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 <linux/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
tlbcam_sz(int idx)70 unsigned long tlbcam_sz(int idx)
71 {
72 return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
73 }
74
75 #ifdef CONFIG_FSL_BOOKE
76 /*
77 * Return PA for this VA if it is mapped by a CAM, or 0
78 */
v_block_mapped(unsigned long va)79 phys_addr_t v_block_mapped(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_block_mapped(phys_addr_t pa)91 unsigned long p_block_mapped(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 #endif
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 #if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
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(__pte(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
calc_cam_sz(unsigned long ram,unsigned long virt,phys_addr_t phys)148 unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
149 phys_addr_t phys)
150 {
151 unsigned int camsize = __ilog2(ram);
152 unsigned int align = __ffs(virt | phys);
153 unsigned long max_cam;
154
155 if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
156 /* Convert (4^max) kB to (2^max) bytes */
157 max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
158 camsize &= ~1U;
159 align &= ~1U;
160 } else {
161 /* Convert (2^max) kB to (2^max) bytes */
162 max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
163 }
164
165 if (camsize > align)
166 camsize = align;
167 if (camsize > max_cam)
168 camsize = max_cam;
169
170 return 1UL << camsize;
171 }
172
map_mem_in_cams_addr(phys_addr_t phys,unsigned long virt,unsigned long ram,int max_cam_idx,bool dryrun)173 static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
174 unsigned long ram, int max_cam_idx,
175 bool dryrun)
176 {
177 int i;
178 unsigned long amount_mapped = 0;
179
180 /* Calculate CAM values */
181 for (i = 0; ram && i < max_cam_idx; i++) {
182 unsigned long cam_sz;
183
184 cam_sz = calc_cam_sz(ram, virt, phys);
185 if (!dryrun)
186 settlbcam(i, virt, phys, cam_sz,
187 pgprot_val(PAGE_KERNEL_X), 0);
188
189 ram -= cam_sz;
190 amount_mapped += cam_sz;
191 virt += cam_sz;
192 phys += cam_sz;
193 }
194
195 if (dryrun)
196 return amount_mapped;
197
198 loadcam_multi(0, i, max_cam_idx);
199 tlbcam_index = i;
200
201 #ifdef CONFIG_PPC64
202 get_paca()->tcd.esel_next = i;
203 get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
204 get_paca()->tcd.esel_first = i;
205 #endif
206
207 return amount_mapped;
208 }
209
map_mem_in_cams(unsigned long ram,int max_cam_idx,bool dryrun)210 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx, bool dryrun)
211 {
212 unsigned long virt = PAGE_OFFSET;
213 phys_addr_t phys = memstart_addr;
214
215 return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx, dryrun);
216 }
217
218 #ifdef CONFIG_PPC32
219
220 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
221 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
222 #endif
223
mmu_mapin_ram(unsigned long top)224 unsigned long __init mmu_mapin_ram(unsigned long top)
225 {
226 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
227 }
228
229 /*
230 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
231 */
MMU_init_hw(void)232 void __init MMU_init_hw(void)
233 {
234 flush_instruction_cache();
235 }
236
adjust_total_lowmem(void)237 void __init adjust_total_lowmem(void)
238 {
239 unsigned long ram;
240 int i;
241
242 /* adjust lowmem size to __max_low_memory */
243 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
244
245 i = switch_to_as1();
246 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, false);
247 restore_to_as0(i, 0, 0, 1);
248
249 pr_info("Memory CAM mapping: ");
250 for (i = 0; i < tlbcam_index - 1; i++)
251 pr_cont("%lu/", tlbcam_sz(i) >> 20);
252 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
253 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
254
255 memblock_set_current_limit(memstart_addr + __max_low_memory);
256 }
257
setup_initial_memory_limit(phys_addr_t first_memblock_base,phys_addr_t first_memblock_size)258 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
259 phys_addr_t first_memblock_size)
260 {
261 phys_addr_t limit = first_memblock_base + first_memblock_size;
262
263 /* 64M mapped initially according to head_fsl_booke.S */
264 memblock_set_current_limit(min_t(u64, limit, 0x04000000));
265 }
266
267 #ifdef CONFIG_RELOCATABLE
268 int __initdata is_second_reloc;
relocate_init(u64 dt_ptr,phys_addr_t start)269 notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
270 {
271 unsigned long base = KERNELBASE;
272
273 kernstart_addr = start;
274 if (is_second_reloc) {
275 virt_phys_offset = PAGE_OFFSET - memstart_addr;
276 return;
277 }
278
279 /*
280 * Relocatable kernel support based on processing of dynamic
281 * relocation entries. Before we get the real memstart_addr,
282 * We will compute the virt_phys_offset like this:
283 * virt_phys_offset = stext.run - kernstart_addr
284 *
285 * stext.run = (KERNELBASE & ~0x3ffffff) +
286 * (kernstart_addr & 0x3ffffff)
287 * When we relocate, we have :
288 *
289 * (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
290 *
291 * hence:
292 * virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
293 * (kernstart_addr & ~0x3ffffff)
294 *
295 */
296 start &= ~0x3ffffff;
297 base &= ~0x3ffffff;
298 virt_phys_offset = base - start;
299 early_get_first_memblock_info(__va(dt_ptr), NULL);
300 /*
301 * We now get the memstart_addr, then we should check if this
302 * address is the same as what the PAGE_OFFSET map to now. If
303 * not we have to change the map of PAGE_OFFSET to memstart_addr
304 * and do a second relocation.
305 */
306 if (start != memstart_addr) {
307 int n;
308 long offset = start - memstart_addr;
309
310 is_second_reloc = 1;
311 n = switch_to_as1();
312 /* map a 64M area for the second relocation */
313 if (memstart_addr > start)
314 map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM,
315 false);
316 else
317 map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
318 0x4000000, CONFIG_LOWMEM_CAM_NUM,
319 false);
320 restore_to_as0(n, offset, __va(dt_ptr), 1);
321 /* We should never reach here */
322 panic("Relocation error");
323 }
324 }
325 #endif
326 #endif
327
