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;
60 #define NUM_TLBCAMS (64)
61 struct tlbcam TLBCAM[NUM_TLBCAMS];
67 } tlbcam_addrs[NUM_TLBCAMS];
69 extern unsigned int tlbcam_index;
71 unsigned long tlbcam_sz(int idx)
73 return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
77 * Return PA for this VA if it is mapped by a CAM, or 0
79 phys_addr_t v_mapped_by_tlbcam(unsigned long va)
82 for (b = 0; b < tlbcam_index; ++b)
83 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
84 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
89 * Return VA for a given PA or 0 if not mapped
91 unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
94 for (b = 0; b < tlbcam_index; ++b)
95 if (pa >= tlbcam_addrs[b].phys
96 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
97 +tlbcam_addrs[b].phys)
98 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
103 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
104 * in particular size must be a power of 4 between 4k and the max supported by
105 * an implementation; max may further be limited by what can be represented in
106 * an unsigned long (for example, 32-bit implementations cannot support a 4GB
109 static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
110 unsigned long size, unsigned long flags, unsigned int pid)
114 tsize = __ilog2(size) - 10;
117 if ((flags & _PAGE_NO_CACHE) == 0)
118 flags |= _PAGE_COHERENT;
121 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
122 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
123 TLBCAM[index].MAS2 = virt & PAGE_MASK;
125 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
126 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
127 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
128 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
129 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
131 TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
132 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
133 if (mmu_has_feature(MMU_FTR_BIG_PHYS))
134 TLBCAM[index].MAS7 = (u64)phys >> 32;
136 /* Below is unlikely -- only for large user pages or similar */
137 if (pte_user(flags)) {
138 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
139 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
142 tlbcam_addrs[index].start = virt;
143 tlbcam_addrs[index].limit = virt + size - 1;
144 tlbcam_addrs[index].phys = phys;
146 loadcam_entry(index);
149 unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
152 unsigned int camsize = __ilog2(ram);
153 unsigned int align = __ffs(virt | phys);
154 unsigned long max_cam;
156 if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
157 /* Convert (4^max) kB to (2^max) bytes */
158 max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
162 /* Convert (2^max) kB to (2^max) bytes */
163 max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
168 if (camsize > max_cam)
171 return 1UL << camsize;
174 static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
175 unsigned long ram, int max_cam_idx)
178 unsigned long amount_mapped = 0;
180 /* Calculate CAM values */
181 for (i = 0; ram && i < max_cam_idx; i++) {
182 unsigned long cam_sz;
184 cam_sz = calc_cam_sz(ram, virt, phys);
185 settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
188 amount_mapped += cam_sz;
194 return amount_mapped;
197 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
199 unsigned long virt = PAGE_OFFSET;
200 phys_addr_t phys = memstart_addr;
202 return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx);
207 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
208 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
211 unsigned long __init mmu_mapin_ram(unsigned long top)
213 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
217 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
219 void __init MMU_init_hw(void)
221 flush_instruction_cache();
224 void __init adjust_total_lowmem(void)
229 /* adjust lowmem size to __max_low_memory */
230 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
233 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
236 pr_info("Memory CAM mapping: ");
237 for (i = 0; i < tlbcam_index - 1; i++)
238 pr_cont("%lu/", tlbcam_sz(i) >> 20);
239 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
240 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
242 memblock_set_current_limit(memstart_addr + __max_low_memory);
245 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
246 phys_addr_t first_memblock_size)
248 phys_addr_t limit = first_memblock_base + first_memblock_size;
250 /* 64M mapped initially according to head_fsl_booke.S */
251 memblock_set_current_limit(min_t(u64, limit, 0x04000000));
254 #ifdef CONFIG_RELOCATABLE
255 notrace void __init relocate_init(phys_addr_t start)
257 unsigned long base = KERNELBASE;
260 * Relocatable kernel support based on processing of dynamic
261 * relocation entries.
262 * Compute the virt_phys_offset :
263 * virt_phys_offset = stext.run - kernstart_addr
265 * stext.run = (KERNELBASE & ~0x3ffffff) + (kernstart_addr & 0x3ffffff)
266 * When we relocate, we have :
268 * (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
271 * virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
272 * (kernstart_addr & ~0x3ffffff)
275 kernstart_addr = start;
278 virt_phys_offset = base - start;