> -----Original Message-----
> From: Joerg Roedel [mailto:[email protected]]
> Sent: 18 May 2021 09:50
> To: Shameerali Kolothum Thodi <[email protected]>
> Cc: [email protected]; [email protected];
> [email protected]; Linuxarm <[email protected]>;
> [email protected]; [email protected]; wanghuiqiang
> <[email protected]>; Guohanjun (Hanjun Guo)
> <[email protected]>; [email protected]; [email protected];
> [email protected]; [email protected]; yangyicong
> <[email protected]>
> Subject: Re: [PATCH v4 2/8] iommu/dma: Introduce generic helper to retrieve
> RMR info
>
> On Thu, May 13, 2021 at 02:45:44PM +0100, Shameer Kolothum wrote:
> > +/**
> > + * struct iommu_rmr - Reserved Memory Region details per IOMMU
> > + * @list: Linked list pointers to hold RMR region info
> > + * @base_address: base address of Reserved Memory Region
> > + * @length: length of memory region
> > + * @sid: associated stream id
> > + * @flags: flags that apply to the RMR node
> > + */
> > +struct iommu_rmr {
> > + struct list_head list;
> > + phys_addr_t base_address;
> > + u64 length;
> > + u32 sid;
> > + u32 flags;
> > +};
> > +
> > +/* RMR Remap permitted */
> > +#define IOMMU_RMR_REMAP_PERMITTED (1 << 0)
> > +
>
> This struct has lots of overlap with 'struct iommu_resv_region'. Any
> reason the existing struct can't be used here?
>
Hmm..main reason is "sid". RMRs are associated with stream ids and
that is used to install bypass STEs/SMRs in SMMU drivers and also to check
whether a dev has any RMR regions associated with it.
I think we could add sid/dev_id to 'struct iommu_resv_region', and modify
iommu_alloc_resv_region() accordingly. That can get rid of the above struct
and iommu_dma_alloc_rmr() fn. Not sure this will complicate things as
the dev_id is only valid for RMR reservation region cases.
Please let me know your thoughts.
Thanks,
Shameer
_______________________________________________
iommu mailing list
[email protected]
https://lists.linuxfoundation.org/mailman/listinfo/iommu
