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 #include <asm/paca.h>
56
57 #include "mmu_decl.h"
58
59 unsigned int tlbcam_index;
60
61 #define NUM_TLBCAMS (64)
62 struct tlbcam TLBCAM[NUM_TLBCAMS];
63
64 struct tlbcamrange {
65 unsigned long start;
66 unsigned long limit;
67 phys_addr_t phys;
68 } tlbcam_addrs[NUM_TLBCAMS];
69
70 extern unsigned int tlbcam_index;
71
tlbcam_sz(int idx)72 unsigned long tlbcam_sz(int idx)
73 {
74 return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
75 }
76
77 /*
78 * Return PA for this VA if it is mapped by a CAM, or 0
79 */
v_mapped_by_tlbcam(unsigned long va)80 phys_addr_t v_mapped_by_tlbcam(unsigned long va)
81 {
82 int b;
83 for (b = 0; b < tlbcam_index; ++b)
84 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
85 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
86 return 0;
87 }
88
89 /*
90 * Return VA for a given PA or 0 if not mapped
91 */
p_mapped_by_tlbcam(phys_addr_t pa)92 unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
93 {
94 int b;
95 for (b = 0; b < tlbcam_index; ++b)
96 if (pa >= tlbcam_addrs[b].phys
97 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
98 +tlbcam_addrs[b].phys)
99 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
100 return 0;
101 }
102
103 /*
104 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
105 * in particular size must be a power of 4 between 4k and the max supported by
106 * an implementation; max may further be limited by what can be represented in
107 * an unsigned long (for example, 32-bit implementations cannot support a 4GB
108 * size).
109 */
settlbcam(int index,unsigned long virt,phys_addr_t phys,unsigned long size,unsigned long flags,unsigned int pid)110 static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
111 unsigned long size, unsigned long flags, unsigned int pid)
112 {
113 unsigned int tsize;
114
115 tsize = __ilog2(size) - 10;
116
117 #ifdef CONFIG_SMP
118 if ((flags & _PAGE_NO_CACHE) == 0)
119 flags |= _PAGE_COHERENT;
120 #endif
121
122 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
123 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
124 TLBCAM[index].MAS2 = virt & PAGE_MASK;
125
126 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
127 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
128 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
129 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
130 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
131
132 TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
133 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
134 if (mmu_has_feature(MMU_FTR_BIG_PHYS))
135 TLBCAM[index].MAS7 = (u64)phys >> 32;
136
137 /* Below is unlikely -- only for large user pages or similar */
138 if (pte_user(flags)) {
139 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
140 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
141 }
142
143 tlbcam_addrs[index].start = virt;
144 tlbcam_addrs[index].limit = virt + size - 1;
145 tlbcam_addrs[index].phys = phys;
146
147 loadcam_entry(index);
148 }
149
calc_cam_sz(unsigned long ram,unsigned long virt,phys_addr_t phys)150 unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
151 phys_addr_t phys)
152 {
153 unsigned int camsize = __ilog2(ram);
154 unsigned int align = __ffs(virt | phys);
155 unsigned long max_cam;
156
157 if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
158 /* Convert (4^max) kB to (2^max) bytes */
159 max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
160 camsize &= ~1U;
161 align &= ~1U;
162 } else {
163 /* Convert (2^max) kB to (2^max) bytes */
164 max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
165 }
166
167 if (camsize > align)
168 camsize = align;
169 if (camsize > max_cam)
170 camsize = max_cam;
171
172 return 1UL << camsize;
173 }
174
map_mem_in_cams_addr(phys_addr_t phys,unsigned long virt,unsigned long ram,int max_cam_idx)175 static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
176 unsigned long ram, int max_cam_idx)
177 {
178 int i;
179 unsigned long amount_mapped = 0;
180
181 /* Calculate CAM values */
182 for (i = 0; ram && i < max_cam_idx; i++) {
