* [PATCH 1/5] ARM: pgtable: move TOP_PTE address definitions to arch/arm/mm/mm.h
2012-01-20 10:34 [PATCH 0/5] Minor cleanups to kernel pte handling Russell King - ARM Linux
@ 2012-01-20 10:35 ` Russell King - ARM Linux
2012-01-25 11:20 ` Catalin Marinas
2012-01-20 10:35 ` [PATCH 2/5] ARM: pgtable: use mk_pte rather than pfn_pte(page_to_pfn()) Russell King - ARM Linux
` (3 subsequent siblings)
4 siblings, 1 reply; 12+ messages in thread
From: Russell King - ARM Linux @ 2012-01-20 10:35 UTC (permalink / raw)
To: linux-arm-kernel
Move the TOP_PTE address definitions to one central place so that it's
easy to discover what they're being used for. This helps to ensure
that there are no overlaps.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/mm/copypage-v4mc.c | 10 +++-------
arch/arm/mm/copypage-v6.c | 16 ++++++----------
arch/arm/mm/copypage-xscale.c | 6 ------
arch/arm/mm/flush.c | 8 +++-----
arch/arm/mm/mm.h | 13 +++++++++++++
5 files changed, 25 insertions(+), 28 deletions(-)
diff --git a/arch/arm/mm/copypage-v4mc.c b/arch/arm/mm/copypage-v4mc.c
index 7d0a8c2..87a23ca 100644
--- a/arch/arm/mm/copypage-v4mc.c
+++ b/arch/arm/mm/copypage-v4mc.c
@@ -23,10 +23,6 @@
#include "mm.h"
-/*
- * 0xffff8000 to 0xffffffff is reserved for any ARM architecture
- * specific hacks for copying pages efficiently.
- */
#define minicache_pgprot __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | \
L_PTE_MT_MINICACHE)
@@ -78,10 +74,10 @@ void v4_mc_copy_user_highpage(struct page *to, struct page *from,
raw_spin_lock(&minicache_lock);
- set_pte_ext(TOP_PTE(0xffff8000), pfn_pte(page_to_pfn(from), minicache_pgprot), 0);
- flush_tlb_kernel_page(0xffff8000);
+ set_pte_ext(TOP_PTE(COPYPAGE_MINICACHE), pfn_pte(page_to_pfn(from), minicache_pgprot), 0);
+ flush_tlb_kernel_page(COPYPAGE_MINICACHE);
- mc_copy_user_page((void *)0xffff8000, kto);
+ mc_copy_user_page((void *)COPYPAGE_MINICACHE, kto);
raw_spin_unlock(&minicache_lock);
diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
index 3d9a155..c00a750 100644
--- a/arch/arm/mm/copypage-v6.c
+++ b/arch/arm/mm/copypage-v6.c
@@ -24,9 +24,6 @@
#error FIX ME
#endif
-#define from_address (0xffff8000)
-#define to_address (0xffffc000)
-
static DEFINE_RAW_SPINLOCK(v6_lock);
/*
@@ -90,11 +87,11 @@ static void v6_copy_user_highpage_aliasing(struct page *to,
*/
raw_spin_lock(&v6_lock);
- set_pte_ext(TOP_PTE(from_address) + offset, pfn_pte(page_to_pfn(from), PAGE_KERNEL), 0);
- set_pte_ext(TOP_PTE(to_address) + offset, pfn_pte(page_to_pfn(to), PAGE_KERNEL), 0);
+ kfrom = COPYPAGE_V6_FROM + (offset << PAGE_SHIFT);
+ kto = COPYPAGE_V6_TO + (offset << PAGE_SHIFT);
- kfrom = from_address + (offset << PAGE_SHIFT);
- kto = to_address + (offset << PAGE_SHIFT);
+ set_pte_ext(TOP_PTE(kfrom), pfn_pte(page_to_pfn(from), PAGE_KERNEL), 0);
+ set_pte_ext(TOP_PTE(kto), pfn_pte(page_to_pfn(to), PAGE_KERNEL), 0);
