On 10/6/22 10:47 AM, Niklas Schnelle wrote:
> While s390-iommu currently implements the map_page()/unmap_page()
> operations which only map/unmap a single page at a time the internal
> s390_iommu_update_trans() API already supports mapping/unmapping a range
> of pages at once. Take advantage of this by implementing the
> map_pages()/unmap_pages() operations instead thus allowing users of the
> IOMMU drivers to map multiple pages in a single call followed by
> a single I/O TLB flush if needed.
>
> Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
> ---
> drivers/iommu/s390-iommu.c | 48 +++++++++++++++++++++++++-------------
> 1 file changed, 32 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
> index ac200f0b81fa..7b92855135ac 100644
> --- a/drivers/iommu/s390-iommu.c
> +++ b/drivers/iommu/s390-iommu.c
> @@ -189,20 +189,15 @@ static void s390_iommu_release_device(struct device *dev)
>
> static int s390_iommu_update_trans(struct s390_domain *s390_domain,
> phys_addr_t pa, dma_addr_t dma_addr,
> - size_t size, int flags)
> + unsigned long nr_pages, int flags)
> {
> phys_addr_t page_addr = pa & PAGE_MASK;
> dma_addr_t start_dma_addr = dma_addr;
> - unsigned long irq_flags, nr_pages, i;
> + unsigned long irq_flags, i;
> struct zpci_dev *zdev;
> unsigned long *entry;
> int rc = 0;
>
> - if (dma_addr < s390_domain->domain.geometry.aperture_start ||
> - (dma_addr + size - 1) > s390_domain->domain.geometry.aperture_end)
> - return -EINVAL;
> -
> - nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
> if (!nr_pages)
> return 0;
>
> @@ -245,11 +240,24 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
> return rc;
> }
>
> -static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova,
> - phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
> +static int s390_iommu_map_pages(struct iommu_domain *domain,
> + unsigned long iova, phys_addr_t paddr,
> + size_t pgsize, size_t pgcount,
> + int prot, gfp_t gfp, size_t *mapped)
> {
> struct s390_domain *s390_domain = to_s390_domain(domain);
> int flags = ZPCI_PTE_VALID, rc = 0;
> + size_t size = pgcount << __ffs(pgsize);
> +
> + if (pgsize != SZ_4K)
> + return -EINVAL;
> +
> + if (iova < s390_domain->domain.geometry.aperture_start ||
> + (iova + size - 1) > s390_domain->domain.geometry.aperture_end)
> + return -EINVAL;
> +
> + if (!IS_ALIGNED(iova | paddr, pgsize))
> + return -EINVAL;
>
> if (!(prot & IOMMU_READ))
> return -EINVAL;
> @@ -258,7 +266,9 @@ static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova,
> flags |= ZPCI_TABLE_PROTECTED;
>
> rc = s390_iommu_update_trans(s390_domain, paddr, iova,
> - size, flags);
> + pgcount, flags);
> + if (!rc)
> + *mapped = size;
>
> return rc;
> }
> @@ -294,21 +304,27 @@ static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain,
> return phys;
> }
>
> -static size_t s390_iommu_unmap(struct iommu_domain *domain,
> - unsigned long iova, size_t size,
> - struct iommu_iotlb_gather *gather)
> +static size_t s390_iommu_unmap_pages(struct iommu_domain *domain,
> + unsigned long iova,
> + size_t pgsize, size_t pgcount,
> + struct iommu_iotlb_gather *gather)
> {
> struct s390_domain *s390_domain = to_s390_domain(domain);
> + size_t size = pgcount << __ffs(pgsize);
> int flags = ZPCI_PTE_INVALID;
> phys_addr_t paddr;
> int rc;
>
> + if (iova < s390_domain->domain.geometry.aperture_start ||
> + (iova + size - 1) > s390_domain->domain.geometry.aperture_end)
> + return 0;
> +
Overall this LGTM and runs well with my testing. But I'm curious why we silently ignore an egregiously bad unmap request here? We've already done an -EINVAL for an attempt to map_pages() something outside of the aperture. If something still tries to unmap_pages() outside of the aperture, that seems like a bug? Maybe this should be surrounded by a if (WARN_ON(... || ...) to signify the unexpected behavior and then still return 0?
Otherwise:
Reviewed-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
> paddr = s390_iommu_iova_to_phys(domain, iova);
> if (!paddr)
> return 0;
>
> rc = s390_iommu_update_trans(s390_domain, paddr, iova,
> - size, flags);
> + pgcount, flags);
> if (rc)
> return 0;
>
> @@ -354,8 +370,8 @@ static const struct iommu_ops s390_iommu_ops = {
> .default_domain_ops = &(const struct iommu_domain_ops) {
> .attach_dev = s390_iommu_attach_device,
> .detach_dev = s390_iommu_detach_device,
> - .map = s390_iommu_map,
> - .unmap = s390_iommu_unmap,
> + .map_pages = s390_iommu_map_pages,
> + .unmap_pages = s390_iommu_unmap_pages,
> .iova_to_phys = s390_iommu_iova_to_phys,
> .free = s390_domain_free,
> }
