Commit f642fb58 authored May 24, 2018 by mike.travis@hpe.com Committed by Ingo Molnar Jun 21, 2018

x86/platform/UV: Add adjustable set memory block size function



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@hpe.com>
Reviewed-by: Andrew Banman <andrew.banman@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dan.j.williams@intel.com
Cc: jgross@suse.com
Cc: kirill.shutemov@linux.intel.com
Cc: mhocko@suse.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/lkml/20180524201711.609546602@stormcage.americas.sgi.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent d6605b6b

arch/x86/mm/init_64.c

+16 −4

Original line number	Diff line number	Diff line
		@@ -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) {

include/linux/memory.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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 */

Admin message