4.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Benjamin Herrenschmidt <b...@kernel.crashing.org>
commit dd7b2f035ec41a409f7a7cec7aabc0ec0eacf476 upstream.
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 error when the code was rewritten
from assembly to C, previously the assembly code did:
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)
Which tests that:
(cpu_features & (NOEXECUTE | COHERENT_ICACHE)) == NOEXECUTE
Which says that the current cpu does have NOEXECUTE, but does not have
COHERENT_ICACHE.
Fixes: 91f1da99792a ("powerpc/mm: Convert 4k hash insert to C")
Fixes: 89ff725051d1 ("powerpc/mm: Convert __hash_page_64K to C")
Fixes: a43c0eb8364c ("powerpc/mm: Convert 4k insert from asm to C")
Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
[mpe: Change log verbosification]
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/powerpc/mm/hash64_4k.c | 2 +-
arch/powerpc/mm/hash64_64k.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
--- 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, uns
*/
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);
--- 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, uns
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, un
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);
