2 * Memory subsystem initialization for Hexagon
4 * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 and
8 * only version 2 as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
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16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 #include <linux/init.h>
23 #include <linux/bootmem.h>
24 #include <asm/atomic.h>
25 #include <linux/highmem.h>
27 #include <asm/sections.h>
28 #include <asm/vm_mmu.h>
31 * Define a startpg just past the end of the kernel image and a lastpg
32 * that corresponds to the end of real or simulated platform memory.
34 #define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET + PHYS_OFFSET))
36 unsigned long bootmem_lastpg
; /* Should be set by platform code */
37 unsigned long __phys_offset
; /* physical kernel offset >> 12 */
39 /* Set as variable to limit PMD copies */
40 int max_kernel_seg
= 0x303;
42 /* indicate pfn's of high memory */
43 unsigned long highstart_pfn
, highend_pfn
;
45 DEFINE_PER_CPU(struct mmu_gather
, mmu_gathers
);
47 /* Default cache attribute for newly created page tables */
48 unsigned long _dflt_cache_att
= CACHEDEF
;
51 * The current "generation" of kernel map, which should not roll
52 * over until Hell freezes over. Actual bound in years needs to be
53 * calculated to confirm.
55 DEFINE_SPINLOCK(kmap_gen_lock
);
57 /* checkpatch says don't init this to 0. */
58 unsigned long long kmap_generation
;
61 * mem_init - initializes memory
64 * Fixes up more stuff for HIGHMEM
65 * Calculates and displays memory available/used
67 void __init
mem_init(void)
69 /* No idea where this is actually declared. Seems to evade LXR. */
71 mem_init_print_info(NULL
);
74 * To-Do: someone somewhere should wipe out the bootmem map
79 * This can be moved to some more virtual-memory-specific
80 * initialization hook at some point. Set the init_mm
81 * descriptors "context" value to point to the initial
82 * kernel segment table's physical address.
84 init_mm
.context
.ptbase
= __pa(init_mm
.pgd
);
88 * free_initmem - frees memory used by stuff declared with __init
90 * Todo: free pages between __init_begin and __init_end; possibly
91 * some devtree related stuff as well.
93 void __ref
free_initmem(void)
98 * free_initrd_mem - frees... initrd memory.
99 * @start - start of init memory
100 * @end - end of init memory
102 * Apparently has to be passed the address of the initrd memory.
104 * Wrapped by #ifdef CONFIG_BLKDEV_INITRD
106 void free_initrd_mem(unsigned long start
, unsigned long end
)
110 void sync_icache_dcache(pte_t pte
)
115 page
= pte_page(pte
);
116 addr
= (unsigned long) page_address(page
);
118 __vmcache_idsync(addr
, PAGE_SIZE
);
122 * In order to set up page allocator "nodes",
123 * somebody has to call free_area_init() for UMA.
125 * In this mode, we only have one pg_data_t
126 * structure: contig_mem_data.
128 void __init
paging_init(void)
130 unsigned long zones_sizes
[MAX_NR_ZONES
] = {0, };
133 * This is not particularly well documented anywhere, but
134 * give ZONE_NORMAL all the memory, including the big holes
135 * left by the kernel+bootmem_map which are already left as reserved
136 * in the bootmem_map; free_area_init should see those bits and
137 * adjust accordingly.
140 zones_sizes
[ZONE_NORMAL
] = max_low_pfn
;
142 free_area_init(zones_sizes
); /* sets up the zonelists and mem_map */
145 * Start of high memory area. Will probably need something more
146 * fancy if we... get more fancy.
148 high_memory
= (void *)((bootmem_lastpg
+ 1) << PAGE_SHIFT
);
152 #define DMA_RESERVE (4)
155 #define DMA_CHUNKSIZE (1<<22)
156 #define DMA_RESERVED_BYTES (DMA_RESERVE * DMA_CHUNKSIZE)
159 * Pick out the memory size. We look for mem=size,
160 * where size is "size[KkMm]"
162 static int __init
early_mem(char *p
)
167 size
= memparse(p
, &endp
);
169 bootmem_lastpg
= PFN_DOWN(size
);
173 early_param("mem", early_mem
);
175 size_t hexagon_coherent_pool_size
= (size_t) (DMA_RESERVE
<< 22);
177 void __init
setup_arch_memory(void)
180 /* XXX Todo: this probably should be cleaned up */
181 u32
*segtable
= (u32
*) &swapper_pg_dir
[0];
185 * Set up boot memory allocator
187 * The Gorman book also talks about these functions.
