From: Lu Baolu<[email protected]>
Sent: Wednesday, April 15, 2020 1:26 PM
Extend qi_submit_sync() function to support multiple descriptors.
Signed-off-by: Jacob Pan<[email protected]>
Signed-off-by: Lu Baolu<[email protected]>
---
drivers/iommu/dmar.c | 39 +++++++++++++++++++++++--------------
include/linux/intel-iommu.h | 1 +
2 files changed, 25 insertions(+), 15 deletions(-)
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index bb42177e2369..61d049e91f84 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1157,12 +1157,11 @@ static inline void reclaim_free_desc(struct
q_inval *qi)
}
}
-static int qi_check_fault(struct intel_iommu *iommu, int index)
+static int qi_check_fault(struct intel_iommu *iommu, int index, int
wait_index)
{
u32 fault;
int head, tail;
struct q_inval *qi = iommu->qi;
- int wait_index = (index + 1) % QI_LENGTH;
int shift = qi_shift(iommu);
if (qi->desc_status[wait_index] == QI_ABORT)
@@ -1234,12 +1233,12 @@ static int qi_check_fault(struct intel_iommu
*iommu, int index)
int qi_submit_sync(struct intel_iommu *iommu, struct qi_desc *desc,
unsigned int count, unsigned long options)
{
- int rc;
struct q_inval *qi = iommu->qi;
- int offset, shift, length;
struct qi_desc wait_desc;
int wait_index, index;
unsigned long flags;
+ int offset, shift;
+ int rc, i;
if (!qi)
return 0;
@@ -1248,32 +1247,41 @@ int qi_submit_sync(struct intel_iommu *iommu,
struct qi_desc *desc,
rc = 0;
raw_spin_lock_irqsave(&qi->q_lock, flags);
- while (qi->free_cnt < 3) {
+ /*
+ * Check if we have enough empty slots in the queue to submit,
+ * the calculation is based on:
+ * # of desc + 1 wait desc + 1 space between head and tail
+ */
+ while (qi->free_cnt < count + 2) {
raw_spin_unlock_irqrestore(&qi->q_lock, flags);
cpu_relax();
raw_spin_lock_irqsave(&qi->q_lock, flags);
}
index = qi->free_head;
- wait_index = (index + 1) % QI_LENGTH;
+ wait_index = (index + count) % QI_LENGTH;
shift = qi_shift(iommu);
- length = 1 << shift;
- qi->desc_status[index] = qi->desc_status[wait_index] = QI_IN_USE;
+ for (i = 0; i < count; i++) {
+ offset = ((index + i) % QI_LENGTH) << shift;
+ memcpy(qi->desc + offset, &desc[i], 1 << shift);
+ qi->desc_status[(index + i) % QI_LENGTH] = QI_IN_USE;
+ }
