linux-stable/arch/ia64/include/asm/numa.h
Matias Bjørling ef78e5ec92 ia64: export node_distance function
The numa_slit variable used by node_distance is available to a
module as long as it is linked at compile-time. However, it is
not available to loadable modules. Leading to errors such as:

  ERROR: "numa_slit" [drivers/nvme/host/nvme-core.ko] undefined!

The error above is caused by the nvme multipath code that makes
use of node_distance for its path calculation. When the patch was
added, the lightnvm subsystem would select nvme and always compile
it in, leading to the node_distance call to always succeed.
However, when this requirement was removed, nvme could be compiled
in as a module, which exposed this bug.

This patch extracts node_distance to a function and exports it.
Since ACPI is depending on node_distance being a simple lookup to
numa_slit, the previous behavior is exposed as slit_distance and its
users updated.

Fixes: f333444708 "nvme: take node locality into account when selecting a path"
Fixes: 73569e1103 "lightnvm: remove dependencies on BLK_DEV_NVME and PCI"
Signed-off-by: Matias Bjøring <mb@lightnvm.io>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-26 18:30:40 -08:00

83 lines
2.3 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* This file contains NUMA specific prototypes and definitions.
*
* 2002/08/05 Erich Focht <efocht@ess.nec.de>
*
*/
#ifndef _ASM_IA64_NUMA_H
#define _ASM_IA64_NUMA_H
#ifdef CONFIG_NUMA
#include <linux/cache.h>
#include <linux/cpumask.h>
#include <linux/numa.h>
#include <linux/smp.h>
#include <linux/threads.h>
#include <asm/mmzone.h>
extern u16 cpu_to_node_map[NR_CPUS] __cacheline_aligned;
extern cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned;
extern pg_data_t *pgdat_list[MAX_NUMNODES];
/* Stuff below this line could be architecture independent */
extern int num_node_memblks; /* total number of memory chunks */
/*
* List of node memory chunks. Filled when parsing SRAT table to
* obtain information about memory nodes.
*/
struct node_memblk_s {
unsigned long start_paddr;
unsigned long size;
int nid; /* which logical node contains this chunk? */
int bank; /* which mem bank on this node */
};
struct node_cpuid_s {
u16 phys_id; /* id << 8 | eid */
int nid; /* logical node containing this CPU */
};
extern struct node_memblk_s node_memblk[NR_NODE_MEMBLKS];
extern struct node_cpuid_s node_cpuid[NR_CPUS];
/*
* ACPI 2.0 SLIT (System Locality Information Table)
* http://devresource.hp.com/devresource/Docs/TechPapers/IA64/slit.pdf
*
* This is a matrix with "distances" between nodes, they should be
* proportional to the memory access latency ratios.
*/
extern u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
#define slit_distance(from,to) (numa_slit[(from) * MAX_NUMNODES + (to)])
extern int __node_distance(int from, int to);
#define node_distance(from,to) __node_distance(from, to)
extern int paddr_to_nid(unsigned long paddr);
#define local_nodeid (cpu_to_node_map[smp_processor_id()])
#define numa_off 0
extern void map_cpu_to_node(int cpu, int nid);
extern void unmap_cpu_from_node(int cpu, int nid);
extern void numa_clear_node(int cpu);
#else /* !CONFIG_NUMA */
#define map_cpu_to_node(cpu, nid) do{}while(0)
#define unmap_cpu_from_node(cpu, nid) do{}while(0)
#define paddr_to_nid(addr) 0
#define numa_clear_node(cpu) do { } while (0)
#endif /* CONFIG_NUMA */
#endif /* _ASM_IA64_NUMA_H */