The following commit has been merged into the locking/core branch of tip:
Commit-ID: d41f6f473d0f825678585fd1d782b4bdb9c3a528
Gitweb: https://git.kernel.org/tip/d41f6f473d0f825678585fd1d782b4bdb9c3a528
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Mon, 15 May 2023 09:57:05 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 19 May 2023 12:35:13 +02:00
x86,amd_iommu: Replace cmpxchg_double()
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
Tested-by: Vasant Hegde <vasant.hegde@xxxxxxx>
Link: https://lore.kernel.org/r/20230515080554.315901115@xxxxxxxxxxxxx
---
drivers/iommu/amd/amd_iommu_types.h | 9 +++++++--
drivers/iommu/amd/iommu.c | 10 ++++------
2 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index 2ddbda3..ab8aa8f 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -986,8 +986,13 @@ union irte_ga_hi {
};
struct irte_ga {
- union irte_ga_lo lo;
- union irte_ga_hi hi;
+ union {
+ struct {
+ union irte_ga_lo lo;
+ union irte_ga_hi hi;
+ };
+ u128 irte;
+ };
};
struct irq_2_irte {
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 4a31464..1e9f85e 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3003,10 +3003,10 @@ out:
static int modify_irte_ga(struct amd_iommu *iommu, u16 devid, int index,
struct irte_ga *irte, struct amd_ir_data *data)
{
- bool ret;
struct irq_remap_table *table;
- unsigned long flags;
struct irte_ga *entry;
+ unsigned long flags;
+ u128 old;
table = get_irq_table(iommu, devid);
if (!table)
@@ -3017,16 +3017,14 @@ static int modify_irte_ga(struct amd_iommu *iommu, u16 devid, int index,
entry = (struct irte_ga *)table->table;
entry = &entry[index];
- 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);
+ old = entry->irte;
+ WARN_ON(!try_cmpxchg128(&entry->irte, &old, irte->irte));
if (data)
data->ref = entry;
|