On Mon May 08, 2017 at 12:09:32PM +0200, Robert Richter wrote:
> On 08.05.17 15:14:37, Linu Cherian wrote:
> > On Sat May 06, 2017 at 12:18:44AM +0200, Robert Richter wrote:
> > > On 05.05.17 17:38:06, Geetha sowjanya wrote:
> > > > From: Linu Cherian <linu.cher...@cavium.com>
> > > >
> > > > With implementations supporting only page 0 register space,
> > > > resource size can be 64k as well and hence perform size checks
> > > > based on SMMU option PAGE0_REGS_ONLY.
> > > >
> > > > For this, arm_smmu_device_dt_probe/acpi_probe has been moved before
> > > > platform_get_resource call, so that SMMU options are set beforehand.
> > > >
> > > > Signed-off-by: Linu Cherian <linu.cher...@cavium.com>
> > > > Signed-off-by: Geetha Sowjanya <geethasowjanya.ak...@cavium.com>
> > > > ---
> > > > drivers/iommu/arm-smmu-v3.c | 26 +++++++++++++++++---------
> > > > 1 file changed, 17 insertions(+), 9 deletions(-)
> > > >
> > > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> > > > index 107b4a6..f027676 100644
> > > > --- a/drivers/iommu/arm-smmu-v3.c
> > > > +++ b/drivers/iommu/arm-smmu-v3.c
> > > > @@ -2672,6 +2672,14 @@ static int arm_smmu_device_dt_probe(struct
> > > > platform_device *pdev,
> > > > return ret;
> > > > }
> > > >
> > > > +static unsigned long arm_smmu_resource_size(struct arm_smmu_device
> > > > *smmu)
> > > > +{
> > > > + if (ARM_SMMU_PAGE0_REGS_ONLY(smmu))
> > > > + return SZ_64K;
> > > > + else
> > > > + return SZ_128K;
> > > > +}
> > > > +
> > >
> > > I think this can be dropped. See below.
> > >
> > > > static int arm_smmu_device_probe(struct platform_device *pdev)
> > > > {
> > > > int irq, ret;
> > > > @@ -2688,9 +2696,17 @@ static int arm_smmu_device_probe(struct
> > > > platform_device *pdev)
> > > > }
> > > > smmu->dev = dev;
> > > >
> > > > + if (dev->of_node) {
> > > > + ret = arm_smmu_device_dt_probe(pdev, smmu);
> > > > + } else {
> > > > + ret = arm_smmu_device_acpi_probe(pdev, smmu);
> > > > + if (ret == -ENODEV)
> > > > + return ret;
> > > > + }
> > > > +
> > > > /* Base address */
> > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > > - if (resource_size(res) + 1 < SZ_128K) {
> > > > + if (resource_size(res) + 1 < arm_smmu_resource_size(smmu)) {
> > > > dev_err(dev, "MMIO region too small (%pr)\n", res);
> > > > return -EINVAL;
> > > > }
> > >
> > > Why not just do the follwoing here:
> > >
> > > /* Base address */
> > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > if (resource_size(res) + 1 < arm_smmu_resource_size(smmu)) {
> > > dev_err(dev, "MMIO region too small (%pr)\n", res);
> > > return -EINVAL;
> > > }
> > > ioaddr = res->start;
> > >
> > > + /*
> > > + * Override the size, for Cavium ThunderX2 implementation
> > > + * which doesn't support the page 1 SMMU register space.
> > > + */
> > > + if (smmu->options & ARM_SMMU_OPT_PAGE0_REGS_ONLY)
> > > + res->end = res->size + SZ_64K -1;
> > > +
> > > smmu->base = devm_ioremap_resource(dev, res);
> > > if (IS_ERR(smmu->base))
> > > return PTR_ERR(smmu->base);
> >
> >
> > This might not work, since platform_device_add is being called from
> > iort.c before the res->end gets fixed up here.
>
> It should. You added it with 128k and you get it back with
> platform_get_resource(), but before ioremap you shrink the size to
> 64k.
>
The smmu devices are located at 64k offsets and not at 128k
offsets and hence this would be result in resource conflict during
platform_add_device ?
Code snippet from platform_add_device:
for (i = 0; i < pdev->num_resources; i++) {
struct resource *p, *r = &pdev->resource[i];
if (r->name == NULL)
r->name = dev_name(&pdev->dev);
p = r->parent;
if (!p) {
if (resource_type(r) == IORESOURCE_MEM)
p = &iomem_resource;
else if (resource_type(r) == IORESOURCE_IO)
p = &ioport_resource;
}
if (p && insert_resource(p, r)) {
dev_err(&pdev->dev, "failed to claim resource %d:
%pR\n", i, r);
ret = -EBUSY;
goto failed;
}
}
--
Linu cherian
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