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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Based upon linux/arch/m68k/mm/sun3mmu.c
4 * Based upon linux/arch/ppc/mm/mmu_context.c
5 *
6 * Implementations of mm routines specific to the Coldfire MMU.
7 *
8 * Copyright (c) 2008 Freescale Semiconductor, Inc.
9 */
10
11#include <linux/kernel.h>
12#include <linux/types.h>
13#include <linux/mm.h>
14#include <linux/init.h>
15#include <linux/string.h>
16#include <linux/memblock.h>
17
18#include <asm/setup.h>
19#include <asm/page.h>
20#include <asm/mmu_context.h>
21#include <asm/mcf_pgalloc.h>
22#include <asm/tlbflush.h>
23#include <asm/pgalloc.h>
24
25#define KMAPAREA(x) ((x >= VMALLOC_START) && (x < KMAP_END))
26
27mm_context_t next_mmu_context;
28unsigned long context_map[LAST_CONTEXT / BITS_PER_LONG + 1];
29atomic_t nr_free_contexts;
30struct mm_struct *context_mm[LAST_CONTEXT+1];
31unsigned long num_pages;
32
33/*
34 * ColdFire paging_init derived from sun3.
35 */
36void __init paging_init(void)
37{
38 pgd_t *pg_dir;
39 pte_t *pg_table;
40 unsigned long address, size;
41 unsigned long next_pgtable, bootmem_end;
42 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
43 int i;
44
45 empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
46 if (!empty_zero_page)
47 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
48 __func__, PAGE_SIZE, PAGE_SIZE);
49
50 pg_dir = swapper_pg_dir;
51 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
52
53 size = num_pages * sizeof(pte_t);
54 size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
55 next_pgtable = (unsigned long) memblock_alloc(size, PAGE_SIZE);
56 if (!next_pgtable)
57 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
58 __func__, size, PAGE_SIZE);
59
60 bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
61 pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
62
63 address = PAGE_OFFSET;
64 while (address < (unsigned long)high_memory) {
65 pg_table = (pte_t *) next_pgtable;
66 next_pgtable += PTRS_PER_PTE * sizeof(pte_t);
67 pgd_val(*pg_dir) = (unsigned long) pg_table;
68 pg_dir++;
69
70 /* now change pg_table to kernel virtual addresses */
71 for (i = 0; i < PTRS_PER_PTE; ++i, ++pg_table) {
72 pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
73 if (address >= (unsigned long) high_memory)
74 pte_val(pte) = 0;
75
76 set_pte(pg_table, pte);
77 address += PAGE_SIZE;
78 }
79 }
80
81 current->mm = NULL;
82 max_zone_pfn[ZONE_DMA] = PFN_DOWN(_ramend);
83 free_area_init(max_zone_pfn);
84}
85
86int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word)
87{
88 unsigned long flags, mmuar, mmutr;
89 struct mm_struct *mm;
90 pgd_t *pgd;
91 p4d_t *p4d;
92 pud_t *pud;
93 pmd_t *pmd;
94 pte_t *pte;
95 int asid;
96
97 local_irq_save(flags);
98
99 mmuar = (dtlb) ? mmu_read(MMUAR) :
100 regs->pc + (extension_word * sizeof(long));
101
102 mm = (!user_mode(regs) && KMAPAREA(mmuar)) ? &init_mm : current->mm;
103 if (!mm) {
104 local_irq_restore(flags);
105 return -1;
106 }
107
108 pgd = pgd_offset(mm, mmuar);
109 if (pgd_none(*pgd)) {
110 local_irq_restore(flags);
111 return -1;
112 }
113
114 p4d = p4d_offset(pgd, mmuar);
115 if (p4d_none(*p4d)) {
116 local_irq_restore(flags);
117 return -1;
118 }
119
120 pud = pud_offset(p4d, mmuar);
121 if (pud_none(*pud)) {
122 local_irq_restore(flags);
123 return -1;
124 }
125
126 pmd = pmd_offset(pud, mmuar);
127 if (pmd_none(*pmd)) {
128 local_irq_restore(flags);
129 return -1;
130 }
131
132 pte = (KMAPAREA(mmuar)) ? pte_offset_kernel(pmd, mmuar)
133 : pte_offset_map(pmd, mmuar);
134 if (pte_none(*pte) || !pte_present(*pte)) {
135 local_irq_restore(flags);
136 return -1;
137 }
138
139 if (write) {
140 if (!pte_write(*pte)) {
141 local_irq_restore(flags);
