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From: Lu Baolu <baolu.lu@linux.intel.com>
To: Joerg Roedel <joro@8bytes.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>,
	Ashok Raj <ashok.raj@intel.com>,
	Aditya Srivastava <yashsri421@gmail.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	YueHaibing <yuehaibing@huawei.com>,
	"Gustavo A . R . Silva" <gustavoars@kernel.org>,
	iommu@lists.linux-foundation.org,
	Colin Ian King <colin.king@canonical.com>,
	Will Deacon <will@kernel.org>
Subject: [PATCH 20/23] iommu/vt-d: Removed unused iommu_count in dmar domain
Date: Thu, 10 Jun 2021 10:01:12 +0800	[thread overview]
Message-ID: <20210610020115.1637656-21-baolu.lu@linux.intel.com> (raw)
In-Reply-To: <20210610020115.1637656-1-baolu.lu@linux.intel.com>

From: Parav Pandit <parav@nvidia.com>

DMAR domain uses per DMAR refcount. It is indexed by iommu seq_id.
Older iommu_count is only incremented and decremented but no decisions
are taken based on this refcount. This is not of much use.

Hence, remove iommu_count and further simplify domain_detach_iommu()
by returning void.

Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210530075053.264218-1-parav@nvidia.com
---
 include/linux/intel-iommu.h |  1 -
 drivers/iommu/intel/iommu.c | 11 +++--------
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 2621eff04c82..574b932dfe86 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -561,7 +561,6 @@ struct dmar_domain {
 	int		agaw;
 
 	int		flags;		/* flags to find out type of domain */
-	int		iommu_count;	/* reference count of iommu */
 	int		iommu_superpage;/* Level of superpages supported:
 					   0 == 4KiB (no superpages), 1 == 2MiB,
 					   2 == 1GiB, 3 == 512GiB, 4 == 1TiB */
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 430ef2232d47..dd8ecfbfdb23 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1920,7 +1920,6 @@ static int domain_attach_iommu(struct dmar_domain *domain,
 	assert_spin_locked(&iommu->lock);
 
 	domain->iommu_refcnt[iommu->seq_id] += 1;
-	domain->iommu_count += 1;
 	if (domain->iommu_refcnt[iommu->seq_id] == 1) {
 		ndomains = cap_ndoms(iommu->cap);
 		num      = find_first_zero_bit(iommu->domain_ids, ndomains);
@@ -1928,7 +1927,6 @@ static int domain_attach_iommu(struct dmar_domain *domain,
 		if (num >= ndomains) {
 			pr_err("%s: No free domain ids\n", iommu->name);
 			domain->iommu_refcnt[iommu->seq_id] -= 1;
-			domain->iommu_count -= 1;
 			return -ENOSPC;
 		}
 
@@ -1944,16 +1942,15 @@ static int domain_attach_iommu(struct dmar_domain *domain,
 	return 0;
 }
 
-static int domain_detach_iommu(struct dmar_domain *domain,
-			       struct intel_iommu *iommu)
+static void domain_detach_iommu(struct dmar_domain *domain,
+				struct intel_iommu *iommu)
 {
-	int num, count;
+	int num;
 
 	assert_spin_locked(&device_domain_lock);
 	assert_spin_locked(&iommu->lock);
 
 	domain->iommu_refcnt[iommu->seq_id] -= 1;
-	count = --domain->iommu_count;
 	if (domain->iommu_refcnt[iommu->seq_id] == 0) {
 		num = domain->iommu_did[iommu->seq_id];
 		clear_bit(num, iommu->domain_ids);
@@ -1962,8 +1959,6 @@ static int domain_detach_iommu(struct dmar_domain *domain,
 		domain_update_iommu_cap(domain);
 		domain->iommu_did[iommu->seq_id] = 0;
 	}
-
-	return count;
 }
 
 static inline int guestwidth_to_adjustwidth(int gaw)
-- 
2.25.1

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  parent reply	other threads:[~2021-06-10  2:04 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-10  2:00 [PATCH 00/23] [PULL REQUEST] Intel IOMMU Updates for Linux v5.14 Lu Baolu
2021-06-10  2:00 ` [PATCH 01/23] iommu/vt-d: Remove redundant assignment to variable agaw Lu Baolu
2021-06-10  2:00 ` [PATCH 02/23] iommu/vt-d: Fix kernel-doc syntax in file header Lu Baolu
2021-06-10  2:00 ` [PATCH 03/23] iommu/vt-d: Tweak the description of a DMA fault Lu Baolu
2021-06-10  2:00 ` [PATCH 04/23] iommu/vt-d: Select PCI_ATS explicitly Lu Baolu
2021-06-10  2:00 ` [PATCH 05/23] iommu/vt-d: Support asynchronous IOMMU nested capabilities Lu Baolu
2021-06-10  2:00 ` [PATCH 06/23] iommu/vt-d: Add pasid private data helpers Lu Baolu
2021-06-10  2:00 ` [PATCH 07/23] iommu/vt-d: Use iommu_sva_alloc(free)_pasid() helpers Lu Baolu
2021-06-10  2:01 ` [PATCH 08/23] iommu/vt-d: Use common helper to lookup svm devices Lu Baolu
2021-06-10  2:01 ` [PATCH 09/23] iommu/vt-d: Refactor prq_event_thread() Lu Baolu
2021-06-10  2:01 ` [PATCH 10/23] iommu/vt-d: Allocate/register iopf queue for sva devices Lu Baolu
2021-06-10  2:01 ` [PATCH 11/23] iommu/vt-d: Report prq to io-pgfault framework Lu Baolu
2021-06-10  2:01 ` [PATCH 12/23] iommu/vt-d: Add prq_report trace event Lu Baolu
2021-06-10  2:01 ` [PATCH 13/23] iommu/vt-d: Add common code for dmar latency performance monitors Lu Baolu
2021-06-10  2:01 ` [PATCH 14/23] iommu/vt-d: Expose latency monitor data through debugfs Lu Baolu
2021-06-10  2:01 ` [PATCH 15/23] iommu/vt-d: Add cache invalidation latency sampling Lu Baolu
2021-06-10  2:01 ` [PATCH 16/23] iommu/vt-d: Add PRQ handling " Lu Baolu
2021-06-10  2:01 ` [PATCH 17/23] iommu/vt-d: Fix out-bounds-warning in intel/svm.c Lu Baolu
2021-06-10  2:01 ` [PATCH 18/23] iommu/vt-d: Use DEVICE_ATTR_RO macro Lu Baolu
2021-06-10  2:01 ` [PATCH 19/23] iommu/vt-d: Use bitfields for DMAR capabilities Lu Baolu
2021-06-10  2:01 ` Lu Baolu [this message]
2021-06-10  2:01 ` [PATCH 21/23] iommu/vt-d: Remove unnecessary braces Lu Baolu
2021-06-10  2:01 ` [PATCH 22/23] iommu/vt-d: Define counter explicitly as unsigned int Lu Baolu
2021-06-10  2:01 ` [PATCH 23/23] iommu/vt-d: No need to typecast Lu Baolu
2021-06-10  7:13 ` [PATCH 00/23] [PULL REQUEST] Intel IOMMU Updates for Linux v5.14 Joerg Roedel

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