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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [arch/] [mips/] [mm/] [init.c] - Rev 199
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/* * arch/mips/mm/init.c * * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds * Ported to MIPS by Ralf Baechle */ #include <linux/config.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/head.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 <asm/cachectl.h> #include <asm/jazzdma.h> #include <asm/vector.h> #include <asm/system.h> #include <asm/segment.h> #include <asm/pgtable.h> extern void deskstation_tyne_dma_init(void); extern void sound_mem_init(void); extern void die_if_kernel(char *,struct pt_regs *,long); extern void show_net_buffers(void); extern char empty_zero_page[PAGE_SIZE]; /* * BAD_PAGE is the page that is used for page faults when linux * is out-of-memory. Older versions of linux just did a * do_exit(), but using this instead means there is less risk * for a process dying in kernel mode, possibly leaving a inode * unused etc.. * * BAD_PAGETABLE is the accompanying page-table: it is initialized * to point to BAD_PAGE entries. * * ZERO_PAGE is a special page that is used for zero-initialized * data and COW. */ pte_t * __bad_pagetable(void) { extern char empty_bad_page_table[PAGE_SIZE]; unsigned long page; unsigned long dummy1, dummy2; page = ((unsigned long)empty_bad_page_table) + (PT_OFFSET - PAGE_OFFSET); #if __mips__ >= 3 /* * Use 64bit code even for Linux/MIPS 32bit on R4000 */ __asm__ __volatile__( ".set\tnoreorder\n" ".set\tnoat\n\t" ".set\tmips3\n\t" "dsll32\t$1,%2,0\n\t" "dsrl32\t%2,$1,0\n\t" "or\t%2,$1\n" "1:\tsd\t%2,(%0)\n\t" "subu\t%1,1\n\t" "bnez\t%1,1b\n\t" "addiu\t%0,8\n\t" ".set\tmips0\n\t" ".set\tat\n" ".set\treorder" :"=r" (dummy1), "=r" (dummy2) :"r" (pte_val(BAD_PAGE)), "0" (page), "1" (PAGE_SIZE/8)); #else __asm__ __volatile__( ".set\tnoreorder\n" "1:\tsw\t%2,(%0)\n\t" "subu\t%1,1\n\t" "bnez\t%1,1b\n\t" "addiu\t%0,4\n\t" ".set\treorder" :"=r" (dummy1), "=r" (dummy2) :"r" (pte_val(BAD_PAGE)), "0" (page), "1" (PAGE_SIZE/4)); #endif return (pte_t *)page; } static inline void __zeropage(unsigned long page) { unsigned long dummy1, dummy2; #ifdef __R4000__ /* * Use 64bit code even for Linux/MIPS 32bit on R4000 */ __asm__ __volatile__( ".set\tnoreorder\n" ".set\tnoat\n\t" ".set\tmips3\n" "1:\tsd\t$0,(%0)\n\t" "subu\t%1,1\n\t" "bnez\t%1,1b\n\t" "addiu\t%0,8\n\t" ".set\tmips0\n\t" ".set\tat\n" ".set\treorder" :"=r" (dummy1), "=r" (dummy2) :"0" (page), "1" (PAGE_SIZE/8)); #else __asm__ __volatile__( ".set\tnoreorder\n" "1:\tsw\t$0,(%0)\n\t" "subu\t%1,1\n\t" "bnez\t%1,1b\n\t" "addiu\t%0,4\n\t" ".set\treorder" :"=r" (dummy1), "=r" (dummy2) :"0" (page), "1" (PAGE_SIZE/4)); #endif } static inline void zeropage(unsigned long page) { sys_cacheflush((void *)page, PAGE_SIZE, BCACHE); sync_mem(); __zeropage(page + (PT_OFFSET - PAGE_OFFSET)); } pte_t __bad_page(void) { extern char empty_bad_page[PAGE_SIZE]; unsigned long page = (unsigned long)empty_bad_page; zeropage(page); return pte_mkdirty(mk_pte(page, PAGE_SHARED)); } unsigned long __zero_page(void) { unsigned long page = (unsigned long) empty_zero_page; zeropage(page); return page; } /* * This is horribly inefficient ... */ void __copy_page(unsigned long from, unsigned