188 * This needs to change for highmem setups.
191 /* Prior to this, bootmem_lastpg is actually mem size */
192 bootmem_lastpg
+= ARCH_PFN_OFFSET
;
194 /* Memory size needs to be a multiple of 16M */
195 bootmem_lastpg
= PFN_DOWN((bootmem_lastpg
<< PAGE_SHIFT
) &
196 ~((BIG_KERNEL_PAGE_SIZE
) - 1));
199 * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached)
203 max_low_pfn
= bootmem_lastpg
- PFN_DOWN(DMA_RESERVED_BYTES
);
204 min_low_pfn
= ARCH_PFN_OFFSET
;
205 bootmap_size
= init_bootmem_node(NODE_DATA(0), bootmem_startpg
, min_low_pfn
, max_low_pfn
);
207 printk(KERN_INFO
"bootmem_startpg: 0x%08lx\n", bootmem_startpg
);
208 printk(KERN_INFO
"bootmem_lastpg: 0x%08lx\n", bootmem_lastpg
);
209 printk(KERN_INFO
"bootmap_size: %d\n", bootmap_size
);
210 printk(KERN_INFO
"min_low_pfn: 0x%08lx\n", min_low_pfn
);
211 printk(KERN_INFO
"max_low_pfn: 0x%08lx\n", max_low_pfn
);
214 * The default VM page tables (will be) populated with
215 * VA=PA+PAGE_OFFSET mapping. We go in and invalidate entries
216 * higher than what we have memory for.
219 /* this is pointer arithmetic; each entry covers 4MB */
220 segtable
= segtable
+ (PAGE_OFFSET
>> 22);
222 /* this actually only goes to the end of the first gig */
223 segtable_end
= segtable
+ (1<<(30-22));
226 * Move forward to the start of empty pages; take into account
230 segtable
+= (bootmem_lastpg
-ARCH_PFN_OFFSET
)>>(22-PAGE_SHIFT
);
234 for (i
= 1 ; i
<= DMA_RESERVE
; i
++)
235 segtable
[-i
] = ((segtable
[-i
] & __HVM_PTE_PGMASK_4MB
)
236 | __HVM_PTE_R
| __HVM_PTE_W
| __HVM_PTE_X
237 | __HEXAGON_C_UNC
<< 6
241 printk(KERN_INFO
"clearing segtable from %p to %p\n", segtable
,
243 while (segtable
< (segtable_end
-8))
244 *(segtable
++) = __HVM_PDE_S_INVALID
;
245 /* stop the pointer at the device I/O 4MB page */
247 printk(KERN_INFO
"segtable = %p (should be equal to _K_io_map)\n",
251 /* Other half of the early device table from vm_init_segtable. */
252 printk(KERN_INFO
"&_K_init_devicetable = 0x%08x\n",
253 (unsigned long) _K_init_devicetable
-PAGE_OFFSET
);
254 *segtable
= ((u32
) (unsigned long) _K_init_devicetable
-PAGE_OFFSET
) |
256 printk(KERN_INFO
"*segtable = 0x%08x\n", *segtable
);
260 * Free all the memory that wasn't taken up by the bootmap, the DMA
261 * reserve, or kernel itself.
263 free_bootmem(PFN_PHYS(bootmem_startpg
) + bootmap_size
,
264 PFN_PHYS(bootmem_lastpg
- bootmem_startpg
) - bootmap_size
-
268 * The bootmem allocator seemingly just lives to feed memory
269 * to the paging system
271 printk(KERN_INFO
"PAGE_SIZE=%lu\n", PAGE_SIZE
);
272 paging_init(); /* See Gorman Book, 2.3 */
275 * At this point, the page allocator is kind of initialized, but
276 * apparently no pages are available (just like with the bootmem
277 * allocator), and need to be freed themselves via mem_init(),
278 * which is called by start_kernel() later on in the process