* [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels
@ 2011-08-16 14:14 Dave Martin
2011-08-16 14:14 ` [PATCH 1/3] ARM: Make cpu_alignment into a global variable Dave Martin
` (3 more replies)
0 siblings, 4 replies; 18+ messages in thread
From: Dave Martin @ 2011-08-16 14:14 UTC (permalink / raw)
To: linux-arm-kernel
In kernels which support v6 and v7 platforms in a single binary
such as omap2plus_defconfig for example, undefined instruction
exceptions taken on Thumb instructions are not processed correctly,
because the kernel assumes at build-time that Thumb-2 won't be
supported in userspace.
This series implements a workaround, by allowing the __und_usr
handler to check the CPU architecture at runtime, in affected
kernels.
Changes since RFC:
* Renamed the global variable to __cpu_architecture and provided
cpu_architecture() as in inline function in <asm/system.h>.
This brings back the old API, but more efficiently.
* Dropped all the patches required to handle the reverted API
change.
* cpu_architecture is now declared __pure, which may lead to
slightly more efficient code in some cases.
* Added BUG_ON() to cpu_architecture() so that if
__cpu_architecture is not set early enough, it gets noticed.
Thanks to Tixy and Nicolas Pitre for their helpful feedback which
helped slim down this series.
Dave Martin (3):
ARM: Make cpu_alignment into a global variable
ARM: entry: Remove unnecessary masking when decoding Thumb-2
instructions
ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels
arch/arm/include/asm/system.h | 11 +++++++++-
arch/arm/kernel/entry-armv.S | 44 ++++++++++++++++++++++++++++++++++++----
arch/arm/kernel/setup.c | 5 +++-
3 files changed, 53 insertions(+), 7 deletions(-)
--
1.7.4.1
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 1/3] ARM: Make cpu_alignment into a global variable
2011-08-16 14:14 [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels Dave Martin
@ 2011-08-16 14:14 ` Dave Martin
2011-08-16 16:15 ` Nicolas Pitre
2011-08-17 11:31 ` Sergei Shtylyov
2011-08-16 14:14 ` [PATCH 2/3] ARM: entry: Remove unnecessary masking when decoding Thumb-2 instructions Dave Martin
` (2 subsequent siblings)
3 siblings, 2 replies; 18+ messages in thread
From: Dave Martin @ 2011-08-16 14:14 UTC (permalink / raw)
To: linux-arm-kernel
The CPU architecture really should not be changing at runtime, so
make it a global variable instead of a function.
The cpu_architecture() function in <asm/system.h> remains the
correct way to read this variable from C code.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
---
arch/arm/include/asm/system.h | 11 ++++++++++-
arch/arm/kernel/setup.c | 5 ++++-
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 832888d..b0445f7 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -57,6 +57,8 @@
#ifndef __ASSEMBLY__
+#include <linux/bug.h>
+#include <linux/compiler.h>
#include <linux/linkage.h>
#include <linux/irqflags.h>
@@ -104,7 +106,14 @@ struct mm_struct;
extern void show_pte(struct mm_struct *mm, unsigned long addr);
extern void __show_regs(struct pt_regs *);
-extern int cpu_architecture(void);
+extern int __cpu_architecture;
+
+static inline int __pure cpu_architecture(void)
+{
+ BUG_ON(__cpu_architecture == CPU_ARCH_UNKNOWN);
+ return __cpu_architecture;
+}
+
extern void cpu_init(void);
void arm_machine_restart(char mode, const char *cmd);
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 70bca64..1e0c1b3 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -42,6 +42,7 @@
#include <asm/cacheflush.h>
#include <asm/cachetype.h>
#include <asm/tlbflush.h>
+#include <asm/system.h>
#include <asm/prom.h>
#include <asm/mach/arch.h>
@@ -114,6 +115,7 @@ struct cpu_cache_fns cpu_cache __read_mostly;
struct outer_cache_fns outer_cache __read_mostly;
EXPORT_SYMBOL(outer_cache);
#endif
+int __cpu_architecture __read_mostly = CPU_ARCH_UNKNOWN;
struct stack {
u32 irq[3];
@@ -210,7 +212,7 @@ static const char *proc_arch[] = {
"?(17)",
};
-int cpu_architecture(void)
