From: Kumar Gala <galak@kernel.crashing.org>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH v3 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support
Date: Wed, 3 Sep 2008 13:09:02 -0500 [thread overview]
Message-ID: <1220465344-16753-2-git-send-email-galak@kernel.crashing.org> (raw)
In-Reply-To: <1220465344-16753-1-git-send-email-galak@kernel.crashing.org>
There are some minor issues with support 64-bit PTEs on a 32-bit processor
when dealing with SMP.
* We need to order the stores in set_pte_at to make sure the flag word
is set second.
* Change pte_clear to use pte_update so only the flag word is cleared
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
Fixed pte_clear to not break on 6xx.
- k
arch/powerpc/include/asm/pgtable-ppc32.h | 15 +++++++++++----
1 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index 6fe39e3..dff1b7e 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h
@@ -517,7 +517,8 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
#define pte_none(pte) ((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
#define pte_present(pte) (pte_val(pte) & _PAGE_PRESENT)
-#define pte_clear(mm,addr,ptep) do { set_pte_at((mm), (addr), (ptep), __pte(0)); } while (0)
+#define pte_clear(mm, addr, ptep) \
+ do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)
#define pmd_none(pmd) (!pmd_val(pmd))
#define pmd_bad(pmd) (pmd_val(pmd) & _PMD_BAD)
@@ -612,9 +613,6 @@ static inline unsigned long pte_update(pte_t *p,
return old;
}
#else /* CONFIG_PTE_64BIT */
-/* TODO: Change that to only modify the low word and move set_pte_at()
- * out of line
- */
static inline unsigned long long pte_update(pte_t *p,
unsigned long clr,
unsigned long set)
@@ -658,8 +656,17 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
#if _PAGE_HASHPTE != 0
pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte) & ~_PAGE_HASHPTE);
#else
+#if defined(CONFIG_PTE_64BIT) && defined(CONFIG_SMP)
+ __asm__ __volatile__("\
+ stw%U0%X0 %2,%0\n\
+ eieio\n\
+ stw%U0%X0 %L2,%1"
+ : "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
+ : "r" (pte) : "memory");
+#else
*ptep = pte;
#endif
+#endif
}
/*
--
1.5.5.1
next prev parent reply other threads:[~2008-09-03 18:09 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-03 18:09 [PATCH v3 1/4] powerpc: Introduce local (non-broadcast) forms of tlb invalidates Kumar Gala
2008-09-03 18:09 ` Kumar Gala [this message]
2008-09-03 18:09 ` [PATCH v3 3/4] powerpc/fsl-booke: Fixup 64-bit PTE reading for SMP support Kumar Gala
2008-09-03 18:09 ` [PATCH v3 4/4] powerpc/mm: Implement _PAGE_SPECIAL & pte_special() for 32-bit Kumar Gala
2008-09-04 3:15 ` Benjamin Herrenschmidt
2008-09-04 3:14 ` [PATCH v3 3/4] powerpc/fsl-booke: Fixup 64-bit PTE reading for SMP support Benjamin Herrenschmidt
2008-09-04 3:12 ` [PATCH v3 2/4] powerpc: Fixes for CONFIG_PTE_64BIT " Benjamin Herrenschmidt
2008-09-05 19:44 ` Kumar Gala
2008-09-05 22:38 ` Benjamin Herrenschmidt
2008-09-06 15:32 ` Kumar Gala
2008-09-04 19:17 ` [PATCH v3 1/4] powerpc: Introduce local (non-broadcast) forms of tlb invalidates Rafal Jaworowski
2008-09-04 21:30 ` Benjamin Herrenschmidt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1220465344-16753-2-git-send-email-galak@kernel.crashing.org \
--to=galak@kernel.crashing.org \
--cc=linuxppc-dev@ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).