x86: unify kmap_atomic_pfn() and iomap_atomic_prot_pfn()

kmap_atomic_pfn() and iomap_atomic_prot_pfn() are almost same
except pgprot. This patch removes the code duplication for these
two functions.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090311143317.GA22244@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/highmem.h

@@ -63,6 +63,7 @@ void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot);
 void *kmap_atomic(struct page *page, enum km_type type);
 void kunmap_atomic(void *kvaddr, enum km_type type);
 void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
+void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);
 struct page *kmap_atomic_to_page(void *ptr);
 
 #ifndef CONFIG_PARAVIRT

arch/x86/mm/highmem_32.c

@@ -121,23 +121,28 @@ void kunmap_atomic(void *kvaddr, enum km_type type)
 	pagefault_enable();
 }
 
-/* This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
+void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
 {
 	enum fixed_addresses idx;
 	unsigned long vaddr;
 
 	pagefault_disable();
 
-	idx = type + KM_TYPE_NR*smp_processor_id();
+	idx = type + KM_TYPE_NR * smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-	set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot));
+	set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
 	arch_flush_lazy_mmu_mode();
 
 	return (void*) vaddr;
 }
+
+/* This is the same as kmap_atomic() but can map memory that doesn't
+ * have a struct page associated with it.
+ */
+void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
+{
+	return kmap_atomic_prot_pfn(pfn, type, kmap_prot);
+}
 EXPORT_SYMBOL_GPL(kmap_atomic_pfn); /* temporarily in use by i915 GEM until vmap */
 
 struct page *kmap_atomic_to_page(void *ptr)

arch/x86/mm/iomap_32.c

@@ -18,6 +18,7 @@
 
 #include <asm/iomap.h>
 #include <asm/pat.h>
+#include <asm/highmem.h>
 #include <linux/module.h>
 
 int is_io_mapping_possible(resource_size_t base, unsigned long size)
@@ -36,11 +37,6 @@ EXPORT_SYMBOL_GPL(is_io_mapping_possible);
 void *
 iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
 {
-	enum fixed_addresses idx;
-	unsigned long vaddr;
-
-	pagefault_disable();
-
 	/*
 	 * For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS.
 	 * PAGE_KERNEL_WC maps to PWT, which translates to uncached if the
@@ -50,12 +46,7 @@ iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
 	if (!pat_enabled && pgprot_val(prot) == pgprot_val(PAGE_KERNEL_WC))
 		prot = PAGE_KERNEL_UC_MINUS;
 
-	idx = type + KM_TYPE_NR*smp_processor_id();
-	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-	set_pte(kmap_pte-idx, pfn_pte(pfn, prot));
-	arch_flush_lazy_mmu_mode();
-
-	return (void*) vaddr;
+	return kmap_atomic_prot_pfn(pfn, type, prot);
 }
 EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);