* [PATCH v2 11/11] powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000
@ 2015-01-20 9:57 ` Christophe Leroy
0 siblings, 0 replies; 6+ messages in thread
From: Christophe Leroy @ 2015-01-20 9:57 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, scottwood
Cc: linux-kernel, linuxppc-dev, Joakim Tjernlund
By default, TASK_SIZE is set to 0x80000000 for PPC_8xx, which is most likely
sufficient for most cases. However, kernel configuration allows to set TASK_SIZE
to another value, so the 8xx shall handle it.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
v2: no change
arch/powerpc/kernel/head_8xx.S | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index ead6448..92a6456 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -48,6 +48,19 @@
mtspr spr, reg
#endif
+/* Macro to test if an address is a kernel address */
+#if CONFIG_TASK_SIZE <= 0x80000000
+#define IS_KERNEL(tmp, addr) \
+ andis. tmp, addr, 0x8000 /* Address >= 0x80000000 */
+#define BRANCH_UNLESS_KERNEL(label) beq label
+#else
+#define IS_KERNEL(tmp, addr) \
+ rlwinm tmp, addr, 16, 16, 31; \
+ cmpli cr0, tmp, PAGE_OFFSET >> 16
+#define BRANCH_UNLESS_KERNEL(label) blt label
+#endif
+
+
/*
* Value for the bits that have fixed value in RPN entries.
* Also used for tagging DAR for DTLBerror.
@@ -322,9 +335,9 @@ InstructionTLBMiss:
mfspr r11, SPRN_SRR0 /* Get effective address of fault */
DO_8xx_CPU15(r10, r11)
mfcr r10
- andis. r11, r11, 0x8000 /* Address >= 0x80000000 */
+ IS_KERNEL(r11, r11)
mfspr r11, SPRN_M_TW /* Get level 1 table */
- beq 3f
+ BRANCH_UNLESS_KERNEL(3f)
lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha
3:
mtcr r10
@@ -379,9 +392,9 @@ DataStoreTLBMiss:
* kernel page tables.
*/
mfspr r11, SPRN_MD_EPN
- andis. r11, r11, 0x8000
+ IS_KERNEL(r11, r11)
mfspr r11, SPRN_M_TW /* Get level 1 table */
- beq 3f
+ BRANCH_UNLESS_KERNEL(3f)
lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha
3:
mtcr r10
@@ -516,9 +529,9 @@ FixupDAR:/* Entry point for dcbx workaround. */
mtspr SPRN_SPRG_SCRATCH2, r10
/* fetch instruction from memory. */
mfspr r10, SPRN_SRR0
- andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
+ IS_KERNEL(r11, r10)
mfspr r11, SPRN_M_TW /* Get level 1 table */
- beq 3f
+ BRANCH_UNLESS_KERNEL(3f)
lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha
/* Insert level 1 index */
3: rlwimi r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
--
2.1.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 11/11] powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000
@ 2015-01-20 9:57 ` Christophe Leroy
0 siblings, 0 replies; 6+ messages in thread
From: Christophe Leroy @ 2015-01-20 9:57 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, scottwood
Cc: linuxppc-dev, linux-kernel
By default, TASK_SIZE is set to 0x80000000 for PPC_8xx, which is most likely
sufficient for most cases. However, kernel configuration allows to set TASK_SIZE
to another value, so the 8xx shall handle it.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
v2: no change
arch/powerpc/kernel/head_8xx.S | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index ead6448..92a6456 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -48,6 +48,19 @@
mtspr spr, reg
#endif
+/* Macro to test if an address is a kernel address */
+#if CONFIG_TASK_SIZE <= 0x80000000
+#define IS_KERNEL(tmp, addr) \
+ andis. tmp, addr, 0x8000 /* Address >= 0x80000000 */
+#define BRANCH_UNLESS_KERNEL(label) beq label
+#else
+#define IS_KERNEL(tmp, addr) \
+ rlwinm tmp, addr, 16, 16, 31; \
+ cmpli cr0, tmp, PAGE_OFFSET >> 16
+#define BRANCH_UNLESS_KERNEL(label) blt label
+#endif
+
+
/*
* Value for the bits that have fixed value in RPN entries.
* Also used for tagging DAR for DTLBerror.