+static int __init __get_cpu_architecture(void)
{
int cpu_arch;
@@ -413,6 +415,7 @@ static void __init setup_processor(void)
}
cpu_name = list->cpu_name;
+ __cpu_architecture = __get_cpu_architecture();
#ifdef MULTI_CPU
processor = *list->proc;
--
1.7.4.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH 2/3] ARM: entry: Remove unnecessary masking when decoding Thumb-2 instructions
2011-08-16 14:14 [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels Dave Martin
2011-08-16 14:14 ` [PATCH 1/3] ARM: Make cpu_alignment into a global variable Dave Martin
@ 2011-08-16 14:14 ` Dave Martin
2011-08-16 16:17 ` Nicolas Pitre
2011-08-16 14:14 ` [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels Dave Martin
2011-08-16 14:58 ` [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels Tixy
3 siblings, 1 reply; 18+ messages in thread
From: Dave Martin @ 2011-08-16 14:14 UTC (permalink / raw)
To: linux-arm-kernel
When testing whether a Thumb-2 instruction is 32 bits long or not,
the masking done in order to test bits 11-15 of the first
instruction halfword won't affect the result of the comparison, so
remove it.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
---
arch/arm/kernel/entry-armv.S | 6 ++----
1 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index a87cbf8..b7236d4 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -262,8 +262,7 @@ __und_svc:
ldr r0, [r4, #-4]
#else
ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2
- and r9, r0, #0xf800
- cmp r9, #0xe800 @ 32-bit instruction if xx >= 0
+ cmp r0, #0xe800 @ 32-bit instruction if xx >= 0
ldrhhs r9, [r4] @ bottom 16 bits
orrhs r0, r9, r0, lsl #16
#endif
@@ -445,8 +444,7 @@ __und_usr:
ARM( ldrht r5, [r4], #2 )
THUMB( ldrht r5, [r4] )
THUMB( add r4, r4, #2 )
- and r0, r5, #0xf800 @ mask bits 111x x... .... ....
- cmp r0, #0xe800 @ 32bit instruction if xx != 0
+ cmp r5, #0xe800 @ 32bit instruction if xx != 0
blo __und_usr_unknown
3: ldrht r0, [r4]
add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
--
1.7.4.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels
2011-08-16 14:14 [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels Dave Martin
2011-08-16 14:14 ` [PATCH 1/3] ARM: Make cpu_alignment into a global variable Dave Martin
2011-08-16 14:14 ` [PATCH 2/3] ARM: entry: Remove unnecessary masking when decoding Thumb-2 instructions Dave Martin
@ 2011-08-16 14:14 ` Dave Martin
2011-08-16 14:51 ` Tixy
2011-08-16 14:58 ` [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels Tixy
3 siblings, 1 reply; 18+ messages in thread
From: Dave Martin @ 2011-08-16 14:14 UTC (permalink / raw)
To: linux-arm-kernel
When v6 and >=v7 boards are supported in the same kernel, the
__und_usr code currently makes a build-time assumption that Thumb-2
instructions occurring in userspace don't need to be supported.
Strictly speaking this is incorrect.
This patch fixes the above case by doing a run-time check on the
CPU architecture in these cases. This only affects kernels which
support v6 and >=v7 CPUs together: plain v6 and plain v7 kernels
are unaffected.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
---
arch/arm/kernel/entry-armv.S | 38 +++++++++++++++++++++++++++++++++++++-
1 files changed, 37 insertions(+), 1 deletions(-)
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index b7236d4..9ad50c4 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -24,6 +24,7 @@
#include <asm/unwind.h>
#include <asm/unistd.h>
#include <asm/tls.h>
+#include <asm/system.h>
#include "entry-header.S"
#include <asm/entry-macro-multi.S>
@@ -439,7 +440,27 @@ __und_usr:
#endif
beq call_fpe
@ Thumb instruction
-#if __LINUX_ARM_ARCH__ >= 7
+#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
+/*
+ * Thumb-2 instruction handling. Note that because pre-v6 and >= v6 platforms
+ * can never be supported in a single kernel, this code is not applicable at
+ * all when __LINUX_ARM_ARCH__ < 6. This allows simplifying assumptions to be
+ * made about .arch directives.
