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-rw-r--r--arch/arm26/mm/init.c412
1 files changed, 412 insertions, 0 deletions
diff --git a/arch/arm26/mm/init.c b/arch/arm26/mm/init.c
new file mode 100644
index 0000000..1f09a9d
--- /dev/null
+++ b/arch/arm26/mm/init.c
@@ -0,0 +1,412 @@
+/*
+ * linux/arch/arm26/mm/init.c
+ *
+ * Copyright (C) 1995-2002 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/config.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/initrd.h>
+#include <linux/bootmem.h>
+#include <linux/blkdev.h>
+
+#include <asm/segment.h>
+#include <asm/mach-types.h>
+#include <asm/dma.h>
+#include <asm/hardware.h>
+#include <asm/setup.h>
+#include <asm/tlb.h>
+
+#include <asm/map.h>
+
+
+#define TABLE_SIZE PTRS_PER_PTE * sizeof(pte_t))
+
+struct mmu_gather mmu_gathers[NR_CPUS];
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+extern char _stext, _text, _etext, _end, __init_begin, __init_end;
+#ifdef CONFIG_XIP_KERNEL
+extern char _endtext, _sdata;
+#endif
+extern unsigned long phys_initrd_start;
+extern unsigned long phys_initrd_size;
+
+/*
+ * The sole use of this is to pass memory configuration
+ * data from paging_init to mem_init.
+ */
+static struct meminfo meminfo __initdata = { 0, };
+
+/*
+ * empty_zero_page is a special page that is used for
+ * zero-initialized data and COW.
+ */
+struct page *empty_zero_page;
+
+void show_mem(void)
+{
+ int free = 0, total = 0, reserved = 0;
+ int shared = 0, cached = 0, slab = 0;
+ struct page *page, *end;
+
+ printk("Mem-info:\n");
+ show_free_areas();
+ printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
+
+
+ page = NODE_MEM_MAP(0);
+ end = page + NODE_DATA(0)->node_spanned_pages;
+
+ do {
+ total++;
+ if (PageReserved(page))
+ reserved++;
+ else if (PageSwapCache(page))
+ cached++;
+ else if (PageSlab(page))
+ slab++;
+ else if (!page_count(page))
+ free++;
+ else
+ shared += page_count(page) - 1;
+ page++;
+ } while (page < end);
+
+ printk("%d pages of RAM\n", total);
+ printk("%d free pages\n", free);
+ printk("%d reserved pages\n", reserved);
+ printk("%d slab pages\n", slab);
+ printk("%d pages shared\n", shared);
+ printk("%d pages swap cached\n", cached);
+}
+
+struct node_info {
+ unsigned int start;
+ unsigned int end;
+ int bootmap_pages;
+};
+
+#define PFN_DOWN(x) ((x) >> PAGE_SHIFT)
+#define PFN_UP(x) (PAGE_ALIGN(x) >> PAGE_SHIFT)
+#define PFN_SIZE(x) ((x) >> PAGE_SHIFT)
+#define PFN_RANGE(s,e) PFN_SIZE(PAGE_ALIGN((unsigned long)(e)) - \
+ (((unsigned long)(s)) & PAGE_MASK))
+
+/*
+ * FIXME: We really want to avoid allocating the bootmap bitmap
+ * over the top of the initrd. Hopefully, this is located towards
+ * the start of a bank, so if we allocate the bootmap bitmap at
+ * the end, we won't clash.
+ */
+static unsigned int __init
+find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
+{
+ unsigned int start_pfn, bootmap_pfn;
+ unsigned int start, end;
+
+ start_pfn = PFN_UP((unsigned long)&_end);
+ bootmap_pfn = 0;
+
+ /* ARM26 machines only have one node */
+ if (mi->bank->node != 0)
+ BUG();
+
+ start = PFN_UP(mi->bank->start);
+ end = PFN_DOWN(mi->bank->size + mi->bank->start);
+
+ if (start < start_pfn)
+ start = start_pfn;
+
+ if (end <= start)
+ BUG();
+
+ if (end - start >= bootmap_pages)
+ bootmap_pfn = start;
+ else
+ BUG();
+
+ return bootmap_pfn;
+}
+
+/*
+ * Scan the memory info structure and pull out:
+ * - the end of memory
+ * - the number of nodes
+ * - the pfn range of each node
+ * - the number of bootmem bitmap pages
+ */
+static void __init
+find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
+{
+ unsigned int memend_pfn = 0;
+
+ nodes_clear(node_online_map);
+ node_set_online(0);
+
+ np->bootmap_pages = 0;
+
+ if (mi->bank->size == 0) {
+ BUG();
+ }
+
+ /*
+ * Get the start and end pfns for this bank
+ */
+ np->start = PFN_UP(mi->bank->start);
+ np->end = PFN_DOWN(mi->bank->start + mi->bank->size);
+
+ if (memend_pfn < np->end)
+ memend_pfn = np->end;
+
+ /*
+ * Calculate the number of pages we require to
+ * store the bootmem bitmaps.
+ */
+ np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);
+
+ /*
+ * This doesn't seem to be used by the Linux memory
+ * manager any more. If we can get rid of it, we
+ * also get rid of some of the stuff above as well.
+ */
+ max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
+ max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
+ mi->end = memend_pfn << PAGE_SHIFT;
+
+}
+
+/*
+ * Initialise the bootmem allocator for all nodes. This is called
+ * early during the architecture specific initialisation.
+ */
+void __init bootmem_init(struct meminfo *mi)
+{
+ struct node_info node_info;
+ unsigned int bootmap_pfn;
+ pg_data_t *pgdat = NODE_DATA(0);
+
+ find_memend_and_nodes(mi, &node_info);
+
+ bootmap_pfn = find_bootmap_pfn(mi, node_info.bootmap_pages);
+
+ /*
+ * Note that node 0 must always have some pages.
