[PATCH v12 0/5] arm64, numa: Add numa support for arm64 platforms

From: Ard Biesheuvel <***@linaro.org>

There are two problems with the UEFI stub DT memory node removal
routine:
- it deletes nodes as it traverses the tree, which happens to work
but is not supported, as deletion invalidates the node iterator;
- deleting memory nodes entirely may discard annotations in the form
of additional properties on the nodes.

Since the discovery of DT memory nodes occurs strictly before the
UEFI init sequence, we can simply clear the memblock memory table
before parsing the UEFI memory map. This way, it is no longer
necessary to remove the nodes, so we can remove that logic from the
stub as well.

Signed-off-by: Ard Biesheuvel <***@linaro.org>
Signed-off-by: David Daney <***@cavium.com>
---
drivers/firmware/efi/arm-init.c | 8 ++++++++
drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
2 files changed, 9 insertions(+), 23 deletions(-)

diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index 9e15d57..40c9d85 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -143,6 +143,14 @@ static __init void reserve_regions(void)
if (efi_enabled(EFI_DBG))
pr_info("Processing EFI memory map:\n");

+ /*
+ * Discard memblocks discovered so far: if there are any at this
+ * point, they originate from memory nodes in the DT, and UEFI
+ * uses its own memory map instead.
+ */
+ memblock_dump_all();
+ memblock_remove(0, ULLONG_MAX);
+
for_each_efi_memory_desc(&memmap, md) {
paddr = md->phys_addr;
npages = md->num_pages;
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index cf7b7d4..9df1560 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -24,7 +24,7 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
unsigned long map_size, unsigned long desc_size,
u32 desc_ver)
{
- int node, prev, num_rsv;
+ int node, num_rsv;
int status;
u32 fdt_val32;
u64 fdt_val64;
@@ -54,28 +54,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
goto fdt_set_fail;

/*
- * Delete any memory nodes present. We must delete nodes which
- * early_init_dt_scan_memory may try to use.
- */
- prev = 0;
- for (;;) {
- const char *type;
- int len;
-
- node = fdt_next_node(fdt, prev, NULL);
- if (node < 0)
- break;
-
- type = fdt_getprop(fdt, node, "device_type", &len);
- if (type && strncmp(type, "memory", len) == 0) {
- fdt_del_node(fdt, node);
- continue;
- }
-
- prev = node;
- }
-
- /*
* Delete all memory reserve map entries. When booting via UEFI,
* kernel will use the UEFI memory map to find reserved regions.
*/

--
1.8.3.1

Mark Rutland

2016-02-23 11:58:21 UTC

Hi,

Post by David Daney
There are two problems with the UEFI stub DT memory node removal
- it deletes nodes as it traverses the tree, which happens to work
but is not supported, as deletion invalidates the node iterator;
- deleting memory nodes entirely may discard annotations in the form
of additional properties on the nodes.
Since the discovery of DT memory nodes occurs strictly before the
UEFI init sequence, we can simply clear the memblock memory table
before parsing the UEFI memory map. This way, it is no longer
necessary to remove the nodes, so we can remove that logic from the
stub as well.

This is a little bit scary, but I guess this works.

My only concern is that when we get kexec, a subsequent kernel must also
have EFI memory map support, or things go bad for the next EFI-aware
kernel after that (as things like the runtime services may have been
corrupted by the kernel in the middle). It's difficult to fix the
general case later.

A different option would be to support status="disabled" for the memory
nodes, and ignore these in early_init_dt_scan_memory. That way a kernel
cannot use memory without first having parsed the EFI memory map, and we
can still get NUMA info from the disabled nodes.

You'd still need a new kernel to take into account status, but at least
we'd know all kernels would avoid using RAM that potentially needs to be
preserved.

Ard, Rob, thoughts?

Mark.

