Messages in this thread | | | Date | Thu, 3 May 2018 15:44:02 +0200 | From | Joerg Roedel <> | Subject | Re: [PATCH v4 1/2] iommu - Enable debugfs exposure of the IOMMU |
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On Mon, Apr 30, 2018 at 02:58:49PM -0500, Gary R Hook wrote: > Provide base enablement for using debugfs to expose internal data of > an IOMMU driver. When called, create the /sys/kernel/debug/iommu > directory. Emit a strong warning at boot time to indicate that this > feature is enabled. > > This patch adds a top-level function that will create the (above) > directory, under which a driver may create a hw-specific directory for > its use. The function > > iommu_debugfs_setup()
That function should be called in iommu core-code, in case we want to export some generic information from there.
Each driver then calls a separate function like
dentry = iommu_debugfs_driver_dir("amd_iommu");
to create a driver-specific directory.
> +config IOMMU_DEBUGFS > + bool "Enable IOMMU internals in DebugFS"
s/Enable/Export/
> + * static struct dentry *my_debugfs; > + * > + * struct dentry *d_top;
Missing newline
> + * if (!my_debugfs) { > + * d_top = iommu_debugfs_setup(); > + * if (d_top) > + * my_debugfs = debugfs_create_dir("vendor", d_top); > + * } > + * > + * Since the IOMMU driver can not be removed from the running system, there > + * is no need for an "off" function. > + */ > +struct dentry *iommu_debugfs_setup(void) > +{ > + if (!iommu_debugfs_dir) { > + iommu_debugfs_dir = debugfs_create_dir("iommu", NULL); > + if (iommu_debugfs_dir) > + pr_warn("WARNING: IOMMU DEBUGFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL\n");
This warning needs to be a lot bigger. See the trace_printk() warning for an example of what I have in mind.
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