From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751858AbcEUCmW (ORCPT ); Fri, 20 May 2016 22:42:22 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:35909 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751600AbcEUCmS (ORCPT ); Fri, 20 May 2016 22:42:18 -0400 From: Wei Yang To: joro@8bytes.org Cc: dwmw2@infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Wei Yang Subject: [PATCH] iommu/vt-d: reduce extra first level entry in iommu->domains Date: Sat, 21 May 2016 02:41:51 +0000 Message-Id: <1463798511-4015-1-git-send-email-richard.weiyang@gmail.com> X-Mailer: git-send-email 2.5.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In commit <8bf478163e69> ("iommu/vt-d: Split up iommu->domains array"), it it splits iommu->domains in two levels. Each first level contains 256 entries of second level. In case of the ndomains is exact a multiple of 256, it would have one more extra first level entry for current implementation. This patch refines this calculation to reduce the extra first level entry. Signed-off-by: Wei Yang --- drivers/iommu/intel-iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index e3061d3..2204ca4 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1634,7 +1634,7 @@ static int iommu_init_domains(struct intel_iommu *iommu) return -ENOMEM; } - size = ((ndomains >> 8) + 1) * sizeof(struct dmar_domain **); + size = (ALIGN(ndomains, 256) >> 8) * sizeof(struct dmar_domain **); iommu->domains = kzalloc(size, GFP_KERNEL); if (iommu->domains) { @@ -1699,7 +1699,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu) static void free_dmar_iommu(struct intel_iommu *iommu) { if ((iommu->domains) && (iommu->domain_ids)) { - int elems = (cap_ndoms(iommu->cap) >> 8) + 1; + int elems = ALIGN(cap_ndoms(iommu->cap), 256) >> 8; int i; for (i = 0; i < elems; i++) -- 1.7.9.5 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Yang Subject: [PATCH] iommu/vt-d: reduce extra first level entry in iommu->domains Date: Sat, 21 May 2016 02:41:51 +0000 Message-ID: <1463798511-4015-1-git-send-email-richard.weiyang@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Wei Yang List-Id: iommu@lists.linux-foundation.org In commit <8bf478163e69> ("iommu/vt-d: Split up iommu->domains array"), it it splits iommu->domains in two levels. Each first level contains 256 entries of second level. In case of the ndomains is exact a multiple of 256, it would have one more extra first level entry for current implementation. This patch refines this calculation to reduce the extra first level entry. Signed-off-by: Wei Yang --- drivers/iommu/intel-iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index e3061d3..2204ca4 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1634,7 +1634,7 @@ static int iommu_init_domains(struct intel_iommu *iommu) return -ENOMEM; } - size = ((ndomains >> 8) + 1) * sizeof(struct dmar_domain **); + size = (ALIGN(ndomains, 256) >> 8) * sizeof(struct dmar_domain **); iommu->domains = kzalloc(size, GFP_KERNEL); if (iommu->domains) { @@ -1699,7 +1699,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu) static void free_dmar_iommu(struct intel_iommu *iommu) { if ((iommu->domains) && (iommu->domain_ids)) { - int elems = (cap_ndoms(iommu->cap) >> 8) + 1; + int elems = ALIGN(cap_ndoms(iommu->cap), 256) >> 8; int i; for (i = 0; i < elems; i++) -- 1.7.9.5