Add hash_supports_debug_pagealloc() helper to detect whether debug_pagealloc can be supported on hash or not. This checks for both, whether debug_pagealloc config is enabled and the linear map should fit within rma_size/4 region size. This can then be used early during htab_init_page_sizes() to decide linear map pagesize if hash supports either debug_pagealloc or kfence. Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx> --- arch/powerpc/mm/book3s64/hash_utils.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index b6da25719e37..3ffc98b3deb1 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -329,25 +329,26 @@ static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long idx, } #endif +static inline bool hash_supports_debug_pagealloc(void) +{ + unsigned long max_hash_count = ppc64_rma_size / 4; + unsigned long linear_map_count = memblock_end_of_DRAM() >> PAGE_SHIFT; + + if (!debug_pagealloc_enabled() || linear_map_count > max_hash_count) + return false; + return true; +} + #ifdef CONFIG_DEBUG_PAGEALLOC static u8 *linear_map_hash_slots; static unsigned long linear_map_hash_count; static DEFINE_RAW_SPINLOCK(linear_map_hash_lock); static void hash_debug_pagealloc_alloc_slots(void) { - unsigned long max_hash_count = ppc64_rma_size / 4; - - if (!debug_pagealloc_enabled()) - return; - linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT; - if (unlikely(linear_map_hash_count > max_hash_count)) { - pr_info("linear map size (%llu) greater than 4 times RMA region (%llu). Disabling debug_pagealloc\n", - ((u64)linear_map_hash_count << PAGE_SHIFT), - ppc64_rma_size); - linear_map_hash_count = 0; + if (!hash_supports_debug_pagealloc()) return; - } + linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT; linear_map_hash_slots = memblock_alloc_try_nid( linear_map_hash_count, 1, MEMBLOCK_LOW_LIMIT, ppc64_rma_size, NUMA_NO_NODE); @@ -1076,7 +1077,7 @@ static void __init htab_init_page_sizes(void) bool aligned = true; init_hpte_page_sizes(); - if (!debug_pagealloc_enabled() && !kfence_early_init_enabled()) { + if (!hash_supports_debug_pagealloc() && !kfence_early_init_enabled()) { /* * Pick a size for the linear mapping. Currently, we only * support 16M, 1M and 4K which is the default -- 2.46.0