1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Memory subsystem initialization for Hexagon
4 *
5 * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
6 */
7
8 #include <linux/init.h>
9 #include <linux/mm.h>
10 #include <linux/memblock.h>
11 #include <asm/atomic.h>
12 #include <linux/highmem.h>
13 #include <asm/tlb.h>
14 #include <asm/sections.h>
15 #include <asm/setup.h>
16 #include <asm/vm_mmu.h>
17
18 /*
19 * Define a startpg just past the end of the kernel image and a lastpg
20 * that corresponds to the end of real or simulated platform memory.
21 */
22 #define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET + PHYS_OFFSET))
23
24 unsigned long bootmem_lastpg; /* Should be set by platform code */
25 unsigned long __phys_offset; /* physical kernel offset >> 12 */
26
27 /* Set as variable to limit PMD copies */
28 int max_kernel_seg = 0x303;
29
30 /* indicate pfn's of high memory */
31 unsigned long highstart_pfn, highend_pfn;
32
33 /* Default cache attribute for newly created page tables */
34 unsigned long _dflt_cache_att = CACHEDEF;
35
36 /*
37 * The current "generation" of kernel map, which should not roll
38 * over until Hell freezes over. Actual bound in years needs to be
39 * calculated to confirm.
40 */
41 DEFINE_SPINLOCK(kmap_gen_lock);
42
43 /* checkpatch says don't init this to 0. */
44 unsigned long long kmap_generation;
45
46 /*
47 * mem_init - initializes memory
48 *
49 * Frees up bootmem
50 * Fixes up more stuff for HIGHMEM
51 * Calculates and displays memory available/used
52 */
mem_init(void)53 void __init mem_init(void)
54 {
55 /* No idea where this is actually declared. Seems to evade LXR. */
56 memblock_free_all();
57
58 /*
59 * To-Do: someone somewhere should wipe out the bootmem map
60 * after we're done?
61 */
62
63 /*
64 * This can be moved to some more virtual-memory-specific
65 * initialization hook at some point. Set the init_mm
66 * descriptors "context" value to point to the initial
67 * kernel segment table's physical address.
68 */
69 init_mm.context.ptbase = __pa(init_mm.pgd);
70 }
71
sync_icache_dcache(pte_t pte)72 void sync_icache_dcache(pte_t pte)
73 {
74 unsigned long addr;
75 struct page *page;
76
77 page = pte_page(pte);
78 addr = (unsigned long) page_address(page);
79
80 __vmcache_idsync(addr, PAGE_SIZE);
81 }
82
83 /*
84 * In order to set up page allocator "nodes",
85 * somebody has to call free_area_init() for UMA.
86 *
87 * In this mode, we only have one pg_data_t
88 * structure: contig_mem_data.
89 */
paging_init(void)90 static void __init paging_init(void)
91 {
92 unsigned long max_zone_pfn[MAX_NR_ZONES] = {0, };
93
94 /*
95 * This is not particularly well documented anywhere, but
96 * give ZONE_NORMAL all the memory, including the big holes
97 * left by the kernel+bootmem_map which are already left as reserved
98 * in the bootmem_map; free_area_init should see those bits and
99 * adjust accordingly.
100 */
101
102 max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
103
104 free_area_init(max_zone_pfn); /* sets up the zonelists and mem_map */
105
106 /*
107 * Start of high memory area. Will probably need something more
108 * fancy if we... get more fancy.
109 */
110 high_memory = (void *)((bootmem_lastpg + 1) << PAGE_SHIFT);
111 }
112
113 #ifndef DMA_RESERVE
114 #define DMA_RESERVE (4)
115 #endif
116
117 #define DMA_CHUNKSIZE (1<<22)
118 #define DMA_RESERVED_BYTES (DMA_RESERVE * DMA_CHUNKSIZE)
119
120 /*
121 * Pick out the memory size. We look for mem=size,
122 * where size is "size[KkMm]"
123 */
early_mem(char * p)124 static int __init early_mem(char *p)
125 {
126 unsigned long size;
127 char *endp;
128
129 size = memparse(p, &endp);
130
131 bootmem_lastpg = PFN_DOWN(size);
132
133 return 0;
134 }
135 early_param("mem", early_mem);
136
137 size_t hexagon_coherent_pool_size = (size_t) (DMA_RESERVE << 22);
138
setup_arch_memory(void)139 void __init setup_arch_memory(void)
140 {
141 /* XXX Todo: this probably should be cleaned up */
142 u32 *segtable = (u32 *) &swapper_pg_dir[0];
143 u32 *segtable_end;
144
145 /*
146 * Set up boot memory allocator
147 *
148 * The Gorman book also talks about these functions.
149 * This needs to change for highmem setups.