@@ -322,9 +335,9 @@ InstructionTLBMiss:
mfspr r11, SPRN_SRR0 /* Get effective address of fault */
DO_8xx_CPU15(r10, r11)
mfcr r10
- andis. r11, r11, 0x8000 /* Address >= 0x80000000 */
+ IS_KERNEL(r11, r11)
mfspr r11, SPRN_M_TW /* Get level 1 table */
- beq 3f
+ BRANCH_UNLESS_KERNEL(3f)
lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha
3:
mtcr r10
@@ -379,9 +392,9 @@ DataStoreTLBMiss:
* kernel page tables.
*/
mfspr r11, SPRN_MD_EPN
- andis. r11, r11, 0x8000
+ IS_KERNEL(r11, r11)
mfspr r11, SPRN_M_TW /* Get level 1 table */
- beq 3f
+ BRANCH_UNLESS_KERNEL(3f)
lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha
3:
mtcr r10
@@ -516,9 +529,9 @@ FixupDAR:/* Entry point for dcbx workaround. */
mtspr SPRN_SPRG_SCRATCH2, r10
/* fetch instruction from memory. */
mfspr r10, SPRN_SRR0
- andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
+ IS_KERNEL(r11, r10)
mfspr r11, SPRN_M_TW /* Get level 1 table */
- beq 3f
+ BRANCH_UNLESS_KERNEL(3f)
lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha
/* Insert level 1 index */
3: rlwimi r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
--
2.1.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 11/11] powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000
2015-01-20 9:57 ` Christophe Leroy
@ 2015-03-21 0:47 ` Scott Wood
-1 siblings, 0 replies; 6+ messages in thread
From: Scott Wood @ 2015-03-21 0:47 UTC (permalink / raw)
To: Christophe Leroy
Cc: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
linux-kernel, linuxppc-dev, Joakim Tjernlund
On Tue, 2015-01-20 at 10:57 +0100, Christophe Leroy wrote:
> By default, TASK_SIZE is set to 0x80000000 for PPC_8xx, which is most likely
> sufficient for most cases. However, kernel configuration allows to set TASK_SIZE
> to another value, so the 8xx shall handle it.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>
> ---
> v2: no change
>
> arch/powerpc/kernel/head_8xx.S | 25 +++++++++++++++++++------
> 1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
> index ead6448..92a6456 100644
> --- a/arch/powerpc/kernel/head_8xx.S
> +++ b/arch/powerpc/kernel/head_8xx.S
> @@ -48,6 +48,19 @@
> mtspr spr, reg
> #endif
>
> +/* Macro to test if an address is a kernel address */
> +#if CONFIG_TASK_SIZE <= 0x80000000
> +#define IS_KERNEL(tmp, addr) \
> + andis. tmp, addr, 0x8000 /* Address >= 0x80000000 */
> +#define BRANCH_UNLESS_KERNEL(label) beq label
> +#else
This works if CONFIG_TASK_SIZE == 0x80000000, but what if it's less, and
you have a kernel address < 0x80000000?
-Scott
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 11/11] powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000
@ 2015-03-21 0:47 ` Scott Wood
0 siblings, 0 replies; 6+ messages in thread
From: Scott Wood @ 2015-03-21 0:47 UTC (permalink / raw)
To: Christophe Leroy; +Cc: linux-kernel, Paul Mackerras, linuxppc-dev
On Tue, 2015-01-20 at 10:57 +0100, Christophe Leroy wrote:
> By default, TASK_SIZE is set to 0x80000000 for PPC_8xx, which is most likely
> sufficient for most cases. However, kernel configuration allows to set TASK_SIZE
> to another value, so the 8xx shall handle it.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>
> ---
> v2: no change
>
> arch/powerpc/kernel/head_8xx.S | 25 +++++++++++++++++++------
> 1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
> index ead6448..92a6456 100644
> --- a/arch/powerpc/kernel/head_8xx.S
> +++ b/arch/powerpc/kernel/head_8xx.S
> @@ -48,6 +48,19 @@
> mtspr spr, reg
> #endif
>
> +/* Macro to test if an address is a kernel address */
> +#if CONFIG_TASK_SIZE <= 0x80000000
> +#define IS_KERNEL(tmp, addr) \
> + andis. tmp, addr, 0x8000 /* Address >= 0x80000000 */
> +#define BRANCH_UNLESS_KERNEL(label) beq label
> +#else
This works if CONFIG_TASK_SIZE == 0x80000000, but what if it's less, and
you have a kernel address < 0x80000000?
