From 02a8c61a8b06a4a082b58c3e643b28036c6be60f Mon Sep 17 00:00:00 2001 From: Joao Martins Date: Fri, 2 Feb 2024 13:34:12 +0000 Subject: [PATCH] iommufd/selftest: Refactor mock_domain_read_and_clear_dirty() Move the clearing of the dirty bit of the mock domain into mock_domain_test_and_clear_dirty() helper, simplifying the caller function. Additionally, rework the mock_domain_read_and_clear_dirty() loop to iterate over a potentially variable IO page size. No functional change intended with the loop refactor. This is in preparation for dirty tracking support for IOMMU hugepage mock domains. Link: https://lore.kernel.org/r/20240202133415.23819-7-joao.m.martins@oracle.com Signed-off-by: Joao Martins Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/selftest.c | 64 ++++++++++++++++++++++---------- 1 file changed, 45 insertions(+), 19 deletions(-) diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c index d9e9920c7eba41..796e7e3ec0cfd8 100644 --- a/drivers/iommu/iommufd/selftest.c +++ b/drivers/iommu/iommufd/selftest.c @@ -191,6 +191,34 @@ static int mock_domain_set_dirty_tracking(struct iommu_domain *domain, return 0; } +static bool mock_test_and_clear_dirty(struct mock_iommu_domain *mock, + unsigned long iova, size_t page_size, + unsigned long flags) +{ + unsigned long cur, end = iova + page_size - 1; + bool dirty = false; + void *ent, *old; + + for (cur = iova; cur < end; cur += MOCK_IO_PAGE_SIZE) { + ent = xa_load(&mock->pfns, cur / MOCK_IO_PAGE_SIZE); + if (!ent || !(xa_to_value(ent) & MOCK_PFN_DIRTY_IOVA)) + continue; + + dirty = true; + /* Clear dirty */ + if (!(flags & IOMMU_DIRTY_NO_CLEAR)) { + unsigned long val; + + val = xa_to_value(ent) & ~MOCK_PFN_DIRTY_IOVA; + old = xa_store(&mock->pfns, cur / MOCK_IO_PAGE_SIZE, + xa_mk_value(val), GFP_KERNEL); + WARN_ON_ONCE(ent != old); + } + } + + return dirty; +} + static int mock_domain_read_and_clear_dirty(struct iommu_domain *domain, unsigned long iova, size_t size, unsigned long flags, @@ -198,31 +226,29 @@ static int mock_domain_read_and_clear_dirty(struct iommu_domain *domain, { struct mock_iommu_domain *mock = container_of(domain, struct mock_iommu_domain, domain); - unsigned long i, max = size / MOCK_IO_PAGE_SIZE; - void *ent, *old; + unsigned long end = iova + size; + void *ent; if (!(mock->flags & MOCK_DIRTY_TRACK) && dirty->bitmap) return -EINVAL; - for (i = 0; i < max; i++) { - unsigned long cur = iova + i * MOCK_IO_PAGE_SIZE; + do { + unsigned long pgsize = MOCK_IO_PAGE_SIZE; + unsigned long head; - ent = xa_load(&mock->pfns, cur / MOCK_IO_PAGE_SIZE); - if (ent && (xa_to_value(ent) & MOCK_PFN_DIRTY_IOVA)) { - /* Clear dirty */ - if (!(flags & IOMMU_DIRTY_NO_CLEAR)) { - unsigned long val; - - val = xa_to_value(ent) & ~MOCK_PFN_DIRTY_IOVA; - old = xa_store(&mock->pfns, - cur / MOCK_IO_PAGE_SIZE, - xa_mk_value(val), GFP_KERNEL); - WARN_ON_ONCE(ent != old); - } - iommu_dirty_bitmap_record(dirty, cur, - MOCK_IO_PAGE_SIZE); + ent = xa_load(&mock->pfns, iova / MOCK_IO_PAGE_SIZE); + if (!ent) { + iova += pgsize; + continue; } - } + + head = iova & ~(pgsize - 1); + + /* Clear dirty */ + if (mock_test_and_clear_dirty(mock, head, pgsize, flags)) + iommu_dirty_bitmap_record(dirty, head, pgsize); + iova = head + pgsize; + } while (iova < end); return 0; }