1 /*
2 * Modifications by Kumar Gala (galak@kernel.crashing.org) to support
3 * E500 Book E processors.
4 *
5 * Copyright 2004,2010 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 *
18 * Derived from "arch/i386/mm/init.c"
19 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
20 *
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.
25 *
26 */
27
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>
36 #include <linux/mm.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>
44
45 #include <asm/pgalloc.h>
46 #include <asm/prom.h>
47 #include <asm/io.h>
48 #include <asm/mmu_context.h>
49 #include <asm/pgtable.h>
50 #include <asm/mmu.h>
51 #include <asm/uaccess.h>
52 #include <asm/smp.h>
53 #include <asm/machdep.h>
54 #include <asm/setup.h>
55
56 #include "mmu_decl.h"
57
58 unsigned int tlbcam_index;
59
60 #define NUM_TLBCAMS (64)
61 struct tlbcam TLBCAM[NUM_TLBCAMS];
62
63 struct tlbcamrange {
64 unsigned long start;
65 unsigned long limit;
66 phys_addr_t phys;
67 } tlbcam_addrs[NUM_TLBCAMS];
68
69 extern unsigned int tlbcam_index;
70
tlbcam_sz(int idx)71 unsigned long tlbcam_sz(int idx)
72 {
73 return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
74 }
75
76 /*
77 * Return PA for this VA if it is mapped by a CAM, or 0
78 */
v_mapped_by_tlbcam(unsigned long va)79 phys_addr_t v_mapped_by_tlbcam(unsigned long va)
80 {
81 int b;
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);
85 return 0;
86 }
87
88 /*
89 * Return VA for a given PA or 0 if not mapped
90 */
p_mapped_by_tlbcam(phys_addr_t pa)91 unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
92 {
93 int b;
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);
99 return 0;
100 }
101
102 /*
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
107 * size).
108 */
settlbcam(int index,unsigned long virt,phys_addr_t phys,unsigned long size,unsigned long flags,unsigned int pid)109 static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
110 unsigned long size, unsigned long flags, unsigned int pid)
111 {
112 unsigned int tsize;
113
114 tsize = __ilog2(size) - 10;
115
116 #ifdef CONFIG_SMP
117 if ((flags & _PAGE_NO_CACHE) == 0)
118 flags |= _PAGE_COHERENT;
119 #endif
120
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;
124
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;
130
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;
135
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);
140 }
141
142 tlbcam_addrs[index].start = virt;
143 tlbcam_addrs[index].limit = virt + size - 1;
144 tlbcam_addrs[index].phys = phys;
145
146 loadcam_entry(index);
147 }
148
calc_cam_sz(unsigned long ram,unsigned long virt,phys_addr_t phys)149 unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
150 phys_addr_t phys)
151 {
152 unsigned int camsize = __ilog2(ram) & ~1U;
153 unsigned int align = __ffs(virt | phys) & ~1U;
154 unsigned long max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xf;
155
156 /* Convert (4^max) kB to (2^max) bytes */
157 max_cam = max_cam * 2 + 10;
158
159 if (camsize > align)
160 camsize = align;
161 if (camsize > max_cam)
162 camsize = max_cam;
163
164 return 1UL << camsize;
165 }
166
map_mem_in_cams(unsigned long ram,int max_cam_idx)167 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
168 {
169 int i;
170 unsigned long virt = PAGE_OFFSET;
171 phys_addr_t phys = memstart_addr;
172 unsigned long amount_mapped = 0;
173
174 /* Calculate CAM values */
175 for (i = 0; ram && i < max_cam_idx; i++) {
176 unsigned long cam_sz;
177
178 cam_sz = calc_cam_sz(ram, virt, phys);
179 settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
180
181 ram -= cam_sz;
182 amount_mapped += cam_sz;
183 virt += cam_sz;
184 phys += cam_sz;
185 }
186 tlbcam_index = i;
187
188 return amount_mapped;
189 }
190
191 #ifdef CONFIG_PPC32
192
193 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
194 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
195 #endif
196
mmu_mapin_ram(unsigned long top)197 unsigned long __init mmu_mapin_ram(unsigned long top)
198 {
199 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
200 }
201
202 /*
203 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
204 */
MMU_init_hw(void)205 void __init MMU_init_hw(void)
206 {
207 flush_instruction_cache();
208 }
209
adjust_total_lowmem(void)210 void __init adjust_total_lowmem(void)
211 {
212 unsigned long ram;
213 int i;
214
215 /* adjust lowmem size to __max_low_memory */
216 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
217
218 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
219
220 pr_info("Memory CAM mapping: ");
221 for (i = 0; i < tlbcam_index - 1; i++)
222 pr_cont("%lu/", tlbcam_sz(i) >> 20);
223 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
224 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
225
226 memblock_set_current_limit(memstart_addr + __max_low_memory);
227 }
228
setup_initial_memory_limit(phys_addr_t first_memblock_base,phys_addr_t first_memblock_size)229 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
230 phys_addr_t first_memblock_size)
231 {
232 phys_addr_t limit = first_memblock_base + first_memblock_size;
233
234 /* 64M mapped initially according to head_fsl_booke.S */
235 memblock_set_current_limit(min_t(u64, limit, 0x04000000));
236 }
237 #endif
238