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-rw-r--r--arch/s390/mm/init.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
new file mode 100644
index 000000000..4e30c015a
--- /dev/null
+++ b/arch/s390/mm/init.c
@@ -0,0 +1,385 @@
+/*
+ * arch/s390/mm/init.c
+ *
+ * S390 version
+ * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Author(s): Hartmut Penner (hp@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 = 0;
+
+/*
+ * 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..
+ *
+ * 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.
+ */
+
+pgd_t swapper_pg_dir[512] __attribute__ ((__aligned__ (4096)));
+unsigned long empty_bad_page[1024] __attribute__ ((__aligned__ (4096)));
+unsigned long empty_zero_page[1024] __attribute__ ((__aligned__ (4096)));
+pte_t empty_bad_pte_table[1024] __attribute__ ((__aligned__ (4096)));
+
+static int test_access(unsigned long loc)
+{
+ static const int ssm_mask = 0x07000000L;
+ int rc, i;
+
+ rc = 0;
+ for (i=0; i<4; i++) {
+ __asm__ __volatile__(
+ " slr %0,%0\n"
+ " ssm %1\n"
+ " tprot 0(%2),0\n"
+ "0: jne 1f\n"
+ " lhi %0,1\n"
+ "1: ssm %3\n"
+ ".section __ex_table,\"a\"\n"
+ " .align 4\n"
+ " .long 0b,1b\n"
+ ".previous"
+ : "+&d" (rc) : "i" (0), "a" (loc), "m" (ssm_mask)
+ : "cc");
+ if (rc == 0)
+ break;
+ loc += 0x100000;
+ }
+ return rc;
+}
+
+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;
+}
+
+static inline void invalidate_page(pte_t *pte)
+{
+ int i;
+ for (i=0;i<PTRS_PER_PTE;i++)
+ pte_clear(pte++);
+}
+
+void __handle_bad_pmd(pmd_t *pmd)
+{
+ pmd_ERROR(*pmd);
+ pmd_val(*pmd) = _PAGE_TABLE + __pa(get_bad_pte_table());
+}
+
+void __handle_bad_pmd_kernel(pmd_t *pmd)
+{
+ pmd_ERROR(*pmd);
+ pmd_val(*pmd) = _KERNPG_TABLE + __pa(get_bad_pte_table());
+}
+
+pte_t *get_pte_kernel_slow(pmd_t *pmd, unsigned long offset)
+{
+ pte_t *pte;
+
+ pte = (pte_t *) __get_free_page(GFP_KERNEL);
+ if (pmd_none(*pmd)) {
+ if (pte) {
+ invalidate_page(pte);
+ pmd_val(pmd[0]) = _KERNPG_TABLE + __pa(pte);
+ pmd_val(pmd[1]) = _KERNPG_TABLE + __pa(pte)+1024;
+ pmd_val(pmd[2]) = _KERNPG_TABLE + __pa(pte)+2048;
+ pmd_val(pmd[3]) = _KERNPG_TABLE + __pa(pte)+3072;
+ return pte + offset;
+ }
+ pte = get_bad_pte_table();
+ pmd_val(pmd[0]) = _KERNPG_TABLE + __pa(pte);
+ pmd_val(pmd[1]) = _KERNPG_TABLE + __pa(pte)+1024;
+ pmd_val(pmd[2]) = _KERNPG_TABLE + __pa(pte)+2048;
+ pmd_val(pmd[3]) = _KERNPG_TABLE + __pa(pte)+3072;
+ return NULL;
+ }
+ free_page((unsigned long)pte);
+ if (pmd_bad(*pmd)) {
+ __handle_bad_pmd_kernel(pmd);
+ return NULL;
+ }
+ return (pte_t *) pmd_page(*pmd) + offset;
+}
+
+pte_t *get_pte_slow(pmd_t *pmd, unsigned long offset)
+{
+ unsigned long pte;
+
+ pte = (unsigned long) __get_free_page(GFP_KERNEL);
+ if (pmd_none(*pmd)) {
+ if (pte) {
+ invalidate_page((pte_t*) pte);
+ pmd_val(pmd[0]) = _PAGE_TABLE + __pa(pte);
+ pmd_val(pmd[1]) = _PAGE_TABLE + __pa(pte)+1024;
+ pmd_val(pmd[2]) = _PAGE_TABLE + __pa(pte)+2048;
+ pmd_val(pmd[3]) = _PAGE_TABLE + __pa(pte)+3072;
+ return (pte_t *) pte + offset;
+ }
+ pte = (unsigned long) get_bad_pte_table();
+ pmd_val(pmd[0]) = _PAGE_TABLE + __pa(pte);
+ pmd_val(pmd[1]) = _PAGE_TABLE + __pa(pte)+1024;
+ pmd_val(pmd[2]) = _PAGE_TABLE + __pa(pte)+2048;
+ pmd_val(pmd[3]) = _PAGE_TABLE + __pa(pte)+3072;
+ return NULL;
+ }
+ free_page(pte);
+ if (pmd_bad(*pmd)) {
+ __handle_bad_pmd(pmd);
+ return NULL;
+ }
+ 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++;
+ if(pmd_quicklist)
+ free_pmd_slow(get_pmd_fast()), freed++;
+ if(pte_quicklist)
+ free_pte_slow(get_pte_fast()), freed++;
+ } while(pgtable_cache_size > low);
+ }
+ return freed;
+}
+
+void show_mem(void)
+{
+ int i,free = 0,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 (!atomic_read(&mem_map[i].count))
+ free++;
+ else
+ 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 - note that the first 4MB are
+ * already mapped by head.S.
