From: "Mark A. Greer" <mgreer@mvista•com>
To: akpm <akpm@osdl•org>
Cc: Brian Waite <waite@skycomputers•com>,
Embedded PPC Linux list <linuxppc-embedded@ozlabs•org>
Subject: Re: [PATCH][PPC32] fix locking bugs in mv64x60 code
Date: Wed, 02 Feb 2005 17:21:38 -0700 [thread overview]
Message-ID: <42016E92.50905@mvista.com> (raw)
In-Reply-To: <42016E33.9070804@mvista.com>
[-- Attachment #1: Type: text/plain, Size: 478 bytes --]
And with the patch this time...
--
Mark A. Greer wrote:
> [Original patch slightly edited by mgreer]
>
> This patch fixes 2 SMP deadlocks. The first is that mv64x60_read() was
> returning before the unlock. The second was mv64x60_modify() locks the
> spin lock and calls mv64x60_read() and mv64x60_write() which also lock
> the same spin lock.
>
> Please apply.
>
> Signed-Off-By: Brian Waite <waite@skycomputers•com>
> Signed-off-by: Mark A. Greer <mgreer@mvista•com>
>
>
[-- Attachment #2: mv_smp.patch --]
[-- Type: text/plain, Size: 1368 bytes --]
diff -Nru a/arch/ppc/syslib/mv64x60.c b/arch/ppc/syslib/mv64x60.c
--- a/arch/ppc/syslib/mv64x60.c 2005-02-02 17:15:26 -07:00
+++ b/arch/ppc/syslib/mv64x60.c 2005-02-02 17:15:26 -07:00
@@ -32,7 +32,7 @@
u8 mv64x60_pci_exclude_bridge = 1;
-spinlock_t mv64x60_lock; /* Only really used by PIC code once init done */
+spinlock_t mv64x60_lock = SPIN_LOCK_UNLOCKED;
static phys_addr_t mv64x60_bridge_pbase = 0;
static void *mv64x60_bridge_vbase = 0;
diff -Nru a/include/asm-ppc/mv64x60.h b/include/asm-ppc/mv64x60.h
--- a/include/asm-ppc/mv64x60.h 2005-02-02 17:15:26 -07:00
+++ b/include/asm-ppc/mv64x60.h 2005-02-02 17:15:26 -07:00
@@ -254,10 +254,12 @@
extern inline u32
mv64x60_read(struct mv64x60_handle *bh, u32 offset) {
ulong flags;
+ u32 reg;
spin_lock_irqsave(&mv64x60_lock, flags);
- return in_le32(bh->v_base + offset);
+ reg = in_le32(bh->v_base + offset);
spin_unlock_irqrestore(&mv64x60_lock, flags);
+ return reg;
}
extern inline void
@@ -267,9 +269,9 @@
ulong flags;
spin_lock_irqsave(&mv64x60_lock, flags);
- reg = mv64x60_read(bh, offs) & (~mask); /* zero bits we care about */
- reg |= data & mask; /* set bits from the data */
- mv64x60_write(bh, offs, reg);
+ reg = in_le32(bh->v_base + offs) & (~mask);
+ reg |= data & mask;
+ out_le32(bh->v_base + offs, reg);
spin_unlock_irqrestore(&mv64x60_lock, flags);
}
prev parent reply other threads:[~2005-02-03 0:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-02-03 0:20 [PATCH][PPC32] fix locking bugs in mv64x60 code Mark A. Greer
2005-02-03 0:21 ` Mark A. Greer [this message]
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