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authorLu Baolu <baolu.lu@linux.intel.com>2022-07-12 03:08:55 +0300
committerJoerg Roedel <jroedel@suse.de>2022-07-15 11:21:35 +0300
commit2e1c8dafb8c2c459baa5aef5b338c15edd9b9b5b (patch)
tree946fe8d79d344ae29e9f30d64d2a27223e025e41 /drivers/iommu
parent8ac0b64b9735ae896d200dd952c22999742b4414 (diff)
downloadlinux-2e1c8dafb8c2c459baa5aef5b338c15edd9b9b5b.tar.xz
iommu/vt-d: Unnecessary spinlock for root table alloc and free
The IOMMU root table is allocated and freed in the IOMMU initialization code in static boot or hot-remove paths. There's no need for a spinlock. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20220706025524.2904370-5-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/intel/iommu.c18
1 files changed, 5 insertions, 13 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 77915d61f7ec..ff49c9460ede 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -809,14 +809,12 @@ static int device_context_mapped(struct intel_iommu *iommu, u8 bus, u8 devfn)
static void free_context_table(struct intel_iommu *iommu)
{
- int i;
- unsigned long flags;
struct context_entry *context;
+ int i;
+
+ if (!iommu->root_entry)
+ return;
- spin_lock_irqsave(&iommu->lock, flags);
- if (!iommu->root_entry) {
- goto out;
- }
for (i = 0; i < ROOT_ENTRY_NR; i++) {
context = iommu_context_addr(iommu, i, 0, 0);
if (context)
@@ -828,12 +826,10 @@ static void free_context_table(struct intel_iommu *iommu)
context = iommu_context_addr(iommu, i, 0x80, 0);
if (context)
free_pgtable_page(context);
-
}
+
free_pgtable_page(iommu->root_entry);
iommu->root_entry = NULL;
-out:
- spin_unlock_irqrestore(&iommu->lock, flags);
}
#ifdef CONFIG_DMAR_DEBUG
@@ -1232,7 +1228,6 @@ static void domain_unmap(struct dmar_domain *domain, unsigned long start_pfn,
static int iommu_alloc_root_entry(struct intel_iommu *iommu)
{
struct root_entry *root;
- unsigned long flags;
root = (struct root_entry *)alloc_pgtable_page(iommu->node);
if (!root) {
@@ -1242,10 +1237,7 @@ static int iommu_alloc_root_entry(struct intel_iommu *iommu)
}
__iommu_flush_cache(iommu, root, ROOT_SIZE);
-
- spin_lock_irqsave(&iommu->lock, flags);
iommu->root_entry = root;
- spin_unlock_irqrestore(&iommu->lock, flags);
return 0;
}