iommu: Allow selecting page sizes per domain

Many IOMMUs support multiple page table formats, meaning that any given
domain may only support a subset of the hardware page sizes presented in
iommu_ops->pgsize_bitmap. There are also certain use-cases where the
creator of a domain may want to control which page sizes are used, for
example to force the use of hugepage mappings to reduce pagetable walk
depth.

To this end, add a per-domain pgsize_bitmap to represent the subset of
page sizes actually in use, to make it possible for domains with
different requirements to coexist.

Signed-off-by: Will Deacon <will.deacon@arm.com>
[rm: hijacked and rebased original patch with new commit message]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 886cb3a7832629914c527d7645aa236b8a21e22a..99432999b52fc9877452aa16f866946cbdfc6fb8 100644 (file)
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -94,7 +94,7 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size
                return -ENODEV;
 
        /* Use the smallest supported page size for IOVA granularity */
-       order = __ffs(domain->ops->pgsize_bitmap);
+       order = __ffs(domain->pgsize_bitmap);
        base_pfn = max_t(unsigned long, 1, base >> order);
        end_pfn = (base + size - 1) >> order;
 

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index b9df1411c8942c18b266b11e1cf572ecf9bcad15..ab4d014e3687c6ab077fa20648e1fbe38976e7ce 100644 (file)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -337,9 +337,9 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group,
        if (!domain || domain->type != IOMMU_DOMAIN_DMA)
                return 0;
 
-       BUG_ON(!domain->ops->pgsize_bitmap);
+       BUG_ON(!domain->pgsize_bitmap);
 
-       pg_size = 1UL << __ffs(domain->ops->pgsize_bitmap);
+       pg_size = 1UL << __ffs(domain->pgsize_bitmap);
        INIT_LIST_HEAD(&mappings);
 
        iommu_get_dm_regions(dev, &mappings);
@@ -1073,6 +1073,8 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
 
        domain->ops  = bus->iommu_ops;
        domain->type = type;
+       /* Assume all sizes by default; the driver may override this later */
+       domain->pgsize_bitmap  = bus->iommu_ops->pgsize_bitmap;
 
        return domain;
 }
@@ -1297,7 +1299,7 @@ static size_t iommu_pgsize(struct iommu_domain *domain,
        pgsize = (1UL << (pgsize_idx + 1)) - 1;
 
        /* throw away page sizes not supported by the hardware */
-       pgsize &= domain->ops->pgsize_bitmap;
+       pgsize &= domain->pgsize_bitmap;
 
        /* make sure we're still sane */
        BUG_ON(!pgsize);
@@ -1319,14 +1321,14 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova,
        int ret = 0;
 
        if (unlikely(domain->ops->map == NULL ||
-                    domain->ops->pgsize_bitmap == 0UL))
+                    domain->pgsize_bitmap == 0UL))
                return -ENODEV;
 
        if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))
                return -EINVAL;
 
        /* find out the minimum page size supported */
-       min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);
+       min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
 
        /*
         * both the virtual address and the physical one, as well as
@@ -1373,14 +1375,14 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
        unsigned long orig_iova = iova;
 
        if (unlikely(domain->ops->unmap == NULL ||
-                    domain->ops->pgsize_bitmap == 0UL))
+                    domain->pgsize_bitmap == 0UL))
                return -ENODEV;
 
        if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))
                return -EINVAL;
 
        /* find out the minimum page size supported */
-       min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);
+       min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
 
        /*
         * The virtual address, as well as the size of the mapping, must be
@@ -1426,10 +1428,10 @@ size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
        unsigned int i, min_pagesz;
        int ret;
 
-       if (unlikely(domain->ops->pgsize_bitmap == 0UL))
+       if (unlikely(domain->pgsize_bitmap == 0UL))
                return 0;
 
-       min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap);
+       min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
 
        for_each_sg(sg, s, nents, i) {
                phys_addr_t phys = page_to_phys(sg_page(s)) + s->offset;
@@ -1510,7 +1512,7 @@ int iommu_domain_get_attr(struct iommu_domain *domain,
                break;
        case DOMAIN_ATTR_PAGING:
                paging  = data;
-               *paging = (domain->ops->pgsize_bitmap != 0UL);
+               *paging = (domain->pgsize_bitmap != 0UL);
                break;
        case DOMAIN_ATTR_WINDOWS:
                count = data;

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 929a66a81b2b41ea190ad6ae031581b5f3e88dc1..e6b25276cfecfa057fb7eeade2503fce7242eabc 100644 (file)
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -264,7 +264,7 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_data *data)
        }
 
        /* Update our support page sizes bitmap */
-       mtk_iommu_ops.pgsize_bitmap = dom->cfg.pgsize_bitmap;
+       dom->domain.pgsize_bitmap = dom->cfg.pgsize_bitmap;
 
        writel(data->m4u_dom->cfg.arm_v7s_cfg.ttbr[0],
               data->base + REG_MMU_PT_BASE_ADDR);

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 75b24e93cedb3da273a589bb129b6ce502b247fd..15a65823aad9cb84f1f8e2696836a6156ffb7700 100644 (file)
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -407,7 +407,7 @@ static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu)
 
        mutex_lock(&iommu->lock);
        list_for_each_entry(domain, &iommu->domain_list, next)
-               bitmap &= domain->domain->ops->pgsize_bitmap;
+               bitmap &= domain->domain->pgsize_bitmap;
        mutex_unlock(&iommu->lock);
 
        /*

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 8a2570443b801e1d0571a89a3b6b3829b3642e0c..7811294bc0f79e5a2e2c4088e7017de55a06dcf8 100644 (file)
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -78,6 +78,7 @@ struct iommu_domain_geometry {
 struct iommu_domain {
        unsigned type;
        const struct iommu_ops *ops;
+       unsigned long pgsize_bitmap;    /* Bitmap of page sizes in use */
        iommu_fault_handler_t handler;
        void *handler_token;
        struct iommu_domain_geometry geometry;
@@ -155,7 +156,7 @@ struct iommu_dm_region {
  * @domain_set_windows: Set the number of windows for a domain
  * @domain_get_windows: Return the number of windows for a domain
  * @of_xlate: add OF master IDs to iommu grouping
- * @pgsize_bitmap: bitmap of supported page sizes
+ * @pgsize_bitmap: bitmap of all possible supported page sizes
  */
 struct iommu_ops {
        bool (*capable)(enum iommu_cap);