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![Michal Simek](/assets/img/avatar_default.png)
Systems with small amount of memory need to be handled differently. Linux can't allocate the whole 32MB with two TLBs because then there is no MMU protection. Signed-off-by: Michal Simek <monstr@monstr.eu>
502 lines
13 KiB
C
502 lines
13 KiB
C
/*
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* Copyright (C) 2007-2008 Michal Simek <monstr@monstr.eu>
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* Copyright (C) 2006 Atmark Techno, Inc.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/bootmem.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/memblock.h>
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#include <linux/mm.h> /* mem_init */
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#include <linux/initrd.h>
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#include <linux/pagemap.h>
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#include <linux/pfn.h>
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#include <linux/slab.h>
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#include <linux/swap.h>
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#include <linux/export.h>
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#include <asm/page.h>
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#include <asm/mmu_context.h>
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#include <asm/pgalloc.h>
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#include <asm/sections.h>
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#include <asm/tlb.h>
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#include <asm/fixmap.h>
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/* Use for MMU and noMMU because of PCI generic code */
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int mem_init_done;
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#ifndef CONFIG_MMU
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unsigned int __page_offset;
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EXPORT_SYMBOL(__page_offset);
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#else
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static int init_bootmem_done;
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#endif /* CONFIG_MMU */
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char *klimit = _end;
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/*
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* Initialize the bootmem system and give it all the memory we
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* have available.
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*/
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unsigned long memory_start;
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EXPORT_SYMBOL(memory_start);
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unsigned long memory_size;
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EXPORT_SYMBOL(memory_size);
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unsigned long lowmem_size;
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#ifdef CONFIG_HIGHMEM
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pte_t *kmap_pte;
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EXPORT_SYMBOL(kmap_pte);
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pgprot_t kmap_prot;
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EXPORT_SYMBOL(kmap_prot);
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static inline pte_t *virt_to_kpte(unsigned long vaddr)
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{
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return pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr),
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vaddr), vaddr);
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}
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static void __init highmem_init(void)
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{
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pr_debug("%x\n", (u32)PKMAP_BASE);
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map_page(PKMAP_BASE, 0, 0); /* XXX gross */
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pkmap_page_table = virt_to_kpte(PKMAP_BASE);
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kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
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kmap_prot = PAGE_KERNEL;
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}
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static unsigned long highmem_setup(void)
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{
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unsigned long pfn;
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unsigned long reservedpages = 0;
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for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
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struct page *page = pfn_to_page(pfn);
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/* FIXME not sure about */
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if (memblock_is_reserved(pfn << PAGE_SHIFT))
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continue;
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ClearPageReserved(page);
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init_page_count(page);
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__free_page(page);
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totalhigh_pages++;
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reservedpages++;
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}
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totalram_pages += totalhigh_pages;
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printk(KERN_INFO "High memory: %luk\n",
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totalhigh_pages << (PAGE_SHIFT-10));
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return reservedpages;
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}
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#endif /* CONFIG_HIGHMEM */
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/*
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* paging_init() sets up the page tables - in fact we've already done this.
