patch-2.4.2 linux/arch/s390x/mm/init.c

• Lines: 406
• Date: Tue Feb 13 14:13:44 2001
• Orig file: v2.4.1/linux/arch/s390x/mm/init.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.1/linux/arch/s390x/mm/init.c linux/arch/s390x/mm/init.c
@@ -0,0 +1,405 @@
+/*
+ *  arch/s390/mm/init.c
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Hartmut Penner (hpenner@de.ibm.com)
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1995  Linus Torvalds
+ */
+
+#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>
+#ifdef CONFIG_BLK_DEV_INITRD
+#include <linux/blk.h>
+#endif
+#include <linux/pagemap.h>
+#include <linux/bootmem.h>
+
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/dma.h>
+#include <asm/lowcore.h>
+
+static unsigned long totalram_pages;
+
+/*
+ * empty_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 an inode
+ * unused etc..
+ *
+ * empty_bad_pte_table is the accompanying page-table: it is initialized
+ * to point to BAD_PAGE entries.
+ *
+ * empty_bad_pmd_table is the accompanying segment table: it is initialized
+ * to point to empty_bad_pte_table page tables.
+ *
+ * ZERO_PAGE is a special page that is used for zero-initialized
+ * data and COW.
+ */
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
+char  empty_bad_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+pmd_t empty_bad_pmd_table[PTRS_PER_PMD] __attribute__((__aligned__(PAGE_SIZE)));
+pte_t empty_bad_pte_table[PTRS_PER_PTE] __attribute__((__aligned__(PAGE_SIZE)));
+
+static int test_access(unsigned long loc)
+{
+	static const int ssm_mask = 0x07000000L;
+	int rc, i;
+
+        rc = 0;
+	for (i=0; i<2; i++) {
+		__asm__ __volatile__(
+                        "    slgr  %0,%0\n"
+			"    ssm   %1\n"
+			"    tprot 0(%2),0\n"
+			"0:  jne   1f\n"
+			"    lghi  %0,1\n"
+			"1:  ssm   %3\n"
+                        ".section __ex_table,\"a\"\n"
+                        "   .align 8\n"
+                        "   .quad  0b,1b\n"
+                        ".previous"
+			: "+&d" (rc) : "i" (0), "a" (loc), "m" (ssm_mask)
+			: "cc");
+		if (rc == 0)
+			break;
+		loc += 0x100000;
+	}
+	return rc;
+}
+
+static pmd_t *get_bad_pmd_table(void)
+{
+       pmd_t v;
+       int i;
+
+       pmd_set(&v, empty_bad_pte_table);
+
+       for (i = 0; i < PTRS_PER_PMD; i++)
+               empty_bad_pmd_table[i] = v;
+
+       return empty_bad_pmd_table;
+}
+
+static pte_t *get_bad_pte_table(void)
+{
+	pte_t v;
+	int i;
+
+	v = pte_mkdirty(mk_pte_phys(__pa(empty_bad_page), PAGE_SHARED));
+
+	for (i = 0; i < PAGE_SIZE/sizeof(pte_t); i++)
+		empty_bad_pte_table[i] = v;
+
+	return empty_bad_pte_table;
+}
+
+pmd_t *
+get_pmd_slow(pgd_t *pgd, unsigned long offset)
+{
+        pmd_t *pmd;
+        int i;
+
+        pmd = (pmd_t *) __get_free_pages(GFP_KERNEL,2);
+        if (pgd_none(*pgd)) {
+                if (pmd) {
+                        for (i = 0; i < PTRS_PER_PMD; i++)
+                                pmd_clear(pmd+i);
+                        pgd_set(pgd, pmd);
+                        return pmd + offset;
+                }
+                pmd = (pmd_t *) get_bad_pmd_table();
+                pgd_set(pgd, pmd);
+                return NULL;
+        }
+        free_pages((unsigned long)pmd,2);
+        if (pgd_bad(*pgd))
+		BUG();
+        return (pmd_t *) pgd_page(*pgd) + offset;
+}
+
+pte_t *get_pte_slow(pmd_t *pmd, unsigned long offset)
+{
+        pte_t *pte;
+        int i;
+
+        pte = (pte_t*) __get_free_page(GFP_KERNEL);
+        if (pmd_none(*pmd)) {
+                if (pte) {
+                        for (i=0;i<PTRS_PER_PTE;i++)
+                                pte_clear(pte+i);
+                        pmd_set(pmd,pte);
+                        return pte + offset;
