x86: enhance early_ioremap()

[safe/jmp/linux-2.6] / arch / x86 / mm / ioremap_32.c

diff --git a/arch/x86/mm/ioremap_32.c b/arch/x86/mm/ioremap_32.c
index bfd7b8b..63f76ec 100644 (file)
--- a/arch/x86/mm/ioremap_32.c
+++ b/arch/x86/mm/ioremap_32.c
@@ -291,23 +291,28 @@ static inline void __init early_clear_fixmap(enum fixed_addresses idx)
                __early_set_fixmap(idx, 0, __pgprot(0));
 }
 
+
+int __initdata early_ioremap_nested;
+
 void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
 {
        unsigned long offset, last_addr;
-       unsigned int nrpages;
-       enum fixed_addresses idx;
+       unsigned int nrpages, nesting;
+       enum fixed_addresses idx0, idx;
+
+       WARN_ON(system_state != SYSTEM_BOOTING);
+
+       nesting = early_ioremap_nested;
 
        /* 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 (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
-               return phys_to_virt(phys_addr);
+       if (nesting >= FIX_BTMAPS_NESTING)
+               return NULL;
 
+       early_ioremap_nested++;
        /*
         * Mappings have to be page-aligned
         */
@@ -325,14 +330,16 @@ void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
        /*
         * Ok, go for it..
         */
-       idx = FIX_BTMAP_BEGIN;
+       idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
+       idx = idx0;
        while (nrpages > 0) {
                early_set_fixmap(idx, phys_addr);
                phys_addr += PAGE_SIZE;
                --idx;
                --nrpages;
        }
-       return (void*) (offset + fix_to_virt(FIX_BTMAP_BEGIN));
+
+       return (void*) (offset + fix_to_virt(idx0));
 }
 
 void __init early_iounmap(void *addr, unsigned long size)
@@ -341,17 +348,26 @@ void __init early_iounmap(void *addr, unsigned long size)
        unsigned long offset;
        unsigned int nrpages;
        enum fixed_addresses idx;
+       unsigned int nesting;
+
+       nesting = --early_ioremap_nested;
 
        virt_addr = (unsigned long)addr;
        if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN))
                return;
+
        offset = virt_addr & ~PAGE_MASK;
        nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
 
-       idx = FIX_BTMAP_BEGIN;
+       idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
        while (nrpages > 0) {
                early_clear_fixmap(idx);
                --idx;
                --nrpages;
        }
 }
+
+void __this_fixmap_does_not_exist(void)
+{
+       WARN_ON(1);
+}