--- /dev/null
+/*
+ * 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 <linux/module.h>
+#include <asm/io.h>
+#include <asm/fixmap.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+
+#define ISA_START_ADDRESS 0x0
+#define ISA_END_ADDRESS 0x100000
+
+#if 0 /* not PAE safe */
+/* These hacky macros avoid phys->machine translations. */
+#define __direct_pte(x) ((pte_t) { (x) } )
+#define __direct_mk_pte(page_nr,pgprot) \
+ __direct_pte(((page_nr) << PAGE_SHIFT) | pgprot_val(pgprot))
+#define direct_mk_pte_phys(physpage, pgprot) \
+ __direct_mk_pte((physpage) >> PAGE_SHIFT, pgprot)
+#endif
+
+static int direct_remap_area_pte_fn(pte_t *pte,
+ struct page *pmd_page,
+ unsigned long address,
+ void *data)
+{
+ mmu_update_t **v = (mmu_update_t **)data;
+
+ (*v)->ptr = ((u64)pfn_to_mfn(page_to_pfn(pmd_page)) <<
+ PAGE_SHIFT) | ((unsigned long)pte & ~PAGE_MASK);
+ (*v)++;
+
+ return 0;
+}
+
+static int __direct_remap_pfn_range(struct mm_struct *mm,
+ unsigned long address,
+ unsigned long mfn,
+ unsigned long size,
+ pgprot_t prot,
+ domid_t domid)
+{
+ int rc;
+ unsigned long i, start_address;
+ mmu_update_t *u, *v, *w;
+
+ u = v = w = (mmu_update_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
+ if (u == NULL)
+ return -ENOMEM;
+
+ start_address = address;
+
+ flush_cache_all();
+
+ for (i = 0; i < size; i += PAGE_SIZE) {
+ if ((v - u) == (PAGE_SIZE / sizeof(mmu_update_t))) {
+ /* Fill in the PTE pointers. */
+ rc = apply_to_page_range(mm, start_address,
+ address - start_address,
+ direct_remap_area_pte_fn, &w);
+ if (rc)
+ goto out;
+ w = u;
+ rc = -EFAULT;
+ if (HYPERVISOR_mmu_update(u, v - u, NULL, domid) < 0)
+ goto out;
+ v = u;
+ start_address = address;
+ }
+
+ /*
+ * Fill in the machine address: PTE ptr is done later by
+ * __direct_remap_area_pages().
+ */
+ v->val = pte_val_ma(pfn_pte_ma(mfn, prot));
+
+ mfn++;
+ address += PAGE_SIZE;
+ v++;
+ }
+
+ if (v != u) {
+ /* get the ptep's filled in */
+ rc = apply_to_page_range(mm, start_address,
+ address - start_address,
+ direct_remap_area_pte_fn, &w);
+ if (rc)
+ goto out;
+ rc = -EFAULT;
+ if (unlikely(HYPERVISOR_mmu_update(u, v - u, NULL, domid) < 0))
+ goto out;
+ }
+
+ rc = 0;
+
+ out:
+ flush_tlb_all();
+
+ free_page((unsigned long)u);
+
+ return rc;
+}
+
+int direct_remap_pfn_range(struct vm_area_struct *vma,
+ unsigned long address,
+ unsigned long mfn,
+ unsigned long size,
+ pgprot_t prot,
+ domid_t domid)
+{
+ /* Same as remap_pfn_range(). */
+ vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
+
+ if (domid == DOMID_SELF)
+ return -EINVAL;
+
+ vma->vm_mm->context.has_foreign_mappings = 1;
+
+ return __direct_remap_pfn_range(
+ vma->vm_mm, address, mfn, size, prot, domid);
+}
+EXPORT_SYMBOL(direct_remap_pfn_range);
+
+int direct_kernel_remap_pfn_range(unsigned long address,
+ unsigned long mfn,
+ unsigned long size,
+ pgprot_t prot,
+ domid_t domid)
+{
+ return __direct_remap_pfn_range(
+ &init_mm, address, mfn, size, prot, domid);
+}
+EXPORT_SYMBOL(direct_kernel_remap_pfn_range);
+
+static int lookup_pte_fn(
+ pte_t *pte, struct page *pmd_page, unsigned long addr, void *data)
+{
+ uint64_t *ptep = (uint64_t *)data;
+ if (ptep)
+ *ptep = ((uint64_t)pfn_to_mfn(page_to_pfn(pmd_page)) <<
+ PAGE_SHIFT) | ((unsigned long)pte & ~PAGE_MASK);
+ return 0;
+}
+
+int create_lookup_pte_addr(struct mm_struct *mm,
+ unsigned long address,
+ uint64_t *ptep)
+{
+ return apply_to_page_range(mm, address, PAGE_SIZE,
+ lookup_pte_fn, ptep);
+}
+
+EXPORT_SYMBOL(create_lookup_pte_addr);
+
+static int noop_fn(
