4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: mike.travis@xxxxxxx <mike.travis@xxxxxxx> commit f642fb5864a6e3645edce6f85ffe7b44d5e9b990 upstream. Add a new function to "adjust" the current fixed UV memory block size of 2GB so it can be changed to a different physical boundary. This is out of necessity so arch dependent code can accommodate specific BIOS requirements which can align these new PMEM modules at less than the default boundaries. A "set order" type of function was used to insure that the memory block size will be a power of two value without requiring a validity check. 64GB was chosen as the upper limit for memory block size values to accommodate upcoming 4PB systems which have 6 more bits of physical address space (46 becoming 52). Signed-off-by: Mike Travis <mike.travis@xxxxxxx> Reviewed-by: Andrew Banman <andrew.banman@xxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Dimitri Sivanich <dimitri.sivanich@xxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Russ Anderson <russ.anderson@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: dan.j.williams@xxxxxxxxx Cc: jgross@xxxxxxxx Cc: kirill.shutemov@xxxxxxxxxxxxxxx Cc: mhocko@xxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Link: https://lkml.kernel.org/lkml/20180524201711.609546602@xxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/mm/init_64.c | 20 ++++++++++++++++---- include/linux/memory.h | 1 + 2 files changed, 17 insertions(+), 4 deletions(-) --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1350,16 +1350,28 @@ int kern_addr_valid(unsigned long addr) /* Amount of ram needed to start using large blocks */ #define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30) +/* Adjustable memory block size */ +static unsigned long set_memory_block_size; +int __init set_memory_block_size_order(unsigned int order) +{ + unsigned long size = 1UL << order; + + if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE) + return -EINVAL; + + set_memory_block_size = size; + return 0; +} + static unsigned long probe_memory_block_size(void) { unsigned long boot_mem_end = max_pfn << PAGE_SHIFT; unsigned long bz; - /* If this is UV system, always set 2G block size */ - if (is_uv_system()) { - bz = MAX_BLOCK_SIZE; + /* If memory block size has been set, then use it */ + bz = set_memory_block_size; + if (bz) goto done; - } /* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */ if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) { --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -38,6 +38,7 @@ struct memory_block { int arch_get_memory_phys_device(unsigned long start_pfn); unsigned long memory_block_size_bytes(void); +int set_memory_block_size_order(unsigned int order); /* These states are exposed to userspace as text strings in sysfs */ #define MEM_ONLINE (1<<0) /* exposed to userspace */
