When parsing CFMWS, we need to know the current block size expected to avoid accidentally adjusting the size upward. This causes a value to be cached in a static global. Update the static global if the value is subsequently updated. Print a warning that this has occurred for debugging purposes if blocksize is changed at an unexpected time. Signed-off-by: Gregory Price <gourry@xxxxxxxxxx> --- arch/x86/mm/init_64.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index ff253648706f..0db7ce11e5c5 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1424,6 +1424,7 @@ void mark_rodata_ro(void) /* Adjustable memory block size */ static unsigned long set_memory_block_size; +static unsigned long memory_block_size_probed; int __init set_memory_block_size_order(unsigned int order) { unsigned long size = 1UL << order; @@ -1432,6 +1433,19 @@ int __init set_memory_block_size_order(unsigned int order) return -EINVAL; set_memory_block_size = size; + + /* + * If the block size has already been probed, we need to change it. + * This can happen during ACPI/CFMWS parsing, since it needs to + * probe the system for the existing block size to avoid increasing + * the block size if lower memory happens to be misaligned + */ + if (memory_block_size_probed) { + memory_block_size_probed = size; + pr_warn("x86/mm: Memory block size changed: %ldMB\n", + size >> 20); + } + return 0; } @@ -1471,7 +1485,6 @@ static unsigned long probe_memory_block_size(void) return bz; } -static unsigned long memory_block_size_probed; unsigned long memory_block_size_bytes(void) { if (!memory_block_size_probed) -- 2.43.0