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Commit 0ddab1d2 authored by Toshi Kani's avatar Toshi Kani Committed by Linus Torvalds
Browse files

lib/ioremap.c: add huge I/O map capability interfaces 



Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when
I/O mappings with pud/pmd are enabled on the kernel.

ioremap_huge_init() calls arch_ioremap_pud_supported() and
arch_ioremap_pmd_supported() to initialize the capabilities at boot-time.

A new kernel option "nohugeiomap" is also added, so that user can disable
the huge I/O map capabilities when necessary.

Signed-off-by: default avatarToshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0f616be1

Documentation/kernel-parameters.txt

+2 −0
Original line number Diff line number Diff line
@@ -2323,6 +2323,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			register save and restore. The kernel will only save

			legacy floating-point registers on task switch.



	nohugeiomap	[KNL,x86] Disable kernel huge I/O mappings.



	noxsave		[BUGS=X86] Disables x86 extended register state save

			and restore using xsave. The kernel will fallback to

			enabling legacy floating-point and sse state.

arch/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -446,6 +446,9 @@ config HAVE_IRQ_TIME_ACCOUNTING 
config HAVE_ARCH_TRANSPARENT_HUGEPAGE

	bool



config HAVE_ARCH_HUGE_VMAP

	bool



config HAVE_ARCH_SOFT_DIRTY

	bool

include/linux/io.h

+8 −0
Original line number Diff line number Diff line
@@ -38,6 +38,14 @@ static inline int ioremap_page_range(unsigned long addr, unsigned long end, 
}

#endif



#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP

void __init ioremap_huge_init(void);

int arch_ioremap_pud_supported(void);

int arch_ioremap_pmd_supported(void);

#else

static inline void ioremap_huge_init(void) { }

#endif



/*

 * Managed iomap interface

 */

init/main.c

+2 −0
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ 
#include <linux/list.h>

#include <linux/integrity.h>

#include <linux/proc_ns.h>

#include <linux/io.h>



#include <asm/io.h>

#include <asm/bugs.h>
@@ -484,6 +485,7 @@ static void __init mm_init(void) 
	percpu_init_late();

	pgtable_init();

	vmalloc_init();

	ioremap_huge_init();

}



asmlinkage __visible void __init start_kernel(void)

lib/ioremap.c

+37 −0
Original line number Diff line number Diff line
@@ -13,6 +13,43 @@ 
#include <asm/cacheflush.h>

#include <asm/pgtable.h>



#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP

int __read_mostly ioremap_pud_capable;

int __read_mostly ioremap_pmd_capable;

int __read_mostly ioremap_huge_disabled;



static int __init set_nohugeiomap(char *str)

{

	ioremap_huge_disabled = 1;

	return 0;

}

early_param("nohugeiomap", set_nohugeiomap);



void __init ioremap_huge_init(void)

{

	if (!ioremap_huge_disabled) {

		if (arch_ioremap_pud_supported())

			ioremap_pud_capable = 1;

		if (arch_ioremap_pmd_supported())

			ioremap_pmd_capable = 1;

	}

}



static inline int ioremap_pud_enabled(void)

{

	return ioremap_pud_capable;

}



static inline int ioremap_pmd_enabled(void)

{

	return ioremap_pmd_capable;

}



#else	/* !CONFIG_HAVE_ARCH_HUGE_VMAP */

static inline int ioremap_pud_enabled(void) { return 0; }

static inline int ioremap_pmd_enabled(void) { return 0; }

#endif	/* CONFIG_HAVE_ARCH_HUGE_VMAP */



static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,

		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)

{