> -----Original Message----- > From: Robin Murphy [mailto:robin.murphy@xxxxxxx] > Sent: 22 March 2022 18:27 > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx>; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; > iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx > Cc: Linuxarm <linuxarm@xxxxxxxxxx>; lorenzo.pieralisi@xxxxxxx; > joro@xxxxxxxxxx; will@xxxxxxxxxx; wanghuiqiang > <wanghuiqiang@xxxxxxxxxx>; Guohanjun (Hanjun Guo) > <guohanjun@xxxxxxxxxx>; steven.price@xxxxxxx; Sami.Mujawar@xxxxxxx; > jon@xxxxxxxxxxxxx; eric.auger@xxxxxxxxxx; yangyicong > <yangyicong@xxxxxxxxxx> > Subject: Re: [PATCH v8 02/11] iommu: Introduce a union to struct > iommu_resv_region > > On 2022-02-21 15:43, Shameer Kolothum wrote: > > A union is introduced to struct iommu_resv_region to hold > > any firmware specific data. This is in preparation to add > > support for IORT RMR reserve regions and the union now holds > > the RMR specific information. > > > > Signed-off-by: Shameer Kolothum > <shameerali.kolothum.thodi@xxxxxxxxxx> > > --- > > include/linux/iommu.h | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > > index de0c57a567c8..b06952a75f95 100644 > > --- a/include/linux/iommu.h > > +++ b/include/linux/iommu.h > > @@ -126,6 +126,11 @@ enum iommu_resv_type { > > IOMMU_RESV_SW_MSI, > > }; > > > > +struct iommu_iort_rmr_data { > > + u32 *sids; /* Stream Ids associated with IORT RMR entry */ > > Please make this const. > > Further nit: capitalisation of "IDs" in the comment, otherwise I might > worry about the possibility of Stream Egos too :P True :). Will do that. Thanks, Shameer > > > + u32 num_sids; > > +}; > > + > > /** > > * struct iommu_resv_region - descriptor for a reserved memory region > > * @list: Linked list pointers > > @@ -133,6 +138,7 @@ enum iommu_resv_type { > > * @length: Length of the region in bytes > > * @prot: IOMMU Protection flags (READ/WRITE/...) > > * @type: Type of the reserved region > > + * @fw_data: FW specific reserved region data > > Nit: we've got plenty of room to spell out "Firmware-specific", and it > never hurts to make documentation as easy to read as possible. > > Thanks, > Robin. > > > */ > > struct iommu_resv_region { > > struct list_head list; > > @@ -140,6 +146,9 @@ struct iommu_resv_region { > > size_t length; > > int prot; > > enum iommu_resv_type type; > > + union { > > + struct iommu_iort_rmr_data rmr; > > + } fw_data; > > }; > > > > /**
