[PATCH v2 2/5] iommu/amd - Add a 'verbose' switch for IOMMU debugfs

[Gary R Hook]

Enable more descriptive debugfs output via a 'verbose' variable.

Signed-off-by: Gary R Hook <gary.h...@amd.com>
---
 drivers/iommu/amd_iommu_debugfs.c |   14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu_debugfs.c 
b/drivers/iommu/amd_iommu_debugfs.c
index b0395a47bc32..481f4d86f8f8 100644
--- a/drivers/iommu/amd_iommu_debugfs.c
+++ b/drivers/iommu/amd_iommu_debugfs.c
@@ -27,6 +27,8 @@ static DEFINE_RWLOCK(iommu_debugfs_lock);
 
 #define        MAX_NAME_LEN    20
 
+static unsigned int amd_iommu_verbose = 0;
+
 static unsigned int amd_iommu_count_valid_dtes(int start, int end)
 {
        unsigned int n = 0;
@@ -61,7 +63,10 @@ static ssize_t amd_iommu_debugfs_dtecount_read(struct file 
*filp,
                return -ENOMEM;
 
        n = amd_iommu_count_valid_dtes(0, 0xFFFF);
-       oboff += OSCNPRINTF("%d\n", n);
+       if (amd_iommu_verbose)
+               oboff += OSCNPRINTF("# DTEs:  %d\n", n);
+       else
+               oboff += OSCNPRINTF("%d\n", n);
 
        ret = simple_read_from_buffer(ubuf, count, offp, obuf, oboff);
        kfree(obuf);
@@ -79,6 +84,7 @@ static const struct file_operations 
amd_iommu_debugfs_dtecount_ops = {
 void amd_iommu_debugfs_setup(struct amd_iommu *iommu)
 {
        char name[MAX_NAME_LEN + 1];
+       struct dentry *d_verbose;
        struct dentry *d_dte;
        unsigned long flags;
 
@@ -97,6 +103,12 @@ void amd_iommu_debugfs_setup(struct amd_iommu *iommu)
        if (!iommu->debugfs_instance)
                goto err;
 
+       d_verbose = debugfs_create_u32("verbose", 0600,
+                                      iommu->debugfs_instance,
+                                      &amd_iommu_verbose);
+       if (!d_verbose)
+               goto err;
+
        d_dte = debugfs_create_file("count", 0400,
                                    iommu->debugfs_instance, iommu,
                                    &amd_iommu_debugfs_dtecount_ops);