flush_tlb_kernel_page(kfrom);
flush_tlb_kernel_page(kto);
@@ -111,8 +108,7 @@ static void v6_copy_user_highpage_aliasing(struct page *to,
*/
static void v6_clear_user_highpage_aliasing(struct page *page, unsigned long vaddr)
{
- unsigned int offset = CACHE_COLOUR(vaddr);
- unsigned long to = to_address + (offset << PAGE_SHIFT);
+ unsigned long to = COPYPAGE_V6_TO + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
/* FIXME: not highmem safe */
discard_old_kernel_data(page_address(page));
@@ -123,7 +119,7 @@ static void v6_clear_user_highpage_aliasing(struct page *page, unsigned long vad
*/
raw_spin_lock(&v6_lock);
- set_pte_ext(TOP_PTE(to_address) + offset, pfn_pte(page_to_pfn(page), PAGE_KERNEL), 0);
+ set_pte_ext(TOP_PTE(to), pfn_pte(page_to_pfn(page), PAGE_KERNEL), 0);
flush_tlb_kernel_page(to);
clear_page((void *)to);
diff --git a/arch/arm/mm/copypage-xscale.c b/arch/arm/mm/copypage-xscale.c
index 610c24c..90f3bb5 100644
--- a/arch/arm/mm/copypage-xscale.c
+++ b/arch/arm/mm/copypage-xscale.c
@@ -23,12 +23,6 @@
#include "mm.h"
-/*
- * 0xffff8000 to 0xffffffff is reserved for any ARM architecture
- * specific hacks for copying pages efficiently.
- */
-#define COPYPAGE_MINICACHE 0xffff8000
-
#define minicache_pgprot __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | \
L_PTE_MT_MINICACHE)
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 1a8d4aa..f4d407a 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -23,11 +23,9 @@
#ifdef CONFIG_CPU_CACHE_VIPT
-#define ALIAS_FLUSH_START 0xffff4000
-
static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
{
- unsigned long to = ALIAS_FLUSH_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
+ unsigned long to = FLUSH_ALIAS_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
const int zero = 0;
set_pte_ext(TOP_PTE(to), pfn_pte(pfn, PAGE_KERNEL), 0);
@@ -46,8 +44,8 @@ static void flush_icache_alias(unsigned long pfn, unsigned long vaddr, unsigned
unsigned long offset = vaddr & (PAGE_SIZE - 1);
unsigned long to;
- set_pte_ext(TOP_PTE(ALIAS_FLUSH_START) + colour, pfn_pte(pfn, PAGE_KERNEL), 0);
- to = ALIAS_FLUSH_START + (colour << PAGE_SHIFT) + offset;
+ set_pte_ext(TOP_PTE(FLUSH_ALIAS_START) + colour, pfn_pte(pfn, PAGE_KERNEL), 0);
+ to = FLUSH_ALIAS_START + (colour << PAGE_SHIFT) + offset;
flush_tlb_kernel_page(to);
flush_icache_range(to, to + len);
}
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index 70f6d3ea..6ee1ff2 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -5,6 +5,19 @@ extern pmd_t *top_pmd;
#define TOP_PTE(x) pte_offset_kernel(top_pmd, x)
+/*
+ * 0xffff8000 to 0xffffffff is reserved for any ARM architecture
+ * specific hacks for copying pages efficiently, while 0xffff4000
+ * is reserved for VIPT aliasing flushing by generic code.
+ *
+ * Note that we don't allow VIPT aliasing caches with SMP.