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*/
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static void __init paging_init(void)
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{
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unsigned long zones_size[MAX_NR_ZONES];
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#ifdef CONFIG_MMU
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int idx;
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/* Setup fixmaps */
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for (idx = 0; idx < __end_of_fixed_addresses; idx++)
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clear_fixmap(idx);
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#endif
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/* Clean every zones */
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memset(zones_size, 0, sizeof(zones_size));
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#ifdef CONFIG_HIGHMEM
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highmem_init();
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zones_size[ZONE_DMA] = max_low_pfn;
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zones_size[ZONE_HIGHMEM] = max_pfn;
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#else
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zones_size[ZONE_DMA] = max_pfn;
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#endif
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/* We don't have holes in memory map */
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free_area_init_nodes(zones_size);
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}
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void __init setup_memory(void)
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{
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unsigned long map_size;
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struct memblock_region *reg;
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#ifndef CONFIG_MMU
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u32 kernel_align_start, kernel_align_size;
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/* Find main memory where is the kernel */
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for_each_memblock(memory, reg) {
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memory_start = (u32)reg->base;
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lowmem_size = reg->size;
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if ((memory_start <= (u32)_text) &&
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((u32)_text <= (memory_start + lowmem_size - 1))) {
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memory_size = lowmem_size;
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PAGE_OFFSET = memory_start;
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printk(KERN_INFO "%s: Main mem: 0x%x, "
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"size 0x%08x\n", __func__, (u32) memory_start,
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(u32) memory_size);
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break;
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}
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}
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if (!memory_start || !memory_size) {
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panic("%s: Missing memory setting 0x%08x, size=0x%08x\n",
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__func__, (u32) memory_start, (u32) memory_size);
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}
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/* reservation of region where is the kernel */
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kernel_align_start = PAGE_DOWN((u32)_text);
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/* ALIGN can be remove because _end in vmlinux.lds.S is align */
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kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
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printk(KERN_INFO "%s: kernel addr:0x%08x-0x%08x size=0x%08x\n",
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__func__, kernel_align_start, kernel_align_start
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+ kernel_align_size, kernel_align_size);
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memblock_reserve(kernel_align_start, kernel_align_size);
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#endif
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/*
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* Kernel:
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* start: base phys address of kernel - page align
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* end: base phys address of kernel - page align
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*
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* min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
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* max_low_pfn
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* max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
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* num_physpages - number of all pages
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*/
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/* memory start is from the kernel end (aligned) to higher addr */
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min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
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/* RAM is assumed contiguous */
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num_physpages = max_mapnr = memory_size >> PAGE_SHIFT;
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max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
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max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
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printk(KERN_INFO "%s: max_mapnr: %#lx\n", __func__, max_mapnr);
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printk(KERN_INFO "%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
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printk(KERN_INFO "%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
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printk(KERN_INFO "%s: max_pfn: %#lx\n", __func__, max_pfn);
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/*
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* Find an area to use for the bootmem bitmap.
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* We look for the first area which is at least
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* 128kB in length (128kB is enough for a bitmap
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* for 4GB of memory, using 4kB pages), plus 1 page
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* (in case the address isn't page-aligned).
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*/
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map_size = init_bootmem_node(NODE_DATA(0),
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PFN_UP(TOPHYS((u32)klimit)), min_low_pfn, max_low_pfn);
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memblock_reserve(PFN_UP(TOPHYS((u32)klimit)) << PAGE_SHIFT, map_size);
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/* Add active regions with valid PFNs */
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for_each_memblock(memory, reg) {
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unsigned long start_pfn, end_pfn;
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start_pfn = memblock_region_memory_base_pfn(reg);
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end_pfn = memblock_region_memory_end_pfn(reg);
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memblock_set_node(start_pfn << PAGE_SHIFT,
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(end_pfn - start_pfn) << PAGE_SHIFT, 0);
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}
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/* free bootmem is whole main memory */
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free_bootmem_with_active_regions(0, max_low_pfn);
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/* reserve allocate blocks */
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for_each_memblock(reserved, reg) {
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unsigned long top = reg->base + reg->size - 1;
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pr_debug("reserved - 0x%08x-0x%08x, %lx, %lx\n",
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(u32) reg->base, (u32) reg->size, top,
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memory_start + lowmem_size - 1);
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if (top <= (memory_start + lowmem_size - 1)) {
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reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
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} else if (reg->base < (memory_start + lowmem_size - 1)) {
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unsigned long trunc_size = memory_start + lowmem_size -
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reg->base;
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reserve_bootmem(reg->base, trunc_size, BOOTMEM_DEFAULT);
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}
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}
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/* XXX need to clip this if using highmem? */
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sparse_memory_present_with_active_regions(0);
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#ifdef CONFIG_MMU
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init_bootmem_done = 1;
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#endif
