2 * This file contains the routines for handling the MMU on those
3 * PowerPC implementations where the MMU substantially follows the
4 * architecture specification. This includes the 6xx, 7xx, 7xxx,
5 * and 8260 implementations but excludes the 8xx and 4xx.
8 * Derived from arch/ppc/mm/init.c:
9 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
11 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
12 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
13 * Copyright (C) 1996 Paul Mackerras
15 * Derived from "arch/i386/mm/init.c"
16 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
25 #include <linux/kernel.h>
27 #include <linux/init.h>
28 #include <linux/highmem.h>
29 #include <linux/memblock.h>
33 #include <asm/machdep.h>
34 #include <asm/code-patching.h>
35 #include <asm/sections.h>
39 struct hash_pte
*Hash
, *Hash_end
;
40 unsigned long Hash_size
, Hash_mask
;
43 struct ppc_bat BATS
[8][2]; /* 8 pairs of IBAT, DBAT */
45 struct batrange
{ /* stores address ranges mapped by BATs */
52 * Return PA for this VA if it is mapped by a BAT, or 0
54 phys_addr_t
v_block_mapped(unsigned long va
)
57 for (b
= 0; b
< ARRAY_SIZE(bat_addrs
); ++b
)
58 if (va
>= bat_addrs
[b
].start
&& va
< bat_addrs
[b
].limit
)
59 return bat_addrs
[b
].phys
+ (va
- bat_addrs
[b
].start
);
64 * Return VA for a given PA or 0 if not mapped
66 unsigned long p_block_mapped(phys_addr_t pa
)
69 for (b
= 0; b
< ARRAY_SIZE(bat_addrs
); ++b
)
70 if (pa
>= bat_addrs
[b
].phys
71 && pa
< (bat_addrs
[b
].limit
-bat_addrs
[b
].start
)
73 return bat_addrs
[b
].start
+(pa
-bat_addrs
[b
].phys
);
77 static int find_free_bat(void)
81 if (cpu_has_feature(CPU_FTR_601
)) {
82 for (b
= 0; b
< 4; b
++) {
83 struct ppc_bat
*bat
= BATS
[b
];
85 if (!(bat
[0].batl
& 0x40))
89 int n
= mmu_has_feature(MMU_FTR_USE_HIGH_BATS
) ? 8 : 4;
91 for (b
= 0; b
< n
; b
++) {
92 struct ppc_bat
*bat
= BATS
[b
];
94 if (!(bat
[1].batu
& 3))
101 static unsigned int block_size(unsigned long base
, unsigned long top
)
103 unsigned int max_size
= (cpu_has_feature(CPU_FTR_601
) ? 8 : 256) << 20;
104 unsigned int base_shift
= (fls(base
) - 1) & 31;
105 unsigned int block_shift
= (fls(top
- base
) - 1) & 31;
107 return min3(max_size
, 1U << base_shift
, 1U << block_shift
);
111 * Set up one of the IBAT (block address translation) register pairs.
112 * The parameters are not checked; in particular size must be a power
113 * of 2 between 128k and 256M.
116 static void setibat(int index
, unsigned long virt
, phys_addr_t phys
,
117 unsigned int size
, pgprot_t prot
)
119 unsigned int bl
= (size
>> 17) - 1;
121 struct ppc_bat
*bat
= BATS
[index
];
122 unsigned long flags
= pgprot_val(prot
);
124 if (!cpu_has_feature(CPU_FTR_NEED_COHERENT
))
125 flags
&= ~_PAGE_COHERENT
;
127 wimgxpp
= (flags
& _PAGE_COHERENT
) | (_PAGE_EXEC
? BPP_RX
: BPP_XX
);
128 bat
[0].batu
= virt
| (bl
<< 2) | 2; /* Vs=1, Vp=0 */
129 bat
[0].batl
= BAT_PHYS_ADDR(phys
) | wimgxpp
;
130 if (flags
& _PAGE_USER
)
131 bat
[0].batu
|= 1; /* Vp = 1 */
134 static void clearibat(int index
)
136 struct ppc_bat
*bat
= BATS
[index
];
142 static unsigned long __init
__mmu_mapin_ram(unsigned long base
, unsigned long top