142 return -1;
143 }
144 set_pte(pte, pte_mkdirty(*pte));
145 }
146
147 set_pte(pte, pte_mkyoung(*pte));
148 asid = mm->context & 0xff;
149 if (!pte_dirty(*pte) && !KMAPAREA(mmuar))
150 set_pte(pte, pte_wrprotect(*pte));
151
152 mmutr = (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) | MMUTR_V;
153 if ((mmuar < TASK_UNMAPPED_BASE) || (mmuar >= TASK_SIZE))
154 mmutr |= (pte->pte & CF_PAGE_MMUTR_MASK) >> CF_PAGE_MMUTR_SHIFT;
155 mmu_write(MMUTR, mmutr);
156
157 mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) |
158 ((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X);
159
160 if (dtlb)
161 mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA);
162 else
163 mmu_write(MMUOR, MMUOR_ITLB | MMUOR_ACC | MMUOR_UAA);
164
165 local_irq_restore(flags);
166 return 0;
167}
168
169void __init cf_bootmem_alloc(void)
170{
171 unsigned long memstart;
172
173 /* _rambase and _ramend will be naturally page aligned */
174 m68k_memory[0].addr = _rambase;
175 m68k_memory[0].size = _ramend - _rambase;
176
177 memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0,
178 MEMBLOCK_NONE);
179
180 /* compute total pages in system */
181 num_pages = PFN_DOWN(_ramend - _rambase);
182
183 /* page numbers */
184 memstart = PAGE_ALIGN(_ramstart);
185 min_low_pfn = PFN_DOWN(_rambase);
186 max_pfn = max_low_pfn = PFN_DOWN(_ramend);
187 high_memory = (void *)_ramend;
188
189 /* Reserve kernel text/data/bss */
190 memblock_reserve(_rambase, memstart - _rambase);
191
192 m68k_virt_to_node_shift = fls(_ramend - 1) - 6;
193 module_fixup(NULL, __start_fixup, __stop_fixup);
194
195 /* setup node data */
196 m68k_setup_node(0);
197}
198
199/*
200 * Initialize the context management stuff.
201 * The following was taken from arch/ppc/mmu_context.c
202 */
203void __init cf_mmu_context_init(void)
204{
205 /*
206 * Some processors have too few contexts to reserve one for
207 * init_mm, and require using context 0 for a normal task.
208 * Other processors reserve the use of context zero for the kernel.
209 * This code assumes FIRST_CONTEXT < 32.
210 */
211 context_map[0] = (1 << FIRST_CONTEXT) - 1;
212 next_mmu_context = FIRST_CONTEXT;
213 atomic_set(&nr_free_contexts, LAST_CONTEXT - FIRST_CONTEXT + 1);
214}
215
216/*
217 * Steal a context from a task that has one at the moment.
218 * This isn't an LRU system, it just frees up each context in
219 * turn (sort-of pseudo-random replacement :). This would be the
220 * place to implement an LRU scheme if anyone was motivated to do it.
221 * -- paulus
222 */
223void steal_context(void)
224{
225 struct mm_struct *mm;
226 /*
227 * free up context `next_mmu_context'
228 * if we shouldn't free context 0, don't...
229 */
230 if (next_mmu_context < FIRST_CONTEXT)
231 next_mmu_context = FIRST_CONTEXT;
232 mm = context_mm[next_mmu_context];
233 flush_tlb_mm(mm);
234 destroy_context(mm);
235}
236
237static const pgprot_t protection_map[16] = {
238 [VM_NONE] = PAGE_NONE,
239 [VM_READ] = __pgprot(CF_PAGE_VALID |
240 CF_PAGE_ACCESSED |
241 CF_PAGE_READABLE),
242 [VM_WRITE] = __pgprot(CF_PAGE_VALID |
243 CF_PAGE_ACCESSED |
244 CF_PAGE_WRITABLE),
245 [VM_WRITE | VM_READ] = __pgprot(CF_PAGE_VALID |
246 CF_PAGE_ACCESSED |
247 CF_PAGE_READABLE |
248 CF_PAGE_WRITABLE),
249 [VM_EXEC] = __pgprot(CF_PAGE_VALID |
250 CF_PAGE_ACCESSED |
251 CF_PAGE_EXEC),
252 [VM_EXEC | VM_READ] = __pgprot(CF_PAGE_VALID |
253 CF_PAGE_ACCESSED |
254 CF_PAGE_READABLE |
255 CF_PAGE_EXEC),
256 [VM_EXEC | VM_WRITE] = __pgprot(CF_PAGE_VALID |
257 CF_PAGE_ACCESSED |
258 CF_PAGE_WRITABLE |
259 CF_PAGE_EXEC),
260 [VM_EXEC | VM_WRITE | VM_READ] = __pgprot(CF_PAGE_VALID |
261 CF_PAGE_ACCESSED |
262 CF_PAGE_READABLE |
263 CF_PAGE_WRITABLE |
264 CF_PAGE_EXEC),
265 [VM_SHARED] = PAGE_NONE,