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paging_init();
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}
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void free_init_pages(char *what, unsigned long begin, unsigned long end)
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{
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unsigned long addr;
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for (addr = begin; addr < end; addr += PAGE_SIZE) {
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ClearPageReserved(virt_to_page(addr));
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init_page_count(virt_to_page(addr));
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free_page(addr);
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totalram_pages++;
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}
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printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
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}
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#ifdef CONFIG_BLK_DEV_INITRD
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void free_initrd_mem(unsigned long start, unsigned long end)
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{
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int pages = 0;
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for (; start < end; start += PAGE_SIZE) {
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ClearPageReserved(virt_to_page(start));
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init_page_count(virt_to_page(start));
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free_page(start);
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totalram_pages++;
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pages++;
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}
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printk(KERN_NOTICE "Freeing initrd memory: %dk freed\n",
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(int)(pages * (PAGE_SIZE / 1024)));
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}
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#endif
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void free_initmem(void)
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{
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free_init_pages("unused kernel memory",
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(unsigned long)(&__init_begin),
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(unsigned long)(&__init_end));
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}
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void __init mem_init(void)
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{
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pg_data_t *pgdat;
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unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
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high_memory = (void *)__va(memory_start + lowmem_size - 1);
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/* this will put all memory onto the freelists */
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totalram_pages += free_all_bootmem();
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for_each_online_pgdat(pgdat) {
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unsigned long i;
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struct page *page;
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for (i = 0; i < pgdat->node_spanned_pages; i++) {
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if (!pfn_valid(pgdat->node_start_pfn + i))
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continue;
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page = pgdat_page_nr(pgdat, i);
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if (PageReserved(page))
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reservedpages++;
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}
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}
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#ifdef CONFIG_HIGHMEM
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reservedpages -= highmem_setup();
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#endif
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codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
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datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
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initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
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bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
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pr_info("Memory: %luk/%luk available (%luk kernel code, "
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"%luk reserved, %luk data, %luk bss, %luk init)\n",
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nr_free_pages() << (PAGE_SHIFT-10),
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num_physpages << (PAGE_SHIFT-10),
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codesize >> 10,
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reservedpages << (PAGE_SHIFT-10),
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datasize >> 10,
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bsssize >> 10,
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initsize >> 10);
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#ifdef CONFIG_MMU
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pr_info("Kernel virtual memory layout:\n");
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pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
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#ifdef CONFIG_HIGHMEM
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pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
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PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
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#endif /* CONFIG_HIGHMEM */
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pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
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ioremap_bot, ioremap_base);
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pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
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(unsigned long)VMALLOC_START, VMALLOC_END);
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#endif
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mem_init_done = 1;
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}
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#ifndef CONFIG_MMU
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int page_is_ram(unsigned long pfn)
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{
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return __range_ok(pfn, 0);
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}
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#else
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int page_is_ram(unsigned long pfn)
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{
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return pfn < max_low_pfn;
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}
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/*
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* Check for command-line options that affect what MMU_init will do.
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*/
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static void mm_cmdline_setup(void)
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{
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unsigned long maxmem = 0;
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char *p = cmd_line;
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/* Look for mem= option on command line */
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p = strstr(cmd_line, "mem=");
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if (p) {
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p += 4;
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maxmem = memparse(p, &p);
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if (maxmem && memory_size > maxmem) {
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memory_size = maxmem;
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memblock.memory.regions[0].size = memory_size;
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}
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}
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}
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/*
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* MMU_init_hw does the chip-specific initialization of the MMU hardware.
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*/
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static void __init mmu_init_hw(void)
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{
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/*
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* The Zone Protection Register (ZPR) defines how protection will
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* be applied to every page which is a member of a given zone. At
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* present, we utilize only two of the zones.
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* The zone index bits (of ZSEL) in the PTE are used for software
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* indicators, except the LSB. For user access, zone 1 is used,
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* for kernel access, zone 0 is used. We set all but zone 1
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* to zero, allowing only kernel access as indicated in the PTE.