)
146 while ((idx
= find_free_bat()) != -1 && base
!= top
) {
147 unsigned int size
= block_size(base
, top
);
149 if (size
< 128 << 10)
151 setbat(idx
, PAGE_OFFSET
+ base
, base
, size
, PAGE_KERNEL_X
);
158 unsigned long __init
mmu_mapin_ram(unsigned long base
, unsigned long top
)
161 unsigned long border
= (unsigned long)__init_begin
- PAGE_OFFSET
;
163 if (__map_without_bats
) {
164 pr_debug("RAM mapped without BATs\n");
168 if (!strict_kernel_rwx_enabled() || base
>= border
|| top
<= border
)
169 return __mmu_mapin_ram(base
, top
);
171 done
= __mmu_mapin_ram(base
, border
);
172 if (done
!= border
- base
)
175 return done
+ __mmu_mapin_ram(border
, top
);
178 void mmu_mark_initmem_nx(void)
180 int nb
= mmu_has_feature(MMU_FTR_USE_HIGH_BATS
) ? 8 : 4;
182 unsigned long base
= (unsigned long)_stext
- PAGE_OFFSET
;
183 unsigned long top
= (unsigned long)_etext
- PAGE_OFFSET
;
186 if (cpu_has_feature(CPU_FTR_601
))
189 for (i
= 0; i
< nb
- 1 && base
< top
&& top
- base
> (128 << 10);) {
190 size
= block_size(base
, top
);
191 setibat(i
++, PAGE_OFFSET
+ base
, base
, size
, PAGE_KERNEL_TEXT
);
195 size
= block_size(base
, top
);
196 size
= max(size
, 128UL << 10);
197 if ((top
- base
) > size
) {
198 if (strict_kernel_rwx_enabled())
199 pr_warn("Kernel _etext not properly aligned\n");
202 setibat(i
++, PAGE_OFFSET
+ base
, base
, size
, PAGE_KERNEL_TEXT
);
210 for (i
= TASK_SIZE
>> 28; i
< 16; i
++) {
211 /* Do not set NX on VM space for modules */
212 if (IS_ENABLED(CONFIG_MODULES
) &&
213 (VMALLOC_START
& 0xf0000000) == i
<< 28)
215 mtsrin(mfsrin(i
<< 28) | 0x10000000, i
<< 28);
219 void mmu_mark_rodata_ro(void)
221 int nb
= mmu_has_feature(MMU_FTR_USE_HIGH_BATS
) ? 8 : 4;
224 if (cpu_has_feature(CPU_FTR_601
))
227 for (i
= 0; i
< nb
; i
++) {
228 struct ppc_bat
*bat
= BATS
[i
];
230 if (bat_addrs
[i
].start
< (unsigned long)__init_begin
)
231 bat
[1].batl
= (bat
[1].batl
& ~BPP_RW
) | BPP_RX
;
238 * Set up one of the I/D BAT (block address translation) register pairs.
239 * The parameters are not checked; in particular size must be a power
240 * of 2 between 128k and 256M.
241 * On 603+, only set IBAT when _PAGE_EXEC is set
243 void __init
setbat(int index
, unsigned long virt
, phys_addr_t phys
,
244 unsigned int size
, pgprot_t prot
)
248 struct ppc_bat
*bat
= BATS
[index
];
249 unsigned long flags
= pgprot_val(prot
);
251 if ((flags
& _PAGE_NO_CACHE
) ||
252 (cpu_has_feature(CPU_FTR_NEED_COHERENT
) == 0))
253 flags
&= ~_PAGE_COHERENT
;
255 bl
= (size
>> 17) - 1;
256 if (PVR_VER(mfspr(SPRN_PVR
)) != 1) {
259 wimgxpp
= flags
& (_PAGE_WRITETHRU
| _PAGE_NO_CACHE
260 | _PAGE_COHERENT
| _PAGE_GUARDED
);
261 wimgxpp
|= (flags
& _PAGE_RW
)? BPP_RW
: BPP_RX
;
262 bat
[1].batu
= virt
| (bl
<< 2) | 2; /* Vs=1, Vp=0 */
263 bat
[1].batl
= BAT_PHYS_ADDR(phys
) | wimgxpp
;
264 if (flags
& _PAGE_USER
)
265 bat
[1].batu
|= 1; /* Vp = 1 */
266 if (flags
& _PAGE_GUARDED
) {
267 /* G bit must be zero in IBATs */
268 flags
&= ~_PAGE_EXEC
;
270 if (flags
& _PAGE_EXEC
)
273 bat
[0].batu
= bat
[0].batl
= 0;
278 wimgxpp
= flags
& (_PAGE_WRITETHRU
| _PAGE_NO_CACHE
280 wimgxpp
|= (flags
& _PAGE_RW
)?
