tegra-smmu: Fix grep in 12000000.iommu debugfs.

grep in /sys/kernel/debug/12000000.iommu/ failing
because inside masters/ some devices didn't have pointers
set for cfg, so added check in debugfs show for NULL pointer.

And other issue is accessing registers inside gnsr dir.
These registers are not ioremapped or access to them is
not allowed in case of hypervisor. So removed gnsr node
creation in hypervisor case.

Bug 200772838

Change-Id: I2dc0cbe9f71db90246a60de5db27158b555737a4
Signed-off-by: Achal Verma <achalv@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2597304
Reviewed-by: Dmitry Pervushin <dpervushin@nvidia.com>
Reviewed-by: Amrita Deshmukh <amritad@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2606024
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: Phoenix Jung <pjung@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 81 insertions, 66 deletions

diff --git a/drivers/iommu/arm-smmu-t19x.c b/drivers/iommu/arm-smmu-t19x.c
index 3fc77f81b..6cc33b726 100644
--- a/drivers/iommu/arm-smmu-t19x.c
+++ b/drivers/iommu/arm-smmu-t19x.c
@@ -15,7 +15,7 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
  * Copyright (C) 2013 ARM Limited
- * Copyright (c) 2015-2020, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2015-2021, NVIDIA CORPORATION. All rights reserved.
  *
  * Author: Will Deacon <will.deacon@arm.com>
  *
@@ -1680,12 +1680,18 @@ static int smmu_master_show(struct seq_file *s, void *unused)
         int i;
         struct arm_smmu_master *master = s->private;
 
+        if (!master->cfg)
+                return 0;
         for (i = 0; i < master->cfg->num_streamids; i++)
                 seq_printf(s, "streamids: % 3d ", master->cfg->streamids[i]);
         seq_printf(s, "\n");
+
+        if (!master->cfg->smrs)
+                return 0;
         for (i = 0; i < master->cfg->num_streamids; i++)
                 seq_printf(s, "smrs:      % 3d ", master->cfg->smrs[i].idx);
         seq_printf(s, "\n");
+
         return 0;
 }
 
@@ -2979,9 +2985,11 @@ static void arm_smmu_debugfs_create(struct arm_smmu_device *smmu)
         if (!dent_gr)
                 goto err_out;
 
-        dent_gnsr = debugfs_create_dir("gnsr", smmu->debugfs_root);
-        if (!dent_gnsr)
-                goto err_out;
+        if (!is_tegra_hypervisor_mode()) {
+                dent_gnsr = debugfs_create_dir("gnsr", smmu->debugfs_root);
+                if (!dent_gnsr)
+                        goto err_out;
+        }
 
         smmu->masters_root = debugfs_create_dir("masters", smmu->debugfs_root);
         if (!smmu->masters_root)
@@ -3042,75 +3050,82 @@ static void arm_smmu_debugfs_create(struct arm_smmu_device *smmu)
         debugfs_create_regset32("regdump", S_IRUGO, smmu->debugfs_root,
                                 smmu->regset);
 
-        bytes = sizeof(*smmu->perf_regset);
-        bytes += ARRAY_SIZE(arm_smmu_gnsr0_regs) * sizeof(*regs);
-        /*
-         * Account the number of bytes for two sets of
-         * counter group registers
-         */
-        bytes += 2 * PMCG_SIZE * sizeof(*regs);
-        /*
-         * Account the number of bytes for two sets of
-         * event counter registers
-         */
-        bytes += 2 * PMEV_SIZE * sizeof(*regs);
-
-        /* Allocate memory for Perf Monitor registers */
-        smmu->perf_regset =  kzalloc(bytes, GFP_KERNEL);
-        if (!smmu->perf_regset)
-                goto err_out;
-
-        /*
-         * perf_regset base address is placed at offset (3 * smmu_pagesize)
-         * from smmu->base address
-         */
-        smmu->perf_regset->base = smmu->base[0] + 3 * (1 << smmu->pgshift);
-        smmu->perf_regset->nregs = ARRAY_SIZE(arm_smmu_gnsr0_regs) +
-                2 * PMCG_SIZE + 2 * PMEV_SIZE;
-        smmu->perf_regset->regs =
-                (struct debugfs_reg32 *)(smmu->perf_regset + 1);
-
-        regs = (struct debugfs_reg32 *)smmu->perf_regset->regs;
-
-        for (i = 0; i < ARRAY_SIZE(arm_smmu_gnsr0_regs); i++) {
-                regs->name = arm_smmu_gnsr0_regs[i].name;
-                regs->offset = arm_smmu_gnsr0_regs[i].offset;
-                regs++;
-        }
+        if (!is_tegra_hypervisor_mode()) {
+                bytes = sizeof(*smmu->perf_regset);
+                bytes += ARRAY_SIZE(arm_smmu_gnsr0_regs) * sizeof(*regs);
+                /*
+                 * Account the number of bytes for two sets of
+                 * counter group registers
+                 */
+                bytes += 2 * PMCG_SIZE * sizeof(*regs);
+                /*
+                 * Account the number of bytes for two sets of
+                 * event counter registers
+                 */
+                bytes += 2 * PMEV_SIZE * sizeof(*regs);
 
