[tip:x86/mm] x86, mm: Correct the implementation of is_untracked_pat_range()

From: tip-bot for H. Peter Anvin
Date: Tue Dec 01 2009 - 02:37:33 EST


Commit-ID: ccef086454d4c97e7b722e9303390207d681cb4c
Gitweb: http://git.kernel.org/tip/ccef086454d4c97e7b722e9303390207d681cb4c
Author: H. Peter Anvin <hpa@xxxxxxxxx>
AuthorDate: Mon, 30 Nov 2009 21:33:51 -0800
Committer: H. Peter Anvin <hpa@xxxxxxxxx>
CommitDate: Mon, 30 Nov 2009 21:33:51 -0800

x86, mm: Correct the implementation of is_untracked_pat_range()

The semantics the PAT code expect of is_untracked_pat_range() is "is
this range completely contained inside the untracked region." This
means that checkin 8a27138924f64d2f30c1022f909f74480046bc3f was
technically wrong, because the implementation needlessly confusing.

The sane interface is for it to take a semiclosed range like just
about everything else (as evidenced by the sheer number of "- 1"'s
removed by that patch) so change the actual implementation to match.

Reported-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Jack Steiner <steiner@xxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
LKML-Reference: <20091119202341.GA4420@xxxxxxx>
---
arch/x86/include/asm/e820.h | 6 +++++-
arch/x86/kernel/apic/x2apic_uv_x.c | 2 +-
2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/e820.h b/arch/x86/include/asm/e820.h
index 68b4e0e..761249e 100644
--- a/arch/x86/include/asm/e820.h
+++ b/arch/x86/include/asm/e820.h
@@ -133,9 +133,13 @@ extern void e820_reserve_resources_late(void);
extern void setup_memory_map(void);
extern char *default_machine_specific_memory_setup(void);

+/*
+ * Returns true iff the specified range [s,e) is completely contained inside
+ * the ISA region.
+ */
static inline bool is_ISA_range(u64 s, u64 e)
{
- return s >= ISA_START_ADDRESS && e < ISA_END_ADDRESS;
+ return s >= ISA_START_ADDRESS && e <= ISA_END_ADDRESS;
}

#endif /* __KERNEL__ */
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 597a47b..1e09417 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -39,7 +39,7 @@ static u64 gru_start_paddr, gru_end_paddr;

static inline bool is_GRU_range(u64 start, u64 end)
{
- return start >= gru_start_paddr && end < gru_end_paddr;
+ return start >= gru_start_paddr && end <= gru_end_paddr;
}

static bool uv_is_untracked_pat_range(u64 start, u64 end)
--
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