+ */
+#if __LINUX_ARM_ARCH__ < 7
+/* If the target CPU may not be Thumb-2-capable, a run-time check is needed: */
+#define NEED_CPU_ARCHITECTURE
+ ldr r5, .LCcpu_architecture
+ ldr r5, [r5]
+ cmp r5, #CPU_ARCH_ARMv7
+ blo __und_usr_unknown
+/*
+ * The following code won't get run unless the running CPU really is v7, so
+ * coding round the lack of ldrht on older arches is pointless. Temporarily
+ * override the assembler target arch with the minimum required instead:
+ */
+ .arch armv6t2
+#endif
2:
ARM( ldrht r5, [r4], #2 )
THUMB( ldrht r5, [r4] )
@@ -449,7 +470,16 @@ __und_usr:
3: ldrht r0, [r4]
add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
orr r0, r0, r5, lsl #16
+
+#if __LINUX_ARM_ARCH__ < 7
+/* If the target arch was overridden, change it back: */
+#ifdef CONFIG_CPU_32v6K
+ .arch armv6k
#else
+ .arch armv6
+#endif
+#endif /* __LINUX_ARM_ARCH__ < 7 */
+#else /* !(CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7) */
b __und_usr_unknown
#endif
UNWIND(.fnend )
@@ -576,6 +606,12 @@ call_fpe:
movw_pc lr @ CP#14 (Debug)
movw_pc lr @ CP#15 (Control)
+#ifdef NEED_CPU_ARCHITECTURE
+ .align 2
+.LCcpu_architecture:
+ .word __cpu_architecture
+#endif
+
#ifdef CONFIG_NEON
.align 6
--
1.7.4.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels
2011-08-16 14:14 ` [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels Dave Martin
@ 2011-08-16 14:51 ` Tixy
2011-08-16 15:47 ` Nicolas Pitre
0 siblings, 1 reply; 18+ messages in thread
From: Tixy @ 2011-08-16 14:51 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 2011-08-16 at 15:14 +0100, Dave Martin wrote:
[...]
> +#ifdef NEED_CPU_ARCHITECTURE
> + .align 2
> +.LCcpu_architecture:
> + .word __cpu_architecture
> +#endif
What's the convention about the prefix '.LC' as opposed to just '.L'?
--
Tixy
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels
2011-08-16 14:14 [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels Dave Martin
` (2 preceding siblings ...)
2011-08-16 14:14 ` [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels Dave Martin
@ 2011-08-16 14:58 ` Tixy
2011-08-16 16:06 ` Dave Martin
3 siblings, 1 reply; 18+ messages in thread
From: Tixy @ 2011-08-16 14:58 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 2011-08-16 at 15:14 +0100, Dave Martin wrote:
> In kernels which support v6 and v7 platforms in a single binary
> such as omap2plus_defconfig for example, undefined instruction
> exceptions taken on Thumb instructions are not processed correctly,
> because the kernel assumes at build-time that Thumb-2 won't be
> supported in userspace.
>
> This series implements a workaround, by allowing the __und_usr
> handler to check the CPU architecture at runtime, in affected
> kernels.
>
> Changes since RFC:
> * Renamed the global variable to __cpu_architecture and provided
> cpu_architecture() as in inline function in <asm/system.h>.
> This brings back the old API, but more efficiently.
> * Dropped all the patches required to handle the reverted API
> change.
> * cpu_architecture is now declared __pure, which may lead to
> slightly more efficient code in some cases.
> * Added BUG_ON() to cpu_architecture() so that if
> __cpu_architecture is not set early enough, it gets noticed.
>
> Thanks to Tixy and Nicolas Pitre for their helpful feedback which
> helped slim down this series.
>
> Dave Martin (3):
> ARM: Make cpu_alignment into a global variable
> ARM: entry: Remove unnecessary masking when decoding Thumb-2
> instructions
> ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels
>
> arch/arm/include/asm/system.h | 11 +++++++++-
> arch/arm/kernel/entry-armv.S | 44 ++++++++++++++++++++++++++++++++++++----
> arch/arm/kernel/setup.c | 5 +++-
> 3 files changed, 53 insertions(+), 7 deletions(-)
>
Looks good to me.