281 ((flags
& _PAGE_USER
)? PP_RWRW
: PP_RWXX
): PP_RXRX
;
282 bat
->batu
= virt
| wimgxpp
| 4; /* Ks=0, Ku=1 */
283 bat
->batl
= phys
| bl
| 0x40; /* V=1 */
286 bat_addrs
[index
].start
= virt
;
287 bat_addrs
[index
].limit
= virt
+ ((bl
+ 1) << 17) - 1;
288 bat_addrs
[index
].phys
= phys
;
292 * Preload a translation in the hash table
294 void hash_preload(struct mm_struct
*mm
, unsigned long ea
,
295 bool is_exec
, unsigned long trap
)
301 pmd
= pmd_offset(pud_offset(pgd_offset(mm
, ea
), ea
), ea
);
303 add_hash_page(mm
->context
.id
, ea
, pmd_val(*pmd
));
307 * Initialize the hash table and patch the instructions in hashtable.S.
309 void __init
MMU_init_hw(void)
311 unsigned int hmask
, mb
, mb2
;
312 unsigned int n_hpteg
, lg_n_hpteg
;
314 if (!mmu_has_feature(MMU_FTR_HPTE_TABLE
))
317 if ( ppc_md
.progress
) ppc_md
.progress("hash:enter", 0x105);
319 #define LG_HPTEG_SIZE 6 /* 64 bytes per HPTEG */
320 #define SDR1_LOW_BITS ((n_hpteg - 1) >> 10)
321 #define MIN_N_HPTEG 1024 /* min 64kB hash table */
324 * Allow 1 HPTE (1/8 HPTEG) for each page of memory.
325 * This is less than the recommended amount, but then
328 n_hpteg
= total_memory
/ (PAGE_SIZE
* 8);
329 if (n_hpteg
< MIN_N_HPTEG
)
330 n_hpteg
= MIN_N_HPTEG
;
331 lg_n_hpteg
= __ilog2(n_hpteg
);
332 if (n_hpteg
& (n_hpteg
- 1)) {
333 ++lg_n_hpteg
; /* round up if not power of 2 */
334 n_hpteg
= 1 << lg_n_hpteg
;
336 Hash_size
= n_hpteg
<< LG_HPTEG_SIZE
;
339 * Find some memory for the hash table.
341 if ( ppc_md
.progress
) ppc_md
.progress("hash:find piece", 0x322);
342 Hash
= __va(memblock_phys_alloc(Hash_size
, Hash_size
));
343 memset(Hash
, 0, Hash_size
);
344 _SDR1
= __pa(Hash
) | SDR1_LOW_BITS
;
346 Hash_end
= (struct hash_pte
*) ((unsigned long)Hash
+ Hash_size
);
348 printk("Total memory = %lldMB; using %ldkB for hash table (at %p)\n",
349 (unsigned long long)(total_memory
>> 20), Hash_size
>> 10, Hash
);
353 * Patch up the instructions in hashtable.S:create_hpte
355 if ( ppc_md
.progress
) ppc_md
.progress("hash:patch", 0x345);
356 Hash_mask
= n_hpteg
- 1;
357 hmask
= Hash_mask
>> (16 - LG_HPTEG_SIZE
);
358 mb2
= mb
= 32 - LG_HPTEG_SIZE
- lg_n_hpteg
;
360 mb2
= 16 - LG_HPTEG_SIZE
;
362 modify_instruction_site(&patch__hash_page_A0
, 0xffff,
363 ((unsigned int)Hash
- PAGE_OFFSET
) >> 16);
364 modify_instruction_site(&patch__hash_page_A1
, 0x7c0, mb
<< 6);
365 modify_instruction_site(&patch__hash_page_A2
, 0x7c0, mb2
<< 6);
366 modify_instruction_site(&patch__hash_page_B
, 0xffff, hmask
);
367 modify_instruction_site(&patch__hash_page_C
, 0xffff, hmask
);
370 * Patch up the instructions in hashtable.S:flush_hash_page
372 modify_instruction_site(&patch__flush_hash_A0
, 0xffff,
373 ((unsigned int)Hash
- PAGE_OFFSET
) >> 16);
374 modify_instruction_site(&patch__flush_hash_A1
, 0x7c0, mb
<< 6);
375 modify_instruction_site(&patch__flush_hash_A2
, 0x7c0, mb2
<< 6);
376 modify_instruction_site(&patch__flush_hash_B
, 0xffff, hmask
);
378 if ( ppc_md
.progress
) ppc_md
.progress("hash:done", 0x205);
381 void setup_initial_memory_limit(phys_addr_t first_memblock_base
,
382 phys_addr_t first_memblock_size
)
384 /* We don't currently support the first MEMBLOCK not mapping 0
385 * physical on those processors
387 BUG_ON(first_memblock_base
!= 0);
389 /* 601 can only access 16MB at the moment */
390 if (PVR_VER(mfspr(SPRN_PVR
)) == 1)
391 memblock_set_current_limit(min_t(u64
, first_memblock_size
, 0x01000000));
392 else /* Anything else has 256M mapped */
393 memblock_set_current_limit(min_t(u64
, first_memblock_size
, 0x10000000));