1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Modifications by Kumar Gala (galak@kernel.crashing.org) to support
4 * E500 Book E processors.
5 *
6 * Copyright 2004,2010 Freescale Semiconductor, Inc.
7 *
8 * This file contains the routines for initializing the MMU
9 * on the 4xx series of chips.
10 * -- paulus
11 *
12 * Derived from arch/ppc/mm/init.c:
13 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
14 *
15 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
16 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
17 * Copyright (C) 1996 Paul Mackerras
18 *
19 * Derived from "arch/i386/mm/init.c"
20 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
21 */
22
23 #include <linux/signal.h>
24 #include <linux/sched.h>
25 #include <linux/kernel.h>
26 #include <linux/errno.h>
27 #include <linux/string.h>
28 #include <linux/types.h>
29 #include <linux/ptrace.h>
30 #include <linux/mman.h>
31 #include <linux/mm.h>
32 #include <linux/swap.h>
33 #include <linux/stddef.h>
34 #include <linux/vmalloc.h>
35 #include <linux/init.h>
36 #include <linux/delay.h>
37 #include <linux/highmem.h>
38 #include <linux/memblock.h>
39
40 #include <asm/prom.h>
41 #include <asm/io.h>
42 #include <asm/mmu_context.h>
43 #include <asm/mmu.h>
44 #include <linux/uaccess.h>
45 #include <asm/smp.h>
46 #include <asm/machdep.h>
47 #include <asm/setup.h>
48 #include <asm/paca.h>
49
50 #include <mm/mmu_decl.h>
51
52 unsigned int tlbcam_index;
53
54 #define NUM_TLBCAMS (64)
55 struct tlbcam TLBCAM[NUM_TLBCAMS];
56
57 struct tlbcamrange {
58 unsigned long start;
59 unsigned long limit;
60 phys_addr_t phys;
61 } tlbcam_addrs[NUM_TLBCAMS];
62
tlbcam_sz(int idx)63 unsigned long tlbcam_sz(int idx)
64 {
65 return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
66 }
67
68 #ifdef CONFIG_FSL_BOOKE
69 /*
70 * Return PA for this VA if it is mapped by a CAM, or 0
71 */
v_block_mapped(unsigned long va)72 phys_addr_t v_block_mapped(unsigned long va)
73 {
74 int b;
75 for (b = 0; b < tlbcam_index; ++b)
76 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
77 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
78 return 0;
79 }
80
81 /*
82 * Return VA for a given PA or 0 if not mapped
83 */
p_block_mapped(phys_addr_t pa)84 unsigned long p_block_mapped(phys_addr_t pa)
85 {
86 int b;
87 for (b = 0; b < tlbcam_index; ++b)
88 if (pa >= tlbcam_addrs[b].phys
89 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
90 +tlbcam_addrs[b].phys)
91 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
92 return 0;
93 }
94 #endif
95
96 /*
97 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
98 * in particular size must be a power of 4 between 4k and the max supported by
99 * an implementation; max may further be limited by what can be represented in
100 * an unsigned long (for example, 32-bit implementations cannot support a 4GB
101 * size).
