Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / arch / x86_64 / mm / ioremap.c

diff --git a/arch/x86_64/mm/ioremap.c b/arch/x86_64/mm/ioremap.c
index bae79b8..ae20706 100644 (file)
--- a/arch/x86_64/mm/ioremap.c
+++ b/arch/x86_64/mm/ioremap.c
@@ -18,6 +18,9 @@
 #include <asm/tlbflush.h>
 #include <asm/proto.h>
 
+#define ISA_START_ADDRESS      0xa0000
+#define ISA_END_ADDRESS                0x100000
+
 static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
        unsigned long phys_addr, unsigned long flags)
 {
@@ -57,7 +60,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned lo
        if (address >= end)
                BUG();
        do {
-               pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
+               pte_t * pte = pte_alloc_kernel(pmd, address);
                if (!pte)
                        return -ENOMEM;
                remap_area_pte(pte, address, end - address, address + phys_addr, flags);
@@ -102,7 +105,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
        flush_cache_all();
        if (address >= end)
                BUG();
-       spin_lock(&init_mm.page_table_lock);
        do {
                pud_t *pud;
                pud = pud_alloc(&init_mm, pgd, address);
@@ -116,7 +118,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
                address = (address + PGDIR_SIZE) & PGDIR_MASK;
                pgd++;
        } while (address && (address < end));
-       spin_unlock(&init_mm.page_table_lock);
        flush_tlb_all();
        return error;
 }
@@ -130,7 +131,7 @@ ioremap_change_attr(unsigned long phys_addr, unsigned long size,
                                        unsigned long flags)
 {
        int err = 0;
-       if (flags && phys_addr + size - 1 < (end_pfn_map << PAGE_SHIFT)) {
+       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);
 
@@ -172,10 +173,10 @@ void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned l
        /*
         * Don't remap the low PCI/ISA area, it's always mapped..
         */
-       if (phys_addr >= 0xA0000 && last_addr < 0x100000)
+       if (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
                return (__force void __iomem *)phys_to_virt(phys_addr);
 
-#ifndef CONFIG_DISCONTIGMEM
+#ifdef CONFIG_FLATMEM
        /*
         * Don't allow anybody to remap normal RAM that we're using..
         */
@@ -211,7 +212,7 @@ void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned l
                remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr));
                return NULL;
        }
-       if (ioremap_change_attr(phys_addr, size, flags) < 0) {
+       if (flags && ioremap_change_attr(phys_addr, size, flags) < 0) {
                area->flags &= 0xffffff;
                vunmap(addr);
                return NULL;
@@ -246,32 +247,47 @@ void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size)
        return __ioremap(phys_addr, size, _PAGE_PCD);
 }
 
+/**
+ * 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, **pprev;
+       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;
 
-       write_lock(&vmlist_lock);
-       for (p = vmlist, pprev = &vmlist; p != NULL; pprev = &p->next, p = *pprev)
-               if (p->addr == (void *)(PAGE_MASK & (unsigned long)addr))
+       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;
-       if (!p) { 
-               printk("__iounmap: bad address %p\n", addr);
-               goto out_unlock;
        }
-       *pprev = p->next;
-       unmap_vm_area(p);
-       if ((p->flags >> 20) &&
-               p->phys_addr + p->size - 1 < virt_to_phys(high_memory)) {
-               /* p->size includes the guard page, but cpa doesn't like that */
-               change_page_attr_addr((unsigned long)(__va(p->phys_addr)),
-                                (p->size - PAGE_SIZE) >> PAGE_SHIFT,
-                                PAGE_KERNEL);                           
-               global_flush_tlb();
-       } 
-out_unlock:
-       write_unlock(&vmlist_lock);
+       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); 
 }