266 [VM_SHARED | VM_READ] = __pgprot(CF_PAGE_VALID |
267 CF_PAGE_ACCESSED |
268 CF_PAGE_READABLE),
269 [VM_SHARED | VM_WRITE] = PAGE_SHARED,
270 [VM_SHARED | VM_WRITE | VM_READ] = __pgprot(CF_PAGE_VALID |
271 CF_PAGE_ACCESSED |
272 CF_PAGE_READABLE |
273 CF_PAGE_SHARED),
274 [VM_SHARED | VM_EXEC] = __pgprot(CF_PAGE_VALID |
275 CF_PAGE_ACCESSED |
276 CF_PAGE_EXEC),
277 [VM_SHARED | VM_EXEC | VM_READ] = __pgprot(CF_PAGE_VALID |
278 CF_PAGE_ACCESSED |
279 CF_PAGE_READABLE |
280 CF_PAGE_EXEC),
281 [VM_SHARED | VM_EXEC | VM_WRITE] = __pgprot(CF_PAGE_VALID |
282 CF_PAGE_ACCESSED |
283 CF_PAGE_SHARED |
284 CF_PAGE_EXEC),
285 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __pgprot(CF_PAGE_VALID |
286 CF_PAGE_ACCESSED |
287 CF_PAGE_READABLE |
288 CF_PAGE_SHARED |
289 CF_PAGE_EXEC)
290};
291DECLARE_VM_GET_PAGE_PROT
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Based upon linux/arch/m68k/mm/sun3mmu.c
4 * Based upon linux/arch/ppc/mm/mmu_context.c
5 *
6 * Implementations of mm routines specific to the Coldfire MMU.
7 *
8 * Copyright (c) 2008 Freescale Semiconductor, Inc.
9 */
10
11#include <linux/kernel.h>
12#include <linux/types.h>
13#include <linux/mm.h>
14#include <linux/init.h>
15#include <linux/string.h>
16#include <linux/memblock.h>
17
18#include <asm/setup.h>
19#include <asm/page.h>
20#include <asm/pgtable.h>
21#include <asm/mmu_context.h>
22#include <asm/mcf_pgalloc.h>
23#include <asm/tlbflush.h>
24
25#define KMAPAREA(x) ((x >= VMALLOC_START) && (x < KMAP_END))
26
27mm_context_t next_mmu_context;
28unsigned long context_map[LAST_CONTEXT / BITS_PER_LONG + 1];
29atomic_t nr_free_contexts;
30struct mm_struct *context_mm[LAST_CONTEXT+1];
31unsigned long num_pages;
32
33/*
34 * ColdFire paging_init derived from sun3.
35 */
36void __init paging_init(void)
37{
38 pgd_t *pg_dir;
39 pte_t *pg_table;
40 unsigned long address, size;
41 unsigned long next_pgtable, bootmem_end;
42 unsigned long zones_size[MAX_NR_ZONES];
43 enum zone_type zone;
44 int i;
45
46 empty_zero_page = (void *) memblock_alloc(PAGE_SIZE, PAGE_SIZE);
47 if (!empty_zero_page)
48 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
49 __func__, PAGE_SIZE, PAGE_SIZE);
50
51 pg_dir = swapper_pg_dir;
52 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
53
54 size = num_pages * sizeof(pte_t);
55 size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
56 next_pgtable = (unsigned long) memblock_alloc(size, PAGE_SIZE);
57 if (!next_pgtable)
58 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
59 __func__, size, PAGE_SIZE);
60
61 bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
62 pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
63
64 address = PAGE_OFFSET;
65 while (address < (unsigned long)high_memory) {
66 pg_table = (pte_t *) next_pgtable;
67 next_pgtable += PTRS_PER_PTE * sizeof(pte_t);
68 pgd_val(*pg_dir) = (unsigned long) pg_table;
69 pg_dir++;
70
71 /* now change pg_table to kernel virtual addresses */
72 for (i = 0; i < PTRS_PER_PTE; ++i, ++pg_table) {
73 pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
74 if (address >= (unsigned long) high_memory)
75 pte_val(pte) = 0;
76
77 set_pte(pg_table, pte);
78 address += PAGE_SIZE;
79 }
80 }
81
82 current->mm = NULL;
83
84 for (zone = 0; zone < MAX_NR_ZONES; zone++)
85 zones_size[zone] = 0x0;
86 zones_size[ZONE_DMA] = num_pages;
87 free_area_init(zones_size);
88}
89
90int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word)
91{
92 unsigned long flags, mmuar, mmutr;
93 struct mm_struct *mm;
94 pgd_t *pgd;
95 pmd_t *pmd;
96 pte_t *pte;
97 int asid;
98
99 local_irq_save(flags);
100
101 mmuar = (dtlb) ? mmu_read(MMUAR) :
102 regs->pc + (extension_word * sizeof(long));
103
104 mm = (!user_mode(regs) && KMAPAREA(mmuar)) ? &init_mm : current->mm;
