1 files changed, 320 insertions, 0 deletions
diff --git a/arch/i386/mm/ioremap.c b/arch/i386/mm/ioremap.c
new file mode 100644
index 00000000000..db06f739991
--- /dev/null
+++ b/arch/i386/mm/ioremap.c
@@ -0,0 +1,320 @@
+/*
+ * arch/i386/mm/ioremap.c
+ *
+ * Re-map IO memory to kernel address space so that we can access it.
+ * This is needed for high PCI addresses that aren't mapped in the
+ * 640k-1MB IO memory area on PC's
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <asm/io.h>
+#include <asm/fixmap.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/pgtable.h>
+
+#define ISA_START_ADDRESS	0xa0000
+#define ISA_END_ADDRESS		0x100000
+
+static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
+		unsigned long end, unsigned long phys_addr, unsigned long flags)
+{
+	pte_t *pte;
+	unsigned long pfn;
+
+	pfn = phys_addr >> PAGE_SHIFT;
+	pte = pte_alloc_kernel(&init_mm, pmd, addr);
+	if (!pte)
+		return -ENOMEM;
+	do {
+		BUG_ON(!pte_none(*pte));
+		set_pte(pte, pfn_pte(pfn, __pgprot(_PAGE_PRESENT | _PAGE_RW | 
+					_PAGE_DIRTY | _PAGE_ACCESSED | flags)));
+		pfn++;
+	} while (pte++, addr += PAGE_SIZE, addr != end);
+	return 0;
+}
+
+static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
+		unsigned long end, unsigned long phys_addr, unsigned long flags)
+{
+	pmd_t *pmd;
+	unsigned long next;
+
+	phys_addr -= addr;
+	pmd = pmd_alloc(&init_mm, pud, addr);
+	if (!pmd)
+		return -ENOMEM;
+	do {
+		next = pmd_addr_end(addr, end);
+		if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, flags))
+			return -ENOMEM;
+	} while (pmd++, addr = next, addr != end);
+	return 0;
+}
+
+static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
+		unsigned long end, unsigned long phys_addr, unsigned long flags)
+{
+	pud_t *pud;
+	unsigned long next;
+
+	phys_addr -= addr;
+	pud = pud_alloc(&init_mm, pgd, addr);
+	if (!pud)
+		return -ENOMEM;
+	do {
+		next = pud_addr_end(addr, end);
+		if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, flags))
+			return -ENOMEM;
+	} while (pud++, addr = next, addr != end);
+	return 0;
+}
+
+static int ioremap_page_range(unsigned long addr,
+		unsigned long end, unsigned long phys_addr, unsigned long flags)
+{
+	pgd_t *pgd;
+	unsigned long next;
+	int err;
+
+	BUG_ON(addr >= end);
+	flush_cache_all();
+	phys_addr -= addr;
+	pgd = pgd_offset_k(addr);
+	spin_lock(&init_mm.page_table_lock);
+	do {
+		next = pgd_addr_end(addr, end);
+		err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, flags);
+		if (err)
+			break;
+	} while (pgd++, addr = next, addr != end);
+	spin_unlock(&init_mm.page_table_lock);
+	flush_tlb_all();
+	return err;
+}
+
+/*
+ * Generic mapping function (not visible outside):
+ */
+
+/*
+ * Remap an arbitrary physical address space into the kernel virtual
+ * address space. Needed when the kernel wants to access high addresses
+ * directly.
+ *
+ * NOTE! We need to allow non-page-aligned mappings too: we will obviously
+ * have to convert them into an offset in a page-aligned mapping, but the
+ * caller shouldn't need to know that small detail.
+ */
+void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
+{
+	void __iomem * addr;
+	struct vm_struct * area;
+	unsigned long offset, last_addr;
+
+	/* Don't allow wraparound or zero size */
+	last_addr = phys_addr + size - 1;
+	if (!size || last_addr < phys_addr)
+		return NULL;
+
+	/*
+	 * Don't remap the low PCI/ISA area, it's always mapped..
+	 */
+	if (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
+		return (void __iomem *) phys_to_virt(phys_addr);
+
+	/*
+	 * Don't allow anybody to remap normal RAM that we're using..
+	 */
+	if (phys_addr <= virt_to_phys(high_memory - 1)) {
+		char *t_addr, *t_end;
+		struct page *page;
+
+		t_addr = __va(phys_addr);
+		t_end = t_addr + (size - 1);
+	   
+		for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
+			if(!PageReserved(page))
+				return NULL;
+	}
+
+	/*
+	 * Mappings have to be page-aligned
+	 */
+	offset = phys_addr & ~PAGE_MASK;
+	phys_addr &= PAGE_MASK;
+	size = PAGE_ALIGN(last_addr+1) - phys_addr;
+
+	/*
+	 * Ok, go for it..
