Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932130AbbDJGkv (ORCPT ); Fri, 10 Apr 2015 02:40:51 -0400 Received: from e23smtp04.au.ibm.com ([202.81.31.146]:51059 "EHLO e23smtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754216AbbDJGcp (ORCPT ); Fri, 10 Apr 2015 02:32:45 -0400 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Benjamin Herrenschmidt , Paul Mackerras , Alex Williamson , linux-kernel@vger.kernel.org Subject: [PATCH kernel v8 15/31] powerpc/iommu: Fix IOMMU ownership control functions Date: Fri, 10 Apr 2015 16:30:57 +1000 Message-Id: <1428647473-11738-16-git-send-email-aik@ozlabs.ru> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1428647473-11738-1-git-send-email-aik@ozlabs.ru> References: <1428647473-11738-1-git-send-email-aik@ozlabs.ru> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15041006-0013-0000-0000-00000112F15B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2750 Lines: 89 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/