From: Will Deacon Date: Mon, 17 Nov 2014 23:31:12 +0000 (+0000) Subject: iommu: add self-consistency tests to ARM LPAE IO page table allocator X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=fe4b991dcd84e0104cf2e29223a819335ed048a7;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git iommu: add self-consistency tests to ARM LPAE IO page table allocator This patch adds a series of basic self-consistency tests to the ARM LPAE IO page table allocator that exercise corner cases in map/unmap, as well as testing all valid configurations of pagesize, ias and stage. Signed-off-by: Will Deacon --- diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 306454fbc52d..9fd9909867cd 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -28,6 +28,15 @@ config IOMMU_IO_PGTABLE_LPAE sizes at both stage-1 and stage-2, as well as address spaces up to 48-bits in size. +config IOMMU_IO_PGTABLE_LPAE_SELFTEST + bool "LPAE selftests" + depends on IOMMU_IO_PGTABLE_LPAE + help + Enable self-tests for LPAE page table allocator. This performs + a series of page-table consistency checks during boot. + + If unsure, say N here. + endmenu config OF_IOMMU diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index dbe6178a53e9..52fb21487f02 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -193,6 +193,8 @@ struct arm_lpae_io_pgtable { typedef u64 arm_lpae_iopte; +static bool selftest_running = false; + static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data, unsigned long iova, phys_addr_t paddr, arm_lpae_iopte prot, int lvl, @@ -201,8 +203,10 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data, arm_lpae_iopte pte = prot; /* We require an unmap first */ - if (WARN_ON(iopte_leaf(*ptep, lvl))) + if (iopte_leaf(*ptep, lvl)) { + WARN_ON(!selftest_running); return -EEXIST; + } if (lvl == ARM_LPAE_MAX_LEVELS - 1) pte |= ARM_LPAE_PTE_TYPE_PAGE; @@ -779,3 +783,197 @@ struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = { .alloc = arm_32_lpae_alloc_pgtable_s2, .free = arm_lpae_free_pgtable, }; + +#ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE_SELFTEST + +static struct io_pgtable_cfg *cfg_cookie; + +static void dummy_tlb_flush_all(void *cookie) +{ + WARN_ON(cookie != cfg_cookie); +} + +static void dummy_tlb_add_flush(unsigned long iova, size_t size, bool leaf, + void *cookie) +{ + WARN_ON(cookie != cfg_cookie); + WARN_ON(!(size & cfg_cookie->pgsize_bitmap)); +} + +static void dummy_tlb_sync(void *cookie) +{ + WARN_ON(cookie != cfg_cookie); +} + +static void dummy_flush_pgtable(void *ptr, size_t size, void *cookie) +{ + WARN_ON(cookie != cfg_cookie); +} + +static struct iommu_gather_ops dummy_tlb_ops __initdata = { + .tlb_flush_all = dummy_tlb_flush_all, + .tlb_add_flush = dummy_tlb_add_flush, + .tlb_sync = dummy_tlb_sync, + .flush_pgtable = dummy_flush_pgtable, +}; + +static void __init arm_lpae_dump_ops(struct io_pgtable_ops *ops) +{ + struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops); + struct io_pgtable_cfg *cfg = &data->iop.cfg; + + pr_err("cfg: pgsize_bitmap 0x%lx, ias %u-bit\n", + cfg->pgsize_bitmap, cfg->ias); + pr_err("data: %d levels, 0x%zx pgd_size, %lu pg_shift, %lu bits_per_level, pgd @ %p\n", + data->levels, data->pgd_size, data->pg_shift, + data->bits_per_level, data->pgd); +} + +#define __FAIL(ops, i) ({ \ + WARN(1, "selftest: test failed for fmt idx %d\n", (i)); \ + arm_lpae_dump_ops(ops); \ + selftest_running = false; \ + -EFAULT; \ +}) + +static int __init arm_lpae_run_tests(struct io_pgtable_cfg *cfg) +{ + static const enum io_pgtable_fmt fmts[] = { + ARM_64_LPAE_S1, + ARM_64_LPAE_S2, + }; + + int i, j; + unsigned long iova; + size_t size; + struct io_pgtable_ops *ops; + + selftest_running = true; + + for (i = 0; i < ARRAY_SIZE(fmts); ++i) { + cfg_cookie = cfg; + ops = alloc_io_pgtable_ops(fmts[i], cfg, cfg); + if (!ops) { + pr_err("selftest: failed to allocate io pgtable ops\n"); + return -ENOMEM; + } + + /* + * Initial sanity checks. + * Empty page tables shouldn't provide any translations. + */ + if (ops->iova_to_phys(ops, 42)) + return __FAIL(ops, i); + + if (ops->iova_to_phys(ops, SZ_1G + 42)) + return __FAIL(ops, i); + + if (ops->iova_to_phys(ops, SZ_2G + 42)) + return __FAIL(ops, i); + + /* + * Distinct mappings of different granule sizes. + */ + iova = 0; + j = find_first_bit(&cfg->pgsize_bitmap, BITS_PER_LONG); + while (j != BITS_PER_LONG) { + size = 1UL << j; + + if (ops->map(ops, iova, iova, size, IOMMU_READ | + IOMMU_WRITE | + IOMMU_NOEXEC | + IOMMU_CACHE)) + return __FAIL(ops, i); + + /* Overlapping mappings */ + if (!ops->map(ops, iova, iova + size, size, + IOMMU_READ | IOMMU_NOEXEC)) + return __FAIL(ops, i); + + if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) + return __FAIL(ops, i); + + iova += SZ_1G; + j++; + j = find_next_bit(&cfg->pgsize_bitmap, BITS_PER_LONG, j); + } + + /* Partial unmap */ + size = 1UL << __ffs(cfg->pgsize_bitmap); + if (ops->unmap(ops, SZ_1G + size, size) != size) + return __FAIL(ops, i); + + /* Remap of partial unmap */ + if (ops->map(ops, SZ_1G + size, size, size, IOMMU_READ)) + return __FAIL(ops, i); + + if (ops->iova_to_phys(ops, SZ_1G + size + 42) != (size + 42)) + return __FAIL(ops, i); + + /* Full unmap */ + iova = 0; + j = find_first_bit(&cfg->pgsize_bitmap, BITS_PER_LONG); + while (j != BITS_PER_LONG) { + size = 1UL << j; + + if (ops->unmap(ops, iova, size) != size) + return __FAIL(ops, i); + + if (ops->iova_to_phys(ops, iova + 42)) + return __FAIL(ops, i); + + /* Remap full block */ + if (ops->map(ops, iova, iova, size, IOMMU_WRITE)) + return __FAIL(ops, i); + + if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) + return __FAIL(ops, i); + + iova += SZ_1G; + j++; + j = find_next_bit(&cfg->pgsize_bitmap, BITS_PER_LONG, j); + } + + free_io_pgtable_ops(ops); + } + + selftest_running = false; + return 0; +} + +static int __init arm_lpae_do_selftests(void) +{ + static const unsigned long pgsize[] = { + SZ_4K | SZ_2M | SZ_1G, + SZ_16K | SZ_32M, + SZ_64K | SZ_512M, + }; + + static const unsigned int ias[] = { + 32, 36, 40, 42, 44, 48, + }; + + int i, j, pass = 0, fail = 0; + struct io_pgtable_cfg cfg = { + .tlb = &dummy_tlb_ops, + .oas = 48, + }; + + for (i = 0; i < ARRAY_SIZE(pgsize); ++i) { + for (j = 0; j < ARRAY_SIZE(ias); ++j) { + cfg.pgsize_bitmap = pgsize[i]; + cfg.ias = ias[j]; + pr_info("selftest: pgsize_bitmap 0x%08lx, IAS %u\n", + pgsize[i], ias[j]); + if (arm_lpae_run_tests(&cfg)) + fail++; + else + pass++; + } + } + + pr_info("selftest: completed with %d PASS %d FAIL\n", pass, fail); + return fail ? -EFAULT : 0; +} +subsys_initcall(arm_lpae_do_selftests); +#endif