105 if (!mm) {
106 local_irq_restore(flags);
107 return -1;
108 }
109
110 pgd = pgd_offset(mm, mmuar);
111 if (pgd_none(*pgd)) {
112 local_irq_restore(flags);
113 return -1;
114 }
115
116 pmd = pmd_offset(pgd, mmuar);
117 if (pmd_none(*pmd)) {
118 local_irq_restore(flags);
119 return -1;
120 }
121
122 pte = (KMAPAREA(mmuar)) ? pte_offset_kernel(pmd, mmuar)
123 : pte_offset_map(pmd, mmuar);
124 if (pte_none(*pte) || !pte_present(*pte)) {
125 local_irq_restore(flags);
126 return -1;
127 }
128
129 if (write) {
130 if (!pte_write(*pte)) {
131 local_irq_restore(flags);
132 return -1;
133 }
134 set_pte(pte, pte_mkdirty(*pte));
135 }
136
137 set_pte(pte, pte_mkyoung(*pte));
138 asid = mm->context & 0xff;
139 if (!pte_dirty(*pte) && !KMAPAREA(mmuar))
140 set_pte(pte, pte_wrprotect(*pte));
141
142 mmutr = (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) | MMUTR_V;
143 if ((mmuar < TASK_UNMAPPED_BASE) || (mmuar >= TASK_SIZE))
144 mmutr |= (pte->pte & CF_PAGE_MMUTR_MASK) >> CF_PAGE_MMUTR_SHIFT;
145 mmu_write(MMUTR, mmutr);
146
147 mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) |
148 ((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X);
149
150 if (dtlb)
151 mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA);
152 else
153 mmu_write(MMUOR, MMUOR_ITLB | MMUOR_ACC | MMUOR_UAA);
154
155 local_irq_restore(flags);
156 return 0;
157}
158
159void __init cf_bootmem_alloc(void)
160{
161 unsigned long memstart;
162
163 /* _rambase and _ramend will be naturally page aligned */
164 m68k_memory[0].addr = _rambase;
165 m68k_memory[0].size = _ramend - _rambase;
166
167 memblock_add(m68k_memory[0].addr, m68k_memory[0].size);
168
169 /* compute total pages in system */
170 num_pages = PFN_DOWN(_ramend - _rambase);
171
172 /* page numbers */
173 memstart = PAGE_ALIGN(_ramstart);
174 min_low_pfn = PFN_DOWN(_rambase);
175 max_pfn = max_low_pfn = PFN_DOWN(_ramend);
176 high_memory = (void *)_ramend;
177
178 /* Reserve kernel text/data/bss */
179 memblock_reserve(_rambase, memstart - _rambase);
180
181 m68k_virt_to_node_shift = fls(_ramend - 1) - 6;
182 module_fixup(NULL, __start_fixup, __stop_fixup);
183
184 /* setup node data */
185 m68k_setup_node(0);
186}
187
188/*
189 * Initialize the context management stuff.
190 * The following was taken from arch/ppc/mmu_context.c
191 */
192void __init cf_mmu_context_init(void)
193{
194 /*
195 * Some processors have too few contexts to reserve one for
196 * init_mm, and require using context 0 for a normal task.
197 * Other processors reserve the use of context zero for the kernel.
198 * This code assumes FIRST_CONTEXT < 32.
199 */
200 context_map[0] = (1 << FIRST_CONTEXT) - 1;
201 next_mmu_context = FIRST_CONTEXT;
202 atomic_set(&nr_free_contexts, LAST_CONTEXT - FIRST_CONTEXT + 1);
203}
204
205/*
206 * Steal a context from a task that has one at the moment.
207 * This is only used on 8xx and 4xx and we presently assume that
208 * they don't do SMP. If they do then thicfpgalloc.hs will have to check
209 * whether the MM we steal is in use.
210 * We also assume that this is only used on systems that don't
211 * use an MMU hash table - this is true for 8xx and 4xx.
212 * This isn't an LRU system, it just frees up each context in
213 * turn (sort-of pseudo-random replacement :). This would be the
214 * place to implement an LRU scheme if anyone was motivated to do it.
215 * -- paulus
216 */
217void steal_context(void)
218{
219 struct mm_struct *mm;
220 /*
221 * free up context `next_mmu_context'
222 * if we shouldn't free context 0, don't...
223 */
224 if (next_mmu_context < FIRST_CONTEXT)
225 next_mmu_context = FIRST_CONTEXT;
226 mm = context_mm[next_mmu_context];
227 flush_tlb_mm(mm);
228 destroy_context(mm);
229}
230