1 files changed, 283 insertions, 0 deletions
diff --git a/arch/x86_64/mm/ioremap.c b/arch/x86_64/mm/ioremap.c
new file mode 100644
index 00000000000..74ec8554b19
--- /dev/null
+++ b/arch/x86_64/mm/ioremap.c
@@ -0,0 +1,283 @@
+/*
+ * arch/x86_64/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/pgalloc.h>
+#include <asm/fixmap.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/proto.h>
+
+#define ISA_START_ADDRESS      0xa0000
+#define ISA_END_ADDRESS                0x100000
+
+static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
+	unsigned long phys_addr, unsigned long flags)
+{
+	unsigned long end;
+	unsigned long pfn;
+
+	address &= ~PMD_MASK;
+	end = address + size;
+	if (end > PMD_SIZE)
+		end = PMD_SIZE;
+	if (address >= end)
+		BUG();
+	pfn = phys_addr >> PAGE_SHIFT;
+	do {
+		if (!pte_none(*pte)) {
+			printk("remap_area_pte: page already exists\n");
+			BUG();
+		}
+		set_pte(pte, pfn_pte(pfn, __pgprot(_PAGE_PRESENT | _PAGE_RW | 
+					_PAGE_GLOBAL | _PAGE_DIRTY | _PAGE_ACCESSED | flags)));
+		address += PAGE_SIZE;
+		pfn++;
+		pte++;
+	} while (address && (address < end));
+}
+
+static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
+	unsigned long phys_addr, unsigned long flags)
+{
+	unsigned long end;
+
+	address &= ~PUD_MASK;
+	end = address + size;
+	if (end > PUD_SIZE)
+		end = PUD_SIZE;
+	phys_addr -= address;
+	if (address >= end)
+		BUG();
+	do {
+		pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
+		if (!pte)
+			return -ENOMEM;
+		remap_area_pte(pte, address, end - address, address + phys_addr, flags);
+		address = (address + PMD_SIZE) & PMD_MASK;
+		pmd++;
+	} while (address && (address < end));
+	return 0;
+}
+
+static inline int remap_area_pud(pud_t * pud, unsigned long address, unsigned long size,
+	unsigned long phys_addr, unsigned long flags)
+{
+	unsigned long end;
+
+	address &= ~PGDIR_MASK;
+	end = address + size;
+	if (end > PGDIR_SIZE)
+		end = PGDIR_SIZE;
+	phys_addr -= address;
+	if (address >= end)
+		BUG();
+	do {
+		pmd_t * pmd = pmd_alloc(&init_mm, pud, address);
+		if (!pmd)
+			return -ENOMEM;
+		remap_area_pmd(pmd, address, end - address, address + phys_addr, flags);
+		address = (address + PUD_SIZE) & PUD_MASK;
+		pud++;
+	} while (address && (address < end));
+	return 0;
+}
+
+static int remap_area_pages(unsigned long address, unsigned long phys_addr,
+				 unsigned long size, unsigned long flags)
+{
+	int error;
+	pgd_t *pgd;
+	unsigned long end = address + size;
+
+	phys_addr -= address;
+	pgd = pgd_offset_k(address);
+	flush_cache_all();
+	if (address >= end)
+		BUG();
+	spin_lock(&init_mm.page_table_lock);
+	do {
+		pud_t *pud;
+		pud = pud_alloc(&init_mm, pgd, address);
+		error = -ENOMEM;
+		if (!pud)
+			break;
+		if (remap_area_pud(pud, address, end - address,
+					 phys_addr + address, flags))
+			break;
+		error = 0;
+		address = (address + PGDIR_SIZE) & PGDIR_MASK;
+		pgd++;
+	} while (address && (address < end));
+	spin_unlock(&init_mm.page_table_lock);
+	flush_tlb_all();
+	return error;
+}
+
+/*
+ * Fix up the linear direct mapping of the kernel to avoid cache attribute
+ * conflicts.
+ */
+static int
+ioremap_change_attr(unsigned long phys_addr, unsigned long size,
+					unsigned long flags)
+{
+	int err = 0;
+	if (flags && phys_addr + size - 1 < (end_pfn_map << PAGE_SHIFT)) {
+		unsigned long npages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+		unsigned long vaddr = (unsigned long) __va(phys_addr);
+
+		/*
+ 		 * Must use a address here and not struct page because the phys addr
+		 * can be a in hole between nodes and not have an memmap entry.
+		 */
+		err = change_page_attr_addr(vaddr,npages,__pgprot(__PAGE_KERNEL|flags));
+		if (!err)
+			global_flush_tlb();
+	}
+	return err;
+}
+
+/*
+ * Generic mapping function
+ */
+
+/*
+ * 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 * 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 (__force void __iomem *)phys_to_virt(phys_addr);
+
+#ifndef CONFIG_DISCONTIGMEM
+	/*
+	 * Don't allow anybody to remap normal RAM that we're using..
+	 */
+	if (last_addr < virt_to_phys(high_memory)) {
+		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;
+	}
+#endif
+
+	/*
+	 * 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 = area->addr;
+	if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
+		remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr));
+		return NULL;
+	}
+	if (ioremap_change_attr(phys_addr, size, flags) < 0) {
+		area->flags &= 0xffffff;
+		vunmap(addr);
+		return NULL;
+	}
+	return (__force void __iomem *) (offset + (char *)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)
+{
+	return __ioremap(phys_addr, size, _PAGE_PCD);
+}
+
+void iounmap(volatile void __iomem *addr)
+{
+	struct vm_struct *p, **pprev;
+
+	if (addr <= high_memory) 
+		return; 
+	if (addr >= phys_to_virt(ISA_START_ADDRESS) &&
+		addr < phys_to_virt(ISA_END_ADDRESS))
+		return;
+
+	write_lock(&vmlist_lock);
+	for (p = vmlist, pprev = &vmlist; p != NULL; pprev = &p->next, p = *pprev)
+		if (p->addr == (void *)(PAGE_MASK & (unsigned long)addr))
+			break;
+	if (!p) { 
+		printk("__iounmap: bad address %p\n", addr);
+		goto out_unlock;
+	}
+	*pprev = p->next;
+	unmap_vm_area(p);
+	if ((p->flags >> 20) &&
+		p->phys_addr + p->size - 1 < virt_to_phys(high_memory)) {
+		/* 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();
+	} 
+out_unlock:
+	write_unlock(&vmlist_lock);
+	kfree(p); 
+}