patch-2.4.22 linux-2.4.22/arch/mips/mm/remap.c

• Lines: 116
• Date: 2003-08-25 04:44:40.000000000 -0700
• Orig file: linux-2.4.21/arch/mips/mm/remap.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.21/arch/mips/mm/remap.c linux-2.4.22/arch/mips/mm/remap.c
@@ -0,0 +1,115 @@
+/* 
+ * arch/mips/mm/remap.c
+ * A copy of mm/memory.c with modifications to handle 64 bit
+ * physical addresses.
+ */
+
+/*
+ * maps a range of physical memory into the requested pages. the old
+ * mappings are removed. any references to nonexistent pages results
+ * in null mappings (currently treated as "copy-on-access")
+ */
+
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/swap.h>
+#include <linux/smp_lock.h>
+#include <linux/swapctl.h>
+#include <linux/iobuf.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/module.h>
+
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+#include <asm/tlb.h>
+
+/*
+ * Return indicates whether a page was freed so caller can adjust rss
+ */
+static inline void forget_pte(pte_t page)
+{
+	if (!pte_none(page)) {
+		printk("forget_pte: old mapping existed!\n");
+		BUG();
+	}
+}
+
+static inline void remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
+	phys_t phys_addr, pgprot_t prot)
+{
+	unsigned long end;
+
+	address &= ~PMD_MASK;
+	end = address + size;
+	if (end > PMD_SIZE)
+		end = PMD_SIZE;
+	do {
+		struct page *page;
+		pte_t oldpage;
+		oldpage = ptep_get_and_clear(pte);
+
+		page = virt_to_page(__va(phys_addr));
+		if ((!VALID_PAGE(page)) || PageReserved(page))
+ 			set_pte(pte, mk_pte_phys(phys_addr, prot));
+		forget_pte(oldpage);
+		address += PAGE_SIZE;
+		phys_addr += PAGE_SIZE;
+		pte++;
+	} while (address && (address < end));
+}
+
+static inline int remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
+	phys_t phys_addr, pgprot_t prot)
+{
+	unsigned long end;
+
+	address &= ~PGDIR_MASK;
+	end = address + size;
+	if (end > PGDIR_SIZE)
+		end = PGDIR_SIZE;
+	phys_addr -= address;
+	do {
+		pte_t * pte = pte_alloc(mm, pmd, address);
+		if (!pte)
+			return -ENOMEM;
+		remap_pte_range(pte, address, end - address, address + phys_addr, prot);
+		address = (address + PMD_SIZE) & PMD_MASK;
+		pmd++;
+	} while (address && (address < end));
+	return 0;
+}
+
+extern phys_t (*fixup_bigphys_addr)(phys_t phys_addr, phys_t size);
+/*  Note: this is only safe if the mm semaphore is held when called. */
+int remap_page_range_high(unsigned long from, phys_t phys_addr, unsigned long size, pgprot_t prot)
+{
+	int error = 0;
+	pgd_t * dir;
+	unsigned long beg = from;
+	unsigned long end = from + size;
+	struct mm_struct *mm = current->mm;
+
+	phys_addr = fixup_bigphys_addr(phys_addr, size);
+	phys_addr -= from;
+	dir = pgd_offset(mm, from);
+	flush_cache_range(mm, beg, end);
+	if (from >= end)
+		BUG();
+
+	spin_lock(&mm->page_table_lock);
+	do {
+		pmd_t *pmd = pmd_alloc(mm, dir, from);
+		error = -ENOMEM;
+		if (!pmd)
+			break;
+		error = remap_pmd_range(mm, pmd, from, end - from, phys_addr + from, prot);
+		if (error)
+			break;
+		from = (from + PGDIR_SIZE) & PGDIR_MASK;
+		dir++;
+	} while (from && (from < end));
+	spin_unlock(&mm->page_table_lock);
+	flush_tlb_range(mm, beg, end);
+	return error;
+}