[PATCH 0/4] arm64: pmd accessor fixes

[PATCH 0/4] arm64: pmd accessor fixes

[Catalin Marinas]

The first two patches are follow-ups on the hardware AF/DBM support, so
they should go in as fixes (on top of current arm64 for-next/core
branch). The third patch is a minor clean-up while the last one
implements pmd_present() following recent discussions around
pmd_mknotpresent() (and it's also a cc stable).

Catalin Marinas (4):
  arm64: Fix typo in the pmdp_huge_get_and_clear() definition
  arm64: Implement pmdp_set_access_flags() for hardware AF/DBM
  arm64: Replace hard-coded values in the pmd/pud_bad() macros
  arm64: Ensure pmd_present() returns false after pmd_mknotpresent()

 arch/arm64/include/asm/pgtable-hwdef.h |  1 -
 arch/arm64/include/asm/pgtable.h       | 26 ++++++++++++++++++--------
 2 files changed, 18 insertions(+), 9 deletions(-)

[PATCH 1/4] arm64: Fix typo in the pmdp_huge_get_and_clear() definition

[Catalin Marinas]

With hardware AF/DBM support, pmd modifications (transparent huge pages)
should be performed atomically using load/store exclusive. The initial
patches defined the get-and-clear function and __HAVE_ARCH_* macro
without the "huge" word, leaving the pmdp_huge_get_and_clear() to the
default, non-atomic implementation.

Fixes: 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits")
Cc: <stable@vger.kernel.org> # 4.3+
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/include/asm/pgtable.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index e021cbf11043..5237331e97f4 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -605,9 +605,9 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-#define __HAVE_ARCH_PMDP_GET_AND_CLEAR
-static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
-				       unsigned long address, pmd_t *pmdp)
+#define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
+static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
+					    unsigned long address, pmd_t *pmdp)
 {
 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
 }

[PATCH 2/4] arm64: Implement pmdp_set_access_flags() for hardware AF/DBM

[Catalin Marinas]

The update to the accessed or dirty states for block mappings must be
done atomically on hardware with support for automatic AF/DBM. The
ptep_set_access_flags() function has been fixed as part of commit
66dbd6e61a52 ("arm64: Implement ptep_set_access_flags() for hardware
AF/DBM"). This patch brings pmdp_set_access_flags() in line with the pte
counterpart.

Fixes: 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits")
Cc: <stable@vger.kernel.org> # 4.4.x: 66dbd6e61a52: arm64: Implement ptep_set_access_flags() for hardware AF/DBM
Cc: <stable@vger.kernel.org> # 4.3+
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/include/asm/pgtable.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 5237331e97f4..bdfbaf96b426 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -553,6 +553,16 @@ extern int ptep_set_access_flags(struct vm_area_struct *vma,
 				 unsigned long address, pte_t *ptep,
 				 pte_t entry, int dirty);
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
+static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
+					unsigned long address, pmd_t *pmdp,
+					pmd_t entry, int dirty)
+{
+	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
+}
+#endif
+
 /*
  * Atomic pte/pmd modifications.
  */

[PATCH 3/4] arm64: Replace hard-coded values in the pmd/pud_bad() macros

[Catalin Marinas]

This patch replaces the hard-coded value 2 with PMD_TABLE_BIT in the
pmd/pud_bad() macros. Note that using these macros on pmd_trans_huge()
entries is giving incorrect results
(pmd_none_or_trans_huge_or_clear_bad() correctly checks for
pmd_trans_huge before pmd_bad).

Additionally, white-space clean-up for pmd_mkclean().

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/include/asm/pgtable.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index bdfbaf96b426..a8b8f4eb7bff 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -305,7 +305,7 @@ static inline int pmd_protnone(pmd_t pmd)
 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
-#define pmd_mkclean(pmd)       pte_pmd(pte_mkclean(pmd_pte(pmd)))
+#define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
@@ -349,7 +349,7 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 #define pmd_none(pmd)		(!pmd_val(pmd))
 #define pmd_present(pmd)	(pmd_val(pmd))
 
-#define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))
+#define pmd_bad(pmd)		(!(pmd_val(pmd) & PMD_TABLE_BIT))
 
 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
 				 PMD_TYPE_TABLE)
@@ -415,7 +415,7 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
 
 #define pud_none(pud)		(!pud_val(pud))
-#define pud_bad(pud)		(!(pud_val(pud) & 2))
+#define pud_bad(pud)		(!(pud_val(pud) & PUD_TABLE_BIT))
 #define pud_present(pud)	(pud_val(pud))
 
 static inline void set_pud(pud_t *pudp, pud_t pud)

[PATCH 4/4] arm64: Ensure pmd_present() returns false after pmd_mknotpresent()

[Catalin Marinas]

Currently, pmd_present() only checks for a non-zero value, returning
true even after pmd_mknotpresent() (which only clears the type bits).
This patch converts pmd_present() to using pte_present(), similar to the
other pmd_*() checks. As a side effect, it will return true for
PROT_NONE mappings, though they are not yet used by the kernel with
transparent huge pages.

For consistency, also change pmd_mknotpresent() to only clear the
PMD_SECT_VALID bit, even though the PMD_TABLE_BIT is already 0 for block
mappings (no functional change). The unused PMD_SECT_PROT_NONE
definition is removed as transparent huge pages use the pte page prot
values.

Fixes: 9c7e535fcc17 ("arm64: mm: Route pmd thp functions through pte equivalents")
Cc: <stable@vger.kernel.org> # 3.15+
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/include/asm/pgtable-hwdef.h | 1 -
 arch/arm64/include/asm/pgtable.h       | 4 ++--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
index 5c25b831273d..9786f770088d 100644
--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -133,7 +133,6 @@
  * Section
  */
 #define PMD_SECT_VALID		(_AT(pmdval_t, 1) << 0)
-#define PMD_SECT_PROT_NONE	(_AT(pmdval_t, 1) << 58)
 #define PMD_SECT_USER		(_AT(pmdval_t, 1) << 6)		/* AP[1] */
 #define PMD_SECT_RDONLY		(_AT(pmdval_t, 1) << 7)		/* AP[2] */
 #define PMD_SECT_S		(_AT(pmdval_t, 3) << 8)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index a8b8f4eb7bff..7b2806812d95 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -300,6 +300,7 @@ static inline int pmd_protnone(pmd_t pmd)
 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+#define pmd_present(pmd)	pte_present(pmd_pte(pmd))
 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
@@ -308,7 +309,7 @@ static inline int pmd_protnone(pmd_t pmd)
 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
-#define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
+#define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
 
 #define __HAVE_ARCH_PMD_WRITE
 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
@@ -347,7 +348,6 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 				     unsigned long size, pgprot_t vma_prot);
 
 #define pmd_none(pmd)		(!pmd_val(pmd))
-#define pmd_present(pmd)	(pmd_val(pmd))
 
 #define pmd_bad(pmd)		(!(pmd_val(pmd) & PMD_TABLE_BIT))