From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Will Deacon <will@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-mm@kvack.org
Subject: [PATCH 3/3] powerpc/8xx: Provide ptep_get() with 16k pages
Date: Mon, 15 Jun 2020 12:57:59 +0000 (UTC) [thread overview]
Message-ID: <341688399c1b102756046d19ea6ce39db1ae4742.1592225558.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1592225557.git.christophe.leroy@csgroup.eu>
READ_ONCE() now enforces atomic read, which leads to:
CC mm/gup.o
In file included from ./include/linux/kernel.h:11:0,
from mm/gup.c:2:
In function 'gup_hugepte.constprop',
inlined from 'gup_huge_pd.isra.79' at mm/gup.c:2465:8:
./include/linux/compiler.h:392:38: error: call to '__compiletime_assert_222' declared with attribute error: Unsupported access size for {READ,WRITE}_ONCE().
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
./include/linux/compiler.h:373:4: note: in definition of macro '__compiletime_assert'
prefix ## suffix(); \
^
./include/linux/compiler.h:392:2: note: in expansion of macro '_compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
./include/linux/compiler.h:405:2: note: in expansion of macro 'compiletime_assert'
compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
^
./include/linux/compiler.h:291:2: note: in expansion of macro 'compiletime_assert_rwonce_type'
compiletime_assert_rwonce_type(x); \
^
mm/gup.c:2428:8: note: in expansion of macro 'READ_ONCE'
pte = READ_ONCE(*ptep);
^
In function 'gup_get_pte',
inlined from 'gup_pte_range' at mm/gup.c:2228:9,
inlined from 'gup_pmd_range' at mm/gup.c:2613:15,
inlined from 'gup_pud_range' at mm/gup.c:2641:15,
inlined from 'gup_p4d_range' at mm/gup.c:2666:15,
inlined from 'gup_pgd_range' at mm/gup.c:2694:15,
inlined from 'internal_get_user_pages_fast' at mm/gup.c:2795:3:
./include/linux/compiler.h:392:38: error: call to '__compiletime_assert_219' declared with attribute error: Unsupported access size for {READ,WRITE}_ONCE().
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
./include/linux/compiler.h:373:4: note: in definition of macro '__compiletime_assert'
prefix ## suffix(); \
^
./include/linux/compiler.h:392:2: note: in expansion of macro '_compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
./include/linux/compiler.h:405:2: note: in expansion of macro 'compiletime_assert'
compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
^
./include/linux/compiler.h:291:2: note: in expansion of macro 'compiletime_assert_rwonce_type'
compiletime_assert_rwonce_type(x); \
^
mm/gup.c:2199:9: note: in expansion of macro 'READ_ONCE'
return READ_ONCE(*ptep);
^
make[2]: *** [mm/gup.o] Error 1
Define ptep_get() on 8xx when using 16k pages.
Fixes: 2ab3a0a02905 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/nohash/32/pgtable.h | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
index b56f14160ae5..77addb599ce7 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -286,6 +286,16 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
return __pte(pte_update(mm, addr, ptep, ~0, 0, 0));
}
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
+#define __HAVE_ARCH_PTEP_GET
+static inline pte_t ptep_get(pte_t *ptep)
+{
+ pte_t pte = {READ_ONCE(ptep->pte), 0, 0, 0};
+
+ return pte;
+}
+#endif
+
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
--
2.25.0
next prev parent reply other threads:[~2020-06-15 12:58 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-15 12:57 [PATCH 0/3] Fix build failure with v5.8-rc1 Christophe Leroy
2020-06-15 12:57 ` [PATCH 1/3] mm/gup: Use huge_ptep_get() in gup_hugepte() Christophe Leroy
2020-06-17 14:14 ` Michael Ellerman
2020-06-15 12:57 ` [PATCH 2/3] mm: Allow arches to provide ptep_get() Christophe Leroy
2020-06-15 12:57 ` Christophe Leroy [this message]
2020-06-15 13:22 ` [PATCH 3/3] powerpc/8xx: Provide ptep_get() with 16k pages Peter Zijlstra
2020-06-17 14:21 ` Michael Ellerman
2020-06-17 14:38 ` Peter Zijlstra
2020-06-17 14:45 ` Christophe Leroy
2020-06-18 1:00 ` Michael Ellerman
2020-06-18 14:19 ` Christophe Leroy
2020-06-18 0:58 ` Michael Ellerman
2020-06-18 14:21 ` Christophe Leroy
2020-06-17 10:57 ` [PATCH 0/3] Fix build failure with v5.8-rc1 Will Deacon
2020-06-17 14:13 ` Michael Ellerman
2020-06-18 12:37 ` Michael Ellerman
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