--- /dev/null
+/*
+ * 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,
+ enum page_cache_mode pcm)
+{
+ unsigned long nrpages = size >> PAGE_SHIFT;
+ int err;
+
+ switch (pcm) {
+ case _PAGE_CACHE_MODE_UC:
+ default:
+ err = _set_memory_uc(vaddr, nrpages);
+ break;
+ case _PAGE_CACHE_MODE_WC:
+ err = _set_memory_wc(vaddr, nrpages);
+ break;
+ case _PAGE_CACHE_MODE_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. It transparently creates kernel huge I/O mapping when
+ * the physical address is aligned by a huge page size (1GB or 2MB) and
+ * the requested size is at least the huge page size.
+ *
+ * NOTE: MTRRs can override PAT memory types with a 4KB granularity.
+ * Therefore, the mapping code falls back to use a smaller page toward 4KB
+ * when a mapping range is covered by non-WB type of MTRRs.
+ *
+ * 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, enum page_cache_mode pcm, 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;
+ enum page_cache_mode new_pcm;
+ pgprot_t prot;
+ int retval;
+ void __iomem *ret_addr;
+ int ram_region;
+
+ /* 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..
+ */
+ /* First check if whole region can be identified as RAM or not */
+ ram_region = region_is_ram(phys_addr, size);
+ if (ram_region > 0) {
+ WARN_ONCE(1, "ioremap on RAM at 0x%lx - 0x%lx\n",
+ (unsigned long int)phys_addr,
+ (unsigned long int)last_addr);
+ return NULL;
+ }
+
+ /* If could not be identified(-1), check page by page */
+ if (ram_region < 0) {
+ 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,
+ pcm, &new_pcm);
+ if (retval) {
+ printk(KERN_ERR "ioremap reserve_memtype failed %d\n", retval);
+ return NULL;
+ }
+
+ if (pcm != new_pcm) {
+ if (!is_new_memtype_allowed(phys_addr, size, pcm, new_pcm)) {
+ printk(KERN_ERR
+ "ioremap error for 0x%llx-0x%llx, requested 0x%x, got 0x%x\n",
+ (unsigned long long)phys_addr,
+ (unsigned long long)(phys_addr + size),
+ pcm, new_pcm);
+ goto err_free_memtype;
+ }
+ pcm = new_pcm;
+ }
+
+ prot = PAGE_KERNEL_IO;
+ switch (pcm) {
+ case _PAGE_CACHE_MODE_UC:
+ default:
+ prot = __pgprot(pgprot_val(prot) |
+ cachemode2protval(_PAGE_CACHE_MODE_UC));
+ break;
+ case _PAGE_CACHE_MODE_UC_MINUS:
+ prot = __pgprot(pgprot_val(prot) |
+ cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
+ break;
+ case _PAGE_CACHE_MODE_WC:
+ prot = __pgprot(pgprot_val(prot) |
+ cachemode2protval(_PAGE_CACHE_MODE_WC));
+ break;
+ case _PAGE_CACHE_MODE_WB:
+ 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, pcm))
+ 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_MODE_UC : _PAGE_CACHE_MODE_UC_MINUS;
+ *
+ * Till we fix all X drivers to use ioremap_wc(), we will use
+ * UC MINUS.
+ */
+ enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS;
+
+ return __ioremap_caller(phys_addr, size, pcm,
+ __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_MODE_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_MODE_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,
+ pgprot2cachemode(__pgprot(prot_val)),
+ __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);
+
+int arch_ioremap_pud_supported(void)
+{
+#ifdef CONFIG_X86_64
+ return cpu_has_gbpages;
+#else
+ return 0;
+#endif
+}
+
+int arch_ioremap_pmd_supported(void)
+{
+ return cpu_has_pse;
+}
+
+/*
+ * Convert a physical pointer to a virtual kernel pointer for /dev/mem
+ * access
+ */
+void *xlate_dev_mem_ptr(phys_addr_t phys)
+{
+ unsigned long start = phys & PAGE_MASK;
+ unsigned long offset = phys & ~PAGE_MASK;
+ unsigned long vaddr;
+
+ /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
+ if (page_is_ram(start >> PAGE_SHIFT))
+ return __va(phys);
+
+ vaddr = (unsigned long)ioremap_cache(start, PAGE_SIZE);
+ /* Only add the offset on success and return NULL if the ioremap() failed: */
+ if (vaddr)
+ vaddr += offset;
+
+ return (void *)vaddr;
+}
+
+void unxlate_dev_mem_ptr(phys_addr_t 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);
+}
Code Review / kvmfornfv.git / blobdiff