Will Deacon @ 2020-12-09 11:50 MST:
> On Wed, Dec 09, 2020 at 10:07:46AM -0800, Linus Torvalds wrote: >> On Wed, Dec 9, 2020 at 6:12 AM Will Deacon <[email protected]> wrote: >> > >> > Please pull this one-liner AMD IOMMU fix for 5.10. It's actually a fix >> > for a fix, where the size of the interrupt remapping table was increased >> > but a related constant for the size of the interrupt table was forgotten. >> >> Pulled. > > Thanks. > >> However, why didn't this then add some sanity checking for the two >> different #defines to be in sync? >> >> IOW, something like >> >> #define AMD_IOMMU_IRQ_TABLE_SHIFT 9 >> >> #define MAX_IRQS_PER_TABLE (1 << AMD_IOMMU_IRQ_TABLE_SHIFT) >> #define DTE_IRQ_TABLE_LEN ((u64)AMD_IOMMU_IRQ_TABLE_SHIFT << 1) Since the field in the device table entry format expects it to be n where there are 2^n entries in the table I guess it should be: #define DTE_IRQ_TABLE_LEN 9 #define MAX_IRQS_PER_TABLE (1 << DTE_IRQ_TABLE_LEN) >> >> or whatever. Hmm? > > This looks like a worthwhile change to me, but I don't have any hardware > so I've been very reluctant to make even "obvious" driver changes here. > > Suravee -- please can you post a patch implementing the above? > >> That way this won't happen again, but perhaps equally importantly the >> linkage will be more clear, and there won't be those random constants. >> >> Naming above is probably garbage - I assume there's some actual >> architectural name for that irq table length field in the DTE? > > The one in the spec is even better: "IntTabLen". > > Will > _______________________________________________ > iommu mailing list > [email protected] > https://lists.linuxfoundation.org/mailman/listinfo/iommu
