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 #include <linux/of_fdt.h>
40
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 struct tlbcam TLBCAM[NUM_TLBCAMS];
55
56 static struct {
57 unsigned long start;
58 unsigned long limit;
59 phys_addr_t phys;
60 } tlbcam_addrs[NUM_TLBCAMS];
61
62 #ifdef CONFIG_PPC_85xx
63 /*
64 * Return PA for this VA if it is mapped by a CAM, or 0
65 */
v_block_mapped(unsigned long va)66 phys_addr_t v_block_mapped(unsigned long va)
67 {
68 int b;
69 for (b = 0; b < tlbcam_index; ++b)
70 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
71 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
72 return 0;
73 }
74
75 /*
76 * Return VA for a given PA or 0 if not mapped
77 */
p_block_mapped(phys_addr_t pa)78 unsigned long p_block_mapped(phys_addr_t pa)
79 {
80 int b;
81 for (b = 0; b < tlbcam_index; ++b)
82 if (pa >= tlbcam_addrs[b].phys
83 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
84 +tlbcam_addrs[b].phys)
85 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
86 return 0;
87 }
88 #endif
89
90 /*
91 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
92 * in particular size must be a power of 4 between 4k and the max supported by
93 * an implementation; max may further be limited by what can be represented in
94 * an unsigned long (for example, 32-bit implementations cannot support a 4GB
95 * size).
96 */
settlbcam(int index,unsigned long virt,phys_addr_t phys,unsigned long size,unsigned long flags,unsigned int pid)97 static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
98 unsigned long size, unsigned long flags, unsigned int pid)
99 {
100 unsigned int tsize;
101
102 tsize = __ilog2(size) - 10;
103
104 #if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
105 if ((flags & _PAGE_NO_CACHE) == 0)
106 flags |= _PAGE_COHERENT;
107 #endif
108
109 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
110 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
111 TLBCAM[index].MAS2 = virt & PAGE_MASK;
112
113 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
114 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
115 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
116 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
117 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
118
119 TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SR;
120 TLBCAM[index].MAS3 |= (flags & _PAGE_RW) ? MAS3_SW : 0;
121 if (mmu_has_feature(MMU_FTR_BIG_PHYS))
122 TLBCAM[index].MAS7 = (u64)phys >> 32;
123
124 /* Below is unlikely -- only for large user pages or similar */
125 if (pte_user(__pte(flags))) {
126 TLBCAM[index].MAS3 |= MAS3_UR;
127 TLBCAM[index].MAS3 |= (flags & _PAGE_EXEC) ? MAS3_UX : 0;
128 TLBCAM[index].MAS3 |= (flags & _PAGE_RW) ? MAS3_UW : 0;
129 } else {
130 TLBCAM[index].MAS3 |= (flags & _PAGE_EXEC) ? MAS3_SX : 0;
131 }
132
133 tlbcam_addrs[index].start = virt;
134 tlbcam_addrs[index].limit = virt + size - 1;
135 tlbcam_addrs[index].phys = phys;
136 }
137
calc_cam_sz(unsigned long ram,unsigned long virt,phys_addr_t phys)138 static unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
139 phys_addr_t phys)
140 {
141 unsigned int camsize = __ilog2(ram);
142 unsigned int align = __ffs(virt | phys);
143 unsigned long max_cam;
144
145 if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
146 /* Convert (4^max) kB to (2^max) bytes */
147 max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
148 camsize &= ~1U;
149 align &= ~1U;
150 } else {
151 /* Convert (2^max) kB to (2^max) bytes */
152 max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
153 }
154
155 if (camsize > align)
156 camsize = align;
157 if (camsize > max_cam)
158 camsize = max_cam;
159
160 return 1UL << camsize;
161 }
162
map_mem_in_cams_addr(phys_addr_t phys,unsigned long virt,unsigned long ram,int max_cam_idx,bool dryrun,bool init)163 static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
164 unsigned long ram, int max_cam_idx,
165 bool dryrun, bool init)
166 {
167 int i;
168 unsigned long amount_mapped = 0;
169 unsigned long boundary;
170
171 if (strict_kernel_rwx_enabled())
172 boundary = (unsigned long)(_sinittext - _stext);
173 else
174 boundary = ram;
175
176 /* Calculate CAM values */
177 for (i = 0; boundary && i < max_cam_idx; i++) {
178 unsigned long cam_sz;
179 pgprot_t prot = init ? PAGE_KERNEL_X : PAGE_KERNEL_ROX;
180
181 cam_sz = calc_cam_sz(boundary, virt, phys);
182 if (!dryrun)
183 settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0);
184
185 boundary -= cam_sz;
186 amount_mapped += cam_sz;
187 virt += cam_sz;
188 phys += cam_sz;
189 }
190 for (ram -= amount_mapped; ram && i < max_cam_idx; i++) {
191 unsigned long cam_sz;
192 pgprot_t prot = init ? PAGE_KERNEL_X : PAGE_KERNEL;
193
194 cam_sz = calc_cam_sz(ram, virt, phys);
195 if (!dryrun)
196 settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0);
197
198 ram -= cam_sz;
199 amount_mapped += cam_sz;
200 virt += cam_sz;
201 phys += cam_sz;
202 }
203
204 if (dryrun)
205 return amount_mapped;
206
207 if (init) {
