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-rw-r--r--arch/x86/mm/ioremap_64.c210
1 files changed, 210 insertions, 0 deletions
diff --git a/arch/x86/mm/ioremap_64.c b/arch/x86/mm/ioremap_64.c
new file mode 100644
index 00000000000..6cac90aa503
--- /dev/null
+++ b/arch/x86/mm/ioremap_64.c
@@ -0,0 +1,210 @@
+/*
+ * 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 <linux/module.h>
+#include <linux/io.h>
+
+#include <asm/pgalloc.h>
+#include <asm/fixmap.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+#include <asm/proto.h>
+
+unsigned long __phys_addr(unsigned long x)
+{
+ if (x >= __START_KERNEL_map)
+ return x - __START_KERNEL_map + phys_base;
+ return x - PAGE_OFFSET;
+}
+EXPORT_SYMBOL(__phys_addr);
+
+#define ISA_START_ADDRESS 0xa0000
+#define ISA_END_ADDRESS 0x100000
+
+/*
+ * 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 (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;
+ pgprot_t pgprot;
+
+ /* 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);
+
+#ifdef CONFIG_FLATMEM
+ /*
+ * 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
+
+ pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_GLOBAL
+ | _PAGE_DIRTY | _PAGE_ACCESSED | flags);
+ /*
+ * 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 (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
+ phys_addr, pgprot)) {
+ remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr));
+ return NULL;
+ }
+ if (flags && ioremap_change_attr(phys_addr, size, flags) < 0) {
+ area->flags &= 0xffffff;
+ vunmap(addr);
+ return NULL;
+ }
+ return (__force void __iomem *) (offset + (char *)addr);
+}
+EXPORT_SYMBOL(__ioremap);
+
+/**
+ * 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);
+}
+EXPORT_SYMBOL(ioremap_nocache);
+
+/**
+ * iounmap - Free a IO remapping
+ * @addr: virtual address from ioremap_*
+ *
+ * Caller must ensure there is only one unmapping for the same pointer.
+ */
+void iounmap(volatile void __iomem *addr)
+{
+ struct vm_struct *p, *o;
+
+ if (addr <= high_memory)
+ return;
+ if (addr >= phys_to_virt(ISA_START_ADDRESS) &&
+ addr < phys_to_virt(ISA_END_ADDRESS))
+ return;
+
+ addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long __force)addr);
+ /* Use the vm area unlocked, assuming the caller
+ ensures there isn't another iounmap for the same address
+ in parallel. Reuse of the virtual address is prevented by
+ leaving it in the global lists until we're done with it.
+ cpa takes care of the direct mappings. */
+ read_lock(&vmlist_lock);
+ for (p = vmlist; p; p = p->next) {
+ if (p->addr == addr)
+ break;
+ }
+ read_unlock(&vmlist_lock);
+
+ if (!p) {
+ printk("iounmap: bad address %p\n", addr);
+ dump_stack();
+ return;
+ }
+
+ /* Reset the direct mapping. Can block */
+ if (p->flags >> 20)
+ ioremap_change_attr(p->phys_addr, p->size, 0);
+
+ /* Finally remove it */
+ o = remove_vm_area((void *)addr);
+ BUG_ON(p != o || o == NULL);
+ kfree(p);
+}
+EXPORT_SYMBOL(iounmap);
+