x86: warn about RAM pages in ioremap()

[sfrench/cifs-2.6.git] / arch / x86 / mm / ioremap.c

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 1106b7f477bdb555a4be8aca6a2adbdf65b37ef0..3d0a589d92c40ebcf33882bf9d1b331894953037 100644 (file)
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -35,6 +35,18 @@ unsigned long __phys_addr(unsigned long x)
 }
 EXPORT_SYMBOL(__phys_addr);
 
+static inline int phys_addr_valid(unsigned long addr)
+{
+       return addr < (1UL << boot_cpu_data.x86_phys_bits);
+}
+
+#else
+
+static inline int phys_addr_valid(unsigned long addr)
+{
+       return 1;
+}
+
 #endif
 
 int page_is_ram(unsigned long pagenr)
@@ -42,6 +54,22 @@ int page_is_ram(unsigned long pagenr)
        unsigned long addr, end;
        int i;
 
+       /*
+        * A special case is the first 4Kb of memory;
+        * This is a BIOS owned area, not kernel ram, but generally
+        * not listed as such in the E820 table.
+        */
+       if (pagenr == 0)
+               return 0;
+
+       /*
+        * Second special case: Some BIOSen report the PC BIOS
+        * area (640->1Mb) as ram even though it is not.
+        */
+       if (pagenr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
+                   pagenr < (BIOS_END >> PAGE_SHIFT))
+               return 0;
+
        for (i = 0; i < e820.nr_map; i++) {
                /*
                 * Not usable memory:
@@ -51,14 +79,6 @@ int page_is_ram(unsigned long pagenr)
                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;
@@ -98,7 +118,7 @@ static int ioremap_change_attr(unsigned long vaddr, unsigned long size,
  * 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,
+static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size,
                               enum ioremap_mode mode)
 {
        unsigned long pfn, offset, last_addr, vaddr;
@@ -110,6 +130,13 @@ static void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
        if (!size || last_addr < phys_addr)
                return NULL;
 
+       if (!phys_addr_valid(phys_addr)) {
+               printk(KERN_WARNING "ioremap: invalid physical address %lx\n",
+                      phys_addr);
+               WARN_ON_ONCE(1);
+               return NULL;
+       }
+
        /*
         * Don't remap the low PCI/ISA area, it's always mapped..
         */
@@ -119,17 +146,24 @@ static void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
        /*
         * Don't allow anybody to remap normal RAM that we're using..
         */
-       for (pfn = phys_addr >> PAGE_SHIFT; pfn < max_pfn_mapped &&
-            (pfn << PAGE_SHIFT) < last_addr; pfn++) {
-               if (page_is_ram(pfn) && pfn_valid(pfn) &&
-                   !PageReserved(pfn_to_page(pfn)))
+       for (pfn = phys_addr >> PAGE_SHIFT;
+                               (pfn << PAGE_SHIFT) < last_addr; pfn++) {
+
+               int is_ram = page_is_ram(pfn);
+
+               if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
                        return NULL;
+               WARN_ON_ONCE(is_ram);
        }
 
        switch (mode) {
        case IOR_MODE_UNCACHED:
        default:
-               prot = PAGE_KERNEL_NOCACHE;
+               /*
+                * FIXME: we will use UC MINUS for now, as video fb drivers
+                * depend on it. Upcoming ioremap_wc() will fix this behavior.
+                */
+               prot = PAGE_KERNEL_UC_MINUS;
                break;
        case IOR_MODE_CACHED:
                prot = PAGE_KERNEL;
@@ -152,7 +186,7 @@ static void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
        area->phys_addr = phys_addr;
        vaddr = (unsigned long) area->addr;
        if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
-               remove_vm_area((void *)(vaddr & PAGE_MASK));
+               free_vm_area(area);
                return NULL;
        }
 
@@ -185,13 +219,13 @@ static void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
  *
  * Must be freed with iounmap.
  */
-void __iomem *ioremap_nocache(unsigned long phys_addr, unsigned long size)
+void __iomem *ioremap_nocache(resource_size_t 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)
+void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
 {
        return __ioremap(phys_addr, size, IOR_MODE_CACHED);
 }
@@ -260,12 +294,14 @@ static int __init early_ioremap_debug_setup(char *str)
 early_param("early_ioremap_debug", early_ioremap_debug_setup);
 
 static __initdata int after_paging_init;
-static __initdata pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)]
-                               __attribute__((aligned(PAGE_SIZE)));
+static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)]
+               __section(.bss.page_aligned);
 
 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
 {
-       pgd_t *pgd = &swapper_pg_dir[pgd_index(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);
 
@@ -286,7 +322,7 @@ void __init early_ioremap_init(void)
 
        pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
        memset(bm_pte, 0, sizeof(bm_pte));
-       set_pmd(pmd, __pmd(__pa(bm_pte) | _PAGE_TABLE));
+       pmd_populate_kernel(&init_mm, pmd, bm_pte);
 
        /*
         * The boot-ioremap range spans multiple pmds, for which
@@ -316,7 +352,7 @@ void __init early_ioremap_clear(void)
 
        pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
        pmd_clear(pmd);
-       paravirt_release_pt(__pa(pmd) >> PAGE_SHIFT);
+       paravirt_release_pt(__pa(bm_pte) >> PAGE_SHIFT);
        __flush_tlb_all();
 }