From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-x22e.google.com (mail-pb0-x22e.google.com [IPv6:2607:f8b0:400e:c01::22e]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 44FF52C0091 for ; Wed, 26 Jun 2013 16:21:15 +1000 (EST) Received: by mail-pb0-f46.google.com with SMTP id rq2so13714905pbb.33 for ; Tue, 25 Jun 2013 23:21:12 -0700 (PDT) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v2] powerpc/vfio: Add missing locks for take/release TCE table ownership Date: Wed, 26 Jun 2013 16:21:02 +1000 Message-Id: <1372227662-28302-1-git-send-email-aik@ozlabs.ru> Cc: Alexey Kardashevskiy , linux-kernel@vger.kernel.org, Paul Mackerras , Anton Blanchard , David Gibson List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , VFIO IOMMU driver for sPAPR TCE locks the whole DMA window by setting ones to iommu_table.it_map. However this was not protected by the locks which other clients of iommu_table use. The patch fixes this. Signed-off-by: Alexey Kardashevskiy --- v1->v2: * Fixed a potential warning from lockdep. --- arch/powerpc/kernel/iommu.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index b20ff17..5c1fc89 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1076,25 +1076,42 @@ EXPORT_SYMBOL_GPL(iommu_put_tce_user_mode); int iommu_take_ownership(struct iommu_table *tbl) { unsigned long sz = (tbl->it_size + 7) >> 3; + unsigned long i, flags; + int ret = 0; + + spin_lock_irqsave(&tbl->large_pool.lock, flags); + for (i = 0; i < tbl->nr_pools; i++) + spin_lock(&tbl->pools[i].lock); if (tbl->it_offset == 0) clear_bit(0, tbl->it_map); if (!bitmap_empty(tbl->it_map, tbl->it_size)) { pr_err("iommu_tce: it_map is not empty"); - return -EBUSY; + ret = -EBUSY; + goto unlock_exit; } memset(tbl->it_map, 0xff, sz); iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); - return 0; +unlock_exit: + for (i = 0; i < tbl->nr_pools; i++) + spin_unlock(&tbl->pools[i].lock); + spin_unlock_irqrestore(&tbl->large_pool.lock, flags); + + return ret; } EXPORT_SYMBOL_GPL(iommu_take_ownership); void iommu_release_ownership(struct iommu_table *tbl) { unsigned long sz = (tbl->it_size + 7) >> 3; + unsigned long i, flags; + + spin_lock_irqsave(&tbl->large_pool.lock, flags); + for (i = 0; i < tbl->nr_pools; i++) + spin_lock(&tbl->pools[i].lock); iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); memset(tbl->it_map, 0, sz); @@ -1102,6 +1119,10 @@ void iommu_release_ownership(struct iommu_table *tbl) /* Restore bit#0 set by iommu_init_table() */ if (tbl->it_offset == 0) set_bit(0, tbl->it_map); + + for (i = 0; i < tbl->nr_pools; i++) + spin_unlock(&tbl->pools[i].lock); + spin_unlock_irqrestore(&tbl->large_pool.lock, flags); } EXPORT_SYMBOL_GPL(iommu_release_ownership); -- 1.7.10.4