--
Tixy
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels
2011-08-16 14:51 ` Tixy
@ 2011-08-16 15:47 ` Nicolas Pitre
2011-08-16 16:05 ` Dave Martin
0 siblings, 1 reply; 18+ messages in thread
From: Nicolas Pitre @ 2011-08-16 15:47 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 16 Aug 2011, Tixy wrote:
> On Tue, 2011-08-16 at 15:14 +0100, Dave Martin wrote:
> [...]
> > +#ifdef NEED_CPU_ARCHITECTURE
> > + .align 2
> > +.LCcpu_architecture:
> > + .word __cpu_architecture
> > +#endif
>
> What's the convention about the prefix '.LC' as opposed to just '.L'?
The .Lfoo format is more widely used than .LCfoo in the tree.
Nicolas
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels
2011-08-16 15:47 ` Nicolas Pitre
@ 2011-08-16 16:05 ` Dave Martin
2011-08-16 16:14 ` Nicolas Pitre
0 siblings, 1 reply; 18+ messages in thread
From: Dave Martin @ 2011-08-16 16:05 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Aug 16, 2011 at 4:47 PM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote:
> On Tue, 16 Aug 2011, Tixy wrote:
>
>> On Tue, 2011-08-16 at 15:14 +0100, Dave Martin wrote:
>> [...]
>> > +#ifdef NEED_CPU_ARCHITECTURE
>> > + ? .align ?2
>> > +.LCcpu_architecture:
>> > + ? .word ? __cpu_architecture
>> > +#endif
>>
>> What's the convention about the prefix '.LC' as opposed to just '.L'?
>
> The .Lfoo format is more widely used than .LCfoo in the tree.
...but .LCfoo is more widely used in entry-armv.S, for exactly the
same kind of thing.
I thought it best to blend in... anyway, apart from the magic prefix
'.L', it's just a name.
Any concerns about this, or can we leave it as-is?
Cheers
---Dave
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels
2011-08-16 14:58 ` [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels Tixy
@ 2011-08-16 16:06 ` Dave Martin
2011-08-16 16:43 ` Tixy
0 siblings, 1 reply; 18+ messages in thread
From: Dave Martin @ 2011-08-16 16:06 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Aug 16, 2011 at 3:58 PM, Tixy <tixy@yxit.co.uk> wrote:
> On Tue, 2011-08-16 at 15:14 +0100, Dave Martin wrote:
>> In kernels which support v6 and v7 platforms in a single binary
>> such as omap2plus_defconfig for example, undefined instruction
>> exceptions taken on Thumb instructions are not processed correctly,
>> because the kernel assumes at build-time that Thumb-2 won't be
>> supported in userspace.
>>
>> This series implements a workaround, by allowing the __und_usr
>> handler to check the CPU architecture at runtime, in affected
>> kernels.
>>
>> Changes since RFC:
>> ? * Renamed the global variable to __cpu_architecture and provided
>> ? ? cpu_architecture() as in inline function in <asm/system.h>.
>> ? ? This brings back the old API, but more efficiently.
>> ? * Dropped all the patches required to handle the reverted API
>> ? ? change.
>> ? * cpu_architecture is now declared __pure, which may lead to
>> ? ? slightly more efficient code in some cases.
>> ? * Added BUG_ON() to cpu_architecture() so that if
>> ? ? __cpu_architecture is not set early enough, it gets noticed.
>>
>> Thanks to Tixy and Nicolas Pitre for their helpful feedback which
>> helped slim down this series.
>>
>> Dave Martin (3):
>> ? ARM: Make cpu_alignment into a global variable
>> ? ARM: entry: Remove unnecessary masking when decoding Thumb-2
>> ? ? instructions
>> ? ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels
>>
>> ?arch/arm/include/asm/system.h | ? 11 +++++++++-
>> ?arch/arm/kernel/entry-armv.S ?| ? 44 ++++++++++++++++++++++++++++++++++++----
>> ?arch/arm/kernel/setup.c ? ? ? | ? ?5 +++-
>> ?3 files changed, 53 insertions(+), 7 deletions(-)
>>
>
> Looks good to me.
Thanks for looking over it.
Is that a Reviewed-by, or will you go for an Ack?
