2022-10-17 13:26:29

by Niklas Schnelle

Subject: [PATCH v7 6/6] iommu/s390: Implement map_pages()/unmap_pages() instead of map()/unmap()

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.

Reviewed-by: Matthew Rosato <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
---
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 748e2e1b188a..6c407b61b25a 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -196,20 +196,15 @@ 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;

@@ -252,11 +247,24 @@ 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;
@@ -265,7 +273,9 @@ 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;
}
@@ -301,21 +311,27 @@ 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 (WARN_ON(iova < s390_domain->domain.geometry.aperture_start ||
+ (iova + size - 1) > s390_domain->domain.geometry.aperture_end))
+ return 0;
+
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;

@@ -361,8 +377,8 @@ 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,
}
--
2.34.1

2022-10-24 18:35:23

by Jason Gunthorpe

Subject: Re: [PATCH v7 6/6] iommu/s390: Implement map_pages()/unmap_pages() instead of map()/unmap()

On Mon, Oct 17, 2022 at 02:45:58PM +0200, 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.
>
> Reviewed-by: Matthew Rosato <[email protected]>
> Signed-off-by: Niklas Schnelle <[email protected]>
> ---
> drivers/iommu/s390-iommu.c | 48 +++++++++++++++++++++++++-------------
> 1 file changed, 32 insertions(+), 16 deletions(-)

Reviewed-by: Jason Gunthorpe <[email protected]>

Jason