[PATCH v2 3/5] iommu: add self-consistency tests to ARM LPAE IO page table allocator
Will Deacon
will.deacon at arm.com
Fri Jan 9 05:54:15 PST 2015
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 <will.deacon at arm.com>
---
drivers/iommu/Kconfig | 9 ++
drivers/iommu/io-pgtable-arm.c | 200 ++++++++++++++++++++++++++++++++++++++++-
2 files changed, 208 insertions(+), 1 deletion(-)
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
--
2.1.4
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