Post by David Daney
---
drivers/firmware/efi/arm-init.c | 8 ++++++++
drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
2 files changed, 9 insertions(+), 23 deletions(-)
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index 9e15d57..40c9d85 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -143,6 +143,14 @@ static __init void reserve_regions(void)
if (efi_enabled(EFI_DBG))
pr_info("Processing EFI memory map:\n");
+ /*
+ * Discard memblocks discovered so far: if there are any at this
+ * point, they originate from memory nodes in the DT, and UEFI
+ * uses its own memory map instead.
+ */
+ memblock_dump_all();
+ memblock_remove(0, ULLONG_MAX);
+
for_each_efi_memory_desc(&memmap, md) {
paddr = md->phys_addr;
npages = md->num_pages;
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index cf7b7d4..9df1560 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -24,7 +24,7 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
unsigned long map_size, unsigned long desc_size,
u32 desc_ver)
{
- int node, prev, num_rsv;
+ int node, num_rsv;
int status;
u32 fdt_val32;
u64 fdt_val64;
@@ -54,28 +54,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
goto fdt_set_fail;
/*
- * Delete any memory nodes present. We must delete nodes which
- * early_init_dt_scan_memory may try to use.
- */
- prev = 0;
- for (;;) {
- const char *type;
- int len;
-
- node = fdt_next_node(fdt, prev, NULL);
- if (node < 0)
- break;
-
- type = fdt_getprop(fdt, node, "device_type", &len);
- if (type && strncmp(type, "memory", len) == 0) {
- fdt_del_node(fdt, node);
- continue;
- }
-
- prev = node;
- }
-
- /*
* Delete all memory reserve map entries. When booting via UEFI,
* kernel will use the UEFI memory map to find reserved regions.
*/
--
1.8.3.1

Will Deacon

2016-02-23 12:16:52 UTC

Post by Mark Rutland

This is a little bit scary, but I guess this works.
My only concern is that when we get kexec, a subsequent kernel must also
have EFI memory map support, or things go bad for the next EFI-aware
kernel after that (as things like the runtime services may have been
corrupted by the kernel in the middle). It's difficult to fix the
general case later.
A different option would be to support status="disabled" for the memory
nodes, and ignore these in early_init_dt_scan_memory. That way a kernel
cannot use memory without first having parsed the EFI memory map, and we
can still get NUMA info from the disabled nodes.

So in that case, the middle, non-EFI kernel would fail to boot?
Realistically, once you've kexec'd a non-EFI payload, I don't think you
can rely on the EFI state remaining intact for future EFI applications.

Is this really something we should be trying to police in the kernel?

Will

Ard Biesheuvel

2016-02-23 12:20:21 UTC

Post by Mark Rutland

This is a little bit scary, but I guess this works.
My only concern is that when we get kexec, a subsequent kernel must also
have EFI memory map support, or things go bad for the next EFI-aware
kernel after that (as things like the runtime services may have been
corrupted by the kernel in the middle). It's difficult to fix the
general case later.
A different option would be to support status="disabled" for the memory
nodes, and ignore these in early_init_dt_scan_memory. That way a kernel
cannot use memory without first having parsed the EFI memory map, and we
can still get NUMA info from the disabled nodes.

So in that case, the middle, non-EFI kernel would fail to boot?
Realistically, once you've kexec'd a non-EFI payload, I don't think you
can rely on the EFI state remaining intact for future EFI applications.
Is this really something we should be trying to police in the kernel?

Well, we could add entries to /reserved-memory in the stub for all the
regions UEFI cares about, that would probably be sufficient to fix
this case.

Rob Herring

2016-02-23 22:12:18 UTC

This is a little bit scary, but I guess this works.

The way it is worded/implemented is, I agree. But if we simply say both
can be present and the kernel will default to UEFI memory map, that
seems sufficient to me.

Post by Mark Rutland
My only concern is that when we get kexec, a subsequent kernel must also
have EFI memory map support, or things go bad for the next EFI-aware
kernel after that (as things like the runtime services may have been
corrupted by the kernel in the middle). It's difficult to fix the
general case later.
A different option would be to support status="disabled" for the memory
nodes, and ignore these in early_init_dt_scan_memory. That way a kernel
cannot use memory without first having parsed the EFI memory map, and we
can still get NUMA info from the disabled nodes.

