1 files changed, 422 insertions, 0 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
new file mode 100644
index 00000000000..baff1da354e
--- /dev/null
+++ b/arch/x86/mm/ioremap.c
@@ -0,0 +1,422 @@
+/*
+ * 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 <linux/mmiotrace.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>
+#include <asm/pat.h>
+
+#include "physaddr.h"
+
+/*
+ * Fix up the linear direct mapping of the kernel to avoid cache attribute
+ * conflicts.
+ */
+int ioremap_change_attr(unsigned long vaddr, unsigned long size,
+			       unsigned long prot_val)
+{
+	unsigned long nrpages = size >> PAGE_SHIFT;
+	int err;
+
+	switch (prot_val) {
+	case _PAGE_CACHE_UC:
+	default:
+		err = _set_memory_uc(vaddr, nrpages);
+		break;
+	case _PAGE_CACHE_WC:
+		err = _set_memory_wc(vaddr, nrpages);
+		break;
+	case _PAGE_CACHE_WB:
+		err = _set_memory_wb(vaddr, nrpages);
+		break;
+	}
+
+	return err;
+}
+
+static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
+			       void *arg)
+{
+	unsigned long i;
+
+	for (i = 0; i < nr_pages; ++i)
+		if (pfn_valid(start_pfn + i) &&
+		    !PageReserved(pfn_to_page(start_pfn + i)))
+			return 1;
+
+	WARN_ONCE(1, "ioremap on RAM pfn 0x%lx\n", start_pfn);
+
+	return 0;
+}
+
+/*
+ * 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_caller(resource_size_t phys_addr,
+		unsigned long size, unsigned long prot_val, void *caller)
+{
+	unsigned long offset, vaddr;
+	resource_size_t pfn, last_pfn, last_addr;
+	const resource_size_t unaligned_phys_addr = phys_addr;
+	const unsigned long unaligned_size = size;
+	struct vm_struct *area;
+	unsigned long new_prot_val;
+	pgprot_t prot;
+	int retval;
+	void __iomem *ret_addr;
+
+	/* Don't allow wraparound or zero size */
+	last_addr = phys_addr + size - 1;
+	if (!size || last_addr < phys_addr)
+		return NULL;
+
+	if (!phys_addr_valid(phys_addr)) {
+		printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
+		       (unsigned long long)phys_addr);
+		WARN_ON_ONCE(1);
+		return NULL;
+	}
+
+	/*
+	 * Don't remap the low PCI/ISA area, it's always mapped..
+	 */
+	if (is_ISA_range(phys_addr, last_addr))
+		return (__force void __iomem *)phys_to_virt(phys_addr);
+
+	/*
+	 * Don't allow anybody to remap normal RAM that we're using..
+	 */
+	pfn      = phys_addr >> PAGE_SHIFT;
+	last_pfn = last_addr >> PAGE_SHIFT;
+	if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
+				  __ioremap_check_ram) == 1)
+		return NULL;
+
+	/*
+	 * Mappings have to be page-aligned
+	 */
+	offset = phys_addr & ~PAGE_MASK;
+	phys_addr &= PHYSICAL_PAGE_MASK;
+	size = PAGE_ALIGN(last_addr+1) - phys_addr;
+
+	retval = reserve_memtype(phys_addr, (u64)phys_addr + size,
+						prot_val, &new_prot_val);
+	if (retval) {
+		printk(KERN_ERR "ioremap reserve_memtype failed %d\n", retval);
+		return NULL;
+	}
+
+	if (prot_val != new_prot_val) {
+		if (!is_new_memtype_allowed(phys_addr, size,
+					    prot_val, new_prot_val)) {
+			printk(KERN_ERR
+		"ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
+				(unsigned long long)phys_addr,
+				(unsigned long long)(phys_addr + size),
+				prot_val, new_prot_val);
+			goto err_free_memtype;
+		}
+		prot_val = new_prot_val;
+	}
+
+	switch (prot_val) {
+	case _PAGE_CACHE_UC:
+	default:
+		prot = PAGE_KERNEL_IO_NOCACHE;
+		break;
+	case _PAGE_CACHE_UC_MINUS:
+		prot = PAGE_KERNEL_IO_UC_MINUS;
+		break;
+	case _PAGE_CACHE_WC:
+		prot = PAGE_KERNEL_IO_WC;
+		break;
+	case _PAGE_CACHE_WB:
+		prot = PAGE_KERNEL_IO;
+		break;
+	}
+
+	/*
+	 * Ok, go for it..
+	 */
+	area = get_vm_area_caller(size, VM_IOREMAP, caller);
+	if (!area)
+		goto err_free_memtype;
+	area->phys_addr = phys_addr;
+	vaddr = (unsigned long) area->addr;
+
+	if (kernel_map_sync_memtype(phys_addr, size, prot_val))
+		goto err_free_area;
+
+	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot))
+		goto err_free_area;
+
+	ret_addr = (void __iomem *) (vaddr + offset);
+	mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
+
+	/*
+	 * Check if the request spans more than any BAR in the iomem resource
+	 * tree.
