* [PATCH] powerpc/mm: Fix lazy icache flush on pre-POWER5
@ 2016-11-29 2:13 Benjamin Herrenschmidt
2016-11-29 2:55 ` Aneesh Kumar K.V
2016-11-30 12:27 ` Michael Ellerman
0 siblings, 2 replies; 3+ messages in thread
From: Benjamin Herrenschmidt @ 2016-11-29 2:13 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Aneesh Kumar K.V
On 64-bit CPUs with no-execute support and non-snooping icache, such as
970 or POWER4, we have a software mechanism to ensure coherency of the
cache (using exec faults when needed).
This was broken due to a logic inversion when that code was rewritten
from assembly to C.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fixes: 91f1da99792a1d133df94c4753510305353064a1
Fixes: 89ff725051d177556b23d80f2a30f880a657a6c1
Fixes: a43c0eb8364c022725df586e91dd753633374d66
--
diff --git a/arch/powerpc/mm/hash64_4k.c b/arch/powerpc/mm/hash64_4k.c
index 42c702b..6fa450c 100644
--- a/arch/powerpc/mm/hash64_4k.c
+++ b/arch/powerpc/mm/hash64_4k.c
@@ -55,7 +55,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
*/
rflags = htab_convert_pte_flags(new_pte);
- if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
+ if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c
index 3bbbea0..1a68cb1 100644
--- a/arch/powerpc/mm/hash64_64k.c
+++ b/arch/powerpc/mm/hash64_64k.c
@@ -87,7 +87,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
subpg_pte = new_pte & ~subpg_prot;
rflags = htab_convert_pte_flags(subpg_pte);
- if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
+ if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
/*
@@ -258,7 +258,7 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
rflags = htab_convert_pte_flags(new_pte);
- if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
+ if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] powerpc/mm: Fix lazy icache flush on pre-POWER5
2016-11-29 2:13 [PATCH] powerpc/mm: Fix lazy icache flush on pre-POWER5 Benjamin Herrenschmidt
@ 2016-11-29 2:55 ` Aneesh Kumar K.V
2016-11-30 12:27 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Aneesh Kumar K.V @ 2016-11-29 2:55 UTC (permalink / raw)
To: Benjamin Herrenschmidt, linuxppc-dev
Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:
> On 64-bit CPUs with no-execute support and non-snooping icache, such as
> 970 or POWER4, we have a software mechanism to ensure coherency of the
> cache (using exec faults when needed).
>
> This was broken due to a logic inversion when that code was rewritten
> from assembly to C.
The asm code for reference is
BEGIN_FTR_SECTION
mr r4,r30
mr r5,r7
bl hash_page_do_lazy_icache
END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE)
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Fixes: 91f1da99792a1d133df94c4753510305353064a1
> Fixes: 89ff725051d177556b23d80f2a30f880a657a6c1
> Fixes: a43c0eb8364c022725df586e91dd753633374d66
> --
> diff --git a/arch/powerpc/mm/hash64_4k.c b/arch/powerpc/mm/hash64_4k.c
> index 42c702b..6fa450c 100644
> --- a/arch/powerpc/mm/hash64_4k.c
> +++ b/arch/powerpc/mm/hash64_4k.c
> @@ -55,7 +55,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
> */
> rflags = htab_convert_pte_flags(new_pte);
>
> - if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
> + if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
> !cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
> rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
>
> diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c
> index 3bbbea0..1a68cb1 100644
> --- a/arch/powerpc/mm/hash64_64k.c
> +++ b/arch/powerpc/mm/hash64_64k.c
> @@ -87,7 +87,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
> subpg_pte = new_pte & ~subpg_prot;
> rflags = htab_convert_pte_flags(subpg_pte);
>
> - if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
> + if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
> !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
>
> /*
> @@ -258,7 +258,7 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
>
> rflags = htab_convert_pte_flags(new_pte);
>
> - if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
> + if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
> !cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
> rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: powerpc/mm: Fix lazy icache flush on pre-POWER5
2016-11-29 2:13 [PATCH] powerpc/mm: Fix lazy icache flush on pre-POWER5 Benjamin Herrenschmidt
2016-11-29 2:55 ` Aneesh Kumar K.V
@ 2016-11-30 12:27 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Michael Ellerman @ 2016-11-30 12:27 UTC (permalink / raw)
To: Benjamin Herrenschmidt, linuxppc-dev; +Cc: Aneesh Kumar K.V
On Tue, 2016-11-29 at 02:13:46 UTC, Benjamin Herrenschmidt wrote:
> On 64-bit CPUs with no-execute support and non-snooping icache, such as
> 970 or POWER4, we have a software mechanism to ensure coherency of the
> cache (using exec faults when needed).
>
> This was broken due to a logic inversion when that code was rewritten
> from assembly to C.
>
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Fixes: 91f1da99792a1d133df94c4753510305353064a1
> Fixes: 89ff725051d177556b23d80f2a30f880a657a6c1
> Fixes: a43c0eb8364c022725df586e91dd753633374d66
> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Applied to powerpc fixes, thanks.
https://git.kernel.org/powerpc/c/dd7b2f035ec41a409f7a7cec7aabc0
cheers
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-11-29 2:13 [PATCH] powerpc/mm: Fix lazy icache flush on pre-POWER5 Benjamin Herrenschmidt
2016-11-29 2:55 ` Aneesh Kumar K.V
2016-11-30 12:27 ` Michael Ellerman
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