long to) { /* * Now copy page from uncached KSEG1 to KSEG0. The copy destination * is in KSEG0 so that we keep stupid L2 caches happy. */ if(from == (unsigned long) empty_zero_page) { /* * The page copied most is the COW empty_zero_page. Since we * know its contents we can avoid the writeback reading of * the page. Speeds up the standard case a lot. */ __zeropage(to); } else { /* * Force writeback of old page to memory. We don't know the * virtual address, so we have to flush the entire cache ... */ sys_cacheflush(0, ~0, DCACHE); sync_mem(); memcpy((void *) to, (void *) (from + (PT_OFFSET - PAGE_OFFSET)), PAGE_SIZE); } /* * Now writeback the page again if colour has changed. * Actually this does a Hit_Writeback, but due to an artifact in * the R4xx0 implementation this should be slightly faster. * Then sweep chipset controlled secondary caches and the ICACHE. */ if (page_colour(from) != page_colour(to)) sys_cacheflush(0, ~0, DCACHE); sys_cacheflush(0, ~0, ICACHE); } void show_mem(void) { int i, free = 0, total = 0, reserved = 0; int shared = 0; printk("Mem-info:\n"); show_free_areas(); printk("Free swap: %6dkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); i = (high_memory - PAGE_OFFSET) >> PAGE_SHIFT; while (i-- > 0) { total++; if (mem_map[i].reserved) reserved++; else if (!mem_map[i].count) free++; else shared += mem_map[i].count-1; } printk("%d pages of RAM\n", total); printk("%d free pages\n", free); printk("%d reserved pages\n", reserved); printk("%d pages shared\n", shared); show_buffers(); #ifdef CONFIG_NET show_net_buffers(); #endif } extern unsigned long free_area_init(unsigned long, unsigned long); unsigned long paging_init(unsigned long start_mem, unsigned long end_mem) { pgd_init((unsigned long)swapper_pg_dir - (PT_OFFSET - PAGE_OFFSET)); return free_area_init(start_mem, end_mem); } void mem_init(unsigned long start_mem, unsigned long end_mem) { int codepages = 0; int datapages = 0; unsigned long tmp; extern int _etext; #ifdef CONFIG_MIPS_JAZZ start_mem = vdma_init(start_mem, end_mem); #endif end_mem &= PAGE_MASK; high_memory = end_mem; /* mark usable pages in the mem_map[] */ start_mem = PAGE_ALIGN(start_mem); tmp = start_mem; while (tmp < high_memory) { mem_map[MAP_NR(tmp)].reserved = 0; tmp += PAGE_SIZE; } #ifdef CONFIG_DESKSTATION_TYNE deskstation_tyne_dma_init(); #endif #ifdef CONFIG_SOUND sound_mem_init(); #endif for (tmp = PAGE_OFFSET ; tmp < high_memory ; tmp += PAGE_SIZE) { if (mem_map[MAP_NR(tmp)].reserved) { if (tmp < (unsigned long) &_etext) codepages++; else if (tmp < start_mem) datapages++; continue; } mem_map[MAP_NR(tmp)].count = 1; free_page(tmp); } tmp = nr_free_pages << PAGE_SHIFT; printk("Memory: %luk/%luk available (%dk kernel code, %dk data)\n", tmp >> 10, (high_memory - PAGE_OFFSET) >> 10, codepages << (PAGE_SHIFT-10), datapages << (PAGE_SHIFT-10)); return; } void si_meminfo(struct sysinfo *val) { int i; i = high_memory >> PAGE_SHIFT; val->totalram = 0; val->sharedram = 0; val->freeram = nr_free_pages << PAGE_SHIFT; val->bufferram = buffermem; while (i-- > 0) { if (mem_map[i].reserved) continue; val->totalram++; if (!mem_map[i].count) continue; val->sharedram += mem_map[i].count-1; } val->totalram <<= PAGE_SHIFT; val->sharedram <<= PAGE_SHIFT; return; }
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