From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lu Baolu Subject: Re: [PATCH v4 9/9] iommu/vt-d: Remove the obsolete per iommu pasid tables Date: Fri, 13 Jul 2018 09:34:30 +0800 Message-ID: <5B4801A6.1090200@linux.intel.com> References: <1531113778-28238-1-git-send-email-baolu.lu@linux.intel.com> <1531113778-28238-10-git-send-email-baolu.lu@linux.intel.com> <20180711024506.GB2359@xz-mi> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180711024506.GB2359@xz-mi> Sender: linux-kernel-owner@vger.kernel.org To: Peter Xu Cc: Joerg Roedel , David Woodhouse , ashok.raj@intel.com, sanjay.k.kumar@intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, yi.y.sun@intel.com, jacob.jun.pan@intel.com List-Id: iommu@lists.linux-foundation.org Hi Peter, Do you have further comments for this series? I will work out a new version if there are no ones. Thank you for reviewing my patches. Do you allow me to add your reviewed-by to the patches which you've reviewed? Best regards, Lu Baolu On 07/11/2018 10:45 AM, Peter Xu wrote: > On Mon, Jul 09, 2018 at 01:22:58PM +0800, Lu Baolu wrote: >> The obsolete per iommu pasid tables are no longer used. Hence, >> clean up them. >> >> Cc: Ashok Raj >> Cc: Jacob Pan >> Cc: Kevin Tian >> Cc: Liu Yi L >> Signed-off-by: Lu Baolu >> Reviewed-by: Liu Yi L >> --- >> drivers/iommu/intel-iommu.c | 6 +++--- >> drivers/iommu/intel-svm.c | 17 ++--------------- >> include/linux/intel-iommu.h | 5 ++--- >> 3 files changed, 7 insertions(+), 21 deletions(-) >> >> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c >> index f8609b5..9a88081 100644 >> --- a/drivers/iommu/intel-iommu.c >> +++ b/drivers/iommu/intel-iommu.c >> @@ -1755,7 +1755,7 @@ static void free_dmar_iommu(struct intel_iommu *iommu) >> if (pasid_enabled(iommu)) { >> if (ecap_prs(iommu->ecap)) >> intel_svm_finish_prq(iommu); >> - intel_svm_free_pasid_tables(iommu); >> + intel_svm_exit(iommu); >> } >> #endif >> } >> @@ -3336,7 +3336,7 @@ static int __init init_dmars(void) >> hw_pass_through = 0; >> #ifdef CONFIG_INTEL_IOMMU_SVM >> if (pasid_enabled(iommu)) >> - intel_svm_alloc_pasid_tables(iommu); >> + intel_svm_init(iommu); >> #endif >> } >> >> @@ -4330,7 +4330,7 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru) >> >> #ifdef CONFIG_INTEL_IOMMU_SVM >> if (pasid_enabled(iommu)) >> - intel_svm_alloc_pasid_tables(iommu); >> + intel_svm_init(iommu); >> #endif >> >> if (dmaru->ignored) { >> diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c >> index a253cde..eb30836 100644 >> --- a/drivers/iommu/intel-svm.c >> +++ b/drivers/iommu/intel-svm.c >> @@ -38,7 +38,7 @@ struct pasid_state_entry { >> u64 val; >> }; >> >> -int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu) >> +int intel_svm_init(struct intel_iommu *iommu) >> { >> struct page *pages; >> int order; >> @@ -63,15 +63,6 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu) >> iommu->pasid_max = 0x20000; >> >> order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max); >> - pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); >> - if (!pages) { >> - pr_warn("IOMMU: %s: Failed to allocate PASID table\n", >> - iommu->name); >> - return -ENOMEM; >> - } >> - iommu->pasid_table = page_address(pages); >> - pr_info("%s: Allocated order %d PASID table.\n", iommu->name, order); >> - >> if (ecap_dis(iommu->ecap)) { >> /* Just making it explicit... */ >> BUILD_BUG_ON(sizeof(struct pasid_entry) != sizeof(struct pasid_state_entry)); > Then do we still need the so-called pasid state table? I tried to > find out what it did before but I failed since I see that the bit 27 > of the extended cap is marked as reserved now in the latest vt-d spec > (then ecap_dis could be meaningless too). > > Asked since if we don't need both the per-iommu pasid table and the > pasid state table, then maybe we don't need intel_svm_init() at all? > >> @@ -86,14 +77,10 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu) >> return 0; >> } >> >> -int intel_svm_free_pasid_tables(struct intel_iommu *iommu) >> +int intel_svm_exit(struct intel_iommu *iommu) > Same thing applies to this exit() function - after we removed the > per-iommu idr, per-iommu pasid table, and (possibly obsolete) > per-iommu pasid state table, do we need that at all? > > Thanks, > >> { >> int order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max); >> >> - if (iommu->pasid_table) { >> - free_pages((unsigned long)iommu->pasid_table, order); >> - iommu->pasid_table = NULL; >> - } >> if (iommu->pasid_state_table) { >> free_pages((unsigned long)iommu->pasid_state_table, order); >> iommu->pasid_state_table = NULL; >> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h >> index e7901d4..3c43882 100644 >> --- a/include/linux/intel-iommu.h >> +++ b/include/linux/intel-iommu.h >> @@ -453,7 +453,6 @@ struct intel_iommu { >> * devices away to userspace processes (e.g. for DPDK) and don't >> * want to trust that userspace will use *only* the PASID it was >> * told to. But while it's all driver-arbitrated, we're fine. */ >> - struct pasid_entry *pasid_table; >> struct pasid_state_entry *pasid_state_table; >> struct page_req_dsc *prq; >> unsigned char prq_name[16]; /* Name for PRQ interrupt */ >> @@ -526,8 +525,8 @@ int for_each_device_domain(int (*fn)(struct device_domain_info *info, >> void *data), void *data); >> >> #ifdef CONFIG_INTEL_IOMMU_SVM >> -extern int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu); >> -extern int intel_svm_free_pasid_tables(struct intel_iommu *iommu); >> +int intel_svm_init(struct intel_iommu *iommu); >> +int intel_svm_exit(struct intel_iommu *iommu); >> extern int intel_svm_enable_prq(struct intel_iommu *iommu); >> extern int intel_svm_finish_prq(struct intel_iommu *iommu); >> >> -- >> 2.7.4 >> >> _______________________________________________ >> iommu mailing list >> iommu@lists.linux-foundation.org >> https://lists.linuxfoundation.org/mailman/listinfo/iommu