unsigned long virt, phys_addr_t phys,
105 unsigned int size, int flags, unsigned int pid)
107 unsigned int tsize, lz;
109 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size));
110 tsize = (21 - lz) / 2;
113 if ((flags & _PAGE_NO_CACHE) == 0)
114 flags |= _PAGE_COHERENT;
117 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
118 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
119 TLBCAM[index].MAS2 = virt & PAGE_MASK;
121 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
122 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
123 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
124 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
125 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
127 TLBCAM[index].MAS3 = (phys & PAGE_MASK) | MAS3_SX | MAS3_SR;
128 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
130 #ifndef CONFIG_KGDB /* want user access for breakpoints */
131 if (flags & _PAGE_USER) {
132 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
133 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
136 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
137 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
140 tlbcam_addrs[index].start = virt;
141 tlbcam_addrs[index].limit = virt + size - 1;
142 tlbcam_addrs[index].phys = phys;
144 loadcam_entry(index);
147 void invalidate_tlbcam_entry(int index)
149 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index);
150 TLBCAM[index].MAS1 = ~MAS1_VALID;
152 loadcam_entry(index);
155 unsigned long __init mmu_mapin_ram(void)
157 unsigned long virt = PAGE_OFFSET;
158 phys_addr_t phys = memstart_addr;
160 while (cam[tlbcam_index] && tlbcam_index < ARRAY_SIZE(cam)) {
161 settlbcam(tlbcam_index, virt, phys, cam[tlbcam_index], _PAGE_KERNEL, 0);
162 virt += cam[tlbcam_index];
163 phys += cam[tlbcam_index];
167 return virt - PAGE_OFFSET;
171 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
173 void __init MMU_init_hw(void)
175 flush_instruction_cache();
179 adjust_total_lowmem(void)
182 unsigned int max_cam = 28; /* 2^28 = 256 Mb */
183 char buf[ARRAY_SIZE(cam) * 5 + 1], *p = buf;
186 /* adjust lowmem size to __max_low_memory */
187 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
189 /* Calculate CAM values */
190 __max_low_memory = 0;
191 for (i = 0; ram && i < ARRAY_SIZE(cam); i++) {
192 unsigned int camsize = __ilog2(ram) & ~1U;
193 if (camsize > max_cam)
195 cam[i] = 1UL << camsize;
197 __max_low_memory += cam[i];
199 p += sprintf(p, "%lu/", cam[i] >> 20);
201 for (; i < ARRAY_SIZE(cam); i++)
202 p += sprintf(p, "0/");
205 pr_info("Memory CAM mapping: %s Mb, residual: %ldMb\n", buf,
206 (total_lowmem - __max_low_memory) >> 20);
207 __initial_memory_limit_addr = memstart_addr + __max_low_memory;