+ */
+#define COPYPAGE_MINICACHE 0xffff8000
+#define COPYPAGE_V6_FROM 0xffff8000
+#define COPYPAGE_V6_TO 0xffffc000
+/* PFN alias flushing, for VIPT caches */
+#define FLUSH_ALIAS_START 0xffff4000
+
static inline pmd_t *pmd_off_k(unsigned long virt)
{
return pmd_offset(pud_offset(pgd_offset_k(virt), virt), virt);
--
1.7.4.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 2/5] ARM: pgtable: use mk_pte rather than pfn_pte(page_to_pfn())
2012-01-20 10:34 [PATCH 0/5] Minor cleanups to kernel pte handling Russell King - ARM Linux
2012-01-20 10:35 ` [PATCH 1/5] ARM: pgtable: move TOP_PTE address definitions to arch/arm/mm/mm.h Russell King - ARM Linux
@ 2012-01-20 10:35 ` Russell King - ARM Linux
2012-01-25 11:23 ` Catalin Marinas
2012-01-20 10:35 ` [PATCH 3/5] ARM: pgtable: consolidate set_pte_ext(TOP_PTE, ...) + tlb flush Russell King - ARM Linux
` (2 subsequent siblings)
4 siblings, 1 reply; 12+ messages in thread
From: Russell King - ARM Linux @ 2012-01-20 10:35 UTC (permalink / raw)
To: linux-arm-kernel
mk_pte is provided to do this translation for us, so use it rather
than open-coding it in the copypage code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/mm/copypage-v4mc.c | 2 +-
arch/arm/mm/copypage-v6.c | 6 +++---
arch/arm/mm/copypage-xscale.c | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/arm/mm/copypage-v4mc.c b/arch/arm/mm/copypage-v4mc.c
index 87a23ca..e4dc2f4 100644
--- a/arch/arm/mm/copypage-v4mc.c
+++ b/arch/arm/mm/copypage-v4mc.c
@@ -74,7 +74,7 @@ void v4_mc_copy_user_highpage(struct page *to, struct page *from,
raw_spin_lock(&minicache_lock);
- set_pte_ext(TOP_PTE(COPYPAGE_MINICACHE), pfn_pte(page_to_pfn(from), minicache_pgprot), 0);
+ set_pte_ext(TOP_PTE(COPYPAGE_MINICACHE), mk_pte(from, minicache_pgprot), 0);
flush_tlb_kernel_page(COPYPAGE_MINICACHE);
mc_copy_user_page((void *)COPYPAGE_MINICACHE, kto);
diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
index c00a750..8652459 100644
--- a/arch/arm/mm/copypage-v6.c
+++ b/arch/arm/mm/copypage-v6.c
@@ -90,8 +90,8 @@ static void v6_copy_user_highpage_aliasing(struct page *to,
kfrom = COPYPAGE_V6_FROM + (offset << PAGE_SHIFT);
kto = COPYPAGE_V6_TO + (offset << PAGE_SHIFT);
- set_pte_ext(TOP_PTE(kfrom), pfn_pte(page_to_pfn(from), PAGE_KERNEL), 0);
- set_pte_ext(TOP_PTE(kto), pfn_pte(page_to_pfn(to), PAGE_KERNEL), 0);
+ set_pte_ext(TOP_PTE(kfrom), mk_pte(from, PAGE_KERNEL), 0);
+ set_pte_ext(TOP_PTE(kto), mk_pte(to, PAGE_KERNEL), 0);
flush_tlb_kernel_page(kfrom);
flush_tlb_kernel_page(kto);
@@ -119,7 +119,7 @@ static void v6_clear_user_highpage_aliasing(struct page *page, unsigned long vad
*/
raw_spin_lock(&v6_lock);
- set_pte_ext(TOP_PTE(to), pfn_pte(page_to_pfn(page), PAGE_KERNEL), 0);
+ set_pte_ext(TOP_PTE(to), mk_pte(page, PAGE_KERNEL), 0);
flush_tlb_kernel_page(to);
clear_page((void *)to);
