From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757934Ab2JJXBD (ORCPT ); Wed, 10 Oct 2012 19:01:03 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:41010 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756850Ab2JJXA5 (ORCPT ); Wed, 10 Oct 2012 19:00:57 -0400 X-Sasl-enc: UDqnsaSzRrJZ5Atr4dyEtRux7yO6LRY5+0/c8u8By7vM 1349910056 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Alexander Graf , Anton Blanchard , Benjamin Herrenschmidt Subject: [ 007/122] powerpc/iommu: Fix multiple issues with IOMMU pools code Date: Thu, 11 Oct 2012 07:52:53 +0900 Message-Id: <20121010225339.317252972@linuxfoundation.org> X-Mailer: git-send-email 1.8.0.rc0.18.gf84667d In-Reply-To: <20121010225337.989799482@linuxfoundation.org> References: <20121010225337.989799482@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Anton Blanchard commit d900bd7366463fd96a907b2c212242e2b68b27d8 upstream. There are a number of issues in the recent IOMMU pools code: - On a preempt kernel we might switch CPUs in the middle of building a scatter gather list. When this happens the handle hint passed in no longer falls within the local CPU's pool. Check for this and fall back to the pool hint. - We were missing a spin_unlock/spin_lock in one spot where we switch pools. - We need to provide locking around dart_tlb_invalidate_all and dart_tlb_invalidate_one now that the global lock is gone. Reported-by: Alexander Graf Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/iommu.c | 5 ++++- arch/powerpc/sysdev/dart_iommu.c | 12 ++++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -215,7 +215,8 @@ static unsigned long iommu_range_alloc(s spin_lock_irqsave(&(pool->lock), flags); again: - if ((pass == 0) && handle && *handle) + if ((pass == 0) && handle && *handle && + (*handle >= pool->start) && (*handle < pool->end)) start = *handle; else start = pool->hint; @@ -236,7 +237,9 @@ again: * but on second pass, start at 0 in pool 0. */ if ((start & mask) >= limit || pass > 0) { + spin_unlock(&(pool->lock)); pool = &(tbl->pools[0]); + spin_lock(&(pool->lock)); start = pool->start; } else { start &= mask; --- a/arch/powerpc/sysdev/dart_iommu.c +++ b/arch/powerpc/sysdev/dart_iommu.c @@ -74,11 +74,16 @@ static int dart_is_u4; #define DBG(...) +static DEFINE_SPINLOCK(invalidate_lock); + static inline void dart_tlb_invalidate_all(void) { unsigned long l = 0; unsigned int reg, inv_bit; unsigned long limit; + unsigned long flags; + + spin_lock_irqsave(&invalidate_lock, flags); DBG("dart: flush\n"); @@ -111,12 +116,17 @@ retry: panic("DART: TLB did not flush after waiting a long " "time. Buggy U3 ?"); } + + spin_unlock_irqrestore(&invalidate_lock, flags); } static inline void dart_tlb_invalidate_one(unsigned long bus_rpn) { unsigned int reg; unsigned int l, limit; + unsigned long flags; + + spin_lock_irqsave(&invalidate_lock, flags); reg = DART_CNTL_U4_ENABLE | DART_CNTL_U4_IONE | (bus_rpn & DART_CNTL_U4_IONE_MASK); @@ -138,6 +148,8 @@ wait_more: panic("DART: TLB did not flush after waiting a long " "time. Buggy U4 ?"); } + + spin_unlock_irqrestore(&invalidate_lock, flags); } static void dart_flush(struct iommu_table *tbl)