xref: /linux/arch/arm/mm/nommu.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1 /*
2  *  linux/arch/arm/mm/nommu.c
3  *
4  * ARM uCLinux supporting functions.
5  */
6 #include <linux/module.h>
7 #include <linux/mm.h>
8 #include <linux/pagemap.h>
9 #include <linux/bootmem.h>
10 #include <linux/io.h>
11 
12 #include <asm/cacheflush.h>
13 #include <asm/page.h>
14 #include <asm/mach/arch.h>
15 
16 #include "mm.h"
17 
18 /*
19  * Reserve the various regions of node 0
20  */
21 void __init reserve_node_zero(pg_data_t *pgdat)
22 {
23 	/*
24 	 * Register the kernel text and data with bootmem.
25 	 * Note that this can only be in node 0.
26 	 */
27 #ifdef CONFIG_XIP_KERNEL
28 	reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start,
29 			BOOTMEM_DEFAULT);
30 #else
31 	reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext,
32 			BOOTMEM_DEFAULT);
33 #endif
34 
35 	/*
36 	 * Register the exception vector page.
37 	 * some architectures which the DRAM is the exception vector to trap,
38 	 * alloc_page breaks with error, although it is not NULL, but "0."
39 	 */
40 	reserve_bootmem_node(pgdat, CONFIG_VECTORS_BASE, PAGE_SIZE,
41 			BOOTMEM_DEFAULT);
42 }
43 
44 static void __init sanity_check_meminfo(struct meminfo *mi)
45 {
46 	int i, j;
47 
48 	for (i = 0, j = 0; i < mi->nr_banks; i++) {
49 		struct membank *mb = &mi->bank[i];
50 
51 		if (mb->size != 0 && mb->node < MAX_NUMNODES)
52 			mi->bank[j++] = mi->bank[i];
53 	}
54 	mi->nr_banks = j;
55 }
56 
57 /*
58  * paging_init() sets up the page tables, initialises the zone memory
59  * maps, and sets up the zero page, bad page and bad page tables.
60  */
61 void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
62 {
63 	sanity_check_meminfo(mi);
64 	bootmem_init(mi);
65 }
66 
67 /*
68  * We don't need to do anything here for nommu machines.
69  */
70 void setup_mm_for_reboot(char mode)
71 {
72 }
73 
74 void flush_dcache_page(struct page *page)
75 {
76 	__cpuc_flush_dcache_page(page_address(page));
77 }
78 EXPORT_SYMBOL(flush_dcache_page);
79 
80 void __iomem *__arm_ioremap_pfn(unsigned long pfn, unsigned long offset,
81 				size_t size, unsigned int mtype)
82 {
83 	if (pfn >= (0x100000000ULL >> PAGE_SHIFT))
84 		return NULL;
85 	return (void __iomem *) (offset + (pfn << PAGE_SHIFT));
86 }
87 EXPORT_SYMBOL(__arm_ioremap_pfn);
88 
89 void __iomem *__arm_ioremap(unsigned long phys_addr, size_t size,
90 			    unsigned int mtype)
91 {
92 	return (void __iomem *)phys_addr;
93 }
94 EXPORT_SYMBOL(__arm_ioremap);
95 
96 void __iounmap(volatile void __iomem *addr)
97 {
98 }
99 EXPORT_SYMBOL(__iounmap);
100