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* For zone 1, we set a 01 binary (a value of 10 will not work)
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* to allow user access as indicated in the PTE. This also allows
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* kernel access as indicated in the PTE.
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*/
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__asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
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"mts rzpr, r11;"
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: : : "r11");
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}
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/*
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* MMU_init sets up the basic memory mappings for the kernel,
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* including both RAM and possibly some I/O regions,
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* and sets up the page tables and the MMU hardware ready to go.
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*/
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/* called from head.S */
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asmlinkage void __init mmu_init(void)
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{
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unsigned int kstart, ksize;
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if (!memblock.reserved.cnt) {
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printk(KERN_EMERG "Error memory count\n");
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machine_restart(NULL);
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}
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if ((u32) memblock.memory.regions[0].size < 0x400000) {
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printk(KERN_EMERG "Memory must be greater than 4MB\n");
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machine_restart(NULL);
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}
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if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
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printk(KERN_EMERG "Kernel size is greater than memory node\n");
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machine_restart(NULL);
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}
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/* Find main memory where the kernel is */
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memory_start = (u32) memblock.memory.regions[0].base;
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lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
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if (lowmem_size > CONFIG_LOWMEM_SIZE) {
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lowmem_size = CONFIG_LOWMEM_SIZE;
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#ifndef CONFIG_HIGHMEM
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memory_size = lowmem_size;
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#endif
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}
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mm_cmdline_setup(); /* FIXME parse args from command line - not used */
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/*
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* Map out the kernel text/data/bss from the available physical
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* memory.
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*/
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kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
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/* kernel size */
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ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
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memblock_reserve(kstart, ksize);
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#if defined(CONFIG_BLK_DEV_INITRD)
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/* Remove the init RAM disk from the available memory. */
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/* if (initrd_start) {
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mem_pieces_remove(&phys_avail, __pa(initrd_start),
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initrd_end - initrd_start, 1);
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}*/
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#endif /* CONFIG_BLK_DEV_INITRD */
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/* Initialize the MMU hardware */
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mmu_init_hw();
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/* Map in all of RAM starting at CONFIG_KERNEL_START */
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mapin_ram();
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/* Extend vmalloc and ioremap area as big as possible */
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#ifdef CONFIG_HIGHMEM
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ioremap_base = ioremap_bot = PKMAP_BASE;
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#else
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ioremap_base = ioremap_bot = FIXADDR_START;
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#endif
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/* Initialize the context management stuff */
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mmu_context_init();
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/* Shortly after that, the entire linear mapping will be available */
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/* This will also cause that unflatten device tree will be allocated
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* inside 768MB limit */
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memblock_set_current_limit(memory_start + lowmem_size - 1);
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}
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/* This is only called until mem_init is done. */
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void __init *early_get_page(void)
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{
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void *p;
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if (init_bootmem_done) {
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p = alloc_bootmem_pages(PAGE_SIZE);
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} else {
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/*
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* Mem start + kernel_tlb -> here is limit
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* because of mem mapping from head.S
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*/
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p = __va(memblock_alloc_base(PAGE_SIZE, PAGE_SIZE,
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memory_start + kernel_tlb));
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}
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return p;
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}
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#endif /* CONFIG_MMU */
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void * __init_refok alloc_maybe_bootmem(size_t size, gfp_t mask)
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{
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if (mem_init_done)
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return kmalloc(size, mask);
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else
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return alloc_bootmem(size);
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}
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void * __init_refok zalloc_maybe_bootmem(size_t size, gfp_t mask)
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{
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void *p;
|
|
|
|
if (mem_init_done)
|
|
p = kzalloc(size, mask);
|
|
else {
|
|
p = alloc_bootmem(size);
|
|
if (p)
|
|
memset(p, 0, size);
|
|
}
|
|
return p;
|
|
}
|