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.l...@gmail.com>
---
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 2f5dd6310a8f..2674f763f5db 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