+ */
+ if (node_info.end == 0)
+ BUG();
+
+ /*
+ * Initialise the bootmem allocator.
+ */
+ init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end);
+
+ /*
+ * Register all available RAM in this node with the bootmem allocator.
+ */
+ free_bootmem_node(pgdat, mi->bank->start, mi->bank->size);
+
+ /*
+ * Register the kernel text and data with bootmem.
+ * Note: with XIP we dont register .text since
+ * its in ROM.
+ */
+#ifdef CONFIG_XIP_KERNEL
+ reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata);
+#else
+ reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
+#endif
+
+ /*
+ * And don't forget to reserve the allocator bitmap,
+ * which will be freed later.
+ */
+ reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
+ node_info.bootmap_pages << PAGE_SHIFT);
+
+ /*
+ * These should likewise go elsewhere. They pre-reserve
+ * the screen memory region at the start of main system
+ * memory. FIXME - screen RAM is not 512K!
+ */
+ reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+ initrd_start = phys_initrd_start;
+ initrd_end = initrd_start + phys_initrd_size;
+
+ /* Achimedes machines only have one node, so initrd is in node 0 */
+#ifdef CONFIG_XIP_KERNEL
+ /* Only reserve initrd space if it is in RAM */
+ if(initrd_start && initrd_start < 0x03000000){
+#else
+ if(initrd_start){
+#endif
+ reserve_bootmem_node(pgdat, __pa(initrd_start),
+ initrd_end - initrd_start);
+ }
+#endif /* CONFIG_BLK_DEV_INITRD */
+
+
+}
+
+/*
+ * paging_init() sets up the page tables, initialises the zone memory
+ * maps, and sets up the zero page, bad page and bad page tables.
+ */
+void __init paging_init(struct meminfo *mi)
+{
+ void *zero_page;
+ unsigned long zone_size[MAX_NR_ZONES];
+ unsigned long zhole_size[MAX_NR_ZONES];
+ struct bootmem_data *bdata;
+ pg_data_t *pgdat;
+ int i;
+
+ memcpy(&meminfo, mi, sizeof(meminfo));
+
+ /*
+ * allocate the zero page. Note that we count on this going ok.
+ */
+ zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
+
+ /*
+ * initialise the page tables.
+ */
+ memtable_init(mi);
+ flush_tlb_all();
+
+ /*
+ * initialise the zones in node 0 (archimedes have only 1 node)
+ */
+
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ zone_size[i] = 0;
+ zhole_size[i] = 0;
+ }
+
+ pgdat = NODE_DATA(0);
+ bdata = pgdat->bdata;
+ zone_size[0] = bdata->node_low_pfn -
+ (bdata->node_boot_start >> PAGE_SHIFT);
+ if (!zone_size[0])
+ BUG();
+ pgdat->node_mem_map = NULL;
+ free_area_init_node(0, pgdat, zone_size,
+ bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
+
+ /*
+ * finish off the bad pages once
+ * the mem_map is initialised
+ */
+ memzero(zero_page, PAGE_SIZE);
+ empty_zero_page = virt_to_page(zero_page);
+}
+
+static inline void free_area(unsigned long addr, unsigned long end, char *s)
+{
+ unsigned int size = (end - addr) >> 10;
+
+ for (; addr < end; addr += PAGE_SIZE) {
+ struct page *page = virt_to_page(addr);
+ ClearPageReserved(page);
+ set_page_count(page, 1);
+ free_page(addr);
+ totalram_pages++;
+ }
+
+ if (size && s)
+ printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
+}
+
+/*
+ * mem_init() marks the free areas in the mem_map and tells us how much
+ * memory is free. This is done after various parts of the system have
+ * claimed their memory after the kernel image.
+ */
+void __init mem_init(void)
+{
+ unsigned int codepages, datapages, initpages;
+ pg_data_t *pgdat = NODE_DATA(0);
+ extern int sysctl_overcommit_memory;
+
+
+ /* Note: data pages includes BSS */
+#ifdef CONFIG_XIP_KERNEL
+ codepages = &_endtext - &_text;
+ datapages = &_end - &_sdata;
+#else
+ codepages = &_etext - &_text;
+ datapages = &_end - &_etext;
+#endif
+ initpages = &__init_end - &__init_begin;
+
+ high_memory = (void *)__va(meminfo.end);
+ max_mapnr = virt_to_page(high_memory) - mem_map;
+
+ /* this will put all unused low memory onto the freelists */
+ if (pgdat->node_spanned_pages != 0)
+ totalram_pages += free_all_bootmem_node(pgdat);
+
+ num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;
+
+ printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
+ printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
+ "%dK data, %dK init)\n",
+ (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
+ codepages >> 10, datapages >> 10, initpages >> 10);
+
+ /*
+ * Turn on overcommit on tiny machines
+ */
+ if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
+ sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
+ printk("Turning on overcommit\n");
+ }
+}
+
+void free_initmem(void){
+#ifndef CONFIG_XIP_KERNEL
+ free_area((unsigned long)(&__init_begin),
+ (unsigned long)(&__init_end),
+ "init");
+#endif
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+
+static int keep_initrd;
+
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+#ifdef CONFIG_XIP_KERNEL
+ /* Only bin initrd if it is in RAM... */
+ if(!keep_initrd && start < 0x03000000)
+#else
+ if (!keep_initrd)
+#endif
+ free_area(start, end, "initrd");
+}
+
+static int __init keepinitrd_setup(char *__unused)
+{
+ keep_initrd = 1;
+ return 1;
+}
+
+__setup("keepinitrd", keepinitrd_setup);
+#endif
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