208 loadcam_multi(0, i, max_cam_idx);
209 tlbcam_index = i;
210 } else {
211 loadcam_multi(0, i, 0);
212 WARN_ON(i > tlbcam_index);
213 }
214
215 #ifdef CONFIG_PPC64
216 get_paca()->tcd.esel_next = i;
217 get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
218 get_paca()->tcd.esel_first = i;
219 #endif
220
221 return amount_mapped;
222 }
223
map_mem_in_cams(unsigned long ram,int max_cam_idx,bool dryrun,bool init)224 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx, bool dryrun, bool init)
225 {
226 unsigned long virt = PAGE_OFFSET;
227 phys_addr_t phys = memstart_addr;
228
229 return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx, dryrun, init);
230 }
231
232 #ifdef CONFIG_PPC32
233
234 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
235 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
236 #endif
237
mmu_mapin_ram(unsigned long base,unsigned long top)238 unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
239 {
240 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
241 }
242
flush_instruction_cache(void)243 void flush_instruction_cache(void)
244 {
245 unsigned long tmp;
246
247 tmp = mfspr(SPRN_L1CSR1);
248 tmp |= L1CSR1_ICFI | L1CSR1_ICLFR;
249 mtspr(SPRN_L1CSR1, tmp);
250 isync();
251 }
252
253 /*
254 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
255 */
MMU_init_hw(void)256 void __init MMU_init_hw(void)
257 {
258 flush_instruction_cache();
259 }
260
tlbcam_sz(int idx)261 static unsigned long __init tlbcam_sz(int idx)
262 {
263 return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
264 }
265
adjust_total_lowmem(void)266 void __init adjust_total_lowmem(void)
267 {
268 unsigned long ram;
269 int i;
270
271 /* adjust lowmem size to __max_low_memory */
272 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
273
274 i = switch_to_as1();
275 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, false, true);
276 restore_to_as0(i, 0, NULL, 1);
277
278 pr_info("Memory CAM mapping: ");
279 for (i = 0; i < tlbcam_index - 1; i++)
280 pr_cont("%lu/", tlbcam_sz(i) >> 20);
281 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
282 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
283
284 memblock_set_current_limit(memstart_addr + __max_low_memory);
285 }
286
287 #ifdef CONFIG_STRICT_KERNEL_RWX
mmu_mark_rodata_ro(void)288 void mmu_mark_rodata_ro(void)
289 {
290 unsigned long remapped;
291
292 remapped = map_mem_in_cams(__max_low_memory, CONFIG_LOWMEM_CAM_NUM, false, false);
293
294 WARN_ON(__max_low_memory != remapped);
295 }
296 #endif
297
mmu_mark_initmem_nx(void)298 void mmu_mark_initmem_nx(void)
299 {
300 /* Everything is done in mmu_mark_rodata_ro() */
301 }
302
setup_initial_memory_limit(phys_addr_t first_memblock_base,phys_addr_t first_memblock_size)303 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
304 phys_addr_t first_memblock_size)
305 {
306 phys_addr_t limit = first_memblock_base + first_memblock_size;
307
308 /* 64M mapped initially according to head_fsl_booke.S */
309 memblock_set_current_limit(min_t(u64, limit, 0x04000000));
310 }
311
312 #ifdef CONFIG_RELOCATABLE
313 int __initdata is_second_reloc;
relocate_init(u64 dt_ptr,phys_addr_t start)314 notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
315 {
316 unsigned long base = kernstart_virt_addr;
317 phys_addr_t size;
318
319 kernstart_addr = start;
320 if (is_second_reloc) {
321 virt_phys_offset = PAGE_OFFSET - memstart_addr;
322 kaslr_late_init();
323 return;
324 }
325
326 /*
327 * Relocatable kernel support based on processing of dynamic
328 * relocation entries. Before we get the real memstart_addr,
329 * We will compute the virt_phys_offset like this:
330 * virt_phys_offset = stext.run - kernstart_addr
331 *
332 * stext.run = (KERNELBASE & ~0x3ffffff) +
333 * (kernstart_addr & 0x3ffffff)
334 * When we relocate, we have :
335 *
336 * (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
337 *
338 * hence:
339 * virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
340 * (kernstart_addr & ~0x3ffffff)
341 *
342 */
343 start &= ~0x3ffffff;
344 base &= ~0x3ffffff;
345 virt_phys_offset = base - start;
346 early_get_first_memblock_info(__va(dt_ptr), &size);
347 /*
348 * We now get the memstart_addr, then we should check if this
349 * address is the same as what the PAGE_OFFSET map to now. If
350 * not we have to change the map of PAGE_OFFSET to memstart_addr
351 * and do a second relocation.
352 */
353 if (start != memstart_addr) {
354 int n;
355 long offset = start - memstart_addr;
356
357 is_second_reloc = 1;
358 n = switch_to_as1();
359 /* map a 64M area for the second relocation */
360 if (memstart_addr > start)
361 map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM,
362 false, true);
363 else
364 map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
365 0x4000000, CONFIG_LOWMEM_CAM_NUM,
366 false, true);
367 restore_to_as0(n, offset, __va(dt_ptr), 1);
368 /* We should never reach here */
369 panic("Relocation error");
370 }
371
372 kaslr_early_init(__va(dt_ptr), size);
373 }
374 #endif
375 #endif
376