183 unsigned long cam_sz;
184
185 cam_sz = calc_cam_sz(ram, virt, phys);
186 settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
187
188 ram -= cam_sz;
189 amount_mapped += cam_sz;
190 virt += cam_sz;
191 phys += cam_sz;
192 }
193 tlbcam_index = i;
194
195 #ifdef CONFIG_PPC64
196 get_paca()->tcd.esel_next = i;
197 get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
198 get_paca()->tcd.esel_first = i;
199 #endif
200
201 return amount_mapped;
202 }
203
map_mem_in_cams(unsigned long ram,int max_cam_idx)204 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
205 {
206 unsigned long virt = PAGE_OFFSET;
207 phys_addr_t phys = memstart_addr;
208
209 return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx);
210 }
211
212 #ifdef CONFIG_PPC32
213
214 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
215 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
216 #endif
217
mmu_mapin_ram(unsigned long top)218 unsigned long __init mmu_mapin_ram(unsigned long top)
219 {
220 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
221 }
222
223 /*
224 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
225 */
MMU_init_hw(void)226 void __init MMU_init_hw(void)
227 {
228 flush_instruction_cache();
229 }
230
adjust_total_lowmem(void)231 void __init adjust_total_lowmem(void)
232 {
233 unsigned long ram;
234 int i;
235
236 /* adjust lowmem size to __max_low_memory */
237 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
238
239 i = switch_to_as1();
240 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
241 restore_to_as0(i, 0, 0, 1);
242
243 pr_info("Memory CAM mapping: ");
244 for (i = 0; i < tlbcam_index - 1; i++)
245 pr_cont("%lu/", tlbcam_sz(i) >> 20);
246 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
247 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
248
249 memblock_set_current_limit(memstart_addr + __max_low_memory);
250 }
251
setup_initial_memory_limit(phys_addr_t first_memblock_base,phys_addr_t first_memblock_size)252 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
253 phys_addr_t first_memblock_size)
254 {
255 phys_addr_t limit = first_memblock_base + first_memblock_size;
256
257 /* 64M mapped initially according to head_fsl_booke.S */
258 memblock_set_current_limit(min_t(u64, limit, 0x04000000));
259 }
260
261 #ifdef CONFIG_RELOCATABLE
262 int __initdata is_second_reloc;
relocate_init(u64 dt_ptr,phys_addr_t start)263 notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
264 {
265 unsigned long base = KERNELBASE;
266
267 kernstart_addr = start;
268 if (is_second_reloc) {
269 virt_phys_offset = PAGE_OFFSET - memstart_addr;
270 return;
271 }
272
273 /*
274 * Relocatable kernel support based on processing of dynamic
275 * relocation entries. Before we get the real memstart_addr,
276 * We will compute the virt_phys_offset like this:
277 * virt_phys_offset = stext.run - kernstart_addr
278 *
279 * stext.run = (KERNELBASE & ~0x3ffffff) +
280 * (kernstart_addr & 0x3ffffff)
281 * When we relocate, we have :
282 *
283 * (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
284 *
285 * hence:
286 * virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
287 * (kernstart_addr & ~0x3ffffff)
288 *
289 */
290 start &= ~0x3ffffff;
291 base &= ~0x3ffffff;
292 virt_phys_offset = base - start;
293 early_get_first_memblock_info(__va(dt_ptr), NULL);
294 /*
295 * We now get the memstart_addr, then we should check if this
296 * address is the same as what the PAGE_OFFSET map to now. If
297 * not we have to change the map of PAGE_OFFSET to memstart_addr
298 * and do a second relocation.
299 */
300 if (start != memstart_addr) {
301 int n;
302 long offset = start - memstart_addr;
303
304 is_second_reloc = 1;
305 n = switch_to_as1();
306 /* map a 64M area for the second relocation */
307 if (memstart_addr > start)
308 map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM);
309 else
310 map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
311 0x4000000, CONFIG_LOWMEM_CAM_NUM);
312 restore_to_as0(n, offset, __va(dt_ptr), 1);
313 /* We should never reach here */
314 panic("Relocation error");
315 }
316 }
317 #endif
318 #endif
319