That would be a bit strange that the node is disabled, but still used.

What if DT and UEFI tables are out of sync somehow? RAM is multiple
mapped and different addresses were picked for example.

Post by Mark Rutland
You'd still need a new kernel to take into account status, but at least
we'd know all kernels would avoid using RAM that potentially needs to be
preserved.
Ard, Rob, thoughts?

Mark Rutland

2016-02-24 19:38:28 UTC

Post by Rob Herring

This is a little bit scary, but I guess this works.

The way it is worded/implemented is, I agree. But if we simply say both
can be present and the kernel will default to UEFI memory map, that
seems sufficient to me.

That would be a bit strange that the node is disabled, but still used.

I agree this would be strange, and not necessarily a precedent we'd want
to see copied elsewhere.

Per ePAPR, a "disabled" node can be enabled in a binding-specific
manner, so having the presence of a UEFI memory map "enable" the NUMA
information would appear to be permitted.

Post by Rob Herring
What if DT and UEFI tables are out of sync somehow? RAM is multiple
mapped and different addresses were picked for example.

That applies regardless of the status of the memory nodes.

My suggestion was only that we acquired the NUMA node information, and
added this node information (and not any additional extent of memory) to
the UEFI memory map.

This is precisely what we do with Ard's code, with the exception that in
the absence of a UEFI memory map the kernel would know it was not
permitted to access memory.

Mark.

Frank Rowand

2016-02-24 19:03:22 UTC

This is a little bit scary, but I guess this works.
My only concern is that when we get kexec, a subsequent kernel must also
have EFI memory map support, or things go bad for the next EFI-aware
kernel after that (as things like the runtime services may have been
corrupted by the kernel in the middle). It's difficult to fix the
general case later.
A different option would be to support status="disabled" for the memory
nodes, and ignore these in early_init_dt_scan_memory. That way a kernel
cannot use memory without first having parsed the EFI memory map, and we
can still get NUMA info from the disabled nodes.

Please do not play games of treating nodes with status="disabled" as
valid nodes. The mindset should be if it is disabled, it does not exist.

There have been two bugs reported in the last week where code should
have been ignoring disabled nodes and failed to. An audit of code
scanning all nodes instead of all enabled nodes is now on my todo list.

< snip >

-Frank

Rob Herring

2016-02-24 19:31:25 UTC

Post by Frank Rowand

This is a little bit scary, but I guess this works.
My only concern is that when we get kexec, a subsequent kernel must also
have EFI memory map support, or things go bad for the next EFI-aware
kernel after that (as things like the runtime services may have been
corrupted by the kernel in the middle). It's difficult to fix the
general case later.
A different option would be to support status="disabled" for the memory
nodes, and ignore these in early_init_dt_scan_memory. That way a kernel
cannot use memory without first having parsed the EFI memory map, and we
can still get NUMA info from the disabled nodes.

Please do not play games of treating nodes with status="disabled" as
valid nodes. The mindset should be if it is disabled, it does not exist.
There have been two bugs reported in the last week where code should
have been ignoring disabled nodes and failed to. An audit of code
scanning all nodes instead of all enabled nodes is now on my todo list.

Perhaps we should merge the default/available variants of iterators
into one. I suspect there are some valid uses. Otherwise, we could
also just not even populate those nodes in the live tree. There are
some cases where the kernel changes the status.

Rob

Mark Rutland

2016-02-24 19:33:55 UTC

Post by Frank Rowand

This is a little bit scary, but I guess this works.
My only concern is that when we get kexec, a subsequent kernel must also
have EFI memory map support, or things go bad for the next EFI-aware
kernel after that (as things like the runtime services may have been
corrupted by the kernel in the middle). It's difficult to fix the
general case later.
A different option would be to support status="disabled" for the memory
nodes, and ignore these in early_init_dt_scan_memory. That way a kernel
cannot use memory without first having parsed the EFI memory map, and we
can still get NUMA info from the disabled nodes.

