From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp01.au.ibm.com (e23smtp01.au.ibm.com [202.81.31.143]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id C417D1A09F9 for ; Sat, 28 Mar 2015 01:56:55 +1100 (AEDT) Received: from /spool/local by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 28 Mar 2015 00:56:54 +1000 Received: from d23relay07.au.ibm.com (d23relay07.au.ibm.com [9.190.26.37]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 81CA32BB0051 for ; Sat, 28 Mar 2015 01:56:52 +1100 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t2REuibv49741960 for ; Sat, 28 Mar 2015 01:56:52 +1100 Received: from d23av04.au.ibm.com (localhost [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t2REuJZL030916 for ; Sat, 28 Mar 2015 01:56:19 +1100 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH kernel v7 15/31] powerpc/iommu: Fix IOMMU ownership control functions Date: Sat, 28 Mar 2015 01:54:59 +1100 Message-Id: <1427468115-2224-16-git-send-email-aik@ozlabs.ru> In-Reply-To: <1427468115-2224-1-git-send-email-aik@ozlabs.ru> References: <1427468115-2224-1-git-send-email-aik@ozlabs.ru> Cc: Alexey Kardashevskiy , Alex Williamson , Paul Mackerras , linux-kernel@vger.kernel.org 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 7d6089b..068fe4ff 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