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
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 /*
76 * Return PA for this VA if it is mapped by a CAM, or 0
77 */
v_mapped_by_tlbcam(unsigned long va)78 phys_addr_t v_mapped_by_tlbcam(unsigned long va)
79 {
80 int b;
81 for (b = 0; b < tlbcam_index; ++b)
82 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
83 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
84 return 0;
85 }
86
87 /*
88 * Return VA for a given PA or 0 if not mapped
89 */
p_mapped_by_tlbcam(phys_addr_t pa)90 unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
91 {
92 int b;
93 for (b = 0; b < tlbcam_index; ++b)
94 if (pa >= tlbcam_addrs[b].phys
95 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
96 +tlbcam_addrs[b].phys)
97 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
98 return 0;
99 }
100
101 /*
102 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
103 * in particular size must be a power of 4 between 4k and the max supported by
104 * an implementation; max may further be limited by what can be represented in
105 * an unsigned long (for example, 32-bit implementations cannot support a 4GB
106 * size).
107 */
settlbcam(int index,unsigned long virt,phys_addr_t phys,unsigned long size,unsigned long flags,unsigned int pid)108 static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
109 unsigned long size, unsigned long flags, unsigned int pid)
110 {
111 unsigned int tsize;
112
113 tsize = __ilog2(size) - 10;
114
115 #if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
116 if ((flags & _PAGE_NO_CACHE) == 0)
117 flags |= _PAGE_COHERENT;
118 #endif
119
120 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
121 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
122 TLBCAM[index].MAS2 = virt & PAGE_MASK;
123
124 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
125 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
126 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
127 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
128 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
129
130 TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
131 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
132 if (mmu_has_feature(MMU_FTR_BIG_PHYS))
133 TLBCAM[index].MAS7 = (u64)phys >> 32;
134
135 /* Below is unlikely -- only for large user pages or similar */
136 if (pte_user(flags)) {
137 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
138 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
139 }
140
141 tlbcam_addrs[index].start = virt;
142 tlbcam_addrs[index].limit = virt + size - 1;
143 tlbcam_addrs[index].phys = phys;
144 }
145
calc_cam_sz(unsigned long ram,unsigned long virt,phys_addr_t phys)146 unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
147 phys_addr_t phys)
148 {
149 unsigned int camsize = __ilog2(ram);
150 unsigned int align = __ffs(virt | phys);
151 unsigned long max_cam;
152
153 if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
154 /* Convert (4^max) kB to (2^max) bytes */
155 max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
156 camsize &= ~1U;
157 align &= ~1U;
158 } else {
159 /* Convert (2^max) kB to (2^max) bytes */
160 max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
161 }
162
163 if (camsize > align)
164 camsize = align;
165 if (camsize > max_cam)
166 camsize = max_cam;
167
168 return 1UL << camsize;
169 }
170
map_mem_in_cams_addr(phys_addr_t phys,unsigned long virt,unsigned long ram,int max_cam_idx,bool dryrun)171 static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
172 unsigned long ram, int max_cam_idx,
173 bool dryrun)
174 {
175 int i;
176 unsigned long amount_mapped = 0;
177
178 /* Calculate CAM values */
179 for (i = 0; ram && i < max_cam_idx; i++) {
180 unsigned long cam_sz;
181
182 cam_sz = calc_cam_sz(ram, virt, phys);
183 if (!dryrun)
184 settlbcam(i, virt, phys, cam_sz,
185 pgprot_val(PAGE_KERNEL_X), 0);
186
187 ram -= cam_sz;
188 amount_mapped += cam_sz;
189 virt += cam_sz;
190 phys += cam_sz;
191 }
192
193 if (dryrun)
194 return amount_mapped;
195
196 loadcam_multi(0, i, max_cam_idx);
197 tlbcam_index = i;
198
199 #ifdef CONFIG_PPC64
200 get_paca()->tcd.esel_next = i;
201 get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
202 get_paca()->tcd.esel_first = i;
203 #endif
204
205 return amount_mapped;
206 }
207
map_mem_in_cams(unsigned long ram,int max_cam_idx,bool dryrun)208 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx, bool dryrun)
209 {
210 unsigned long virt = PAGE_OFFSET;
211 phys_addr_t phys = memstart_addr;
212
213 return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx, dryrun);
214 }
215
216 #ifdef CONFIG_PPC32
217
218 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
219 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
220 #endif
221
mmu_mapin_ram(unsigned long top)222 unsigned long __init mmu_mapin_ram(unsigned long top)
223 {
224 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
225 }
226
227 /*
228 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
229 */
MMU_init_hw(void)230 void __init MMU_init_hw(void)
231 {
232 flush_instruction_cache();
233 }
234
adjust_total_lowmem(void)235 void __init adjust_total_lowmem(void)
236 {
237 unsigned long ram;
238 int i;
239
240 /* adjust lowmem size to __max_low_memory */
241 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
242
243 i = switch_to_as1();
244 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, false);
245 restore_to_as0(i, 0, 0, 1);
246
247 pr_info("Memory CAM mapping: ");
248 for (i = 0; i < tlbcam_index - 1; i++)
249 pr_cont("%lu/", tlbcam_sz(i) >> 20);
250 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
251 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
252
253 memblock_set_current_limit(memstart_addr + __max_low_memory);
254 }
255
setup_initial_memory_limit(phys_addr_t first_memblock_base,phys_addr_t first_memblock_size)256 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
257 phys_addr_t first_memblock_size)
258 {
259 phys_addr_t limit = first_memblock_base + first_memblock_size;
260
261 /* 64M mapped initially according to head_fsl_booke.S */
262 memblock_set_current_limit(min_t(u64, limit, 0x04000000));
263 }
264
265 #ifdef CONFIG_RELOCATABLE
266 int __initdata is_second_reloc;
relocate_init(u64 dt_ptr,phys_addr_t start)267 notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
268 {
269 unsigned long base = KERNELBASE;
270
271 kernstart_addr = start;
272 if (is_second_reloc) {
273 virt_phys_offset = PAGE_OFFSET - memstart_addr;
274 return;
275 }
276
277 /*
278 * Relocatable kernel support based on processing of dynamic
279 * relocation entries. Before we get the real memstart_addr,
280 * We will compute the virt_phys_offset like this:
281 * virt_phys_offset = stext.run - kernstart_addr
282 *
283 * stext.run = (KERNELBASE & ~0x3ffffff) +
284 * (kernstart_addr & 0x3ffffff)
285 * When we relocate, we have :
286 *
287 * (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
288 *
289 * hence:
290 * virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
291 * (kernstart_addr & ~0x3ffffff)
292 *
293 */
294 start &= ~0x3ffffff;
295 base &= ~0x3ffffff;
296 virt_phys_offset = base - start;
297 early_get_first_memblock_info(__va(dt_ptr), NULL);
298 /*
299 * We now get the memstart_addr, then we should check if this
300 * address is the same as what the PAGE_OFFSET map to now. If
301 * not we have to change the map of PAGE_OFFSET to memstart_addr
302 * and do a second relocation.
303 */
304 if (start != memstart_addr) {
305 int n;
306 long offset = start - memstart_addr;
307
308 is_second_reloc = 1;
309 n = switch_to_as1();
310 /* map a 64M area for the second relocation */
311 if (memstart_addr > start)
312 map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM,
313 false);
314 else
315 map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
316 0x4000000, CONFIG_LOWMEM_CAM_NUM,
317 false);
318 restore_to_as0(n, offset, __va(dt_ptr), 1);
319 /* We should never reach here */
320 panic("Relocation error");
321 }
322 }
323 #endif
324 #endif
325