Please do not play games of treating nodes with status="disabled" as
valid nodes. The mindset should be if it is disabled, it does not exist.

I completely agree with this generally.

The only possible wiggle room is ePAPR's decription of the precise
meaning of the status property being binding-specific (and there may be
some way to later "enable" the node or otehrwise make use of it). As
with above, we'd only be extracting some information in the presence of
a UEFI memory map.

I agree that this is not a great pattern, and we don't necessarily want
that even for "safe" cases like NUMA.

Post by Frank Rowand
There have been two bugs reported in the last week where code should
have been ignoring disabled nodes and failed to. An audit of code
scanning all nodes instead of all enabled nodes is now on my todo list.

That would be great!

Mark.

David Daney

2016-02-23 01:58:45 UTC

From: Ganapatrao Kulkarni <***@caviumnetworks.com>

Attempt to get the memory and CPU NUMA node via of_numa. If that
fails, default the dummy NUMA node and map all memory and CPUs to node
0.

Tested-by: Shannon Zhao <***@linaro.org>
Reviewed-by: Robert Richter <***@cavium.com>
Signed-off-by: Ganapatrao Kulkarni <***@caviumnetworks.com>
Signed-off-by: David Daney <***@cavium.com>
---
arch/arm64/Kconfig | 26 +++
arch/arm64/include/asm/mmzone.h | 12 ++
arch/arm64/include/asm/numa.h | 45 +++++
arch/arm64/include/asm/topology.h | 10 +
arch/arm64/kernel/pci.c | 10 +
arch/arm64/kernel/setup.c | 4 +
arch/arm64/kernel/smp.c | 4 +
arch/arm64/mm/Makefile | 1 +
arch/arm64/mm/init.c | 34 +++-
arch/arm64/mm/mmu.c | 1 +
arch/arm64/mm/numa.c | 403 ++++++++++++++++++++++++++++++++++++++
11 files changed, 545 insertions(+), 5 deletions(-)
create mode 100644 arch/arm64/include/asm/mmzone.h
create mode 100644 arch/arm64/include/asm/numa.h
create mode 100644 arch/arm64/mm/numa.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a969970..9f0972a 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -74,6 +74,7 @@ config ARM64
select HAVE_HW_BREAKPOINT if PERF_EVENTS
select HAVE_IRQ_TIME_ACCOUNTING
select HAVE_MEMBLOCK
+ select HAVE_MEMBLOCK_NODE_MAP if NUMA
select HAVE_PATA_PLATFORM
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
@@ -96,6 +97,7 @@ config ARM64
select SYSCTL_EXCEPTION_TRACE
select HAVE_CONTEXT_TRACKING
select HAVE_ARM_SMCCC
+ select OF_NUMA if NUMA && OF
help
ARM 64-bit (AArch64) Linux support.

@@ -545,6 +547,30 @@ config HOTPLUG_CPU
Say Y here to experiment with turning CPUs off and on. CPUs
can be controlled through /sys/devices/system/cpu.

+# Common NUMA Features
+config NUMA
+ bool "Numa Memory Allocation and Scheduler Support"
+ depends on SMP
+ 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
+
source kernel/Kconfig.preempt
source kernel/Kconfig.hz