102 */
settlbcam(int index,unsigned long virt,phys_addr_t phys,unsigned long size,unsigned long flags,unsigned int pid)103 static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
104 unsigned long size, unsigned long flags, unsigned int pid)
105 {
106 unsigned int tsize;
107
108 tsize = __ilog2(size) - 10;
109
110 #if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
111 if ((flags & _PAGE_NO_CACHE) == 0)
112 flags |= _PAGE_COHERENT;
113 #endif
114
115 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
116 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
117 TLBCAM[index].MAS2 = virt & PAGE_MASK;
118
119 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
120 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
121 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
122 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
123 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
124
125 TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SR;
126 TLBCAM[index].MAS3 |= (flags & _PAGE_RW) ? MAS3_SW : 0;
127 if (mmu_has_feature(MMU_FTR_BIG_PHYS))
128 TLBCAM[index].MAS7 = (u64)phys >> 32;
129
130 /* Below is unlikely -- only for large user pages or similar */
131 if (pte_user(__pte(flags))) {
132 TLBCAM[index].MAS3 |= MAS3_UR;
133 TLBCAM[index].MAS3 |= (flags & _PAGE_EXEC) ? MAS3_UX : 0;
134 TLBCAM[index].MAS3 |= (flags & _PAGE_RW) ? MAS3_UW : 0;
135 } else {
136 TLBCAM[index].MAS3 |= (flags & _PAGE_EXEC) ? MAS3_SX : 0;
137 }
138
139 tlbcam_addrs[index].start = virt;
140 tlbcam_addrs[index].limit = virt + size - 1;
141 tlbcam_addrs[index].phys = phys;
142 }
143
calc_cam_sz(unsigned long ram,unsigned long virt,phys_addr_t phys)144 unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
145 phys_addr_t phys)
146 {
147 unsigned int camsize = __ilog2(ram);
148 unsigned int align = __ffs(virt | phys);
149 unsigned long max_cam;
150
151 if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
152 /* Convert (4^max) kB to (2^max) bytes */
153 max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
154 camsize &= ~1U;
155 align &= ~1U;
156 } else {
157 /* Convert (2^max) kB to (2^max) bytes */
158 max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
159 }
160
161 if (camsize > align)
162 camsize = align;
163 if (camsize > max_cam)
164 camsize = max_cam;
165
166 return 1UL << camsize;
167 }
168
map_mem_in_cams_addr(phys_addr_t phys,unsigned long virt,unsigned long ram,int max_cam_idx,bool dryrun,bool init)169 static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
170 unsigned long ram, int max_cam_idx,
171 bool dryrun, bool init)
172 {
173 int i;
174 unsigned long amount_mapped = 0;
175 unsigned long boundary;
176
177 if (strict_kernel_rwx_enabled())
178 boundary = (unsigned long)(_sinittext - _stext);
179 else
180 boundary = ram;
181
182 /* Calculate CAM values */
183 for (i = 0; boundary && i < max_cam_idx; i++) {
184 unsigned long cam_sz;
185 pgprot_t prot = init ? PAGE_KERNEL_X : PAGE_KERNEL_ROX;
186
187 cam_sz = calc_cam_sz(boundary, virt, phys);
188 if (!dryrun)
189 settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0);
190
191 boundary -= cam_sz;
192 amount_mapped += cam_sz;
193 virt += cam_sz;
194 phys += cam_sz;
195 }
196 for (ram -= amount_mapped; ram && i < max_cam_idx; i++) {
197 unsigned long cam_sz;
198 pgprot_t prot = init ? PAGE_KERNEL_X : PAGE_KERNEL;
199
200 cam_sz = calc_cam_sz(ram, virt, phys);
201 if (!dryrun)
202 settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0);
203
204 ram -= cam_sz;
205 amount_mapped += cam_sz;
206 virt += cam_sz;
207 phys += cam_sz;
208 }
209
210 if (dryrun)
211 return amount_mapped;
212
213 if (init) {
214 loadcam_multi(0, i, max_cam_idx);
215 tlbcam_index = i;
216 } else {
217 loadcam_multi(0, i, 0);
218 WARN_ON(i > tlbcam_index);
219 }
220
221 #ifdef CONFIG_PPC64
222 get_paca()->tcd.esel_next = i;
223 get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
224 get_paca()->tcd.esel_first = i;
225 #endif
226
227 return amount_mapped;
228 }
229
map_mem_in_cams(unsigned long ram,int max_cam_idx,bool dryrun,bool init)230 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx, bool dryrun, bool init)
231 {
232 unsigned long virt = PAGE_OFFSET;
233 phys_addr_t phys = memstart_addr;
234
235 return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx, dryrun, init);