-        for (i = 0; i < PMEV_SIZE; i++) {
-                regs->name = kasprintf(GFP_KERNEL, "GNSR0_PMEVTYPER%d_0", i);
-                if (!regs->name)
+                /* Allocate memory for Perf Monitor registers */
+                smmu->perf_regset =  kzalloc(bytes, GFP_KERNEL);
+                if (!smmu->perf_regset)
                         goto err_out;
-                regs->offset = ARM_SMMU_GNSR0_PMEVTYPER(i);
-                regs++;
 
-                regs->name = kasprintf(GFP_KERNEL, "GNSR0_PMEVCNTR%d_0", i);
-                if (!regs->name)
-                        goto err_out;
-                regs->offset = ARM_SMMU_GNSR0_PMEVCNTR(i);
-                regs++;
-        }
+                /*
+                 * perf_regset base address is placed at offset
+                 * (3 * smmu_pagesize) from smmu->base address
+                 */
+                smmu->perf_regset->base = smmu->base[0] +
+                        3 * (1 << smmu->pgshift);
+                smmu->perf_regset->nregs = ARRAY_SIZE(arm_smmu_gnsr0_regs) +
+                        2 * PMCG_SIZE + 2 * PMEV_SIZE;
+                smmu->perf_regset->regs =
+                        (struct debugfs_reg32 *)(smmu->perf_regset + 1);
+
+                regs = (struct debugfs_reg32 *)smmu->perf_regset->regs;
+
+                for (i = 0; i < ARRAY_SIZE(arm_smmu_gnsr0_regs); i++) {
+                        regs->name = arm_smmu_gnsr0_regs[i].name;
+                        regs->offset = arm_smmu_gnsr0_regs[i].offset;
+                        regs++;
+                }
 
-        for (i = 0; i < PMCG_SIZE; i++) {
-                regs->name = kasprintf(GFP_KERNEL, "GNSR0_PMCGCR%d_0", i);
-                if (!regs->name)
-                        goto err_out;
-                regs->offset = ARM_SMMU_GNSR0_PMCGCR(i);
-                regs++;
+                for (i = 0; i < PMEV_SIZE; i++) {
+                        regs->name = kasprintf(GFP_KERNEL,
+                                "GNSR0_PMEVTYPER%d_0", i);
+                        if (!regs->name)
+                                goto err_out;
+                        regs->offset = ARM_SMMU_GNSR0_PMEVTYPER(i);
+                        regs++;
+
+                        regs->name = kasprintf(GFP_KERNEL,
+                                "GNSR0_PMEVCNTR%d_0", i);
+                        if (!regs->name)
+                                goto err_out;
+                        regs->offset = ARM_SMMU_GNSR0_PMEVCNTR(i);
+                        regs++;
+                }
 
-                regs->name = kasprintf(GFP_KERNEL, "GNSR0_PMCGSMR%d_0", i);
-                if (!regs->name)
+                for (i = 0; i < PMCG_SIZE; i++) {
+                        regs->name = kasprintf(GFP_KERNEL,
+                                "GNSR0_PMCGCR%d_0", i);
+                        if (!regs->name)
                         goto err_out;
-                regs->offset = ARM_SMMU_GNSR0_PMCGSMR(i);
-                regs++;
-        }
+                        regs->offset = ARM_SMMU_GNSR0_PMCGCR(i);
+                        regs++;
+
+                        regs->name = kasprintf(GFP_KERNEL,
+                                "GNSR0_PMCGSMR%d_0", i);
+                        if (!regs->name)
+                                goto err_out;
+                        regs->offset = ARM_SMMU_GNSR0_PMCGSMR(i);
+                        regs++;
+                }
 
-        regs = (struct debugfs_reg32 *)smmu->perf_regset->regs;
-        for (i = 0; i < smmu->perf_regset->nregs; i++) {
-                debugfs_create_file(regs->name, S_IRUGO | S_IWUSR,
-                        dent_gnsr, regs, &smmu_perf_regset_debugfs_fops);
-                regs++;
+                regs = (struct debugfs_reg32 *)smmu->perf_regset->regs;
+                for (i = 0; i < smmu->perf_regset->nregs; i++) {
+                        debugfs_create_file(regs->name, S_IRUGO | S_IWUSR,
+                                dent_gnsr, regs, &smmu_perf_regset_debugfs_fops);
+                        regs++;
+                }
         }
 
         debugfs_create_file("context_filter", S_IRUGO | S_IWUSR,