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

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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: Toshi 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Toshi Kani 2015-04-14 15:47:20 -07:00 committed by Linus Torvalds
parent 0f616be120
commit 0ddab1d2ed
5 changed files with 52 additions and 0 deletions
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2
Documentation/kernel-parameters.txt
View file

@ -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.

3
arch/Kconfig
View file

@ -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

8
include/linux/io.h
View file

@ -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
*/

2
init/main.c
View file

@ -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)

37
lib/ioremap.c
View file

@ -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)
{