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ef78e5ec92
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>
112 lines
2.9 KiB
C
112 lines
2.9 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* This file contains NUMA specific variables and functions which can
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* be split away from DISCONTIGMEM and are used on NUMA machines with
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* contiguous memory.
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*
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* 2002/08/07 Erich Focht <efocht@ess.nec.de>
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*/
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#include <linux/cpu.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/node.h>
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#include <linux/init.h>
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#include <linux/memblock.h>
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#include <linux/module.h>
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#include <asm/mmzone.h>
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#include <asm/numa.h>
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/*
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* The following structures are usually initialized by ACPI or
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* similar mechanisms and describe the NUMA characteristics of the machine.
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*/
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int num_node_memblks;
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struct node_memblk_s node_memblk[NR_NODE_MEMBLKS];
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struct node_cpuid_s node_cpuid[NR_CPUS] =
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{ [0 ... NR_CPUS-1] = { .phys_id = 0, .nid = NUMA_NO_NODE } };
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/*
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* This is a matrix with "distances" between nodes, they should be
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* proportional to the memory access latency ratios.
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*/
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u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
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int __node_distance(int from, int to)
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{
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return slit_distance(from, to);
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}
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EXPORT_SYMBOL(__node_distance);
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/* Identify which cnode a physical address resides on */
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int
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paddr_to_nid(unsigned long paddr)
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{
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int i;
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for (i = 0; i < num_node_memblks; i++)
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if (paddr >= node_memblk[i].start_paddr &&
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paddr < node_memblk[i].start_paddr + node_memblk[i].size)
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break;
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return (i < num_node_memblks) ? node_memblk[i].nid : (num_node_memblks ? -1 : 0);
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}
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#if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
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/*
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* Because of holes evaluate on section limits.
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* If the section of memory exists, then return the node where the section
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* resides. Otherwise return node 0 as the default. This is used by
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* SPARSEMEM to allocate the SPARSEMEM sectionmap on the NUMA node where
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* the section resides.
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*/
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int __meminit __early_pfn_to_nid(unsigned long pfn,
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struct mminit_pfnnid_cache *state)
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{
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int i, section = pfn >> PFN_SECTION_SHIFT, ssec, esec;
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if (section >= state->last_start && section < state->last_end)
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return state->last_nid;
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for (i = 0; i < num_node_memblks; i++) {
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ssec = node_memblk[i].start_paddr >> PA_SECTION_SHIFT;
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esec = (node_memblk[i].start_paddr + node_memblk[i].size +
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((1L << PA_SECTION_SHIFT) - 1)) >> PA_SECTION_SHIFT;
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if (section >= ssec && section < esec) {
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state->last_start = ssec;
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state->last_end = esec;
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state->last_nid = node_memblk[i].nid;
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return node_memblk[i].nid;
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}
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}
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return -1;
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}
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void numa_clear_node(int cpu)
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{
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unmap_cpu_from_node(cpu, NUMA_NO_NODE);
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}
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#ifdef CONFIG_MEMORY_HOTPLUG
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/*
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* SRAT information is stored in node_memblk[], then we can use SRAT
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* information at memory-hot-add if necessary.
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*/
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int memory_add_physaddr_to_nid(u64 addr)
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{
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int nid = paddr_to_nid(addr);
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if (nid < 0)
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return 0;
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return nid;
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}
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EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
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#endif
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#endif
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