Root/arch/blackfin/mm/init.c

1/*
2 * Copyright 2004-2009 Analog Devices Inc.
3 *
4 * Licensed under the GPL-2 or later.
5 */
6
7#include <linux/gfp.h>
8#include <linux/swap.h>
9#include <linux/bootmem.h>
10#include <linux/uaccess.h>
11#include <asm/bfin-global.h>
12#include <asm/pda.h>
13#include <asm/cplbinit.h>
14#include <asm/early_printk.h>
15#include "blackfin_sram.h"
16
17/*
18 * ZERO_PAGE is a special page that is used for zero-initialized data and COW.
19 * Let the bss do its zero-init magic so we don't have to do it ourselves.
20 */
21char empty_zero_page[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
22EXPORT_SYMBOL(empty_zero_page);
23
24#ifndef CONFIG_EXCEPTION_L1_SCRATCH
25#if defined CONFIG_SYSCALL_TAB_L1
26__attribute__((l1_data))
27#endif
28static unsigned long exception_stack[NR_CPUS][1024];
29#endif
30
31struct blackfin_pda cpu_pda[NR_CPUS];
32EXPORT_SYMBOL(cpu_pda);
33
34/*
35 * paging_init() continues the virtual memory environment setup which
36 * was begun by the code in arch/head.S.
37 * The parameters are pointers to where to stick the starting and ending
38 * addresses of available kernel virtual memory.
39 */
40void __init paging_init(void)
41{
42    /*
43     * make sure start_mem is page aligned, otherwise bootmem and
44     * page_alloc get different views of the world
45     */
46    unsigned long end_mem = memory_end & PAGE_MASK;
47
48    unsigned long zones_size[MAX_NR_ZONES] = {
49        [0] = 0,
50        [ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT,
51        [ZONE_NORMAL] = 0,
52#ifdef CONFIG_HIGHMEM
53        [ZONE_HIGHMEM] = 0,
54#endif
55    };
56
57    /* Set up SFC/DFC registers (user data space) */
58    set_fs(KERNEL_DS);
59
60    pr_debug("free_area_init -> start_mem is %#lx virtual_end is %#lx\n",
61            PAGE_ALIGN(memory_start), end_mem);
62    free_area_init(zones_size);
63}
64
65asmlinkage void __init init_pda(void)
66{
67    unsigned int cpu = raw_smp_processor_id();
68
69    early_shadow_stamp();
70
71    /* Initialize the PDA fields holding references to other parts
72       of the memory. The content of such memory is still
73       undefined at the time of the call, we are only setting up
74       valid pointers to it. */
75    memset(&cpu_pda[cpu], 0, sizeof(cpu_pda[cpu]));
76
77    cpu_pda[0].next = &cpu_pda[1];
78    cpu_pda[1].next = &cpu_pda[0];
79
80#ifdef CONFIG_EXCEPTION_L1_SCRATCH
81    cpu_pda[cpu].ex_stack = (unsigned long *)(L1_SCRATCH_START + \
82                    L1_SCRATCH_LENGTH);
83#else
84    cpu_pda[cpu].ex_stack = exception_stack[cpu + 1];
85#endif
86
87#ifdef CONFIG_SMP
88    cpu_pda[cpu].imask = 0x1f;
89#endif
90}
91
92void __init mem_init(void)
93{
94    unsigned int codek = 0, datak = 0, initk = 0;
95    unsigned int reservedpages = 0, freepages = 0;
96    unsigned long tmp;
97    unsigned long start_mem = memory_start;
98    unsigned long end_mem = memory_end;
99
100    end_mem &= PAGE_MASK;
101    high_memory = (void *)end_mem;
102
103    start_mem = PAGE_ALIGN(start_mem);
104    max_mapnr = num_physpages = MAP_NR(high_memory);
105    printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", num_physpages);
106
107    /* This will put all memory onto the freelists. */
108    totalram_pages = free_all_bootmem();
109
110    reservedpages = 0;
111    for (tmp = 0; tmp < max_mapnr; tmp++)
112        if (PageReserved(pfn_to_page(tmp)))
113            reservedpages++;
114    freepages = max_mapnr - reservedpages;
115
116    /* do not count in kernel image between _rambase and _ramstart */
117    reservedpages -= (_ramstart - _rambase) >> PAGE_SHIFT;
118#if (defined(CONFIG_BFIN_EXTMEM_ICACHEABLE) && ANOMALY_05000263)
119    reservedpages += (_ramend - memory_end - DMA_UNCACHED_REGION) >> PAGE_SHIFT;
120#endif
121
122    codek = (_etext - _stext) >> 10;
123    initk = (__init_end - __init_begin) >> 10;
124    datak = ((_ramstart - _rambase) >> 10) - codek - initk;
125
126    printk(KERN_INFO
127         "Memory available: %luk/%luk RAM, "
128        "(%uk init code, %uk kernel code, %uk data, %uk dma, %uk reserved)\n",
129        (unsigned long) freepages << (PAGE_SHIFT-10), _ramend >> 10,
130        initk, codek, datak, DMA_UNCACHED_REGION >> 10, (reservedpages << (PAGE_SHIFT-10)));
131}
132
133static void __init free_init_pages(const char *what, unsigned long begin, unsigned long end)
134{
135    unsigned long addr;
136    /* next to check that the page we free is not a partial page */
137    for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
138        ClearPageReserved(virt_to_page(addr));
139        init_page_count(virt_to_page(addr));
140        free_page(addr);
141        totalram_pages++;
142    }
143    printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
144}
145
146#ifdef CONFIG_BLK_DEV_INITRD
147void __init free_initrd_mem(unsigned long start, unsigned long end)
148{
149#ifndef CONFIG_MPU
150    free_init_pages("initrd memory", start, end);
151#endif
152}
153#endif
154
155void __init_refok free_initmem(void)
156{
157#if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
158    free_init_pages("unused kernel memory",
159            (unsigned long)(&__init_begin),
160            (unsigned long)(&__init_end));
161
162    if (memory_start == (unsigned long)(&__init_end))
163        memory_start = (unsigned long)(&__init_begin);
164#endif
165}
166

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