From e0bf78b0f9594d47dfa7e364a9071442fc1d9445 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Wed, 19 Dec 2018 19:52:14 +1100 Subject: powerpc/mm/iommu/vfio_spapr_tce: Change mm_iommu_get to reference a region Normally mm_iommu_get() should add a reference and mm_iommu_put() should remove it. However historically mm_iommu_find() does the referencing and mm_iommu_get() is doing allocation and referencing. We are going to add another helper to preregister device memory so instead of having mm_iommu_new() (which pre-registers the normal memory and references the region), we need separate helpers for pre-registering and referencing. This renames: - mm_iommu_get to mm_iommu_new; - mm_iommu_find to mm_iommu_get. This changes mm_iommu_get() to reference the region so the name now reflects what it does. This removes the check for exact match from mm_iommu_new() as we want it to fail on existing regions; mm_iommu_get() should be used instead. Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson Signed-off-by: Michael Ellerman --- drivers/vfio/vfio_iommu_spapr_tce.c | 35 +++++++++++++++++++++++------------ 1 file changed, 23 insertions(+), 12 deletions(-) (limited to 'drivers/vfio') diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index ad637250938d..1d8b88928329 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -152,11 +152,12 @@ static long tce_iommu_unregister_pages(struct tce_container *container, struct mm_iommu_table_group_mem_t *mem; struct tce_iommu_prereg *tcemem; bool found = false; + long ret; if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK)) return -EINVAL; - mem = mm_iommu_find(container->mm, vaddr, size >> PAGE_SHIFT); + mem = mm_iommu_get(container->mm, vaddr, size >> PAGE_SHIFT); if (!mem) return -ENOENT; @@ -168,9 +169,13 @@ static long tce_iommu_unregister_pages(struct tce_container *container, } if (!found) - return -ENOENT; + ret = -ENOENT; + else + ret = tce_iommu_prereg_free(container, tcemem); + + mm_iommu_put(container->mm, mem); - return tce_iommu_prereg_free(container, tcemem); + return ret; } static long tce_iommu_register_pages(struct tce_container *container, @@ -185,22 +190,24 @@ static long tce_iommu_register_pages(struct tce_container *container, ((vaddr + size) < vaddr)) return -EINVAL; - mem = mm_iommu_find(container->mm, vaddr, entries); + mem = mm_iommu_get(container->mm, vaddr, entries); if (mem) { list_for_each_entry(tcemem, &container->prereg_list, next) { - if (tcemem->mem == mem) - return -EBUSY; + if (tcemem->mem == mem) { + ret = -EBUSY; + goto put_exit; + } } + } else { + ret = mm_iommu_new(container->mm, vaddr, entries, &mem); + if (ret) + return ret; } - ret = mm_iommu_get(container->mm, vaddr, entries, &mem); - if (ret) - return ret; - tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL); if (!tcemem) { - mm_iommu_put(container->mm, mem); - return -ENOMEM; + ret = -ENOMEM; + goto put_exit; } tcemem->mem = mem; @@ -209,6 +216,10 @@ static long tce_iommu_register_pages(struct tce_container *container, container->enabled = true; return 0; + +put_exit: + mm_iommu_put(container->mm, mem); + return ret; } static bool tce_page_is_contained(struct page *page, unsigned page_shift) -- cgit v1.2.3