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-rw-r--r--arch/ia64/mm/ioremap.c27
1 files changed, 22 insertions, 5 deletions
diff --git a/arch/ia64/mm/ioremap.c b/arch/ia64/mm/ioremap.c
index 643ccc6960c..07bd02b6c37 100644
--- a/arch/ia64/mm/ioremap.c
+++ b/arch/ia64/mm/ioremap.c
@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/efi.h>
#include <asm/io.h>
+#include <asm/meminit.h>
static inline void __iomem *
__ioremap (unsigned long offset, unsigned long size)
@@ -21,16 +22,29 @@ __ioremap (unsigned long offset, unsigned long size)
void __iomem *
ioremap (unsigned long offset, unsigned long size)
{
- if (efi_mem_attribute_range(offset, size, EFI_MEMORY_WB))
- return phys_to_virt(offset);
+ u64 attr;
+ unsigned long gran_base, gran_size;
- if (efi_mem_attribute_range(offset, size, EFI_MEMORY_UC))
+ /*
+ * For things in kern_memmap, we must use the same attribute
+ * as the rest of the kernel. For more details, see
+ * Documentation/ia64/aliasing.txt.
+ */
+ attr = kern_mem_attribute(offset, size);
+ if (attr & EFI_MEMORY_WB)
+ return phys_to_virt(offset);
+ else if (attr & EFI_MEMORY_UC)
return __ioremap(offset, size);
/*
- * Someday this should check ACPI resources so we
- * can do the right thing for hot-plugged regions.
+ * Some chipsets don't support UC access to memory. If
+ * WB is supported for the whole granule, we prefer that.
*/
+ gran_base = GRANULEROUNDDOWN(offset);
+ gran_size = GRANULEROUNDUP(offset + size) - gran_base;
+ if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
+ return phys_to_virt(offset);
+
return __ioremap(offset, size);
}
EXPORT_SYMBOL(ioremap);
@@ -38,6 +52,9 @@ EXPORT_SYMBOL(ioremap);
void __iomem *
ioremap_nocache (unsigned long offset, unsigned long size)
{
+ if (kern_mem_attribute(offset, size) & EFI_MEMORY_WB)
+ return 0;
+
return __ioremap(offset, size);
}
EXPORT_SYMBOL(ioremap_nocache);