xref: /openbmc/linux/arch/arm/mm/nommu.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 
11 #include <asm/cacheflush.h>
12 #include <asm/io.h>
13 #include <asm/page.h>
14 #include <asm/mach/arch.h>
15 
16 #include "mm.h"
17 
18 extern void _stext, __data_start, _end;
19 
20 /*
21  * Reserve the various regions of node 0
22  */
23 void __init reserve_node_zero(pg_data_t *pgdat)
24 {
25 	/*
26 	 * Register the kernel text and data with bootmem.
27 	 * Note that this can only be in node 0.
28 	 */
29 #ifdef CONFIG_XIP_KERNEL
30 	reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);
31 #else
32 	reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
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 }
42 
43 /*
44  * paging_init() sets up the page tables, initialises the zone memory
45  * maps, and sets up the zero page, bad page and bad page tables.
46  */
47 void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
48 {
49 	bootmem_init(mi);
50 }
51 
52 /*
53  * We don't need to do anything here for nommu machines.
54  */
55 void setup_mm_for_reboot(char mode)
56 {
57 }
58 
59 void flush_dcache_page(struct page *page)
60 {
61 	__cpuc_flush_dcache_page(page_address(page));
62 }
63 EXPORT_SYMBOL(flush_dcache_page);
64 
65 void __iomem *__arm_ioremap_pfn(unsigned long pfn, unsigned long offset,
66 				size_t size, unsigned int mtype)
67 {
68 	if (pfn >= (0x100000000ULL >> PAGE_SHIFT))
69 		return NULL;
70 	return (void __iomem *) (offset + (pfn << PAGE_SHIFT));
71 }
72 EXPORT_SYMBOL(__arm_ioremap_pfn);
73 
74 void __iomem *__arm_ioremap(unsigned long phys_addr, size_t size,
75 			    unsigned int mtype)
76 {
77 	return (void __iomem *)phys_addr;
78 }
79 EXPORT_SYMBOL(__arm_ioremap);
80 
81 void __iounmap(volatile void __iomem *addr)
82 {
83 }
84 EXPORT_SYMBOL(__iounmap);
85