From: Scott Wood <scottwood@freescale.com>
To: <linuxppc-dev@lists.ozlabs.org>
Cc: Scott Wood <scottwood@freescale.com>
Subject: [PATCH 1/2] powerpc/booke64: Move mb() to __set_pte_at() with kernel-addr test
Date: Sat, 18 Jul 2015 14:24:57 -0500 [thread overview]
Message-ID: <1437247498-6027-1-git-send-email-scottwood@freescale.com> (raw)
map_kernel() doesn't catch all places that create kernel PTEs. In
particular, vmalloc() calls set_pte_at() directly. This causes a
crash when booting a non-SMP kernel on e6500.
Move the sync to __set_pte(), to be executed only for kernel addresses.
Signed-off-by: Scott Wood <scottwood@freescale.com>
---
arch/powerpc/include/asm/pgtable.h | 11 +++++++++++
arch/powerpc/mm/pgtable_64.c | 10 ----------
2 files changed, 11 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 11a3863..0717693 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -169,6 +169,17 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
* cases, and 32-bit non-hash with 32-bit PTEs.
*/
*ptep = pte;
+
+#ifdef CONFIG_PPC_BOOK3E_64
+ /*
+ * With hardware tablewalk, a sync is needed to ensure that
+ * subsequent accesses see the PTE we just wrote. Unlike userspace
+ * mappings, we can't tolerate spurious faults, so make sure
+ * the new PTE will be seen the first time.
+ */
+ if (is_kernel_addr(addr))
+ mb();
+#endif
#endif
}
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 876232d..e92cb21 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -149,17 +149,7 @@ int map_kernel_page(unsigned long ea, unsigned long pa, int flags)
#endif /* !CONFIG_PPC_MMU_NOHASH */
}
-#ifdef CONFIG_PPC_BOOK3E_64
- /*
- * With hardware tablewalk, a sync is needed to ensure that
- * subsequent accesses see the PTE we just wrote. Unlike userspace
- * mappings, we can't tolerate spurious faults, so make sure
- * the new PTE will be seen the first time.
- */
- mb();
-#else
smp_wmb();
-#endif
return 0;
}
--
2.1.4
next reply other threads:[~2015-07-18 19:25 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-18 19:24 Scott Wood [this message]
2015-07-18 19:24 ` [PATCH 2/2] powerpc/fsl: Force coherent memory on e500mc derivatives Scott Wood
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