From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp08.au.ibm.com (e23smtp08.au.ibm.com [202.81.31.141]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 837271A0AD3 for ; Fri, 13 Mar 2015 19:09:03 +1100 (AEDT) Received: from /spool/local by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 13 Mar 2015 18:09:01 +1000 Received: from d23relay10.au.ibm.com (d23relay10.au.ibm.com [9.190.26.77]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 4963A2CE8057 for ; Fri, 13 Mar 2015 19:09:00 +1100 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay10.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t2D88qAl38141996 for ; Fri, 13 Mar 2015 19:09:00 +1100 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t2D88Qj9016574 for ; Fri, 13 Mar 2015 19:08:27 +1100 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH kernel v6 16/29] powerpc/iommu: Fix IOMMU ownership control functions Date: Fri, 13 Mar 2015 19:07:24 +1100 Message-Id: <1426234057-16165-17-git-send-email-aik@ozlabs.ru> In-Reply-To: <1426234057-16165-1-git-send-email-aik@ozlabs.ru> References: <1426234057-16165-1-git-send-email-aik@ozlabs.ru> Cc: kvm@vger.kernel.org, Alexey Kardashevskiy , linux-kernel@vger.kernel.org, Alex Williamson , Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This adds missing locks in iommu_take_ownership()/ iommu_release_ownership(). This marks all pages busy in iommu_table::it_map in order to catch errors if there is an attempt to use this table while ownership over it is taken. This only clears TCE content if there is no page marked busy in it_map. Clearing must be done outside of the table locks as iommu_clear_tce() called from iommu_clear_tces_and_put_pages() does this. Signed-off-by: Alexey Kardashevskiy --- Changes: v5: * do not store bit#0 value, it has to be set for zero-based table anyway * removed test_and_clear_bit --- arch/powerpc/kernel/iommu.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 8358631..df888a7 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1052,17 +1052,28 @@ EXPORT_SYMBOL_GPL(iommu_tce_build); static int iommu_table_take_ownership(struct iommu_table *tbl) { - unsigned long sz = (tbl->it_size + 7) >> 3; + unsigned long flags, i, sz = (tbl->it_size + 7) >> 3; + 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; + if (tbl->it_offset == 0) + set_bit(0, tbl->it_map); + } else { + memset(tbl->it_map, 0xff, sz); } - memset(tbl->it_map, 0xff, sz); + for (i = 0; i < tbl->nr_pools; i++) + spin_unlock(&tbl->pools[i].lock); + spin_unlock_irqrestore(&tbl->large_pool.lock, flags); return 0; } @@ -1095,7 +1106,11 @@ EXPORT_SYMBOL_GPL(iommu_take_ownership); static void iommu_table_release_ownership(struct iommu_table *tbl) { - unsigned long sz = (tbl->it_size + 7) >> 3; + unsigned long flags, i, sz = (tbl->it_size + 7) >> 3; + + spin_lock_irqsave(&tbl->large_pool.lock, flags); + for (i = 0; i < tbl->nr_pools; i++) + spin_lock(&tbl->pools[i].lock); memset(tbl->it_map, 0, sz); @@ -1103,6 +1118,9 @@ static void iommu_table_release_ownership(struct iommu_table *tbl) 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); } extern void iommu_release_ownership(struct iommu_table_group *table_group) -- 2.0.0