diff --git a/arch/arm/mm/copypage-xscale.c b/arch/arm/mm/copypage-xscale.c
index 90f3bb5..2497dcf 100644
--- a/arch/arm/mm/copypage-xscale.c
+++ b/arch/arm/mm/copypage-xscale.c
@@ -94,7 +94,7 @@ void xscale_mc_copy_user_highpage(struct page *to, struct page *from,
raw_spin_lock(&minicache_lock);
- set_pte_ext(TOP_PTE(COPYPAGE_MINICACHE), pfn_pte(page_to_pfn(from), minicache_pgprot), 0);
+ set_pte_ext(TOP_PTE(COPYPAGE_MINICACHE), mk_pte(from, minicache_pgprot), 0);
flush_tlb_kernel_page(COPYPAGE_MINICACHE);
mc_copy_user_page((void *)COPYPAGE_MINICACHE, kto);
--
1.7.4.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 3/5] ARM: pgtable: consolidate set_pte_ext(TOP_PTE, ...) + tlb flush
2012-01-20 10:34 [PATCH 0/5] Minor cleanups to kernel pte handling Russell King - ARM Linux
2012-01-20 10:35 ` [PATCH 1/5] ARM: pgtable: move TOP_PTE address definitions to arch/arm/mm/mm.h Russell King - ARM Linux
2012-01-20 10:35 ` [PATCH 2/5] ARM: pgtable: use mk_pte rather than pfn_pte(page_to_pfn()) Russell King - ARM Linux
@ 2012-01-20 10:35 ` Russell King - ARM Linux
2012-01-25 11:32 ` Catalin Marinas
2012-01-20 10:36 ` [PATCH 4/5] ARM: pgtable: provide get_top_pte() to complement set_top_pte() Russell King - ARM Linux
2012-01-20 10:36 ` [PATCH 5/5] ARM: pgtable: get rid of TOP_PTE() Russell King - ARM Linux
4 siblings, 1 reply; 12+ messages in thread
From: Russell King - ARM Linux @ 2012-01-20 10:35 UTC (permalink / raw)
To: linux-arm-kernel
A number of places establish a PTE in our top page table and
immediately flush the TLB. Rather than having this at every callsite,
provide an inline function for this purpose.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/mm/copypage-v4mc.c | 3 +--
arch/arm/mm/copypage-v6.c | 10 +++-------
arch/arm/mm/copypage-xscale.c | 3 +--
arch/arm/mm/flush.c | 10 ++++------
arch/arm/mm/highmem.c | 13 +++++--------
arch/arm/mm/mm.h | 6 ++++++
6 files changed, 20 insertions(+), 25 deletions(-)
diff --git a/arch/arm/mm/copypage-v4mc.c b/arch/arm/mm/copypage-v4mc.c
index e4dc2f4..6e06180 100644
--- a/arch/arm/mm/copypage-v4mc.c
+++ b/arch/arm/mm/copypage-v4mc.c
@@ -74,8 +74,7 @@ void v4_mc_copy_user_highpage(struct page *to, struct page *from,
raw_spin_lock(&minicache_lock);
- set_pte_ext(TOP_PTE(COPYPAGE_MINICACHE), mk_pte(from, minicache_pgprot), 0);
- flush_tlb_kernel_page(COPYPAGE_MINICACHE);
+ set_top_pte(COPYPAGE_MINICACHE, mk_pte(from, minicache_pgprot));
mc_copy_user_page((void *)COPYPAGE_MINICACHE, kto);
diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
index 8652459..29c7704 100644
--- a/arch/arm/mm/copypage-v6.c
+++ b/arch/arm/mm/copypage-v6.c
@@ -90,11 +90,8 @@ static void v6_copy_user_highpage_aliasing(struct page *to,
kfrom = COPYPAGE_V6_FROM + (offset << PAGE_SHIFT);
kto = COPYPAGE_V6_TO + (offset << PAGE_SHIFT);
- set_pte_ext(TOP_PTE(kfrom), mk_pte(from, PAGE_KERNEL), 0);
