On Tue, Sep 24, 2013 at 11:42:18AM -0400, Will Deacon wrote:
> On Tue, Sep 24, 2013 at 04:07:00PM +0100, Andreas Herrmann wrote:
> > arm-smmu= arm-smmu driver option
> >
> > off Disable arm-smmu driver (ie. ignore available SMMUs)
> >
> > force_isolation
> > Try to attach each master device on every SMMU to a
> > separate iommu_domain.
> >
> > Default is that driver detects SMMUs but no translation is configured
> > (transactions just bypass translation process).
> >
> > Signed-off-by: Andreas Herrmann <andreas.herrm...@calxeda.com>
> > ---
> > drivers/iommu/arm-smmu.c | 26 ++++++++++++++++++++++++++
> > 1 file changed, 26 insertions(+)
> >
> > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> > index 3eb2259..251564e 100644
> > --- a/drivers/iommu/arm-smmu.c
> > +++ b/drivers/iommu/arm-smmu.c
> > @@ -399,6 +399,9 @@ struct arm_smmu_domain {
> > static DEFINE_SPINLOCK(arm_smmu_devices_lock);
> > static LIST_HEAD(arm_smmu_devices);
> >
> > +static bool arm_smmu_disabled;
> > +static bool arm_smmu_force_isolation;
> > +
> > static struct arm_smmu_master *find_smmu_master(struct arm_smmu_device
> > *smmu,
> > struct device_node *dev_node)
> > {
> > @@ -1837,6 +1840,9 @@ static int arm_smmu_device_dt_probe(struct
> > platform_device *pdev)
> > struct of_phandle_args masterspec;
> > int num_irqs, i, err;
> >
> > + if (arm_smmu_disabled)
> > + return -ENODEV;
> > +
> > smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
> > if (!smmu) {
> > dev_err(dev, "failed to allocate arm_smmu_device\n");
> > @@ -2022,6 +2028,23 @@ static struct platform_driver arm_smmu_driver = {
> > .remove = arm_smmu_device_remove,
> > };
> >
> > +static int __init arm_smmu_parse_options(char *str)
> > +{
> > + if (*str) {
> > + str++;
> > + if (!strncmp(str, "off", 3))
> > + arm_smmu_disabled = true;
> > + else if(!strncmp(str, "force_isolation", 15))
> > + arm_smmu_force_isolation = true;
> > + else {
> > + pr_warn("arm_smmu: invalid parameter (\"%s\")\n", str);
> > + return 0;
> > + }
> > + }
> > + return 1;
> > +}
> > +__setup("arm-smmu", arm_smmu_parse_options);
>
> If this is going to be a common function for IOMMUs, let's instead move the
> command-line parsing out into the generic IOMMU layer, then have an optional
> callback into the low-level IOMMU driver for enabling/disabling it.
Makes sense and I am currently looking into it.
Andreas
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