The patch titled
Subject: mm, x86: document return values of mapping funcs
has been added to the -mm tree. Its filename is
mm-x86-document-return-values-of-mapping-funcs.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-x86-document-return-values-of-mapping-funcs.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-x86-document-return-values-of-mapping-funcs.patch
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From: Toshi Kani <toshi.kani@xxxxxx>
Subject: mm, x86: document return values of mapping funcs
This patchset enhances MTRR checks for the kernel huge I/O mapping, which
was enabled by the patchset below:
https://lkml.org/lkml/2015/3/3/589
The following functional changes are made in patch 7/7.
- Allow pud_set_huge() and pmd_set_huge() to create a huge page
mapping to a range covered by a single MTRR entry of any memory
type.
- Log a pr_warn() message when a specified PMD map range spans more
than a single MTRR entry. Drivers should make a mapping request
aligned to a single MTRR entry when the range is covered by MTRRs.
This patch (of 7):
Document the return values of KVA mapping functions, pud_set_huge(),
pmd_set_huge, pud_clear_huge() and pmd_clear_huge().
Simplify the conditions to select HAVE_ARCH_HUGE_VMAP in the Kconfig,
since X86_PAE depends on X86_32.
There is no functional change in this patch.
Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Robert Elliott <Elliott@xxxxxx>
Cc: Paul Bolle <pebolle@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/Kconfig | 2 +-
arch/x86/mm/pgtable.c | 36 ++++++++++++++++++++++++++++--------
2 files changed, 29 insertions(+), 9 deletions(-)
diff -puN arch/x86/Kconfig~mm-x86-document-return-values-of-mapping-funcs arch/x86/Kconfig
--- a/arch/x86/Kconfig~mm-x86-document-return-values-of-mapping-funcs
+++ a/arch/x86/Kconfig
@@ -99,7 +99,7 @@ config X86
select IRQ_FORCED_THREADING
select HAVE_BPF_JIT if X86_64
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
- select HAVE_ARCH_HUGE_VMAP if X86_64 || (X86_32 && X86_PAE)
+ select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
select ARCH_HAS_SG_CHAIN
select CLKEVT_I8253
select ARCH_HAVE_NMI_SAFE_CMPXCHG
diff -puN arch/x86/mm/pgtable.c~mm-x86-document-return-values-of-mapping-funcs arch/x86/mm/pgtable.c
--- a/arch/x86/mm/pgtable.c~mm-x86-document-return-values-of-mapping-funcs
+++ a/arch/x86/mm/pgtable.c
@@ -563,14 +563,19 @@ void native_set_fixmap(enum fixed_addres
}
#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
+/**
+ * pud_set_huge - setup kernel PUD mapping
+ *
+ * MTRR can override PAT memory types with 4KB granularity. Therefore,
+ * it does not set up a huge page when the range is covered by a non-WB
+ * type of MTRR. 0xFF indicates that MTRR are disabled.
+ *
+ * Return 1 on success, and 0 when no PUD was set.
+ */
int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
{
u8 mtrr;
- /*
- * Do not use a huge page when the range is covered by non-WB type
- * of MTRRs.
- */
mtrr = mtrr_type_lookup(addr, addr + PUD_SIZE);
if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF))
return 0;
@@ -584,14 +589,19 @@ int pud_set_huge(pud_t *pud, phys_addr_t
return 1;
}
+/**
+ * pmd_set_huge - setup kernel PMD mapping
+ *
+ * MTRR can override PAT memory types with 4KB granularity. Therefore,
+ * it does not set up a huge page when the range is covered by a non-WB
+ * type of MTRR. 0xFF indicates that MTRR are disabled.
+ *
+ * Return 1 on success, and 0 when no PMD was set.
+ */
int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
{
u8 mtrr;
- /*
- * Do not use a huge page when the range is covered by non-WB type
- * of MTRRs.
- */
mtrr = mtrr_type_lookup(addr, addr + PMD_SIZE);
if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF))
return 0;
@@ -605,6 +615,11 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t
return 1;
}
+/**
+ * pud_clear_huge - clear kernel PUD mapping when it is set
+ *
+ * Return 1 on success, and 0 when no PUD map was found.
+ */
int pud_clear_huge(pud_t *pud)
{
if (pud_large(*pud)) {
@@ -615,6 +630,11 @@ int pud_clear_huge(pud_t *pud)
return 0;
}
+/**
+ * pmd_clear_huge - clear kernel PMD mapping when it is set
+ *
+ * Return 1 on success, and 0 when no PMD map was found.
+ */
int pmd_clear_huge(pmd_t *pmd)
{
if (pmd_large(*pmd)) {
_
Patches currently in -mm which might be from toshi.kani@xxxxxx are
mm-change-__get_vm_area_node-to-use-fls_long.patch
lib-add-huge-i-o-map-capability-interfaces.patch
lib-add-huge-i-o-map-capability-interfaces-fix.patch
mm-change-ioremap-to-set-up-huge-i-o-mappings.patch
mm-change-ioremap-to-set-up-huge-i-o-mappings-fix.patch
mm-change-vunmap-to-tear-down-huge-kva-mappings.patch
mm-change-vunmap-to-tear-down-huge-kva-mappings-fix.patch
x86-mm-support-huge-i-o-mapping-capability-i-f.patch
x86-mm-support-huge-kva-mappings-on-x86.patch
x86-mm-support-huge-kva-mappings-on-x86-fix.patch
linux-next.patch
mm-x86-document-return-values-of-mapping-funcs.patch
mtrr-x86-fix-mtrr-lookup-to-handle-inclusive-entry.patch
mtrr-x86-remove-a-wrong-address-check-in-__mtrr_type_lookup.patch
mtrr-x86-fix-mtrr-state-checks-in-mtrr_type_lookup.patch
mtrr-x86-define-mtrr_type_invalid-for-mtrr_type_lookup.patch
mtrr-x86-clean-up-mtrr_type_lookup.patch
mtrr-mm-x86-enhance-mtrr-checks-for-kva-huge-page-mapping.patch
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