2 * Modifications by Kumar Gala (galak@kernel.crashing.org) to support
3 * E500 Book E processors.
5 * Copyright 2004,2010 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>
43 #include <linux/memblock.h>
45 #include <asm/pgalloc.h>
48 #include <asm/mmu_context.h>
49 #include <asm/pgtable.h>
51 #include <asm/uaccess.h>
53 #include <asm/machdep.h>
54 #include <asm/setup.h>
58 unsigned int tlbcam_index;
61 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
62 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
65 #define NUM_TLBCAMS (64)
66 struct tlbcam TLBCAM[NUM_TLBCAMS];
72 } tlbcam_addrs[NUM_TLBCAMS];
74 extern unsigned int tlbcam_index;
76 unsigned long tlbcam_sz(int idx)
78 return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
82 * Return PA for this VA if it is mapped by a CAM, or 0
84 phys_addr_t v_mapped_by_tlbcam(unsigned long va)
87 for (b = 0; b < tlbcam_index; ++b)
88 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
89 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
94 * Return VA for a given PA or 0 if not mapped
96 unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
99 for (b = 0; b < tlbcam_index; ++b)
100 if (pa >= tlbcam_addrs[b].phys
101 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
102 +tlbcam_addrs[b].phys)
103 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
108 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
109 * in particular size must be a power of 4 between 4k and 256M (or 1G, for cpus
110 * that support extended page sizes). Note that while some cpus support a
111 * page size of 4G, we don't allow its use here.
113 static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
114 unsigned long size, unsigned long flags, unsigned int pid)
116 unsigned int tsize, lz;
118 asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (size));
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 & MAS3_RPN) | MAS3_SX | MAS3_SR;
137 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
138 if (mmu_has_feature(MMU_FTR_BIG_PHYS))
139 TLBCAM[index].MAS7 = (u64)phys >> 32;
141 if (flags & _PAGE_USER) {
142 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
143 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
146 tlbcam_addrs[index].start = virt;
147 tlbcam_addrs[index].limit = virt + size - 1;
148 tlbcam_addrs[index].phys = phys;
150 loadcam_entry(index);
153 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
156 unsigned long virt = PAGE_OFFSET;
157 phys_addr_t phys = memstart_addr;
158 unsigned long amount_mapped = 0;
159 unsigned long max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xf;
161 /* Convert (4^max) kB to (2^max) bytes */
162 max_cam = max_cam * 2 + 10;
164 /* Calculate CAM values */
165 for (i = 0; ram && i < max_cam_idx; i++) {
166 unsigned int camsize = __ilog2(ram) & ~1U;
167 unsigned int align = __ffs(virt | phys) & ~1U;
168 unsigned long cam_sz;
172 if (camsize > max_cam)
175 cam_sz = 1UL << camsize;
176 settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
179 amount_mapped += cam_sz;
185 return amount_mapped;
188 unsigned long __init mmu_mapin_ram(unsigned long top)
190 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
194 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
196 void __init MMU_init_hw(void)
198 flush_instruction_cache();
201 void __init adjust_total_lowmem(void)
206 /* adjust lowmem size to __max_low_memory */
207 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
209 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
211 pr_info("Memory CAM mapping: ");
212 for (i = 0; i < tlbcam_index - 1; i++)
213 pr_cont("%lu/", tlbcam_sz(i) >> 20);
214 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
215 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
217 memblock_set_current_limit(memstart_addr + __max_low_memory);
220 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
221 phys_addr_t first_memblock_size)
223 phys_addr_t limit = first_memblock_base + first_memblock_size;
225 /* 64M mapped initially according to head_fsl_booke.S */
226 memblock_set_current_limit(min_t(u64, limit, 0x04000000));