On Wed, Jun 14, 2023 at 10:20 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > On Wed, Jun 14, 2023 at 09:47:53PM +0530, Anup Patel wrote: > > On Wed, Jun 14, 2023 at 8:16 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > > > > > On Tue, Jun 13, 2023 at 09:04:11PM +0530, Anup Patel wrote: > > > > We have a separate RISC-V IMSIC MSI address for each CPU so changing > > > > MSI (or IRQ) affinity results in re-programming of MSI address in > > > > the PCIe (or platform) device. > > > > > > > > Currently, the iommu_dma_prepare_msi() is called only once at the > > > > time of IRQ allocation so IOMMU DMA domain will only have mapping > > > > for one MSI page. This means iommu_dma_compose_msi_msg() called > > > > by imsic_irq_compose_msi_msg() will always use the same MSI page > > > > irrespective to target CPU MSI address. In other words, changing > > > > MSI (or IRQ) affinity for device using IOMMU DMA domain will not > > > > work. > > > > > > You didn't answer my question from last time - there seems to be no > > > iommu driver here so why are you messing with iommu_dma_prepare_msi()? > > > > > > This path is only for platforms that have IOMMU drivers that translate > > > the MSI window. You should add this code to link the interrupt > > > controller to the iommu driver when you introduce the iommu driver, > > > not in this series? > > > > > > And, as I said before, I'd like to NOT see new users of > > > iommu_dma_prepare_msi() since it is a very problematic API. > > > > > > This hacking of it here is not making it better :( > > > > I misunderstood your previous comments. > > > > We can certainly deal with this later when the IOMMU > > driver is available for RISC-V. I will drop this patch in the > > next revision. > > Not only just this patch but the calls to iommu_dma_prepare_msi() and > related APIs in the prior patch too. Assume the MSI window is directly > visible to DMA without translation. Okay, I will remove iommu_dma_xyz() usage from IMSIC driver in the next revision. > > When you come with an iommu driver we can discuss how best to proceed. Yes, that's better. Regards, Anup