- set_pte_ext(TOP_PTE(kto), mk_pte(to, PAGE_KERNEL), 0);
-
- flush_tlb_kernel_page(kfrom);
- flush_tlb_kernel_page(kto);
+ set_top_pte(kfrom, mk_pte(from, PAGE_KERNEL));
+ set_top_pte(kto, mk_pte(to, PAGE_KERNEL));
copy_page((void *)kto, (void *)kfrom);
@@ -119,8 +116,7 @@ static void v6_clear_user_highpage_aliasing(struct page *page, unsigned long vad
*/
raw_spin_lock(&v6_lock);
- set_pte_ext(TOP_PTE(to), mk_pte(page, PAGE_KERNEL), 0);
- flush_tlb_kernel_page(to);
+ set_top_pte(to, mk_pte(page, PAGE_KERNEL));
clear_page((void *)to);
raw_spin_unlock(&v6_lock);
diff --git a/arch/arm/mm/copypage-xscale.c b/arch/arm/mm/copypage-xscale.c
index 2497dcf..804eedd 100644
--- a/arch/arm/mm/copypage-xscale.c
+++ b/arch/arm/mm/copypage-xscale.c
@@ -94,8 +94,7 @@ void xscale_mc_copy_user_highpage(struct page *to, struct page *from,
raw_spin_lock(&minicache_lock);
- set_pte_ext(TOP_PTE(COPYPAGE_MINICACHE), mk_pte(from, minicache_pgprot), 0);
- flush_tlb_kernel_page(COPYPAGE_MINICACHE);
+ set_top_pte(COPYPAGE_MINICACHE, mk_pte(from, minicache_pgprot));
mc_copy_user_page((void *)COPYPAGE_MINICACHE, kto);
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index f4d407a..4d0b70f 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -28,8 +28,7 @@ static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
unsigned long to = FLUSH_ALIAS_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
const int zero = 0;
- set_pte_ext(TOP_PTE(to), pfn_pte(pfn, PAGE_KERNEL), 0);
- flush_tlb_kernel_page(to);
+ set_top_pte(to, pfn_pte(pfn, PAGE_KERNEL));
asm( "mcrr p15, 0, %1, %0, c14\n"
" mcr p15, 0, %2, c7, c10, 4"
@@ -40,13 +39,12 @@ static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
static void flush_icache_alias(unsigned long pfn, unsigned long vaddr, unsigned long len)
{
- unsigned long colour = CACHE_COLOUR(vaddr);
+ unsigned long va = FLUSH_ALIAS_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
unsigned long offset = vaddr & (PAGE_SIZE - 1);
unsigned long to;
- set_pte_ext(TOP_PTE(FLUSH_ALIAS_START) + colour, pfn_pte(pfn, PAGE_KERNEL), 0);
- to = FLUSH_ALIAS_START + (colour << PAGE_SHIFT) + offset;
- flush_tlb_kernel_page(to);
+ set_top_pte(va, pfn_pte(pfn, PAGE_KERNEL));
+ to = va + offset;
flush_icache_range(to, to + len);
}
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index 807c057..3535251 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -71,13 +71,12 @@ void *__kmap_atomic(struct page *page)
*/
BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
#endif
- set_pte_ext(TOP_PTE(vaddr), mk_pte(page, kmap_prot), 0);
/*
* When debugging is off, kunmap_atomic leaves the previous mapping
- * in place, so this TLB flush ensures the TLB is updated with the
- * new mapping.
+ * in place, so the contained TLB flush ensures the TLB is updated
+ * with the new mapping.