+ * paging_init will erase this initial mapping
+ */
+
+unsigned long last_valid_pfn;
+
+void __init paging_init(void)
+{
+ pgd_t * pg_dir;
+ pte_t * pg_table;
+ pte_t pte;
+ int i;
+ unsigned long tmp;
+ unsigned long address=0;
+ unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
+ unsigned long end_mem = (unsigned long) __va(max_low_pfn*PAGE_SIZE);
+
+ /* unmap whole virtual address space */
+
+ pg_dir = swapper_pg_dir;
+
+ for (i=0;i<KERNEL_PGD_PTRS;i++)
+ pmd_clear((pmd_t*)pg_dir++);
+
+ /*
+ * map whole physical memory to virtual memory (identity mapping)
+ */
+
+ pg_dir = swapper_pg_dir;
+
+ while (address < end_mem) {
+ /*
+ * pg_table is physical at this point
+ */
+ pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+
+ pg_dir->pgd0 = (_PAGE_TABLE | __pa(pg_table));
+ pg_dir->pgd1 = (_PAGE_TABLE | (__pa(pg_table)+1024));
+ pg_dir->pgd2 = (_PAGE_TABLE | (__pa(pg_table)+2048));
+ pg_dir->pgd3 = (_PAGE_TABLE | (__pa(pg_table)+3072));
+ pg_dir++;
+
+ for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
+ pte = mk_pte_phys(address, PAGE_KERNEL);
+ if (address >= end_mem)
+ pte_clear(&pte);
+ set_pte(pg_table, pte);
+ address += PAGE_SIZE;
+ }
+ }
+
+ /* enable virtual mapping in kernel mode */
+ __asm__ __volatile__(" LCTL 1,1,%0\n"
+ " LCTL 7,7,%0\n"
+ " LCTL 13,13,%0"
+ : :"m" (pgdir_k));
+
+ local_flush_tlb();
+
+ {
+ unsigned long zones_size[MAX_NR_ZONES] = { 0, 0, 0};
+
+ zones_size[ZONE_DMA] = max_low_pfn;
+ free_area_init(zones_size);
+ }
+
+ return;
+}
+
+void __init mem_init(void)
+{
+ int codesize, reservedpages, datasize, initsize;
+ int 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 & 0x3ff) == 0 &&
+ test_access(tmp * PAGE_SIZE) == 0) {
+ printk("4M Segment %lX not available\n",tmp*PAGE_SIZE);
+ do {
+ set_bit(PG_reserved, &mem_map[tmp].flags);
+ reservedpages++;
+ tmp++;
+ } while (tmp < max_low_pfn && (tmp & 0x3ff));
+ } 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 (%dk kernel code, %dk reserved, %dk data, %dk 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(mem_map + MAP_NR(addr));
+ set_page_count(mem_map+MAP_NR(addr), 1);
+ free_page(addr);
+ totalram_pages++;
+ }
+ printk ("Freeing unused kernel memory: %dk 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(mem_map + MAP_NR(start));
+ set_page_count(mem_map+MAP_NR(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->mem_unit = PAGE_SIZE;
+ return;
+}
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