1 files changed, 501 insertions, 0 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
new file mode 100644
index 000000000000..ed795721ca8e
--- /dev/null
+++ b/arch/x86/mm/ioremap.c
@@ -0,0 +1,501 @@
+/*
+ * 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/bootmem.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <asm/cacheflush.h>
+#include <asm/e820.h>
+#include <asm/fixmap.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+
+enum ioremap_mode {
+	IOR_MODE_UNCACHED,
+	IOR_MODE_CACHED,
+};
+
+#ifdef CONFIG_X86_64
+
+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);
+
+#endif
+
+int page_is_ram(unsigned long pagenr)
+{
+	unsigned long addr, end;
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		/*
+		 * Not usable memory:
+		 */
+		if (e820.map[i].type != E820_RAM)
+			continue;
+		addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT;
+		end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT;
+
+		/*
+		 * Sanity check: Some BIOSen report areas as RAM that
+		 * are not. Notably the 640->1Mb area, which is the
+		 * PCI BIOS area.
+		 */
+		if (addr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
+		    end < (BIOS_END >> PAGE_SHIFT))
+			continue;
+
+		if ((pagenr >= addr) && (pagenr < end))
+			return 1;
+	}
+	return 0;
+}
+
+/*
+ * Fix up the linear direct mapping of the kernel to avoid cache attribute
+ * conflicts.
+ */
+static int ioremap_change_attr(unsigned long paddr, unsigned long size,
+			       enum ioremap_mode mode)
+{
+	unsigned long vaddr = (unsigned long)__va(paddr);
+	unsigned long nrpages = size >> PAGE_SHIFT;
+	int err, level;
+
+	/* No change for pages after the last mapping */
+	if ((paddr + size - 1) >= (max_pfn_mapped << PAGE_SHIFT))
+		return 0;
+
+	/*
+	 * If there is no identity map for this address,
+	 * change_page_attr_addr is unnecessary
+	 */
+	if (!lookup_address(vaddr, &level))
+		return 0;
+
+	switch (mode) {
+	case IOR_MODE_UNCACHED:
+	default:
+		err = set_memory_uc(vaddr, nrpages);
+		break;
+	case IOR_MODE_CACHED:
+		err = set_memory_wb(vaddr, nrpages);
+		break;
+	}
+
+	return err;
+}
+
+/*
+ * 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.
+ */
+static void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
+			       enum ioremap_mode mode)
+{
+	void __iomem *addr;
+	struct vm_struct *area;
+	unsigned long offset, last_addr;
+	pgprot_t prot;
+
+	/* 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);
+
+	/*
+	 * Don't allow anybody to remap normal RAM that we're using..
+	 */
+	for (offset = phys_addr >> PAGE_SHIFT; offset < max_pfn_mapped &&
+	     (offset << PAGE_SHIFT) < last_addr; offset++) {
+		if (page_is_ram(offset))
+			return NULL;
+	}
+
+	switch (mode) {
+	case IOR_MODE_UNCACHED:
+	default:
+		prot = PAGE_KERNEL_NOCACHE;
+		break;
+	case IOR_MODE_CACHED:
+		prot = PAGE_KERNEL;
+		break;
+	}
+
+	/*
+	 * 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);
+	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, prot)) {
+		remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr));
+		return NULL;
+	}
+
+	if (ioremap_change_attr(phys_addr, size, mode) < 0) {
+		vunmap(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)
+{
+	return __ioremap(phys_addr, size, IOR_MODE_UNCACHED);
+}
+EXPORT_SYMBOL(ioremap_nocache);
+
+void __iomem *ioremap_cache(unsigned long phys_addr, unsigned long size)
+{
+	return __ioremap(phys_addr, size, IOR_MODE_CACHED);
+}
+EXPORT_SYMBOL(ioremap_cache);
+
+/**
+ * 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 ((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;
+
+	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(KERN_ERR "iounmap: bad address %p\n", addr);
+		dump_stack();
+		return;
+	}
+
+	/* Reset the direct mapping. Can block */
+	ioremap_change_attr(p->phys_addr, p->size, IOR_MODE_CACHED);
+
+	/* Finally remove it */
+	o = remove_vm_area((void *)addr);
+	BUG_ON(p != o || o == NULL);
+	kfree(p);
+}
+EXPORT_SYMBOL(iounmap);
+
+#ifdef CONFIG_X86_32
+
+int __initdata early_ioremap_debug;
+
+static int __init early_ioremap_debug_setup(char *str)
+{
+	early_ioremap_debug = 1;
+
+	return 0;
+}
+early_param("early_ioremap_debug", early_ioremap_debug_setup);
+
+static __initdata int after_paging_init;
+static __initdata unsigned long bm_pte[1024]
+				__attribute__((aligned(PAGE_SIZE)));
+
+static inline unsigned long * __init early_ioremap_pgd(unsigned long addr)
+{
+	return (unsigned long *)swapper_pg_dir + ((addr >> 22) & 1023);
+}
+
+static inline unsigned long * __init early_ioremap_pte(unsigned long addr)
+{
+	return bm_pte + ((addr >> PAGE_SHIFT) & 1023);
+}
+
+void __init early_ioremap_init(void)
+{
+	unsigned long *pgd;
+
+	if (early_ioremap_debug)
