diff options
Diffstat (limited to 'drivers/iommu/amd/iommu.c')
| -rw-r--r-- | drivers/iommu/amd/iommu.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 967f4e96d1eb..a382d7a73eaa 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -3292,6 +3292,7 @@ out: static int modify_irte_ga(u16 devid, int index, struct irte_ga *irte, struct amd_ir_data *data) { + bool ret; struct irq_remap_table *table; struct amd_iommu *iommu; unsigned long flags; @@ -3309,10 +3310,18 @@ static int modify_irte_ga(u16 devid, int index, struct irte_ga *irte, entry = (struct irte_ga *)table->table; entry = &entry[index]; - entry->lo.fields_remap.valid = 0; - entry->hi.val = irte->hi.val; - entry->lo.val = irte->lo.val; - entry->lo.fields_remap.valid = 1; + + ret = cmpxchg_double(&entry->lo.val, &entry->hi.val, + entry->lo.val, entry->hi.val, + irte->lo.val, irte->hi.val); + /* + * We use cmpxchg16 to atomically update the 128-bit IRTE, + * and it cannot be updated by the hardware or other processors + * behind us, so the return value of cmpxchg16 should be the + * same as the old value. + */ + WARN_ON(!ret); + if (data) data->ref = entry; |