patch-2.1.19 linux/arch/sparc64/mm/generic.c

• Lines: 125
• Date: Mon Dec 30 11:59:59 1996
• Orig file: v2.1.18/linux/arch/sparc64/mm/generic.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.18/linux/arch/sparc64/mm/generic.c linux/arch/sparc64/mm/generic.c
@@ -0,0 +1,124 @@
+/* $Id: generic.c,v 1.1 1996/12/26 10:24:23 davem Exp $
+ * generic.c: Generic Sparc mm routines that are not dependent upon
+ *            MMU type but are Sparc specific.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+
+#include <asm/pgtable.h>
+#include <asm/page.h>
+
+
+/* Allocate a block of RAM which is aligned to its size.
+ * This procedure can be used until the call to mem_init().
+ */
+void *sparc_init_alloc(unsigned long *kbrk, unsigned long size)
+{
+        unsigned long mask = size - 1;
+        unsigned long ret;
+
+        if(!size)
+                return 0x0;
+        if(size & mask) {
+                prom_printf("panic: sparc_init_alloc botch\n");
+                prom_halt();
+        }
+        ret = (*kbrk + mask) & ~mask;
+        *kbrk = ret + size;
+        memset((void*) ret, 0, size);
+        return (void*) ret;
+}
+
+static inline void forget_pte(pte_t page)
+{
+	if (pte_none(page))
+		return;
+	if (pte_present(page)) {
+		unsigned long addr = pte_page(page);
+		if (MAP_NR(addr) >= max_mapnr || PageReserved(mem_map+MAP_NR(addr)))
+			return;
+		free_page(addr);
+		if (current->mm->rss <= 0)
+			return;
+		current->mm->rss--;
+		return;
+	}
+	swap_free(pte_val(page));
+}
+
+/* Remap IO memory, the same way as remap_page_range(), but use
+ * the obio memory space.
+ *
+ * They use a pgprot that sets PAGE_IO and does not check the
+ * mem_map table as this is independent of normal memory.
+ */
+static inline void io_remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
+	unsigned long offset, pgprot_t prot, int space)
+{
+	unsigned long end;
+
+	address &= ~PMD_MASK;
+	end = address + size;
+	if (end > PMD_SIZE)
+		end = PMD_SIZE;
+	do {
+		pte_t oldpage = *pte;
+		pte_clear(pte);
+		set_pte(pte, mk_pte_io(offset, prot, space));
+		forget_pte(oldpage);
+		address += PAGE_SIZE;
+		offset += PAGE_SIZE;
+		pte++;
+	} while (address < end);
+}
+
+static inline int io_remap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size,
+	unsigned long offset, pgprot_t prot, int space)
+{
+	unsigned long end;
+
+	address &= ~PGDIR_MASK;
+	end = address + size;
+	if (end > PGDIR_SIZE)
+		end = PGDIR_SIZE;
+	offset -= address;
+	do {
+		pte_t * pte = pte_alloc(pmd, address);
+		if (!pte)
+			return -ENOMEM;
+		io_remap_pte_range(pte, address, end - address, address + offset, prot, space);
+		address = (address + PMD_SIZE) & PMD_MASK;
+		pmd++;
+	} while (address < end);
+	return 0;
+}
+
+int io_remap_page_range(unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot, int space)
+{
+	int error = 0;
+	pgd_t * dir;
+	unsigned long beg = from;
+	unsigned long end = from + size;
+
+	prot = __pgprot(pg_iobits);
+	offset -= from;
+	dir = pgd_offset(current->mm, from);
+	flush_cache_range(current->mm, beg, end);
+	while (from < end) {
+		pmd_t *pmd = pmd_alloc(dir, from);
+		error = -ENOMEM;
+		if (!pmd)
+			break;
+		error = io_remap_pmd_range(pmd, from, end - from, offset + from, prot, space);
+		if (error)
+			break;
+		from = (from + PGDIR_SIZE) & PGDIR_MASK;
+		dir++;
+	}
+	flush_tlb_range(current->mm, beg, end);
+	return error;
+}