| Message ID | 20210513134550.2117-3-shameerali.kolothum.thodi@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | ACPI/IORT: Support for IORT RMR node | expand |
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? Regards, Joerg
> -----Original Message----- > From: Joerg Roedel [mailto:joro@8bytes.org] > Sent: 18 May 2021 09:50 > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> > Cc: linux-arm-kernel@lists.infradead.org; linux-acpi@vger.kernel.org; > iommu@lists.linux-foundation.org; Linuxarm <linuxarm@huawei.com>; > lorenzo.pieralisi@arm.com; robin.murphy@arm.com; wanghuiqiang > <wanghuiqiang@huawei.com>; Guohanjun (Hanjun Guo) > <guohanjun@huawei.com>; steven.price@arm.com; Sami.Mujawar@arm.com; > jon@solid-run.com; eric.auger@redhat.com; yangyicong > <yangyicong@huawei.com> > 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
On 2021-05-19 10:30, Shameerali Kolothum Thodi wrote: > > >> -----Original Message----- >> From: Joerg Roedel [mailto:joro@8bytes.org] >> Sent: 18 May 2021 09:50 >> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> >> Cc: linux-arm-kernel@lists.infradead.org; linux-acpi@vger.kernel.org; >> iommu@lists.linux-foundation.org; Linuxarm <linuxarm@huawei.com>; >> lorenzo.pieralisi@arm.com; robin.murphy@arm.com; wanghuiqiang >> <wanghuiqiang@huawei.com>; Guohanjun (Hanjun Guo) >> <guohanjun@huawei.com>; steven.price@arm.com; Sami.Mujawar@arm.com; >> jon@solid-run.com; eric.auger@redhat.com; yangyicong >> <yangyicong@huawei.com> >> 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. Maybe add a union for FW-specific data to struct resv_region, so that it could eventually subsume AMD's struct unity_map_entry and Intel's struct dmar_rmrr_unit as well? They're essentially doing the same dance. We might still have to create copies of the firmware-allocated entries to actually assign to domains (certainly where one entry covers multiple devices), but kmemdup() is still a lot neater than various translations from private formats. Robin.
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 7bcdd1205535..674bd8815159 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -193,6 +193,39 @@ void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list) } EXPORT_SYMBOL(iommu_dma_get_resv_regions); +/** + * iommu_dma_get_rmrs - Retrieve Reserved Memory Regions(RMRs) associated + * with a given IOMMU + * @iommu_fwnode: fwnode associated with IOMMU + * @list: RMR list to be populated + * + */ +int iommu_dma_get_rmrs(struct fwnode_handle *iommu_fwnode, + struct list_head *list) +{ + return -EINVAL; +} +EXPORT_SYMBOL(iommu_dma_get_rmrs); + +struct iommu_rmr *iommu_dma_alloc_rmr(u64 base, u64 length, u32 sid, + u32 flags) +{ + struct iommu_rmr *rmr; + + rmr = kzalloc(sizeof(*rmr), GFP_KERNEL); + if (!rmr) + return NULL; + + INIT_LIST_HEAD(&rmr->list); + rmr->base_address = base; + rmr->length = length; + rmr->sid = sid; + rmr->flags = flags; + + return rmr; +} +EXPORT_SYMBOL(iommu_dma_alloc_rmr); + static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, phys_addr_t start, phys_addr_t end) { diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index 6e75a2d689b4..319f332c279f 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -42,12 +42,17 @@ void iommu_dma_free_cpu_cached_iovas(unsigned int cpu, extern bool iommu_dma_forcedac; +int iommu_dma_get_rmrs(struct fwnode_handle *iommu, struct list_head *list); +struct iommu_rmr *iommu_dma_alloc_rmr(u64 base, u64 length, u32 sid, u32 flags); + #else /* CONFIG_IOMMU_DMA */ struct iommu_domain; struct msi_desc; struct msi_msg; struct device; +struct fwnode_handle; +struct iommu_rmr; static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size) @@ -83,5 +88,10 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he { } +int iommu_dma_get_rmrs(struct fwnode_handle *iommu, struct list_head *list) +{ + return -ENODEV; +} + #endif /* CONFIG_IOMMU_DMA */ #endif /* __DMA_IOMMU_H */ diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 32d448050bf7..73cd2831cb45 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -555,6 +555,25 @@ struct iommu_sva { struct device *dev; }; +/** + * 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) + int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode, const struct iommu_ops *ops); void iommu_fwspec_free(struct device *dev);
Reserved Memory Regions(RMR) associated with an IOMMU can be described through ACPI IORT tables in systems with devices that require a unity mapping or bypass for those regions. Introduce a generic interface so that IOMMU drivers can retrieve and set up necessary mappings. Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> --- drivers/iommu/dma-iommu.c | 33 +++++++++++++++++++++++++++++++++ include/linux/dma-iommu.h | 10 ++++++++++ include/linux/iommu.h | 19 +++++++++++++++++++ 3 files changed, 62 insertions(+) -- 2.17.1