Re: [PATCH v11 1/3] ACPI/IORT: Add msi address regions reservation helper

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Thu, Dec 14, 2017 at 12:17:50PM +0000, Shameerali Kolothum Thodi wrote:
> Hi Lorenzo,
> 
> > -----Original Message-----
> > From: Lorenzo Pieralisi [mailto:lorenzo.pieralisi@arm.com]
> > Sent: Thursday, December 14, 2017 11:48 AM
> > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> > Cc: robin.murphy@arm.com; marc.zyngier@arm.com; will.deacon@arm.com;
> > joro@8bytes.org; John Garry <john.garry@huawei.com>; xuwei (O)
> > <xuwei5@hisilicon.com>; Guohanjun (Hanjun Guo) <guohanjun@huawei.com>;
> > iommu@lists.linux-foundation.org; linux-arm-kernel@lists.infradead.org; linux-
> > acpi@vger.kernel.org; devicetree@vger.kernel.org; Linuxarm
> > <linuxarm@huawei.com>
> > Subject: Re: [PATCH v11 1/3] ACPI/IORT: Add msi address regions reservation
> > helper
> > 
> > On Wed, Dec 13, 2017 at 11:58:28AM +0000, Shameer Kolothum wrote:
> > > On some platforms msi parent address regions have to be excluded from
> > > normal IOVA allocation in that they are detected and decoded in a HW
> > > specific way by system components and so they cannot be considered normal
> > > IOVA address space.
> > >
> > > Add a helper function that retrieves ITS address regions - the msi
> > > parent - through IORT device <-> ITS mappings and reserves it so that
> > > these regions will not be translated by IOMMU and will be excluded from
> > > IOVA allocations. The function checks for the smmu model number and
> > > only applies the msi reservation if the platform requires it.
> > >
> > > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> > > ---
> > >  drivers/acpi/arm64/iort.c        | 112
> > +++++++++++++++++++++++++++++++++++++--
> > >  drivers/irqchip/irq-gic-v3-its.c |   3 +-
> > >  include/linux/acpi_iort.h        |   7 ++-
> > >  3 files changed, 117 insertions(+), 5 deletions(-)
> > 
> > You need this additional hunk to make it compile on !CONFIG_IOMMU_API:
> 
> Oops..Sorry, missed that. If you are happy with the rest, I will make the below
> change and sent out the v12(hopefully final).

I am ok with it, yes.

Thanks,
Lorenzo

> Please let me know.
> 
> Thanks,
> Shameer
> 
> > 
> > -- >8 --
> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> > index 3e0ce652c3e8..e2f7bddf5522 100644
> > --- a/drivers/acpi/arm64/iort.c
> > +++ b/drivers/acpi/arm64/iort.c
> > @@ -762,25 +762,6 @@ static int __maybe_unused __get_pci_rid(struct
> > pci_dev *pdev, u16 alias,
> >  	return 0;
> >  }
> > 
> > -static __maybe_unused struct acpi_iort_node *iort_get_msi_resv_iommu(
> > -						struct device *dev)
> > -{
> > -	struct acpi_iort_node *iommu;
> > -	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
> > -
> > -	iommu = iort_get_iort_node(fwspec->iommu_fwnode);
> > -
> > -	if (iommu && (iommu->type == ACPI_IORT_NODE_SMMU_V3)) {
> > -		struct acpi_iort_smmu_v3 *smmu;
> > -
> > -		smmu = (struct acpi_iort_smmu_v3 *)iommu->node_data;
> > -		if (smmu->model ==
> > ACPI_IORT_SMMU_V3_HISILICON_HI161X)
> > -			return iommu;
> > -	}
> > -
> > -	return NULL;
> > -}
> > -
> >  static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
> >  			       struct fwnode_handle *fwnode,
> >  			       const struct iommu_ops *ops)
> > @@ -807,6 +788,24 @@ static inline bool iort_iommu_driver_enabled(u8 type)
> >  }
> > 
> >  #ifdef CONFIG_IOMMU_API
> > +static struct acpi_iort_node *iort_get_msi_resv_iommu(struct device *dev)
> > +{
> > +	struct acpi_iort_node *iommu;
> > +	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
> > +
> > +	iommu = iort_get_iort_node(fwspec->iommu_fwnode);
> > +
> > +	if (iommu && (iommu->type == ACPI_IORT_NODE_SMMU_V3)) {
> > +		struct acpi_iort_smmu_v3 *smmu;
> > +
> > +		smmu = (struct acpi_iort_smmu_v3 *)iommu->node_data;
> > +		if (smmu->model ==
> > ACPI_IORT_SMMU_V3_HISILICON_HI161X)
> > +			return iommu;
> > +	}
> > +
> > +	return NULL;
> > +}
> > +
> >  static inline const struct iommu_ops *iort_fwspec_iommu_ops(
> >  				struct iommu_fwspec *fwspec)
> >  {