Cheers
---Dave
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels
2011-08-16 16:05 ` Dave Martin
@ 2011-08-16 16:14 ` Nicolas Pitre
2011-08-16 16:20 ` Dave Martin
0 siblings, 1 reply; 18+ messages in thread
From: Nicolas Pitre @ 2011-08-16 16:14 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 16 Aug 2011, Dave Martin wrote:
> On Tue, Aug 16, 2011 at 4:47 PM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote:
> > On Tue, 16 Aug 2011, Tixy wrote:
> >
> >> On Tue, 2011-08-16 at 15:14 +0100, Dave Martin wrote:
> >> [...]
> >> > +#ifdef NEED_CPU_ARCHITECTURE
> >> > + ? .align ?2
> >> > +.LCcpu_architecture:
> >> > + ? .word ? __cpu_architecture
> >> > +#endif
> >>
> >> What's the convention about the prefix '.LC' as opposed to just '.L'?
> >
> > The .Lfoo format is more widely used than .LCfoo in the tree.
>
> ...but .LCfoo is more widely used in entry-armv.S, for exactly the
> same kind of thing.
Just use the same style then.
Nicolas
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 1/3] ARM: Make cpu_alignment into a global variable
2011-08-16 14:14 ` [PATCH 1/3] ARM: Make cpu_alignment into a global variable Dave Martin
@ 2011-08-16 16:15 ` Nicolas Pitre
2011-08-16 16:21 ` Dave Martin
2011-08-17 11:31 ` Sergei Shtylyov
1 sibling, 1 reply; 18+ messages in thread
From: Nicolas Pitre @ 2011-08-16 16:15 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 16 Aug 2011, Dave Martin wrote:
> The CPU architecture really should not be changing at runtime, so
> make it a global variable instead of a function.
>
> The cpu_architecture() function in <asm/system.h> remains the
> correct way to read this variable from C code.
>
> Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
> ---
> arch/arm/include/asm/system.h | 11 ++++++++++-
> arch/arm/kernel/setup.c | 5 ++++-
> 2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
> index 832888d..b0445f7 100644
> --- a/arch/arm/include/asm/system.h
> +++ b/arch/arm/include/asm/system.h
> @@ -57,6 +57,8 @@
>
> #ifndef __ASSEMBLY__
>
> +#include <linux/bug.h>
> +#include <linux/compiler.h>
> #include <linux/linkage.h>
> #include <linux/irqflags.h>
>
> @@ -104,7 +106,14 @@ struct mm_struct;
> extern void show_pte(struct mm_struct *mm, unsigned long addr);
> extern void __show_regs(struct pt_regs *);
>
> -extern int cpu_architecture(void);
> +extern int __cpu_architecture;
> +
> +static inline int __pure cpu_architecture(void)
> +{
> + BUG_ON(__cpu_architecture == CPU_ARCH_UNKNOWN);
> + return __cpu_architecture;
> +}
> +
> extern void cpu_init(void);
>
> void arm_machine_restart(char mode, const char *cmd);
> diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
> index 70bca64..1e0c1b3 100644
> --- a/arch/arm/kernel/setup.c
> +++ b/arch/arm/kernel/setup.c
> @@ -42,6 +42,7 @@
> #include <asm/cacheflush.h>
> #include <asm/cachetype.h>
> #include <asm/tlbflush.h>
> +#include <asm/system.h>
>
> #include <asm/prom.h>
> #include <asm/mach/arch.h>
> @@ -114,6 +115,7 @@ struct cpu_cache_fns cpu_cache __read_mostly;
> struct outer_cache_fns outer_cache __read_mostly;
> EXPORT_SYMBOL(outer_cache);
> #endif
> +int __cpu_architecture __read_mostly = CPU_ARCH_UNKNOWN;
>
> struct stack {
> u32 irq[3];
> @@ -210,7 +212,7 @@ static const char *proc_arch[] = {
> "?(17)",
> };
>
> -int cpu_architecture(void)
> +static int __init __get_cpu_architecture(void)
> {
> int cpu_arch;
>
> @@ -413,6 +415,7 @@ static void __init setup_processor(void)
> }
>
> cpu_name = list->cpu_name;
> + __cpu_architecture = __get_cpu_architecture();
>
> #ifdef MULTI_CPU
> processor = *list->proc;
> --
> 1.7.4.1
>
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 2/3] ARM: entry: Remove unnecessary masking when decoding Thumb-2 instructions
2011-08-16 14:14 ` [PATCH 2/3] ARM: entry: Remove unnecessary masking when decoding Thumb-2 instructions Dave Martin
@ 2011-08-16 16:17 ` Nicolas Pitre
2011-08-16 16:21 ` Dave Martin
0 siblings, 1 reply; 18+ messages in thread
From: Nicolas Pitre @ 2011-08-16 16:17 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 16 Aug 2011, Dave Martin wrote:
> When testing whether a Thumb-2 instruction is 32 bits long or not,
> the masking done in order to test bits 11-15 of the first
> instruction halfword won't affect the result of the comparison, so
> remove it.
