tlb_sync hook allows nvidia smmu handle tlb sync
across multiple SMMUs as necessary.

Signed-off-by: Krishna Reddy <vdu...@nvidia.com>
---
 drivers/iommu/arm-smmu-nvidia.c | 32 ++++++++++++++++++++++++++++++++
 drivers/iommu/arm-smmu.c        |  8 +++++---
 drivers/iommu/arm-smmu.h        |  4 ++++
 3 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/arm-smmu-nvidia.c b/drivers/iommu/arm-smmu-nvidia.c
index d93ceda..a429b2c 100644
--- a/drivers/iommu/arm-smmu-nvidia.c
+++ b/drivers/iommu/arm-smmu-nvidia.c
@@ -56,11 +56,43 @@ static void nsmmu_write_reg64(struct arm_smmu_device *smmu,
                writeq_relaxed(val, nsmmu_page(smmu, i, page) + offset);
 }
 
+static void nsmmu_tlb_sync_wait(struct arm_smmu_device *smmu, int page,
+                               int sync, int status, int inst)
+{
+       u32 reg;
+       unsigned int spin_cnt, delay;
+
+       for (delay = 1; delay < TLB_LOOP_TIMEOUT; delay *= 2) {
+               for (spin_cnt = TLB_SPIN_COUNT; spin_cnt > 0; spin_cnt--) {
+                       reg = readl_relaxed(
+                             nsmmu_page(smmu, inst, page) + status);
+                       if (!(reg & sTLBGSTATUS_GSACTIVE))
+                               return;
+                       cpu_relax();
+               }
+               udelay(delay);
+       }
+       dev_err_ratelimited(smmu->dev,
+                           "TLB sync timed out -- SMMU may be deadlocked\n");
+}
+
+static void nsmmu_tlb_sync(struct arm_smmu_device *smmu, int page,
+                          int sync, int status)
+{
+       int i;
+
+       arm_smmu_writel(smmu, page, sync, 0);
+
+       for (i = 0; i < to_nsmmu(smmu)->num_inst; i++)
+               nsmmu_tlb_sync_wait(smmu, page, sync, status, i);
+}
+
 static const struct arm_smmu_impl nsmmu_impl = {
        .read_reg = nsmmu_read_reg,
        .write_reg = nsmmu_write_reg,
        .read_reg64 = nsmmu_read_reg64,
        .write_reg64 = nsmmu_write_reg64,
+       .tlb_sync = nsmmu_tlb_sync,
 };
 
 struct arm_smmu_device *nvidia_smmu_impl_init(struct arm_smmu_device *smmu)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 46e1641..f5454e71 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -52,9 +52,6 @@
  */
 #define QCOM_DUMMY_VAL -1
 
-#define TLB_LOOP_TIMEOUT               1000000 /* 1s! */
-#define TLB_SPIN_COUNT                 10
-
 #define MSI_IOVA_BASE                  0x8000000
 #define MSI_IOVA_LENGTH                        0x100000
 
@@ -244,6 +241,11 @@ static void __arm_smmu_tlb_sync(struct arm_smmu_device 
*smmu, int page,
        unsigned int spin_cnt, delay;
        u32 reg;
 
+       if (smmu->impl->tlb_sync) {
+               smmu->impl->tlb_sync(smmu, page, sync, status);
+               return;
+       }
+
        arm_smmu_writel(smmu, page, sync, QCOM_DUMMY_VAL);
        for (delay = 1; delay < TLB_LOOP_TIMEOUT; delay *= 2) {
                for (spin_cnt = TLB_SPIN_COUNT; spin_cnt > 0; spin_cnt--) {
diff --git a/drivers/iommu/arm-smmu.h b/drivers/iommu/arm-smmu.h
index 9645bf1..d3217f1 100644
--- a/drivers/iommu/arm-smmu.h
+++ b/drivers/iommu/arm-smmu.h
@@ -207,6 +207,8 @@ enum arm_smmu_cbar_type {
 /* Maximum number of context banks per SMMU */
 #define ARM_SMMU_MAX_CBS               128
 
+#define TLB_LOOP_TIMEOUT               1000000 /* 1s! */
+#define TLB_SPIN_COUNT                 10
 
 /* Shared driver definitions */
 enum arm_smmu_arch_version {
@@ -336,6 +338,8 @@ struct arm_smmu_impl {
        int (*cfg_probe)(struct arm_smmu_device *smmu);
        int (*reset)(struct arm_smmu_device *smmu);
        int (*init_context)(struct arm_smmu_domain *smmu_domain);
+       void (*tlb_sync)(struct arm_smmu_device *smmu, int page, int sync,
+                        int status);
 };
 
 static inline void __iomem *arm_smmu_page(struct arm_smmu_device *smmu, int n)
-- 
2.1.4

Reply via email to