+ pte_t *pte, struct page *pmd_page, unsigned long addr, void *data)
+{
+ return 0;
+}
+
+int touch_pte_range(struct mm_struct *mm,
+ unsigned long address,
+ unsigned long size)
+{
+ return apply_to_page_range(mm, address, size, noop_fn, NULL);
+}
+
+EXPORT_SYMBOL(touch_pte_range);
+
+void *vm_map_xen_pages (unsigned long maddr, int vm_size, pgprot_t prot)
+{
+ int error;
+
+ struct vm_struct *vma;
+ vma = get_vm_area (vm_size, VM_IOREMAP);
+
+ if (vma == NULL) {
+ printk ("ioremap.c,vm_map_xen_pages(): "
+ "Failed to get VMA area\n");
+ return NULL;
+ }
+
+ error = direct_kernel_remap_pfn_range((unsigned long) vma->addr,
+ maddr >> PAGE_SHIFT, vm_size,
+ prot, DOMID_SELF );
+ if (error == 0) {
+ return vma->addr;
+ } else {
+ printk ("ioremap.c,vm_map_xen_pages(): "
+ "Failed to map xen shared pages into kernel space\n");
+ return NULL;
+ }
+}
+EXPORT_SYMBOL(vm_map_xen_pages);
+
+/*
+ * Does @address reside within a non-highmem page that is local to this virtual
+ * machine (i.e., not an I/O page, nor a memory page belonging to another VM).
+ * See the comment that accompanies mfn_to_local_pfn() in page.h to understand
+ * why this works.
+ */
+static inline int is_local_lowmem(unsigned long address)
+{
+ extern unsigned long max_low_pfn;
+ return (mfn_to_local_pfn(address >> PAGE_SHIFT) < max_low_pfn);
+}
+
+/*
+ * 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;
+ domid_t domid = DOMID_IO;
+
+ /* 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 (xen_start_info->flags & SIF_PRIVILEGED &&
+ phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
+ return (void __iomem *) isa_bus_to_virt(phys_addr);
+
+ /*
+ * Don't allow anybody to remap normal RAM that we're using..
+ */
+ if (is_local_lowmem(phys_addr)) {
+ char *t_addr, *t_end;
+ struct page *page;
+
+ t_addr = bus_to_virt(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;
+
+ domid = DOMID_SELF;
+ }
+
+ /*
+ * 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;
+ flags |= _PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED;
+#ifdef __x86_64__
+ flags |= _PAGE_USER;
+#endif
+ if (__direct_remap_pfn_range(&init_mm, (unsigned long)addr,
+ phys_addr>>PAGE_SHIFT,
+ size, __pgprot(flags), domid)) {
+ vunmap((void __force *) addr);
+ return NULL;
+ }
+ return (void __iomem *) (offset + (char __iomem *)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)
+{
+ 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 (is_local_lowmem(last_addr)) {
+ struct page *ppage = virt_to_page(bus_to_virt(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;
+}
+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 ((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 ((unsigned long) addr >= fix_to_virt(FIX_ISAMAP_BEGIN))
+ 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) && is_local_lowmem(p->phys_addr)) {
+ /* p->size includes the guard page, but cpa doesn't like that */
+ change_page_attr(virt_to_page(bus_to_virt(p->phys_addr)),
+ (p->size - PAGE_SIZE) >> PAGE_SHIFT,
+ PAGE_KERNEL);
+ global_flush_tlb();
+ }
+
+ /* Finally remove it */
+ o = remove_vm_area((void *)addr);
+ BUG_ON(p != o || o == NULL);
+ kfree(p);
+}
+EXPORT_SYMBOL(iounmap);
+
+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 (xen_start_info->flags & SIF_PRIVILEGED &&
+ phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
+ return isa_bus_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;
+ if (virt_addr >= fix_to_virt(FIX_ISAMAP_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;
+ }
+}
git://git.onelab.eu / linux-2.6.git / blobdiff