+	 */
+	WARN_ONCE(iomem_map_sanity_check(unaligned_phys_addr, unaligned_size),
+		  KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
+
+	return ret_addr;
+err_free_area:
+	free_vm_area(area);
+err_free_memtype:
+	free_memtype(phys_addr, phys_addr + size);
+	return NULL;
+}
+
+/**
+ * ioremap_nocache     -   map bus memory into CPU space
+ * @phys_addr:    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(resource_size_t phys_addr, unsigned long size)
+{
+	/*
+	 * Ideally, this should be:
+	 *	pat_enabled ? _PAGE_CACHE_UC : _PAGE_CACHE_UC_MINUS;
+	 *
+	 * Till we fix all X drivers to use ioremap_wc(), we will use
+	 * UC MINUS.
+	 */
+	unsigned long val = _PAGE_CACHE_UC_MINUS;
+
+	return __ioremap_caller(phys_addr, size, val,
+				__builtin_return_address(0));
+}
+EXPORT_SYMBOL(ioremap_nocache);
+
+/**
+ * ioremap_wc	-	map memory into CPU space write combined
+ * @phys_addr:	bus address of the memory
+ * @size:	size of the resource to map
+ *
+ * This version of ioremap ensures that the memory is marked write combining.
+ * Write combining allows faster writes to some hardware devices.
+ *
+ * Must be freed with iounmap.
+ */
+void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
+{
+	if (pat_enabled)
+		return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WC,
+					__builtin_return_address(0));
+	else
+		return ioremap_nocache(phys_addr, size);
+}
+EXPORT_SYMBOL(ioremap_wc);
+
+void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
+{
+	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WB,
+				__builtin_return_address(0));
+}
+EXPORT_SYMBOL(ioremap_cache);
+
+void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
+				unsigned long prot_val)
+{
+	return __ioremap_caller(phys_addr, size, (prot_val & _PAGE_CACHE_MASK),
+				__builtin_return_address(0));
+}
+EXPORT_SYMBOL(ioremap_prot);
+
+/**
+ * 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 ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
+	    (void __force *)addr < phys_to_virt(ISA_END_ADDRESS))
+		return;
+
+	addr = (volatile void __iomem *)
+		(PAGE_MASK & (unsigned long __force)addr);
+
+	mmiotrace_iounmap(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. */
+	p = find_vm_area((void __force *)addr);
+
+	if (!p) {
+		printk(KERN_ERR "iounmap: bad address %p\n", addr);
+		dump_stack();
+		return;
+	}
+
+	free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
+
+	/* Finally remove it */
+	o = remove_vm_area((void __force *)addr);
+	BUG_ON(p != o || o == NULL);
+	kfree(p);
+}
+EXPORT_SYMBOL(iounmap);
+
+/*
+ * Convert a physical pointer to a virtual kernel pointer for /dev/mem
+ * access
+ */
+void *xlate_dev_mem_ptr(unsigned long phys)
+{
+	void *addr;
+	unsigned long start = phys & PAGE_MASK;
+
+	/* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
+	if (page_is_ram(start >> PAGE_SHIFT))
+		return __va(phys);
+
+	addr = (void __force *)ioremap_cache(start, PAGE_SIZE);
+	if (addr)
+		addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
+
+	return addr;
+}
+
+void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
+{
+	if (page_is_ram(phys >> PAGE_SHIFT))
+		return;
+
+	iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
+	return;
+}
+
+static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
+
+static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
+{
+	/* Don't assume we're using swapper_pg_dir at this point */
+	pgd_t *base = __va(read_cr3());
+	pgd_t *pgd = &base[pgd_index(addr)];
+	pud_t *pud = pud_offset(pgd, addr);
+	pmd_t *pmd = pmd_offset(pud, addr);
+
+	return pmd;
+}
+
+static inline pte_t * __init early_ioremap_pte(unsigned long addr)
+{
+	return &bm_pte[pte_index(addr)];
+}
+
+bool __init is_early_ioremap_ptep(pte_t *ptep)
+{
+	return ptep >= &bm_pte[0] && ptep < &bm_pte[PAGE_SIZE/sizeof(pte_t)];
+}
+
+void __init early_ioremap_init(void)
+{
+	pmd_t *pmd;
+
+#ifdef CONFIG_X86_64
+	BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
+#else
+	WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
+#endif
+
+	early_ioremap_setup();
+
+	pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
+	memset(bm_pte, 0, sizeof(bm_pte));
+	pmd_populate_kernel(&init_mm, pmd, bm_pte);
+
+	/*
+	 * The boot-ioremap range spans multiple pmds, for which
+	 * we are not prepared:
+	 */
+#define __FIXADDR_TOP (-PAGE_SIZE)
+	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
+		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
+#undef __FIXADDR_TOP
+	if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
+		WARN_ON(1);
+		printk(KERN_WARNING "pmd %p != %p\n",
+		       pmd, early_ioremap_pmd(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_set_fixmap(enum fixed_addresses idx,
+			       phys_addr_t phys, pgprot_t flags)
+{
+	unsigned long addr = __fix_to_virt(idx);
+	pte_t *pte;
+
+	if (idx >= __end_of_fixed_addresses) {
+		BUG();
+		return;
+	}
+	pte = early_ioremap_pte(addr);
+
+	if (pgprot_val(flags))
+		set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
+	else
+		pte_clear(&init_mm, addr, pte);
+	__flush_tlb_one(addr);
+}