On Mon, 1 Jun 2020, Suravee Suthikulpanit wrote: > Alexander > > On 6/1/20 4:01 PM, Alexander Monakov wrote: > > On Mon, 1 Jun 2020, Suravee Suthikulpanit wrote: > > > > > > Moving init_iommu_perf_ctr just after iommu_flush_all_caches resolves > > > > the issue. This is the earliest point in amd_iommu_init_pci where the > > > > call succeeds on my laptop. > > > > > > According to your description, it should just need to be anywhere after > > > the > > > pci_enable_device() is called for the IOMMU device, isn't it? So, on your > > > system, what if we just move the init_iommu_perf_ctr() here: > > > > No, this doesn't work, as I already said in the paragraph you are responding > > to. See my last sentence in the quoted part. > > > > So the implication is init_device_table_dma together with subsequent cache > > flush is also setting up something that is necessary for counters to be > > writable. > > > > Alexander > > > > Instead of blindly moving the code around to a spot that would just work, > I am trying to understand what might be required here. In this case, > the init_device_table_dma()should not be needed. I suspect it's the IOMMU > invalidate all command that's also needed here. > > I'm also checking with the HW and BIOS team. Meanwhile, could you please give > the following change a try:
Hello. Can you give any update please? Alexander > diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c > index 5b81fd16f5fa..b07458cc1b0b 100644 > --- a/drivers/iommu/amd_iommu_init.c > +++ b/drivers/iommu/amd_iommu_init.c > @@ -1875,6 +1875,8 @@ static int __init amd_iommu_init_pci(void) > ret = iommu_init_pci(iommu); > if (ret) > break; > + iommu_flush_all_caches(iommu); > + init_iommu_perf_ctr(iommu); > } > > /* > -- > 2.17.1 > > Thanks, > Suravee >
