On Tue, May 29, 2018 at 01:23:23PM -0500, Gary R Hook wrote:
Implement a skeleton framework for debugfs support in the
AMD IOMMU. Add a hidden boolean to Kconfig that is defined
for the AMD IOMMU when general IOMMY DebugFS support is
enabled.
Signed-off-by: Gary R Hook <gary.hook@xxxxxxx>
---
drivers/iommu/Kconfig | 4 ++++
drivers/iommu/Makefile | 1 +
drivers/iommu/amd_iommu_debugfs.c | 39 +++++++++++++++++++++++++++++++++++++
drivers/iommu/amd_iommu_init.c | 6 ++++--
drivers/iommu/amd_iommu_proto.h | 6 ++++++
drivers/iommu/amd_iommu_types.h | 5 +++++
6 files changed, 59 insertions(+), 2 deletions(-)
create mode 100644 drivers/iommu/amd_iommu_debugfs.c
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index f9af25ac409f..ec223f6f4ad4 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -137,6 +137,10 @@ config AMD_IOMMU
your BIOS for an option to enable it or if you have an IVRS ACPI
table.
+config AMD_IOMMU_DEBUGFS
+ def_bool y
Why default y? Can you not boot a box without this? If not, it should
not be Y.
+ depends on AMD_IOMMU && IOMMU_DEBUGFS
+
config AMD_IOMMU_V2
tristate "AMD IOMMU Version 2 driver"
depends on AMD_IOMMU
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 74cfbc392862..47fd6ea9de2d 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_IOMMU_IOVA) += iova.o
obj-$(CONFIG_OF_IOMMU) += of_iommu.o
obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o
obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o amd_iommu_init.o
+obj-$(CONFIG_AMD_IOMMU_DEBUGFS) += amd_iommu_debugfs.o
obj-$(CONFIG_AMD_IOMMU_V2) += amd_iommu_v2.o
obj-$(CONFIG_ARM_SMMU) += arm-smmu.o
obj-$(CONFIG_ARM_SMMU_V3) += arm-smmu-v3.o
diff --git a/drivers/iommu/amd_iommu_debugfs.c b/drivers/iommu/amd_iommu_debugfs.c
new file mode 100644
index 000000000000..6dff98552969
--- /dev/null
+++ b/drivers/iommu/amd_iommu_debugfs.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD IOMMU driver
+ *
+ * Copyright (C) 2018 Advanced Micro Devices, Inc.
+ *
+ * Author: Gary R Hook <gary.hook@xxxxxxx>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/iommu.h>
+#include <linux/pci.h>
+#include "amd_iommu_proto.h"
+#include "amd_iommu_types.h"
+
+static struct dentry *amd_iommu_debugfs;
+static DEFINE_MUTEX(amd_iommu_debugfs_lock);
+
+#define MAX_NAME_LEN 20
+
+void amd_iommu_debugfs_setup(struct amd_iommu *iommu)
+{
+ char name[MAX_NAME_LEN + 1];
+
+ mutex_lock(&amd_iommu_debugfs_lock);
+ if (!amd_iommu_debugfs)
+ amd_iommu_debugfs = iommu_debugfs_new_driver_dir("amd");
+ mutex_unlock(&amd_iommu_debugfs_lock);
+
+ if (amd_iommu_debugfs) {
Do not test this.
+ snprintf(name, MAX_NAME_LEN, "iommu%02d", iommu->index);
+ iommu->debugfs = debugfs_create_dir(name,
+ amd_iommu_debugfs);
+ if (!iommu->debugfs) {
No, you don't care about the return value of any debugfs call. Just
save the directory and move on. If it's not correct, find, nothing is
wrong, just keep going.