[RFC/RFT PATCH 6/6] riscv: Add numa support for riscv64 platform

From: Atish Patra
Date: Fri Aug 14 2020 - 17:48:49 EST

Use the generic numa implementation to add NUMA support for RISC-V.
This is based on Greentime's patch[1] but modified to use generic NUMA
implementation and few more fixes.

[1] https://lkml.org/lkml/2020/1/10/233

Co-developed-by: Greentime Hu <greentime.hu@xxxxxxxxxx>
Signed-off-by: Greentime Hu <greentime.hu@xxxxxxxxxx>
Signed-off-by: Atish Patra <atish.patra@xxxxxxx>
---
arch/riscv/Kconfig | 31 ++++++++++++++++++++++++++++++-
arch/riscv/include/asm/mmzone.h | 13 +++++++++++++
arch/riscv/include/asm/numa.h | 8 ++++++++
arch/riscv/include/asm/pci.h | 10 ++++++++++
arch/riscv/kernel/setup.c | 10 ++++++++--
arch/riscv/kernel/smpboot.c | 12 +++++++++++-
arch/riscv/mm/init.c | 4 +++-
7 files changed, 83 insertions(+), 5 deletions(-)
create mode 100644 arch/riscv/include/asm/mmzone.h
create mode 100644 arch/riscv/include/asm/numa.h

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 7b5905529146..4bd67f94aaac 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -137,7 +137,7 @@ config PAGE_OFFSET
default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB

config ARCH_FLATMEM_ENABLE
- def_bool y
+ def_bool !NUMA

config ARCH_SPARSEMEM_ENABLE
def_bool y
@@ -295,6 +295,35 @@ config TUNE_GENERIC

endchoice

+# Common NUMA Features
+config NUMA
+ bool "Numa Memory Allocation and Scheduler Support"
+ select GENERIC_ARCH_NUMA
+ select OF_NUMA
+ select ARCH_SUPPORTS_NUMA_BALANCING
+ help
+ Enable NUMA (Non-Uniform Memory Access) support.
+
+ The kernel will try to allocate memory used by a CPU on the
+ local memory of the CPU and add some more NUMA awareness to the kernel.
+
+config NODES_SHIFT
+ int "Maximum NUMA Nodes (as a power of 2)"
+ range 1 10
+ default "2"
+ depends on NEED_MULTIPLE_NODES
+ help
+ Specify the maximum number of NUMA Nodes available on the target
+ system. Increases memory reserved to accommodate various tables.
+
+config USE_PERCPU_NUMA_NODE_ID
+ def_bool y
+ depends on NUMA
+
+config NEED_PER_CPU_EMBED_FIRST_CHUNK
+ def_bool y
+ depends on NUMA
+
config RISCV_ISA_C
bool "Emit compressed instructions when building Linux"
default y
diff --git a/arch/riscv/include/asm/mmzone.h b/arch/riscv/include/asm/mmzone.h
new file mode 100644
index 000000000000..fa17e01d9ab2
--- /dev/null
+++ b/arch/riscv/include/asm/mmzone.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_MMZONE_H
+#define __ASM_MMZONE_H
+
+#ifdef CONFIG_NUMA
+
+#include <asm/numa.h>
+
+extern struct pglist_data *node_data[];
+#define NODE_DATA(nid) (node_data[(nid)])
+
+#endif /* CONFIG_NUMA */
+#endif /* __ASM_MMZONE_H */
diff --git a/arch/riscv/include/asm/numa.h b/arch/riscv/include/asm/numa.h
new file mode 100644
index 000000000000..8c8cf4297cc3
--- /dev/null
+++ b/arch/riscv/include/asm/numa.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_NUMA_H
+#define __ASM_NUMA_H
+
+#include <asm/topology.h>
+#include <asm-generic/numa.h>
+
+#endif /* __ASM_NUMA_H */
diff --git a/arch/riscv/include/asm/pci.h b/arch/riscv/include/asm/pci.h
index 1c473a1bd986..d6a0e59638c0 100644
--- a/arch/riscv/include/asm/pci.h
+++ b/arch/riscv/include/asm/pci.h
@@ -32,6 +32,16 @@ static inline int pci_proc_domain(struct pci_bus *bus)
/* always show the domain in /proc */
return 1;
}
+
+#ifdef CONFIG_NUMA
+int pcibus_to_node(struct pci_bus *bus);
+#ifndef cpumask_of_pcibus
+#define cpumask_of_pcibus(bus) (pcibus_to_node(bus) == -1 ? \
+ cpu_all_mask : \
+ cpumask_of_node(pcibus_to_node(bus)))
+#endif
+#endif /* CONFIG_NUMA */
+
#endif /* CONFIG_PCI */

