arch/arm64/mmu: allow partial unmap of block mappings again (6255bf1e) · Commits · Wenxi XU / zephyr

arch/arm64/core/mmu.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -373,6 +373,11 @@ static void del_mapping(uint64_t *table, uintptr_t virt, size_t size,
		continue;
		}

		if (step != level_size && is_block_desc(*pte)) {
		/* need to split this block mapping */
		expand_to_table(pte, level);
		}

		if (is_table_desc(*pte, level)) {
		subtable = pte_desc_table(*pte);
		del_mapping(subtable, virt, step, level + 1);
		@@ -380,12 +385,6 @@ static void del_mapping(uint64_t *table, uintptr_t virt, size_t size,
		continue;
		}
		dec_table_ref(subtable);
		} else {
		/*
		* We assume that block mappings will be unmapped
		* as a whole and not partially.
		*/
		__ASSERT(step == level_size, "");
		}

		/* free this entry */

tests/arch/arm64/arm64_mmu/src/main.c

+69 −2

Original line number	Diff line number	Diff line
		@@ -61,7 +61,7 @@ static int mem_map_test(uintptr_t virt_addr, uintptr_t phys_addr, size_t size)
		zassert_true(mapped_nb_free_tables < initial_nb_free_tables,
		"%d vs %d", mapped_nb_free_tables, initial_nb_free_tables);
		zassert_true(mapped_tables_usage > initial_tables_usage,
		"%#x vs %#x", mapped_tables_usage > initial_tables_usage);
		"%#x vs %#x", mapped_tables_usage, initial_tables_usage);

		arch_mem_unmap((void *)virt_addr, size);

		@@ -75,7 +75,7 @@ static int mem_map_test(uintptr_t virt_addr, uintptr_t phys_addr, size_t size)
		zassert_true(unmapped_nb_free_tables == initial_nb_free_tables,
		"%d vs %d", unmapped_nb_free_tables, initial_nb_free_tables);
		zassert_true(unmapped_tables_usage == initial_tables_usage,
		"%#x vs %#x", unmapped_tables_usage > initial_tables_usage);
		"%#x vs %#x", unmapped_tables_usage, initial_tables_usage);

		int tables_used = unmapped_nb_free_tables - mapped_nb_free_tables;
		return tables_used;
		@@ -151,4 +151,71 @@ ZTEST(arm64_mmu, test_arm64_mmu_04_page_and_block)
		zassert_true(tables_used == 2, "used %d tables", tables_used);
		}

		ZTEST(arm64_mmu, test_arm64_mmu_05_hole_in_block)
		{
		/*
		* Create a block mapping.
		*/
		int table_entries = CONFIG_MMU_PAGE_SIZE / sizeof(uint64_t);
		size_t block_size = table_entries * CONFIG_MMU_PAGE_SIZE;
		uintptr_t virt = TEST_VIRT_ADDR & ~(block_size - 1);
		uintptr_t phys = TEST_PHYS_ADDR & ~(block_size - 1);
		size_t size = block_size;

		arch_mem_map((void *)virt, phys, size, K_MEM_ARM_NORMAL_NC);

		int mapped_nb_free_tables = arm64_mmu_nb_free_tables();
		int mapped_tables_usage = arm64_mmu_tables_total_usage();

		TC_PRINT(" After arch_mem_map:\n");
		TC_PRINT(" current free tables: %d\n", mapped_nb_free_tables);
		TC_PRINT(" current total table usage: %#x\n", mapped_tables_usage);

		zassert_true(mapped_nb_free_tables < initial_nb_free_tables,
		"%d vs %d", mapped_nb_free_tables, initial_nb_free_tables);
		zassert_true(mapped_tables_usage > initial_tables_usage,
		"%#x vs %#x", mapped_tables_usage, initial_tables_usage);

		/*
		* Now poke a hole in the middle of this block mapping, effectively
		* splitting it in two disjoint sub-mappings.
		*/
		arch_mem_unmap((void *)(virt + CONFIG_MMU_PAGE_SIZE), CONFIG_MMU_PAGE_SIZE);

		int split_nb_free_tables = arm64_mmu_nb_free_tables();
		int split_tables_usage = arm64_mmu_tables_total_usage();

		TC_PRINT(" After first arch_mem_unmap:\n");
		TC_PRINT(" current free tables: %d\n", split_nb_free_tables);
		TC_PRINT(" current total table usage: %#x\n", split_tables_usage);

		zassert_true(split_nb_free_tables < mapped_nb_free_tables,
		"%d vs %d", split_nb_free_tables, mapped_nb_free_tables);
		zassert_true(split_tables_usage > mapped_tables_usage,
		"%#x vs %#x", split_tables_usage, mapped_tables_usage);

		/*
		* Make sure the hole is actually freed.
		*/
		zassert_true(arch_page_phys_get((void *)(virt + CONFIG_MMU_PAGE_SIZE), NULL)
		== -EFAULT, "");

		/*
		* Then free it all.
		*/
		arch_mem_unmap((void *)virt, size);

		int unmapped_nb_free_tables = arm64_mmu_nb_free_tables();
		int unmapped_tables_usage = arm64_mmu_tables_total_usage();

		TC_PRINT(" After second arch_mem_unmap:\n");
		TC_PRINT(" current free tables: %d\n", unmapped_nb_free_tables);
		TC_PRINT(" current total table usage: %#x\n", unmapped_tables_usage);

		zassert_true(unmapped_nb_free_tables == initial_nb_free_tables,
		"%d vs %d", unmapped_nb_free_tables, initial_nb_free_tables);
		zassert_true(unmapped_tables_usage == initial_tables_usage,
		"%#x vs %#x", unmapped_tables_usage, initial_tables_usage);
		}

		ZTEST_SUITE(arm64_mmu, NULL, arm64_mmu_test_init, NULL, NULL, NULL);

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