Messages in this thread Patch in this message | | | From | Sebastian Andrzej Siewior <> | Subject | [PATCH 04/10] iommu/amd: split irq_lookup_table out of the amd_iommu_devtable_lock | Date | Fri, 23 Feb 2018 23:27:30 +0100 |
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The function get_irq_table() reads/writes irq_lookup_table while holding the amd_iommu_devtable_lock. It also modifies amd_iommu_dev_table[].data[2]. set_dte_entry() is using amd_iommu_dev_table[].data[0|1] (under the domain->lock) so it should be okay. The access to the iommu is serialized with its own (iommu's) lock.
So split out get_irq_table() out of amd_iommu_devtable_lock's lock. The new lock is a raw_spin_lock because modify_irte_ga() is called while desc->lock is held (which is raw).
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- drivers/iommu/amd_iommu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 958efe311057..72487ac43eef 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -82,6 +82,7 @@ static DEFINE_RWLOCK(amd_iommu_devtable_lock); static DEFINE_SPINLOCK(pd_bitmap_lock); +static DEFINE_RAW_SPINLOCK(iommu_table_lock); /* List of all available dev_data structures */ static LLIST_HEAD(dev_data_list); @@ -3594,7 +3595,7 @@ static struct irq_remap_table *get_irq_table(u16 devid, bool ioapic) unsigned long flags; u16 alias; - write_lock_irqsave(&amd_iommu_devtable_lock, flags); + raw_spin_lock_irqsave(&iommu_table_lock, flags); iommu = amd_iommu_rlookup_table[devid]; if (!iommu) @@ -3659,7 +3660,7 @@ static struct irq_remap_table *get_irq_table(u16 devid, bool ioapic) iommu_completion_wait(iommu); out_unlock: - write_unlock_irqrestore(&amd_iommu_devtable_lock, flags); + raw_spin_unlock_irqrestore(&iommu_table_lock, flags); return table; } -- 2.16.1
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