We will parse NUMA nodes distances from device tree or ACPI table. So we need a matrix to record the distances between any two nodes we parsed. Accordingly, we provide this node_set_distance API for device tree or ACPI table parsers to set the distance for any two nodes in this patch. When NUMA initialization failed, __node_distance will return NUMA_REMOTE_DISTANCE, this will help us avoid doing rollback for distance maxtrix when NUMA initialization failed.
Signed-off-by: Wei Chen <wei.c...@arm.com> --- xen/arch/arm/Makefile | 1 + xen/arch/arm/numa.c | 69 ++++++++++++++++++++++++++++++++++++++ xen/include/asm-arm/numa.h | 13 +++++++ 3 files changed, 83 insertions(+) create mode 100644 xen/arch/arm/numa.c diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index ae4efbf76e..41ca311b6b 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -35,6 +35,7 @@ obj-$(CONFIG_LIVEPATCH) += livepatch.o obj-y += mem_access.o obj-y += mm.o obj-y += monitor.o +obj-$(CONFIG_NUMA) += numa.o obj-y += p2m.o obj-y += percpu.o obj-y += platform.o diff --git a/xen/arch/arm/numa.c b/xen/arch/arm/numa.c new file mode 100644 index 0000000000..3f08870d69 --- /dev/null +++ b/xen/arch/arm/numa.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Arm Architecture support layer for NUMA. + * + * Copyright (C) 2021 Arm Ltd + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ +#include <xen/init.h> +#include <xen/numa.h> + +static uint8_t __read_mostly +node_distance_map[MAX_NUMNODES][MAX_NUMNODES] = { + { 0 } +}; + +void __init numa_set_distance(nodeid_t from, nodeid_t to, uint32_t distance) +{ + if ( from >= MAX_NUMNODES || to >= MAX_NUMNODES ) + { + printk(KERN_WARNING + "NUMA: invalid nodes: from=%"PRIu8" to=%"PRIu8" MAX=%"PRIu8"\n", + from, to, MAX_NUMNODES); + return; + } + + /* NUMA defines 0xff as an unreachable node and 0-9 are undefined */ + if ( distance >= NUMA_NO_DISTANCE || + (distance >= NUMA_DISTANCE_UDF_MIN && + distance <= NUMA_DISTANCE_UDF_MAX) || + (from == to && distance != NUMA_LOCAL_DISTANCE) ) + { + printk(KERN_WARNING + "NUMA: invalid distance: from=%"PRIu8" to=%"PRIu8" distance=%"PRIu32"\n", + from, to, distance); + return; + } + + node_distance_map[from][to] = distance; +} + +uint8_t __node_distance(nodeid_t from, nodeid_t to) +{ + /* When NUMA is off, any distance will be treated as remote. */ + if ( srat_disabled() ) + return NUMA_REMOTE_DISTANCE; + + /* + * Check whether the nodes are in the matrix range. + * When any node is out of range, except from and to nodes are the + * same, we treat them as unreachable (return 0xFF) + */ + if ( from >= MAX_NUMNODES || to >= MAX_NUMNODES ) + return from == to ? NUMA_LOCAL_DISTANCE : NUMA_NO_DISTANCE; + + return node_distance_map[from][to]; +} +EXPORT_SYMBOL(__node_distance); diff --git a/xen/include/asm-arm/numa.h b/xen/include/asm-arm/numa.h index 21569e634b..758eafeb05 100644 --- a/xen/include/asm-arm/numa.h +++ b/xen/include/asm-arm/numa.h @@ -9,8 +9,21 @@ typedef u8 nodeid_t; #ifdef CONFIG_NUMA +/* + * In ACPI spec, 0-9 are the reserved values for node distance, + * 10 indicates local node distance, 20 indicates remote node + * distance. Set node distance map in device tree will follow + * the ACPI's definition. + */ +#define NUMA_DISTANCE_UDF_MIN 0 +#define NUMA_DISTANCE_UDF_MAX 9 +#define NUMA_LOCAL_DISTANCE 10 +#define NUMA_REMOTE_DISTANCE 20 + #define NR_NODE_MEMBLKS NR_MEM_BANKS +extern void numa_set_distance(nodeid_t from, nodeid_t to, uint32_t distance); + #else /* Fake one node for now. See also node_online_map. */ -- 2.25.1