150 */
151
152 /* Prior to this, bootmem_lastpg is actually mem size */
153 bootmem_lastpg += ARCH_PFN_OFFSET;
154
155 /* Memory size needs to be a multiple of 16M */
156 bootmem_lastpg = PFN_DOWN((bootmem_lastpg << PAGE_SHIFT) &
157 ~((BIG_KERNEL_PAGE_SIZE) - 1));
158
159 memblock_add(PHYS_OFFSET,
160 (bootmem_lastpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
161
162 /* Reserve kernel text/data/bss */
163 memblock_reserve(PHYS_OFFSET,
164 (bootmem_startpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
165 /*
166 * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached)
167 * memory allocation
168 */
169 max_low_pfn = bootmem_lastpg - PFN_DOWN(DMA_RESERVED_BYTES);
170 min_low_pfn = ARCH_PFN_OFFSET;
171 memblock_reserve(PFN_PHYS(max_low_pfn), DMA_RESERVED_BYTES);
172
173 printk(KERN_INFO "bootmem_startpg: 0x%08lx\n", bootmem_startpg);
174 printk(KERN_INFO "bootmem_lastpg: 0x%08lx\n", bootmem_lastpg);
175 printk(KERN_INFO "min_low_pfn: 0x%08lx\n", min_low_pfn);
176 printk(KERN_INFO "max_low_pfn: 0x%08lx\n", max_low_pfn);
177
178 /*
179 * The default VM page tables (will be) populated with
180 * VA=PA+PAGE_OFFSET mapping. We go in and invalidate entries
181 * higher than what we have memory for.
182 */
183
184 /* this is pointer arithmetic; each entry covers 4MB */
185 segtable = segtable + (PAGE_OFFSET >> 22);
186
187 /* this actually only goes to the end of the first gig */
188 segtable_end = segtable + (1<<(30-22));
189
190 /*
191 * Move forward to the start of empty pages; take into account
192 * phys_offset shift.
193 */
194
195 segtable += (bootmem_lastpg-ARCH_PFN_OFFSET)>>(22-PAGE_SHIFT);
196 {
197 int i;
198
199 for (i = 1 ; i <= DMA_RESERVE ; i++)
200 segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB)
201 | __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X
202 | __HEXAGON_C_UNC << 6
203 | __HVM_PDE_S_4MB);
204 }
205
206 printk(KERN_INFO "clearing segtable from %p to %p\n", segtable,
207 segtable_end);
208 while (segtable < (segtable_end-8))
209 *(segtable++) = __HVM_PDE_S_INVALID;
210 /* stop the pointer at the device I/O 4MB page */
211
212 printk(KERN_INFO "segtable = %p (should be equal to _K_io_map)\n",
213 segtable);
214
215 #if 0
216 /* Other half of the early device table from vm_init_segtable. */
217 printk(KERN_INFO "&_K_init_devicetable = 0x%08x\n",
218 (unsigned long) _K_init_devicetable-PAGE_OFFSET);
219 *segtable = ((u32) (unsigned long) _K_init_devicetable-PAGE_OFFSET) |
220 __HVM_PDE_S_4KB;
221 printk(KERN_INFO "*segtable = 0x%08x\n", *segtable);
222 #endif
223
224 /*
225 * The bootmem allocator seemingly just lives to feed memory
226 * to the paging system
227 */
228 printk(KERN_INFO "PAGE_SIZE=%lu\n", PAGE_SIZE);
229 paging_init(); /* See Gorman Book, 2.3 */
230
231 /*
232 * At this point, the page allocator is kind of initialized, but
233 * apparently no pages are available (just like with the bootmem
234 * allocator), and need to be freed themselves via mem_init(),
235 * which is called by start_kernel() later on in the process
236 */
237 }
238
239 static const pgprot_t protection_map[16] = {
240 [VM_NONE] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
241 CACHEDEF),
242 [VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
243 _PAGE_READ | CACHEDEF),
244 [VM_WRITE] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
245 CACHEDEF),
246 [VM_WRITE | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
247 _PAGE_READ | CACHEDEF),
248 [VM_EXEC] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
249 _PAGE_EXECUTE | CACHEDEF),
250 [VM_EXEC | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
251 _PAGE_EXECUTE | _PAGE_READ |
252 CACHEDEF),
253 [VM_EXEC | VM_WRITE] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
254 _PAGE_EXECUTE | CACHEDEF),
255 [VM_EXEC | VM_WRITE | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
256 _PAGE_EXECUTE | _PAGE_READ |
257 CACHEDEF),
258 [VM_SHARED] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
259 CACHEDEF),
260 [VM_SHARED | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
261 _PAGE_READ | CACHEDEF),
262 [VM_SHARED | VM_WRITE] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
263 _PAGE_WRITE | CACHEDEF),
264 [VM_SHARED | VM_WRITE | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
265 _PAGE_READ | _PAGE_WRITE |
266 CACHEDEF),
267 [VM_SHARED | VM_EXEC] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
268 _PAGE_EXECUTE | CACHEDEF),
269 [VM_SHARED | VM_EXEC | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
270 _PAGE_EXECUTE | _PAGE_READ |
271 CACHEDEF),
272 [VM_SHARED | VM_EXEC | VM_WRITE] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
273 _PAGE_EXECUTE | _PAGE_WRITE |
274 CACHEDEF),
275 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER |
276 _PAGE_READ | _PAGE_EXECUTE |
277 _PAGE_WRITE | CACHEDEF)
278 };
279 DECLARE_VM_GET_PAGE_PROT
280