#endif /* _ASM_RISCV_PCI_H */
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 32bb5a1bea05..1533ee5c6e56 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -104,13 +104,19 @@ void __init setup_arch(char **cmdline_p)

static int __init topology_init(void)
{
- int i;
+ int i, ret;
+
+ for_each_online_node(i)
+ register_one_node(i);

for_each_possible_cpu(i) {
struct cpu *cpu = &per_cpu(cpu_devices, i);

cpu->hotpluggable = cpu_has_hotplug(i);
- register_cpu(cpu, i);
+ ret = register_cpu(cpu, i);
+ if (unlikely(ret))
+ pr_warn("Warning: %s: register_cpu %d failed (%d)\n",
+ __func__, i, ret);
}

return 0;
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 356825a57551..4e9bdb6230de 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -28,6 +28,7 @@
#include <asm/cpu_ops.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
+#include <asm/numa.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/sbi.h>
@@ -46,13 +47,18 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
{
int cpuid;
int ret;
+ unsigned int curr_cpuid;
+
+ curr_cpuid = smp_processor_id();
+ numa_store_cpu_info(curr_cpuid);
+ numa_add_cpu(curr_cpuid);

/* This covers non-smp usecase mandated by "nosmp" option */
if (max_cpus == 0)
return;

for_each_possible_cpu(cpuid) {
- if (cpuid == smp_processor_id())
+ if (cpuid == curr_cpuid)
continue;
if (cpu_ops[cpuid]->cpu_prepare) {
ret = cpu_ops[cpuid]->cpu_prepare(cpuid);
@@ -60,6 +66,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
continue;
}
set_cpu_present(cpuid, true);
+ numa_store_cpu_info(cpuid);
}
}

@@ -80,6 +87,7 @@ void __init setup_smp(void)
if (hart == cpuid_to_hartid_map(0)) {
BUG_ON(found_boot_cpu);
found_boot_cpu = 1;
+ early_map_cpu_to_node(0, of_node_to_nid(dn));
continue;
}
if (cpuid >= NR_CPUS) {
@@ -89,6 +97,7 @@ void __init setup_smp(void)
}

cpuid_to_hartid_map(cpuid) = hart;
+ early_map_cpu_to_node(cpuid, of_node_to_nid(dn));
cpuid++;
}

@@ -155,6 +164,7 @@ asmlinkage __visible void smp_callin(void)
current->active_mm = mm;

notify_cpu_starting(curr_cpuid);
+ numa_add_cpu(curr_cpuid);
update_siblings_masks(curr_cpuid);
set_cpu_online(curr_cpuid, 1);

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index b8905ae2bbe7..d1f4e94626aa 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -20,6 +20,7 @@
#include <asm/soc.h>
#include <asm/io.h>
#include <asm/ptdump.h>
+#include <asm/numa.h>

#include "../kernel/head.h"

@@ -190,7 +191,6 @@ void __init setup_bootmem(void)

early_init_fdt_scan_reserved_mem();
memblock_allow_resize();
- memblock_dump_all();

for_each_memblock(memory, reg) {
unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
@@ -575,9 +575,11 @@ void __init paging_init(void)

void __init misc_mem_init(void)
{
+ arch_numa_init();
sparse_init();
zone_sizes_init();
resource_init();
+ memblock_dump_all();
}

#ifdef CONFIG_SPARSEMEM_VMEMMAP
--
2.24.0