*/
- local_flush_tlb_kernel_page(vaddr);
+ set_top_pte(vaddr, mk_pte(page, kmap_prot));
return (void *)vaddr;
}
@@ -96,8 +95,7 @@ void __kunmap_atomic(void *kvaddr)
__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
- set_pte_ext(TOP_PTE(vaddr), __pte(0), 0);
- local_flush_tlb_kernel_page(vaddr);
+ set_top_pte(vaddr, __pte(0));
#else
(void) idx; /* to kill a warning */
#endif
@@ -123,8 +121,7 @@ void *kmap_atomic_pfn(unsigned long pfn)
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
#endif
- set_pte_ext(TOP_PTE(vaddr), pfn_pte(pfn, kmap_prot), 0);
- local_flush_tlb_kernel_page(vaddr);
+ set_top_pte(vaddr, pfn_pte(pfn, kmap_prot));
return (void *)vaddr;
}
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index 6ee1ff2..a4e7feb 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -18,6 +18,12 @@ extern pmd_t *top_pmd;
/* PFN alias flushing, for VIPT caches */
#define FLUSH_ALIAS_START 0xffff4000
+static inline void set_top_pte(unsigned long va, pte_t pte)
+{
+ set_pte_ext(TOP_PTE(va), pte, 0);
+ local_flush_tlb_kernel_page(va);
+}
+
static inline pmd_t *pmd_off_k(unsigned long virt)
{
return pmd_offset(pud_offset(pgd_offset_k(virt), virt), virt);
--
1.7.4.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 3/5] ARM: pgtable: consolidate set_pte_ext(TOP_PTE, ...) + tlb flush
2012-01-20 10:35 ` [PATCH 3/5] ARM: pgtable: consolidate set_pte_ext(TOP_PTE, ...) + tlb flush Russell King - ARM Linux
@ 2012-01-25 11:32 ` Catalin Marinas
2012-01-26 20:08 ` Russell King - ARM Linux
0 siblings, 1 reply; 12+ messages in thread
From: Catalin Marinas @ 2012-01-25 11:32 UTC (permalink / raw)
To: linux-arm-kernel
On 20 January 2012 10:35, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> A number of places establish a PTE in our top page table and
> immediately flush the TLB. ?Rather than having this at every callsite,
> provide an inline function for this purpose.
...
> +static inline void set_top_pte(unsigned long va, pte_t pte)
> +{
> + ? ? ? set_pte_ext(TOP_PTE(va), pte, 0);
> + ? ? ? local_flush_tlb_kernel_page(va);
> +}
There is a difference with some of the call sites where the
flush_tlb_kernel_page() was used instead of the local variant. The pte
set up via set_top_pte() is indeed accessed on a single CPU and there
are locks around that would prevent migration (with CONFIG_PREEMPT).
So I don't see any problem with this.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
--
Catalin
^ permalink raw reply [flat|nested] 12+ messages in thread* [PATCH 3/5] ARM: pgtable: consolidate set_pte_ext(TOP_PTE, ...) + tlb flush
2012-01-25 11:32 ` Catalin Marinas
@ 2012-01-26 20:08 ` Russell King - ARM Linux
0 siblings, 0 replies; 12+ messages in thread
From: Russell King - ARM Linux @ 2012-01-26 20:08 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Jan 25, 2012 at 11:32:48AM +0000, Catalin Marinas wrote:
> On 20 January 2012 10:35, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
> > A number of places establish a PTE in our top page table and
> > immediately flush the TLB. ?Rather than having this at every callsite,
> > provide an inline function for this purpose.
> ...
> > +static inline void set_top_pte(unsigned long va, pte_t pte)
> > +{
> > + ? ? ? set_pte_ext(TOP_PTE(va), pte, 0);
> > + ? ? ? local_flush_tlb_kernel_page(va);
> > +}
>
> There is a difference with some of the call sites where the
> flush_tlb_kernel_page() was used instead of the local variant. The pte
> set up via set_top_pte() is indeed accessed on a single CPU and there
> are locks around that would prevent migration (with CONFIG_PREEMPT).
> So I don't see any problem with this.
That was indeed part of the intention. I've added a note to the
description to that effect.
> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
>
> --
> Catalin
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 4/5] ARM: pgtable: provide get_top_pte() to complement set_top_pte()
2012-01-20 10:34 [PATCH 0/5] Minor cleanups to kernel pte handling Russell King - ARM Linux
` (2 preceding siblings ...)
