lkml.org 
[lkml]   [2018]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 04/10] iommu/amd: split irq_lookup_table out of the amd_iommu_devtable_lock
Date
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 692b2e3b9af1..5191319d9f0a 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);
@@ -3623,7 +3624,7 @@ static struct irq_remap_table *alloc_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)
@@ -3688,7 +3689,7 @@ static struct irq_remap_table *alloc_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;
}
--
2.16.2
\
 
 \ /
  Last update: 2018-03-16 21:22    [W:0.117 / U:0.592 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site