Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f642fb58 authored by mike.travis@hpe.com's avatar mike.travis@hpe.com Committed by Ingo Molnar
Browse files

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: default avatarMike Travis <mike.travis@hpe.com>
Reviewed-by: default avatarAndrew 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: default avatarIngo 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 */