-Scott
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 11/11] powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000
2015-03-21 0:47 ` Scott Wood
@ 2015-04-07 8:15 ` leroy christophe
-1 siblings, 0 replies; 6+ messages in thread
From: leroy christophe @ 2015-04-07 8:15 UTC (permalink / raw)
To: Scott Wood
Cc: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
linux-kernel, linuxppc-dev, Joakim Tjernlund
Le 21/03/2015 01:47, Scott Wood a écrit :
> On Tue, 2015-01-20 at 10:57 +0100, Christophe Leroy wrote:
>> By default, TASK_SIZE is set to 0x80000000 for PPC_8xx, which is most likely
>> sufficient for most cases. However, kernel configuration allows to set TASK_SIZE
>> to another value, so the 8xx shall handle it.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>
>> ---
>> v2: no change
>>
>> arch/powerpc/kernel/head_8xx.S | 25 +++++++++++++++++++------
>> 1 file changed, 19 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
>> index ead6448..92a6456 100644
>> --- a/arch/powerpc/kernel/head_8xx.S
>> +++ b/arch/powerpc/kernel/head_8xx.S
>> @@ -48,6 +48,19 @@
>> mtspr spr, reg
>> #endif
>>
>> +/* Macro to test if an address is a kernel address */
>> +#if CONFIG_TASK_SIZE <= 0x80000000
>> +#define IS_KERNEL(tmp, addr) \
>> + andis. tmp, addr, 0x8000 /* Address >= 0x80000000 */
>> +#define BRANCH_UNLESS_KERNEL(label) beq label
>> +#else
> This works if CONFIG_TASK_SIZE == 0x80000000, but what if it's less, and
> you have a kernel address < 0x80000000?
>
>
You are right, I didn't realise that PAGE_OFFSET was also configurable
and could be different from 0xC0000000.
andis. (which is what is always used in the current kernel) can be used
if CONFIG_TASK_SIZE <= 0x80000000 AND PAGE_OFFSET >= 0x80000000.
I will resubmit the patch accordingly.
Christophe
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 11/11] powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000
@ 2015-04-07 8:15 ` leroy christophe
0 siblings, 0 replies; 6+ messages in thread
From: leroy christophe @ 2015-04-07 8:15 UTC (permalink / raw)
To: Scott Wood; +Cc: linux-kernel, Paul Mackerras, linuxppc-dev
Le 21/03/2015 01:47, Scott Wood a écrit :
> On Tue, 2015-01-20 at 10:57 +0100, Christophe Leroy wrote:
>> By default, TASK_SIZE is set to 0x80000000 for PPC_8xx, which is most likely
>> sufficient for most cases. However, kernel configuration allows to set TASK_SIZE
>> to another value, so the 8xx shall handle it.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>
>> ---
>> v2: no change
>>
>> arch/powerpc/kernel/head_8xx.S | 25 +++++++++++++++++++------
>> 1 file changed, 19 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
>> index ead6448..92a6456 100644
>> --- a/arch/powerpc/kernel/head_8xx.S
>> +++ b/arch/powerpc/kernel/head_8xx.S
>> @@ -48,6 +48,19 @@
>> mtspr spr, reg
>> #endif
>>
>> +/* Macro to test if an address is a kernel address */
>> +#if CONFIG_TASK_SIZE <= 0x80000000
>> +#define IS_KERNEL(tmp, addr) \
>> + andis. tmp, addr, 0x8000 /* Address >= 0x80000000 */
>> +#define BRANCH_UNLESS_KERNEL(label) beq label
>> +#else
> This works if CONFIG_TASK_SIZE == 0x80000000, but what if it's less, and
> you have a kernel address < 0x80000000?
>
>
You are right, I didn't realise that PAGE_OFFSET was also configurable
and could be different from 0xC0000000.
andis. (which is what is always used in the current kernel) can be used
if CONFIG_TASK_SIZE <= 0x80000000 AND PAGE_OFFSET >= 0x80000000.
I will resubmit the patch accordingly.
Christophe
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2015-04-07 8:16 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2015-01-20 9:57 [PATCH v2 11/11] powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000 Christophe Leroy
2015-01-20 9:57 ` Christophe Leroy
2015-03-21 0:47 ` Scott Wood
2015-03-21 0:47 ` Scott Wood
2015-04-07 8:15 ` leroy christophe
2015-04-07 8:15 ` leroy christophe
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