+		printk(KERN_INFO "early_ioremap_init()\n");
+
+	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
+	*pgd = __pa(bm_pte) | _PAGE_TABLE;
+	memset(bm_pte, 0, sizeof(bm_pte));
+	/*
+	 * The boot-ioremap range spans multiple pgds, for which
+	 * we are not prepared:
+	 */
+	if (pgd != early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END))) {
+		WARN_ON(1);
+		printk(KERN_WARNING "pgd %p != %p\n",
+		       pgd, early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END)));
+		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
+		       fix_to_virt(FIX_BTMAP_BEGIN));
+		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END):   %08lx\n",
+		       fix_to_virt(FIX_BTMAP_END));
+
+		printk(KERN_WARNING "FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
+		printk(KERN_WARNING "FIX_BTMAP_BEGIN:     %d\n",
+		       FIX_BTMAP_BEGIN);
+	}
+}
+
+void __init early_ioremap_clear(void)
+{
+	unsigned long *pgd;
+
+	if (early_ioremap_debug)
+		printk(KERN_INFO "early_ioremap_clear()\n");
+
+	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
+	*pgd = 0;
+	paravirt_release_pt(__pa(pgd) >> PAGE_SHIFT);
+	__flush_tlb_all();
+}
+
+void __init early_ioremap_reset(void)
+{
+	enum fixed_addresses idx;
+	unsigned long *pte, phys, addr;
+
+	after_paging_init = 1;
+	for (idx = FIX_BTMAP_BEGIN; idx >= FIX_BTMAP_END; idx--) {
+		addr = fix_to_virt(idx);
+		pte = early_ioremap_pte(addr);
+		if (!*pte & _PAGE_PRESENT) {
+			phys = *pte & PAGE_MASK;
+			set_fixmap(idx, phys);
+		}
+	}
+}
+
+static void __init __early_set_fixmap(enum fixed_addresses idx,
+				   unsigned long phys, pgprot_t flags)
+{
+	unsigned long *pte, addr = __fix_to_virt(idx);
+
+	if (idx >= __end_of_fixed_addresses) {
+		BUG();
+		return;
+	}
+	pte = early_ioremap_pte(addr);
+	if (pgprot_val(flags))
+		*pte = (phys & PAGE_MASK) | pgprot_val(flags);
+	else
+		*pte = 0;
+	__flush_tlb_one(addr);
+}
+
+static inline void __init early_set_fixmap(enum fixed_addresses idx,
+					unsigned long phys)
+{
+	if (after_paging_init)
+		set_fixmap(idx, phys);
+	else
+		__early_set_fixmap(idx, phys, PAGE_KERNEL);
+}
+
+static inline void __init early_clear_fixmap(enum fixed_addresses idx)
+{
+	if (after_paging_init)
+		clear_fixmap(idx);
+	else
+		__early_set_fixmap(idx, 0, __pgprot(0));
+}
+
+
+int __initdata early_ioremap_nested;
+
+static int __init check_early_ioremap_leak(void)
+{
+	if (!early_ioremap_nested)
+		return 0;
+
+	printk(KERN_WARNING
+	       "Debug warning: early ioremap leak of %d areas detected.\n",
+	       early_ioremap_nested);
+	printk(KERN_WARNING
+	       "please boot with early_ioremap_debug and report the dmesg.\n");
+	WARN_ON(1);
+
+	return 1;
+}
+late_initcall(check_early_ioremap_leak);
+
+void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
+{
+	unsigned long offset, last_addr;
+	unsigned int nrpages, nesting;
+	enum fixed_addresses idx0, idx;
+
+	WARN_ON(system_state != SYSTEM_BOOTING);
+
+	nesting = early_ioremap_nested;
+	if (early_ioremap_debug) {
+		printk(KERN_INFO "early_ioremap(%08lx, %08lx) [%d] => ",
+		       phys_addr, size, nesting);
+		dump_stack();
+	}
+
+	/* Don't allow wraparound or zero size */
+	last_addr = phys_addr + size - 1;
+	if (!size || last_addr < phys_addr) {
+		WARN_ON(1);
+		return NULL;
+	}
+
+	if (nesting >= FIX_BTMAPS_NESTING) {
+		WARN_ON(1);
+		return NULL;
+	}
+	early_ioremap_nested++;
+	/*
+	 * 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) {
+		WARN_ON(1);
+		return NULL;
+	}
+
+	/*
+	 * Ok, go for it..
+	 */
+	idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
+	idx = idx0;
+	while (nrpages > 0) {
+		early_set_fixmap(idx, phys_addr);
+		phys_addr += PAGE_SIZE;
+		--idx;
+		--nrpages;
+	}
+	if (early_ioremap_debug)
+		printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));
+
+	return (void *) (offset + fix_to_virt(idx0));
+}
+
+void __init early_iounmap(void *addr, unsigned long size)
+{
+	unsigned long virt_addr;
+	unsigned long offset;
+	unsigned int nrpages;
+	enum fixed_addresses idx;
+	unsigned int nesting;
+
+	nesting = --early_ioremap_nested;
+	WARN_ON(nesting < 0);
+
+	if (early_ioremap_debug) {
+		printk(KERN_INFO "early_iounmap(%p, %08lx) [%d]\n", addr,
+		       size, nesting);
+		dump_stack();
+	}
+
+	virt_addr = (unsigned long)addr;
+	if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
+		WARN_ON(1);
+		return;
+	}
+	offset = virt_addr & ~PAGE_MASK;
+	nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
+
+	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
+	while (nrpages > 0) {
+		early_clear_fixmap(idx);
+		--idx;
+		--nrpages;
+	}
+}
+
+void __this_fixmap_does_not_exist(void)
+{
+	WARN_ON(1);
+}
+
+#endif /* CONFIG_X86_32 */