>
> Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
> ---
> arch/arm/kernel/entry-armv.S | 6 ++----
> 1 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
> index a87cbf8..b7236d4 100644
> --- a/arch/arm/kernel/entry-armv.S
> +++ b/arch/arm/kernel/entry-armv.S
> @@ -262,8 +262,7 @@ __und_svc:
> ldr r0, [r4, #-4]
> #else
> ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2
> - and r9, r0, #0xf800
> - cmp r9, #0xe800 @ 32-bit instruction if xx >= 0
> + cmp r0, #0xe800 @ 32-bit instruction if xx >= 0
> ldrhhs r9, [r4] @ bottom 16 bits
> orrhs r0, r9, r0, lsl #16
> #endif
> @@ -445,8 +444,7 @@ __und_usr:
> ARM( ldrht r5, [r4], #2 )
> THUMB( ldrht r5, [r4] )
> THUMB( add r4, r4, #2 )
> - and r0, r5, #0xf800 @ mask bits 111x x... .... ....
> - cmp r0, #0xe800 @ 32bit instruction if xx != 0
> + cmp r5, #0xe800 @ 32bit instruction if xx != 0
> blo __und_usr_unknown
> 3: ldrht r0, [r4]
> add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
> --
> 1.7.4.1
>
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels
2011-08-16 16:14 ` Nicolas Pitre
@ 2011-08-16 16:20 ` Dave Martin
0 siblings, 0 replies; 18+ messages in thread
From: Dave Martin @ 2011-08-16 16:20 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Aug 16, 2011 at 12:14:01PM -0400, Nicolas Pitre wrote:
> On Tue, 16 Aug 2011, Dave Martin wrote:
>
> > On Tue, Aug 16, 2011 at 4:47 PM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote:
> > > On Tue, 16 Aug 2011, Tixy wrote:
> > >
> > >> On Tue, 2011-08-16 at 15:14 +0100, Dave Martin wrote:
> > >> [...]
> > >> > +#ifdef NEED_CPU_ARCHITECTURE
> > >> > + ? .align ?2
> > >> > +.LCcpu_architecture:
> > >> > + ? .word ? __cpu_architecture
> > >> > +#endif
> > >>
> > >> What's the convention about the prefix '.LC' as opposed to just '.L'?
> > >
> > > The .Lfoo format is more widely used than .LCfoo in the tree.
> >
> > ...but .LCfoo is more widely used in entry-armv.S, for exactly the
> > same kind of thing.
>
> Just use the same style then.
OK, done.
Cheers
---Dave
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 1/3] ARM: Make cpu_alignment into a global variable
2011-08-16 16:15 ` Nicolas Pitre
@ 2011-08-16 16:21 ` Dave Martin
0 siblings, 0 replies; 18+ messages in thread
From: Dave Martin @ 2011-08-16 16:21 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Aug 16, 2011 at 12:15:59PM -0400, Nicolas Pitre wrote:
> On Tue, 16 Aug 2011, Dave Martin wrote:
>
> > The CPU architecture really should not be changing at runtime, so
> > make it a global variable instead of a function.
> >
> > The cpu_architecture() function in <asm/system.h> remains the
> > correct way to read this variable from C code.