236 }
237
238 #ifdef CONFIG_PPC32
239
240 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
241 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
242 #endif
243
mmu_mapin_ram(unsigned long base,unsigned long top)244 unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
245 {
246 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
247 }
248
flush_instruction_cache(void)249 void flush_instruction_cache(void)
250 {
251 unsigned long tmp;
252
253 tmp = mfspr(SPRN_L1CSR1);
254 tmp |= L1CSR1_ICFI | L1CSR1_ICLFR;
255 mtspr(SPRN_L1CSR1, tmp);
256 isync();
257 }
258
259 /*
260 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
261 */
MMU_init_hw(void)262 void __init MMU_init_hw(void)
263 {
264 flush_instruction_cache();
265 }
266
adjust_total_lowmem(void)267 void __init adjust_total_lowmem(void)
268 {
269 unsigned long ram;
270 int i;
271
272 /* adjust lowmem size to __max_low_memory */
273 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
274
275 i = switch_to_as1();
276 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, false, true);
277 restore_to_as0(i, 0, 0, 1);
278
279 pr_info("Memory CAM mapping: ");
280 for (i = 0; i < tlbcam_index - 1; i++)
281 pr_cont("%lu/", tlbcam_sz(i) >> 20);
282 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
283 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
284
285 memblock_set_current_limit(memstart_addr + __max_low_memory);
286 }
287
288 #ifdef CONFIG_STRICT_KERNEL_RWX
mmu_mark_rodata_ro(void)289 void mmu_mark_rodata_ro(void)
290 {
291 /* Everything is done in mmu_mark_initmem_nx() */
292 }
293 #endif
294
mmu_mark_initmem_nx(void)295 void mmu_mark_initmem_nx(void)
296 {
297 unsigned long remapped;
298
299 if (!strict_kernel_rwx_enabled())
300 return;
301
302 remapped = map_mem_in_cams(__max_low_memory, CONFIG_LOWMEM_CAM_NUM, false, false);
303
304 WARN_ON(__max_low_memory != remapped);
305 }
306
setup_initial_memory_limit(phys_addr_t first_memblock_base,phys_addr_t first_memblock_size)307 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
308 phys_addr_t first_memblock_size)
309 {
310 phys_addr_t limit = first_memblock_base + first_memblock_size;
311
312 /* 64M mapped initially according to head_fsl_booke.S */
313 memblock_set_current_limit(min_t(u64, limit, 0x04000000));
314 }
315
316 #ifdef CONFIG_RELOCATABLE
317 int __initdata is_second_reloc;
relocate_init(u64 dt_ptr,phys_addr_t start)318 notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
319 {
320 unsigned long base = kernstart_virt_addr;
321 phys_addr_t size;
322
323 kernstart_addr = start;
324 if (is_second_reloc) {
325 virt_phys_offset = PAGE_OFFSET - memstart_addr;
326 kaslr_late_init();
327 return;
328 }
329
330 /*
331 * Relocatable kernel support based on processing of dynamic
332 * relocation entries. Before we get the real memstart_addr,
333 * We will compute the virt_phys_offset like this:
334 * virt_phys_offset = stext.run - kernstart_addr
335 *
336 * stext.run = (KERNELBASE & ~0x3ffffff) +
337 * (kernstart_addr & 0x3ffffff)
338 * When we relocate, we have :
339 *
340 * (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
341 *
342 * hence:
343 * virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
344 * (kernstart_addr & ~0x3ffffff)
345 *
346 */
347 start &= ~0x3ffffff;
348 base &= ~0x3ffffff;
349 virt_phys_offset = base - start;
350 early_get_first_memblock_info(__va(dt_ptr), &size);
351 /*
352 * We now get the memstart_addr, then we should check if this
353 * address is the same as what the PAGE_OFFSET map to now. If
354 * not we have to change the map of PAGE_OFFSET to memstart_addr
355 * and do a second relocation.
356 */
357 if (start != memstart_addr) {
358 int n;
359 long offset = start - memstart_addr;
360
361 is_second_reloc = 1;
362 n = switch_to_as1();
363 /* map a 64M area for the second relocation */
364 if (memstart_addr > start)
365 map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM,
366 false, true);
367 else
368 map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
369 0x4000000, CONFIG_LOWMEM_CAM_NUM,
370 false, true);
371 restore_to_as0(n, offset, __va(dt_ptr), 1);
372 /* We should never reach here */
373 panic("Relocation error");
374 }
375
376 kaslr_early_init(__va(dt_ptr), size);
377 }
378 #endif
379 #endif
380