+	 */
+	area = get_vm_area(size, VM_IOREMAP | (flags << 20));
+	if (!area)
+		return NULL;
+	area->phys_addr = phys_addr;
+	addr = (void __iomem *) area->addr;
+	if (ioremap_page_range((unsigned long) addr,
+			(unsigned long) addr + size, phys_addr, flags)) {
+		vunmap((void __force *) addr);
+		return NULL;
+	}
+	return (void __iomem *) (offset + (char __iomem *)addr);
+}
+
+
+/**
+ * ioremap_nocache     -   map bus memory into CPU space
+ * @offset:    bus address of the memory
+ * @size:      size of the resource to map
+ *
+ * ioremap_nocache performs a platform specific sequence of operations to
+ * make bus memory CPU accessible via the readb/readw/readl/writeb/
+ * writew/writel functions and the other mmio helpers. The returned
+ * address is not guaranteed to be usable directly as a virtual
+ * address. 
+ *
+ * This version of ioremap ensures that the memory is marked uncachable
+ * on the CPU as well as honouring existing caching rules from things like
+ * the PCI bus. Note that there are other caches and buffers on many 
+ * busses. In particular driver authors should read up on PCI writes
+ *
+ * It's useful if some control registers are in such an area and
+ * write combining or read caching is not desirable:
+ * 
+ * Must be freed with iounmap.
+ */
+
+void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size)
+{
+	unsigned long last_addr;
+	void __iomem *p = __ioremap(phys_addr, size, _PAGE_PCD);
+	if (!p) 
+		return p; 
+
+	/* Guaranteed to be > phys_addr, as per __ioremap() */
+	last_addr = phys_addr + size - 1;
+
+	if (last_addr < virt_to_phys(high_memory) - 1) {
+		struct page *ppage = virt_to_page(__va(phys_addr));		
+		unsigned long npages;
+
+		phys_addr &= PAGE_MASK;
+
+		/* This might overflow and become zero.. */
+		last_addr = PAGE_ALIGN(last_addr);
+
+		/* .. but that's ok, because modulo-2**n arithmetic will make
+	 	* the page-aligned "last - first" come out right.
+	 	*/
+		npages = (last_addr - phys_addr) >> PAGE_SHIFT;
+
+		if (change_page_attr(ppage, npages, PAGE_KERNEL_NOCACHE) < 0) { 
+			iounmap(p); 
+			p = NULL;
+		}
+		global_flush_tlb();
+	}
+
+	return p;					
+}
+
+void iounmap(volatile void __iomem *addr)
+{
+	struct vm_struct *p;
+	if ((void __force *) addr <= high_memory) 
+		return;
+
+	/*
+	 * __ioremap special-cases the PCI/ISA range by not instantiating a
+	 * vm_area and by simply returning an address into the kernel mapping
+	 * of ISA space.   So handle that here.
+	 */
+	if (addr >= phys_to_virt(ISA_START_ADDRESS) &&
+			addr < phys_to_virt(ISA_END_ADDRESS))
+		return;
+
+	p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
+	if (!p) { 
+		printk("__iounmap: bad address %p\n", addr);
+		return;
+	}
+
+	if ((p->flags >> 20) && p->phys_addr < virt_to_phys(high_memory) - 1) {
+		/* p->size includes the guard page, but cpa doesn't like that */
+		change_page_attr(virt_to_page(__va(p->phys_addr)),
+				 p->size >> PAGE_SHIFT,
+				 PAGE_KERNEL);
+		global_flush_tlb();
+	} 
+	kfree(p); 
+}
+
+void __init *bt_ioremap(unsigned long phys_addr, unsigned long size)
+{
+	unsigned long offset, last_addr;
+	unsigned int nrpages;
+	enum fixed_addresses idx;
+
+	/* Don't allow wraparound or zero size */
+	last_addr = phys_addr + size - 1;
+	if (!size || last_addr < phys_addr)
+		return NULL;
+
+	/*
+	 * Don't remap the low PCI/ISA area, it's always mapped..
+	 */
+	if (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
+		return phys_to_virt(phys_addr);
+
+	/*
+	 * Mappings have to be page-aligned
+	 */
+	offset = phys_addr & ~PAGE_MASK;
+	phys_addr &= PAGE_MASK;
+	size = PAGE_ALIGN(last_addr) - phys_addr;
+
+	/*
+	 * Mappings have to fit in the FIX_BTMAP area.
+	 */
+	nrpages = size >> PAGE_SHIFT;
+	if (nrpages > NR_FIX_BTMAPS)
+		return NULL;
+
+	/*
+	 * Ok, go for it..
+	 */
+	idx = FIX_BTMAP_BEGIN;
+	while (nrpages > 0) {
+		set_fixmap(idx, phys_addr);
+		phys_addr += PAGE_SIZE;
+		--idx;
+		--nrpages;
+	}
+	return (void*) (offset + fix_to_virt(FIX_BTMAP_BEGIN));
+}
+
+void __init bt_iounmap(void *addr, unsigned long size)
+{
+	unsigned long virt_addr;
+	unsigned long offset;
+	unsigned int nrpages;
+	enum fixed_addresses idx;
+
+	virt_addr = (unsigned long)addr;
+	if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN))
+		return;
+	offset = virt_addr & ~PAGE_MASK;
+	nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
+
+	idx = FIX_BTMAP_BEGIN;
+	while (nrpages > 0) {
+		clear_fixmap(idx);
+		--idx;
+		--nrpages;
+	}
+}