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Commit b310f381 authored by venkatesh.pallipadi@intel.com's avatar venkatesh.pallipadi@intel.com Committed by Ingo Molnar
Browse files

x86: PAT add ioremap_wc() interface 



Introduce ioremap_wc for wc remap.

(generic wrapper is in a later patch)

Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent ef354af4

arch/x86/mm/ioremap.c

+30 −0
Original line number Diff line number Diff line
@@ -97,6 +97,9 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size, 
	default:

		err = _set_memory_uc(vaddr, nrpages);

		break;

	case _PAGE_CACHE_WC:

		err = _set_memory_wc(vaddr, nrpages);

		break;

	case _PAGE_CACHE_WB:

		err = _set_memory_wb(vaddr, nrpages);

		break;
@@ -166,8 +169,13 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size, 
		 * Do not fallback to certain memory types with certain

		 * requested type:

		 * - request is uncached, return cannot be write-back

		 * - request is uncached, return cannot be write-combine

		 * - request is write-combine, return cannot be write-back

		 */

		if ((prot_val == _PAGE_CACHE_UC &&

		     (new_prot_val == _PAGE_CACHE_WB ||

		      new_prot_val == _PAGE_CACHE_WC)) ||

		    (prot_val == _PAGE_CACHE_WC &&

		     new_prot_val == _PAGE_CACHE_WB)) {

			free_memtype(phys_addr, phys_addr + size);

			return NULL;
@@ -180,6 +188,9 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size, 
	default:

		prot = PAGE_KERNEL_NOCACHE;

		break;

	case _PAGE_CACHE_WC:

		prot = PAGE_KERNEL_WC;

		break;

	case _PAGE_CACHE_WB:

		prot = PAGE_KERNEL;

		break;
@@ -235,6 +246,25 @@ void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size) 
}

EXPORT_SYMBOL(ioremap_nocache);



/**

 * ioremap_wc	-	map memory into CPU space write combined

 * @offset:	bus address of the memory

 * @size:	size of the resource to map

 *

 * This version of ioremap ensures that the memory is marked write combining.

 * Write combining allows faster writes to some hardware devices.

 *

 * Must be freed with iounmap.

 */

void __iomem *ioremap_wc(unsigned long phys_addr, unsigned long size)

{

	if (pat_wc_enabled)

		return __ioremap(phys_addr, size, _PAGE_CACHE_WC);

	else

		return ioremap_nocache(phys_addr, size);

}

EXPORT_SYMBOL(ioremap_wc);



void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)

{

	return __ioremap(phys_addr, size, _PAGE_CACHE_WB);

include/asm-x86/io.h

+3 −0
Original line number Diff line number Diff line 
#define ARCH_HAS_IOREMAP_WC



#ifdef CONFIG_X86_32

# include "io_32.h"

#else
@@ -5,4 +7,5 @@ 
#endif

extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,

				unsigned long prot_val);

extern void __iomem * ioremap_wc(unsigned long offset, unsigned long size);

include/asm-x86/pgtable.h

+2 −0
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ extern pteval_t __PAGE_KERNEL, __PAGE_KERNEL_EXEC; 
#define __PAGE_KERNEL_RO		(__PAGE_KERNEL & ~_PAGE_RW)

#define __PAGE_KERNEL_RX		(__PAGE_KERNEL_EXEC & ~_PAGE_RW)

#define __PAGE_KERNEL_EXEC_NOCACHE	(__PAGE_KERNEL_EXEC | _PAGE_PCD | _PAGE_PWT)

#define __PAGE_KERNEL_WC		(__PAGE_KERNEL | _PAGE_CACHE_WC)

#define __PAGE_KERNEL_NOCACHE		(__PAGE_KERNEL | _PAGE_PCD | _PAGE_PWT)

#define __PAGE_KERNEL_UC_MINUS		(__PAGE_KERNEL | _PAGE_PCD)

#define __PAGE_KERNEL_VSYSCALL		(__PAGE_KERNEL_RX | _PAGE_USER)
@@ -107,6 +108,7 @@ extern pteval_t __PAGE_KERNEL, __PAGE_KERNEL_EXEC; 
#define PAGE_KERNEL_RO			MAKE_GLOBAL(__PAGE_KERNEL_RO)

#define PAGE_KERNEL_EXEC		MAKE_GLOBAL(__PAGE_KERNEL_EXEC)

#define PAGE_KERNEL_RX			MAKE_GLOBAL(__PAGE_KERNEL_RX)

#define PAGE_KERNEL_WC			MAKE_GLOBAL(__PAGE_KERNEL_WC)

#define PAGE_KERNEL_NOCACHE		MAKE_GLOBAL(__PAGE_KERNEL_NOCACHE)

#define PAGE_KERNEL_UC_MINUS		MAKE_GLOBAL(__PAGE_KERNEL_UC_MINUS)

#define PAGE_KERNEL_EXEC_NOCACHE	MAKE_GLOBAL(__PAGE_KERNEL_EXEC_NOCACHE)