+                }
+		pte = (pte_t*) get_bad_pte_table();
+                pmd_set(pmd,pte);
+                return NULL;
+        }
+        free_page(__pa(pte));
+        if (pmd_bad(*pmd))
+		BUG();
+        return (pte_t *) pmd_page(*pmd) + offset;
+}
+
+int do_check_pgt_cache(int low, int high)
+{
+        int freed = 0;
+        if(pgtable_cache_size > high) {
+                do {
+                        if(pgd_quicklist)
+                                free_pgd_slow(get_pgd_fast()), freed += 4;
+                        if(pmd_quicklist)
+                                free_pmd_slow(get_pmd_fast()), freed += 4;
+                        if(pte_quicklist)
+                                free_pte_slow(get_pte_fast()), freed++;
+                } while(pgtable_cache_size > low);
+        }
+        return freed;
+}
+
+void show_mem(void)
+{
+        int i, total = 0,reserved = 0;
+        int shared = 0, cached = 0;
+
+        printk("Mem-info:\n");
+        show_free_areas();
+        printk("Free swap:       %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
+        i = max_mapnr;
+        while (i-- > 0) {
+                total++;
+                if (PageReserved(mem_map+i))
+                        reserved++;
+                else if (PageSwapCache(mem_map+i))
+                        cached++;
+                else if (page_count(mem_map+i))
+                        shared += atomic_read(&mem_map[i].count) - 1;
+        }
+        printk("%d pages of RAM\n",total);
+        printk("%d reserved pages\n",reserved);
+        printk("%d pages shared\n",shared);
+        printk("%d pages swap cached\n",cached);
+        printk("%ld pages in page table cache\n",pgtable_cache_size);
+        show_buffers();
+}
+
+/* References to section boundaries */
+
+extern unsigned long _text;
+extern unsigned long _etext;
+extern unsigned long _edata;
+extern unsigned long __bss_start;
+extern unsigned long _end;
+
+extern unsigned long __init_begin;
+extern unsigned long __init_end;
+
+/*
+ * paging_init() sets up the page tables
+ */
+
+unsigned long last_valid_pfn;
+
+void __init paging_init(void)
+{
+        pgd_t * pg_dir;
+	pmd_t * pm_dir;
+        pte_t * pt_dir;
+        pte_t   pte;
+	int     i,j,k;
+        unsigned long address=0;
+        unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
+          _REGION_TABLE;
+	unsigned long end_mem = (unsigned long) __va(max_low_pfn*PAGE_SIZE);
+	static const int ssm_mask = 0x04000000L;
+
+	unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
+	unsigned long dma_pfn, high_pfn;
+
+	dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
+	high_pfn = max_low_pfn;
+
+	if (dma_pfn > high_pfn)
+		zones_size[ZONE_DMA] = high_pfn;
+	else {
+		zones_size[ZONE_DMA] = dma_pfn;
+		zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
+	}
+
+	/* Initialize mem_map[].  */
+	free_area_init(zones_size);
+
+
+	/*
+	 * map whole physical memory to virtual memory (identity mapping) 
+	 */
+
+        pg_dir = swapper_pg_dir;
+	
+        for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
+
+                if (address >= end_mem) {
+                  pgd_clear(pg_dir);
+                  continue;
+                }          
+        
+	        pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
+                pgd_set(pg_dir,pm_dir);
+
+                for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
+                  if (address >= end_mem) {
+                    pmd_clear(pm_dir);
+                    continue; 
+                  }          
+
+                        pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+                        pmd_set(pm_dir,pt_dir);
+	
