From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755111Ab3LTIxY (ORCPT ); Fri, 20 Dec 2013 03:53:24 -0500 Received: from g9t1613g.houston.hp.com ([15.240.0.71]:52990 "EHLO g9t1613g.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753971Ab3LTIxX (ORCPT ); Fri, 20 Dec 2013 03:53:23 -0500 X-Greylist: delayed 488 seconds by postgrey-1.27 at vger.kernel.org; Fri, 20 Dec 2013 03:53:23 EST From: "Li, Zhen-Hua" To: David Woodhouse , Joerg Roedel , , Cc: "Li, Zhen-Hua" Subject: [PATCH 1/1] x86/iommu: use bit structures for context_entry Date: Fri, 20 Dec 2013 16:45:01 +0800 Message-Id: <1387529101-29769-1-git-send-email-zhen-hual@hp.com> X-Mailer: git-send-email 1.8.4.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is a structure named context_entry used by intel iommu, and there are some bit operations on it. Use bit structure may make these operations easy. Also the function context_set_address_root may cause problem because it uses |= operation, not set the new value. And this patch can fix it. Signed-off-by: Li, Zhen-Hua --- drivers/iommu/intel-iommu.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 43b9bfe..65cd480 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -221,47 +221,64 @@ get_context_addr_from_root(struct root_entry *root) * 8-23: domain id */ struct context_entry { - u64 lo; - u64 hi; + union { + struct { + u64 present:1, + fpd:1, + translation_type:2, + reserved_l:8, + asr:52; + }; + u64 lo; + }; + union { + struct { + u64 aw:3, + avail:4, + reserved_h1:1, + did:16, + reserved_h2:40; + }; + u64 hi; + }; }; static inline bool context_present(struct context_entry *context) { - return (context->lo & 1); + return context->present; } static inline void context_set_present(struct context_entry *context) { - context->lo |= 1; + context->present = 1; } static inline void context_set_fault_enable(struct context_entry *context) { - context->lo &= (((u64)-1) << 2) | 1; + context->fpd = 1; } static inline void context_set_translation_type(struct context_entry *context, unsigned long value) { - context->lo &= (((u64)-1) << 4) | 3; - context->lo |= (value & 3) << 2; + context->translation_type = value; } static inline void context_set_address_root(struct context_entry *context, unsigned long value) { - context->lo |= value & VTD_PAGE_MASK; + context->asr = value >> VTD_PAGE_SHIFT } static inline void context_set_address_width(struct context_entry *context, unsigned long value) { - context->hi |= value & 7; + context->aw = value; } static inline void context_set_domain_id(struct context_entry *context, unsigned long value) { - context->hi |= (value & ((1 << 16) - 1)) << 8; + context->did = value; } static inline void context_clear_entry(struct context_entry *context) -- 1.8.4.3