2012-01-20 10:35 ` [PATCH 3/5] ARM: pgtable: consolidate set_pte_ext(TOP_PTE, ...) + tlb flush Russell King - ARM Linux
@ 2012-01-20 10:36 ` Russell King - ARM Linux
2012-01-25 11:33 ` Catalin Marinas
2012-01-20 10:36 ` [PATCH 5/5] ARM: pgtable: get rid of TOP_PTE() Russell King - ARM Linux
4 siblings, 1 reply; 12+ messages in thread
From: Russell King - ARM Linux @ 2012-01-20 10:36 UTC (permalink / raw)
To: linux-arm-kernel
Provide get_top_pte() to complement set_top_pte(), moving the only
users of TOP_PTE to arch/arm/mm/mm.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/mm/highmem.c | 8 +++-----
arch/arm/mm/mm.h | 5 +++++
2 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index 3535251..3a9e8aa 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -69,7 +69,7 @@ void *__kmap_atomic(struct page *page)
* With debugging enabled, kunmap_atomic forces that entry to 0.
* Make sure it was indeed properly unmapped.
*/
- BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
+ BUG_ON(!pte_none(get_top_pte(vaddr)));
#endif
/*
* When debugging is off, kunmap_atomic leaves the previous mapping
@@ -119,7 +119,7 @@ void *kmap_atomic_pfn(unsigned long pfn)
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
+ BUG_ON(!pte_none(get_top_pte(vaddr)));
#endif
set_top_pte(vaddr, pfn_pte(pfn, kmap_prot));
@@ -129,11 +129,9 @@ void *kmap_atomic_pfn(unsigned long pfn)
struct page *kmap_atomic_to_page(const void *ptr)
{
unsigned long vaddr = (unsigned long)ptr;
- pte_t *pte;
if (vaddr < FIXADDR_START)
return virt_to_page(ptr);
- pte = TOP_PTE(vaddr);
- return pte_page(*pte);
+ return pte_page(get_top_pte(vaddr));
}
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index a4e7feb..1651d5a 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -24,6 +24,11 @@ static inline void set_top_pte(unsigned long va, pte_t pte)
local_flush_tlb_kernel_page(va);
}
+static inline pte_t get_top_pte(unsigned long va)
+{
+ return *TOP_PTE(va);
+}
+
static inline pmd_t *pmd_off_k(unsigned long virt)
{
return pmd_offset(pud_offset(pgd_offset_k(virt), virt), virt);
--
1.7.4.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 5/5] ARM: pgtable: get rid of TOP_PTE()
2012-01-20 10:34 [PATCH 0/5] Minor cleanups to kernel pte handling Russell King - ARM Linux
` (3 preceding siblings ...)
2012-01-20 10:36 ` [PATCH 4/5] ARM: pgtable: provide get_top_pte() to complement set_top_pte() Russell King - ARM Linux
@ 2012-01-20 10:36 ` Russell King - ARM Linux
2012-01-25 11:34 ` Catalin Marinas
4 siblings, 1 reply; 12+ messages in thread
From: Russell King - ARM Linux @ 2012-01-20 10:36 UTC (permalink / raw)
To: linux-arm-kernel
Get rid of the TOP_PTE() macro as we now have proper accessor functions
instead. No one should be directly referencing the top pte table
anymore.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/mm/mm.h | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index 1651d5a..27f4a61 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -3,8 +3,6 @@
/* the upper-most page table pointer */
extern pmd_t *top_pmd;
-#define TOP_PTE(x) pte_offset_kernel(top_pmd, x)
-
/*
* 0xffff8000 to 0xffffffff is reserved for any ARM architecture
* specific hacks for copying pages efficiently, while 0xffff4000
@@ -20,13 +18,15 @@ extern pmd_t *top_pmd;
static inline void set_top_pte(unsigned long va, pte_t pte)
{
- set_pte_ext(TOP_PTE(va), pte, 0);
+ pte_t *ptep = pte_offset_kernel(top_pmd, va);
+ set_pte_ext(ptep, pte, 0);
local_flush_tlb_kernel_page(va);
}
static inline pte_t get_top_pte(unsigned long va)
{
- return *TOP_PTE(va);
+ pte_t *ptep = pte_offset_kernel(top_pmd, va);
+ return *ptep;
}
static inline pmd_t *pmd_off_k(unsigned long virt)
--
1.7.4.4
^ permalink raw reply related [flat|nested] 12+ messages in thread