+                        for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
+                          pte = mk_pte_phys(address, PAGE_KERNEL);
+                          if (address >= end_mem) {
+                            pte_clear(&pte); 
+                            continue;
+                          }
+                          set_pte(pt_dir, pte);
+                          address += PAGE_SIZE;
+                        }
+                }
+        }
+
+        /* enable virtual mapping in kernel mode */
+        __asm__ __volatile__("lctlg 1,1,%0\n\t"
+                             "lctlg 7,7,%0\n\t"
+                             "lctlg 13,13,%0\n\t"
+                             "ssm   %1"
+			     : :"m" (pgdir_k), "m" (ssm_mask));
+
+        local_flush_tlb();
+
+        return;
+}
+
+void __init mem_init(void)
+{
+	unsigned long codesize, reservedpages, datasize, initsize;
+        unsigned long tmp;
+
+        max_mapnr = num_physpages = max_low_pfn;
+        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
+
+        /* clear the zero-page */
+        memset(empty_zero_page, 0, PAGE_SIZE);
+
+	/* this will put all low memory onto the freelists */
+	totalram_pages += free_all_bootmem();
+
+        /* mark usable pages in the mem_map[] and count reserved pages */
+	reservedpages = 0;
+	tmp = 0;
+	do {
+		if (tmp && (tmp & 0x1ff) == 0 && 
+                    test_access(tmp * PAGE_SIZE) == 0) {
+                        printk("2M Segment 0x%016lX not available\n",
+                               tmp * PAGE_SIZE);
+			do {
+                                set_bit(PG_reserved, &mem_map[tmp].flags);
+				reservedpages++;
+				tmp++;
+			} while (tmp < max_low_pfn && (tmp & 0x1ff));
+		} else {
+			if (PageReserved(mem_map+tmp))
+				reservedpages++;
+			tmp++;
+		}
+	} while (tmp < max_low_pfn);
+
+	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
+	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
+	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
+        printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
+                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
+                max_mapnr << (PAGE_SHIFT-10),
+                codesize >> 10,
+                reservedpages << (PAGE_SHIFT-10),
+                datasize >>10,
+                initsize >> 10);
+}
+
+void free_initmem(void)
+{
+        unsigned long addr;
+
+        addr = (unsigned long)(&__init_begin);
+        for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
+		ClearPageReserved(virt_to_page(addr));
+		set_page_count(virt_to_page(addr), 1);
+		free_page(addr);
+		totalram_pages++;
+        }
+        printk ("Freeing unused kernel memory: %ldk freed\n",
+		(&__init_end - &__init_begin) >> 10);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+        if (start < end)
+                printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
+	for (; start < end; start += PAGE_SIZE) {
+                ClearPageReserved(virt_to_page(start));
+                set_page_count(virt_to_page(start), 1);
+		free_page(start);
+		totalram_pages++;
+	}
+}
+#endif
+
+void si_meminfo(struct sysinfo *val)
+{
+        val->totalram = totalram_pages;
+	val->sharedram = 0;
+	val->freeram = nr_free_pages();
+	val->bufferram = atomic_read(&buffermem_pages);
+	val->totalhigh = 0;
+	val->freehigh = 0;
+	val->mem_unit = PAGE_SIZE;
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only.  This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-indent-level: 4 
+ * c-brace-imaginary-offset: 0
+ * c-brace-offset: -4
+ * c-argdecl-indent: 4
+ * c-label-offset: -4
+ * c-continued-statement-offset: 4
+ * c-continued-brace-offset: 0
+ * indent-tabs-mode: nil
+ * tab-width: 8
+ * End:
+ */