> >
> > Signed-off-by: Dave Martin <dave.martin@linaro.org>
>
> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Thanks
---Dave
>
> > ---
> > arch/arm/include/asm/system.h | 11 ++++++++++-
> > arch/arm/kernel/setup.c | 5 ++++-
> > 2 files changed, 14 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
> > index 832888d..b0445f7 100644
> > --- a/arch/arm/include/asm/system.h
> > +++ b/arch/arm/include/asm/system.h
> > @@ -57,6 +57,8 @@
> >
> > #ifndef __ASSEMBLY__
> >
> > +#include <linux/bug.h>
> > +#include <linux/compiler.h>
> > #include <linux/linkage.h>
> > #include <linux/irqflags.h>
> >
> > @@ -104,7 +106,14 @@ struct mm_struct;
> > extern void show_pte(struct mm_struct *mm, unsigned long addr);
> > extern void __show_regs(struct pt_regs *);
> >
> > -extern int cpu_architecture(void);
> > +extern int __cpu_architecture;
> > +
> > +static inline int __pure cpu_architecture(void)
> > +{
> > + BUG_ON(__cpu_architecture == CPU_ARCH_UNKNOWN);
> > + return __cpu_architecture;
> > +}
> > +
> > extern void cpu_init(void);
> >
> > void arm_machine_restart(char mode, const char *cmd);
> > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
> > index 70bca64..1e0c1b3 100644
> > --- a/arch/arm/kernel/setup.c
> > +++ b/arch/arm/kernel/setup.c
> > @@ -42,6 +42,7 @@
> > #include <asm/cacheflush.h>
> > #include <asm/cachetype.h>
> > #include <asm/tlbflush.h>
> > +#include <asm/system.h>
> >
> > #include <asm/prom.h>
> > #include <asm/mach/arch.h>
> > @@ -114,6 +115,7 @@ struct cpu_cache_fns cpu_cache __read_mostly;
> > struct outer_cache_fns outer_cache __read_mostly;
> > EXPORT_SYMBOL(outer_cache);
> > #endif
> > +int __cpu_architecture __read_mostly = CPU_ARCH_UNKNOWN;
> >
> > struct stack {
> > u32 irq[3];
> > @@ -210,7 +212,7 @@ static const char *proc_arch[] = {
> > "?(17)",
> > };
> >
> > -int cpu_architecture(void)
> > +static int __init __get_cpu_architecture(void)
> > {
> > int cpu_arch;
> >
> > @@ -413,6 +415,7 @@ static void __init setup_processor(void)
> > }
> >
> > cpu_name = list->cpu_name;
> > + __cpu_architecture = __get_cpu_architecture();
> >
> > #ifdef MULTI_CPU
> > processor = *list->proc;
> > --
> > 1.7.4.1
> >
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 2/3] ARM: entry: Remove unnecessary masking when decoding Thumb-2 instructions
2011-08-16 16:17 ` Nicolas Pitre
@ 2011-08-16 16:21 ` Dave Martin
0 siblings, 0 replies; 18+ messages in thread
From: Dave Martin @ 2011-08-16 16:21 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Aug 16, 2011 at 12:17:35PM -0400, Nicolas Pitre wrote:
> On Tue, 16 Aug 2011, Dave Martin wrote:
>
> > When testing whether a Thumb-2 instruction is 32 bits long or not,
> > the masking done in order to test bits 11-15 of the first
> > instruction halfword won't affect the result of the comparison, so
> > remove it.
> >
> > Signed-off-by: Dave Martin <dave.martin@linaro.org>
>
> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
>
Thanks
---Dave
>
> > ---
> > arch/arm/kernel/entry-armv.S | 6 ++----
> > 1 files changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
> > index a87cbf8..b7236d4 100644
> > --- a/arch/arm/kernel/entry-armv.S
> > +++ b/arch/arm/kernel/entry-armv.S
> > @@ -262,8 +262,7 @@ __und_svc:
> > ldr r0, [r4, #-4]
> > #else
> > ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2
> > - and r9, r0, #0xf800
> > - cmp r9, #0xe800 @ 32-bit instruction if xx >= 0
> > + cmp r0, #0xe800 @ 32-bit instruction if xx >= 0
> > ldrhhs r9, [r4] @ bottom 16 bits
> > orrhs r0, r9, r0, lsl #16
> > #endif
> > @@ -445,8 +444,7 @@ __und_usr:
> > ARM( ldrht r5, [r4], #2 )
> > THUMB( ldrht r5, [r4] )
> > THUMB( add r4, r4, #2 )
> > - and r0, r5, #0xf800 @ mask bits 111x x... .... ....
