On 05/14/2018 12:50 PM, Randy Dunlap wrote:
On 05/14/2018 10:20 AM, Gary R Hook wrote:
Implement a skeleton framework for debugfs support in the
AMD IOMMU.
Signed-off-by: Gary R Hook <[email protected]>
---
drivers/iommu/Makefile | 5 +++++
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 | 3 +++
5 files changed, 57 insertions(+), 2 deletions(-)
create mode 100644 drivers/iommu/amd_iommu_debugfs.c
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 74cfbc392862..dd980f7dd8b6 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -30,3 +30,8 @@ obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o
obj-$(CONFIG_S390_IOMMU) += s390-iommu.o
obj-$(CONFIG_QCOM_IOMMU) += qcom_iommu.o
+
+# This ensures that only the required files are compiled
+ifeq ($(CONFIG_IOMMU_DEBUGFS), y)
Most Makefiles don't use a space before the 'y', but since you tested it,
I guess either way works.
Pretty sure whitespace isn't used as a delimiter in this construct. I
could be mistaken. But yes, it's perfectly serviceable.
But why do this in the Makefile at all? Why not just add another Kconfig
symbol and simplify the Makefile?
+obj-$(CONFIG_AMD_IOMMU) += amd_iommu_debugfs.o
+endif
This was brought up a few weeks ago in, I believe, version 3 of this
patch. That question was discussed (because that's what I did the first
time out), and _someone_ _else_ asked about why I didn't just do it the
way I've done it here.
Everyone has a preference.
I chose to simplify the choices and avoid multiple symbols, instead
opting for two switches: choose your device, and decide on Debug FS
enablement for it. IMO Very simple.
I can't fathom a scenario where this wouldn't work. Is there one?
