From: Dave Hansen <dave@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, Gleb Natapov <gleb@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Marcelo Tosatti <mtosatti@redhat.com>,
Rik van Riel <riel@redhat.com>,
Dave Hansen <dave@linux.vnet.ibm.com>
Subject: [PATCH 2/5] pagetable level size/shift/mask helpers
Date: Mon, 21 Jan 2013 09:52:46 -0800 [thread overview]
Message-ID: <20130121175246.6B215415@kernel.stglabs.ibm.com> (raw)
In-Reply-To: <20130121175244.E5839E06@kernel.stglabs.ibm.com>
I plan to use lookup_address() to walk the kernel pagetables
in a later patch. It returns a "pte" and the level in the
pagetables where the "pte" was found. The level is just an
enum and needs to be converted to a useful value in order to
do address calculations with it. These helpers will be used
in at least two places.
This also gives the anonymous enum a real name so that no one
gets confused about what they should be passing in to these
helpers.
"PTE_SHIFT" was chosen for naming consistency with the other
pagetable levels (PGD/PUD/PMD_SHIFT).
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
---
linux-2.6.git-dave/arch/x86/include/asm/pgtable.h | 14 ++++++++++++++
linux-2.6.git-dave/arch/x86/include/asm/pgtable_types.h | 2 +-
2 files changed, 15 insertions(+), 1 deletion(-)
diff -puN arch/x86/include/asm/pgtable.h~pagetable-level-size-helpers arch/x86/include/asm/pgtable.h
--- linux-2.6.git/arch/x86/include/asm/pgtable.h~pagetable-level-size-helpers 2013-01-17 10:22:25.958428542 -0800
+++ linux-2.6.git-dave/arch/x86/include/asm/pgtable.h 2013-01-17 10:22:25.962428578 -0800
@@ -390,6 +390,7 @@ pte_t *populate_extra_pte(unsigned long
#ifndef __ASSEMBLY__
#include <linux/mm_types.h>
+#include <linux/log2.h>
static inline int pte_none(pte_t pte)
{
@@ -781,6 +782,19 @@ static inline void clone_pgd_range(pgd_t
memcpy(dst, src, count * sizeof(pgd_t));
}
+#define PTE_SHIFT ilog2(PTRS_PER_PTE)
+static inline int page_level_shift(enum pg_level level)
+{
+ return (PAGE_SHIFT - PTE_SHIFT) + level * PTE_SHIFT;
+}
+static inline unsigned long page_level_size(enum pg_level level)
+{
+ return 1UL << page_level_shift(level);
+}
+static inline unsigned long page_level_mask(enum pg_level level)
+{
+ return ~(page_level_size(level) - 1);
+}
#include <asm-generic/pgtable.h>
#endif /* __ASSEMBLY__ */
diff -puN arch/x86/include/asm/pgtable_types.h~pagetable-level-size-helpers arch/x86/include/asm/pgtable_types.h
--- linux-2.6.git/arch/x86/include/asm/pgtable_types.h~pagetable-level-size-helpers 2013-01-17 10:22:25.958428542 -0800
+++ linux-2.6.git-dave/arch/x86/include/asm/pgtable_types.h 2013-01-17 10:22:25.966428612 -0800
@@ -331,7 +331,7 @@ extern void native_pagetable_init(void);
struct seq_file;
extern void arch_report_meminfo(struct seq_file *m);
-enum {
+enum pg_level {
PG_LEVEL_NONE,
PG_LEVEL_4K,
PG_LEVEL_2M,
_
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next prev parent reply other threads:[~2013-01-21 17:52 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-21 17:52 [PATCH 0/5] fix illegal use of __pa() in KVM code Dave Hansen
2013-01-21 17:52 ` [PATCH 1/5] make DEBUG_VIRTUAL work earlier in boot Dave Hansen
2013-01-21 17:52 ` Dave Hansen [this message]
2013-01-21 17:52 ` [PATCH 3/5] use new pagetable helpers in try_preserve_large_page() Dave Hansen
2013-01-21 17:52 ` [PATCH 4/5] create slow_virt_to_phys() Dave Hansen
2013-01-21 18:08 ` H. Peter Anvin
2013-01-21 18:18 ` Dave Hansen
2013-01-21 17:52 ` [PATCH 5/5] fix kvm's use of __pa() on percpu areas Dave Hansen
2013-01-21 18:38 ` H. Peter Anvin
2013-01-21 18:59 ` Dave Hansen
2013-01-21 19:22 ` H. Peter Anvin
2013-01-21 19:02 ` Gleb Natapov
-- strict thread matches above, loose matches on Subject: below --
2013-01-22 21:24 [PATCH 0/5] [v3] fix illegal use of __pa() in KVM code Dave Hansen
2013-01-22 21:24 ` [PATCH 2/5] pagetable level size/shift/mask helpers Dave Hansen
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