From: Shaoqin Huang <shaoqin.huang@xxxxxxxxx> Reserve 129th region in the memblock, and this will trigger the memblock_double_array() function, this needs valid memory regions. So using dummy_physical_memory_init() to allocate a valid memory region. At the same time, reserve 128 faked memory region, and make sure these reserved region not intersect with the valid memory region. So memblock_double_array() will choose the valid memory region, and it will success. Also need to restore the reserved.regions after memblock_double_array(), to make sure the subsequent tests can run as normal. Signed-off-by: Shaoqin Huang <shaoqin.huang@xxxxxxxxx> --- tools/testing/memblock/tests/basic_api.c | 90 ++++++++++++++++++++++++ 1 file changed, 90 insertions(+) diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c index 7120fd8e47b1..1924524ad868 100644 --- a/tools/testing/memblock/tests/basic_api.c +++ b/tools/testing/memblock/tests/basic_api.c @@ -895,6 +895,95 @@ static int memblock_reserve_near_max_check(void) return 0; } +/* + * A test that trying to reserve the 129th memory block. + * Expect to trigger memblock_double_array() to double the + * memblock.memory.max, find a new valid memory as + * reserved.regions. + */ +static int memblock_reserve_many_check(void) +{ + int i; + void *orig_region; + struct region r = { + .base = SZ_16K, + .size = MEM_SIZE, + }; + phys_addr_t memory_base = SZ_128K; + phys_addr_t new_reserved_regions_size; + + PREFIX_PUSH(); + + reset_memblock_regions(); + memblock_allow_resize(); + + /* Add a valid memory region used by double_array(). */ + dummy_physical_memory_init(); + memblock_add(dummy_physical_memory_base(), MEM_SIZE); + + for (i = 0; i < INIT_MEMBLOCK_REGIONS; i++) { + /* Reserve some fakes memory region to fulfill the memblock. */ + memblock_reserve(memory_base, MEM_SIZE); + + ASSERT_EQ(memblock.reserved.cnt, i + 1); + ASSERT_EQ(memblock.reserved.total_size, (i + 1) * MEM_SIZE); + + /* Keep the gap so these memory region will not be merged. */ + memory_base += MEM_SIZE * 2; + } + + orig_region = memblock.reserved.regions; + + /* This reserve the 129 memory_region, and makes it double array. */ + memblock_reserve(memory_base, MEM_SIZE); + + /* + * This is the memory region size used by the doubled reserved.regions, + * and it has been reserved due to it has been used. The size is used to + * calculate the total_size that the memblock.reserved have now. + */ + new_reserved_regions_size = PAGE_ALIGN((INIT_MEMBLOCK_REGIONS * 2) * + sizeof(struct memblock_region)); + /* + * The double_array() will find a free memory region as the new + * reserved.regions, and the used memory region will be reserved, so + * there will be one more region exist in the reserved memblock. And the + * one more reserved region's size is new_reserved_regions_size. + */ + ASSERT_EQ(memblock.reserved.cnt, INIT_MEMBLOCK_REGIONS + 2); + ASSERT_EQ(memblock.reserved.total_size, (INIT_MEMBLOCK_REGIONS + 1) * MEM_SIZE + + new_reserved_regions_size); + ASSERT_EQ(memblock.reserved.max, INIT_MEMBLOCK_REGIONS * 2); + + /* + * Now memblock_double_array() works fine. Let's check after the + * double_array(), the memblock_reserve() still works as normal. + */ + memblock_reserve(r.base, r.size); + ASSERT_EQ(memblock.reserved.regions[0].base, r.base); + ASSERT_EQ(memblock.reserved.regions[0].size, r.size); + + ASSERT_EQ(memblock.reserved.cnt, INIT_MEMBLOCK_REGIONS + 3); + ASSERT_EQ(memblock.reserved.total_size, (INIT_MEMBLOCK_REGIONS + 2) * MEM_SIZE + + new_reserved_regions_size); + ASSERT_EQ(memblock.reserved.max, INIT_MEMBLOCK_REGIONS * 2); + + dummy_physical_memory_cleanup(); + + /* + * The current reserved.regions is occupying a range of memory that + * allocated from dummy_physical_memory_init(). After free the memory, + * we must not use it. So restore the origin memory region to make sure + * the tests can run as normal and not affected by the double array. + */ + memblock.reserved.regions = orig_region; + memblock.reserved.cnt = INIT_MEMBLOCK_REGIONS; + + test_pass_pop(); + + return 0; +} + static int memblock_reserve_checks(void) { prefix_reset(); @@ -909,6 +998,7 @@ static int memblock_reserve_checks(void) memblock_reserve_twice_check(); memblock_reserve_between_check(); memblock_reserve_near_max_check(); + memblock_reserve_many_check(); prefix_pop(); -- 2.34.1