Re: [PATCH v2 7/7] iommu/riscv: Paging domain support

Andrew Jones
2024-04-23T17:00:42Z

On Thu, Apr 18, 2024 at 09:32:25AM -0700, Tomasz Jeznach wrote:
...
> +static size_t riscv_iommu_unmap_pages(struct iommu_domain *iommu_domain,
> + unsigned long iova, size_t pgsize, size_t pgcount,
> + struct iommu_iotlb_gather *gather)
> +{
> + struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
> + size_t size = pgcount << __ffs(pgsize);
> + unsigned long *ptr, old;
> + size_t unmapped = 0;
> + size_t pte_size;
> +
> + while (unmapped < size) {
> + ptr = riscv_iommu_pte_fetch(domain, iova, &pte_size);
> + if (!ptr)
> + return unmapped;
> +
> + /* partial unmap is not allowed, fail. */
> + if (iova & ~(pte_size - 1))
^ Shouldn't this ~ be removed?

> + return unmapped;
> +
> + old = READ_ONCE(*ptr);
> + if (cmpxchg_relaxed(ptr, old, 0) != old)
> + continue;
> +
> + iommu_iotlb_gather_add_page(&domain->domain, gather, iova,
> + pte_size);
> +
> + iova += pte_size;
> + unmapped += pte_size;
> + }
> +
> + return unmapped;
> +}
> +

Thanks,
drew