> > - cmp r0, #0xe800 @ 32bit instruction if xx != 0
> > + cmp r5, #0xe800 @ 32bit instruction if xx != 0
> > blo __und_usr_unknown
> > 3: ldrht r0, [r4]
> > add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
> > --
> > 1.7.4.1
> >
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels
2011-08-16 16:06 ` Dave Martin
@ 2011-08-16 16:43 ` Tixy
0 siblings, 0 replies; 18+ messages in thread
From: Tixy @ 2011-08-16 16:43 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 2011-08-16 at 17:06 +0100, Dave Martin wrote:
> On Tue, Aug 16, 2011 at 3:58 PM, Tixy <tixy@yxit.co.uk> wrote:
> > Looks good to me.
>
> Thanks for looking over it.
>
> Is that a Reviewed-by, or will you go for an Ack?
It's certainly a Reviewed-by: Jon Medhurst <tixy@yxit.co.uk>
for all three patches.
I've been re-reading Documentation/SubmittingPatches to try and work out
when it's appropriate to use Acked-by, but it seems a bit woolly -
mostly for maintainers?
--
Tixy
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 1/3] ARM: Make cpu_alignment into a global variable
2011-08-16 14:14 ` [PATCH 1/3] ARM: Make cpu_alignment into a global variable Dave Martin
2011-08-16 16:15 ` Nicolas Pitre
@ 2011-08-17 11:31 ` Sergei Shtylyov
2011-08-17 13:37 ` Dave Martin
1 sibling, 1 reply; 18+ messages in thread
From: Sergei Shtylyov @ 2011-08-17 11:31 UTC (permalink / raw)
To: linux-arm-kernel
Hello.
On 16-08-2011 18:14, Dave Martin wrote:
> The CPU architecture really should not be changing at runtime, so
> make it a global variable instead of a function.
> The cpu_architecture() function in<asm/system.h> remains the
> correct way to read this variable from C code.
> Signed-off-by: Dave Martin<dave.martin@linaro.org>
You're talking of the CPU architecture here but the subject has
"cpu_alignment"...
WBR, Sergei
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH 1/3] ARM: Make cpu_alignment into a global variable
2011-08-17 11:31 ` Sergei Shtylyov
@ 2011-08-17 13:37 ` Dave Martin
0 siblings, 0 replies; 18+ messages in thread
From: Dave Martin @ 2011-08-17 13:37 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Aug 17, 2011 at 03:31:21PM +0400, Sergei Shtylyov wrote:
> Hello.
>
> On 16-08-2011 18:14, Dave Martin wrote:
>
> >The CPU architecture really should not be changing at runtime, so
> >make it a global variable instead of a function.
>
> >The cpu_architecture() function in<asm/system.h> remains the
> >correct way to read this variable from C code.
>
> >Signed-off-by: Dave Martin<dave.martin@linaro.org>
>
> You're talking of the CPU architecture here but the subject has
> "cpu_alignment"...
Hmmm, I guess my brain was on autopilot when I wrote that...
You're right, it should say cpu_architecture in the subject.
I'll fix this before I repost.
Thanks
---Dave
^ permalink raw reply [flat|nested] 18+ messages in thread
end of thread, other threads:[~2011-08-17 13:37 UTC | newest]
Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-08-16 14:14 [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels Dave Martin
2011-08-16 14:14 ` [PATCH 1/3] ARM: Make cpu_alignment into a global variable Dave Martin
2011-08-16 16:15 ` Nicolas Pitre
2011-08-16 16:21 ` Dave Martin
2011-08-17 11:31 ` Sergei Shtylyov
2011-08-17 13:37 ` Dave Martin
2011-08-16 14:14 ` [PATCH 2/3] ARM: entry: Remove unnecessary masking when decoding Thumb-2 instructions Dave Martin
2011-08-16 16:17 ` Nicolas Pitre
2011-08-16 16:21 ` Dave Martin
2011-08-16 14:14 ` [PATCH 3/3] ARM: entry: Fix Thumb-2 undef handling for multi-CPU kernels Dave Martin
2011-08-16 14:51 ` Tixy
2011-08-16 15:47 ` Nicolas Pitre
2011-08-16 16:05 ` Dave Martin
2011-08-16 16:14 ` Nicolas Pitre
2011-08-16 16:20 ` Dave Martin
2011-08-16 14:58 ` [PATCH 0/3] Fix Thumb-2 undef handling for mixed-arch kernels Tixy
2011-08-16 16:06 ` Dave Martin
2011-08-16 16:43 ` Tixy
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.