diff --git a/arch/arm64/include/asm/mmzone.h b/arch/arm64/include/asm/mmzone.h
new file mode 100644
index 0000000..a0de9e6
--- /dev/null
+++ b/arch/arm64/include/asm/mmzone.h
@@ -0,0 +1,12 @@
+#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/arm64/include/asm/numa.h b/arch/arm64/include/asm/numa.h
new file mode 100644
index 0000000..e9b4f29
--- /dev/null
+++ b/arch/arm64/include/asm/numa.h
@@ -0,0 +1,45 @@
+#ifndef __ASM_NUMA_H
+#define __ASM_NUMA_H
+
+#include <asm/topology.h>
+
+#ifdef CONFIG_NUMA
+
+/* currently, arm64 implements flat NUMA topology */
+#define parent_node(node) (node)
+
+int __node_distance(int from, int to);
+#define node_distance(a, b) __node_distance(a, b)
+
+extern nodemask_t numa_nodes_parsed __initdata;
+
+/* Mappings between node number and cpus on that node. */
+extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
+void numa_clear_node(unsigned int cpu);
+
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+const struct cpumask *cpumask_of_node(int node);
+#else
+/* Returns a pointer to the cpumask of CPUs on Node 'node'. */
+static inline const struct cpumask *cpumask_of_node(int node)
+{
+ return node_to_cpumask_map[node];
+}
+#endif
+
+void __init arm64_numa_init(void);
+int __init numa_add_memblk(int nodeid, u64 start, u64 end);
+void __init numa_set_distance(int from, int to, int distance);
+void __init numa_free_distance(void);
+void __init early_map_cpu_to_node(unsigned int cpu, int nid);
+void numa_store_cpu_info(unsigned int cpu);
+
+#else /* CONFIG_NUMA */
+
+static inline void numa_store_cpu_info(unsigned int cpu) { }
+static inline void arm64_numa_init(void) { }
+static inline void early_map_cpu_to_node(unsigned int cpu, int nid) { }
+
+#endif /* CONFIG_NUMA */
+
+#endif /* __ASM_NUMA_H */
diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h
index a3e9d6f..8b57339 100644
--- a/arch/arm64/include/asm/topology.h
+++ b/arch/arm64/include/asm/topology.h
@@ -22,6 +22,16 @@ void init_cpu_topology(void);
void store_cpu_topology(unsigned int cpuid);
const struct cpumask *cpu_coregroup_mask(int cpu);

+#ifdef CONFIG_NUMA
+
+struct pci_bus;
+int pcibus_to_node(struct pci_bus *bus);
+#define cpumask_of_pcibus(bus) (pcibus_to_node(bus) == -1 ? \
+ cpu_all_mask : \
+ cpumask_of_node(pcibus_to_node(bus)))
+
+#endif /* CONFIG_NUMA */
+
#include <asm-generic/topology.h>

#endif /* _ASM_ARM_TOPOLOGY_H */
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index b3d098b..65e6b7d 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -76,6 +76,16 @@ int raw_pci_write(unsigned int domain, unsigned int bus,
return -ENXIO;
}

+#ifdef CONFIG_NUMA
+
+int pcibus_to_node(struct pci_bus *bus)
+{
+ return dev_to_node(&bus->dev);
+}
+EXPORT_SYMBOL(pcibus_to_node);
+
+#endif
+
#ifdef CONFIG_ACPI
/* Root bridge scanning */
struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 8119479..d9b9761 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -53,6 +53,7 @@
#include <asm/cpufeature.h>
#include <asm/cpu_ops.h>
#include <asm/kasan.h>
+#include <asm/numa.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp_plat.h>
@@ -372,6 +373,9 @@ static int __init topology_init(void)
{
int i;

+ for_each_online_node(i)
+ register_one_node(i);
+
for_each_possible_cpu(i) {
struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
cpu->hotpluggable = 1;
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index b1adc51..46c45c8 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -45,6 +45,7 @@
#include <asm/cputype.h>
#include <asm/cpu_ops.h>
#include <asm/mmu_context.h>
+#include <asm/numa.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
@@ -125,6 +126,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
static void smp_store_cpu_info(unsigned int cpuid)
{
store_cpu_topology(cpuid);
+ numa_store_cpu_info(cpuid);
}

/*
@@ -518,6 +520,8 @@ static void __init of_parse_and_init_cpus(void)

pr_debug("cpu logical map 0x%llx\n", hwid);
cpu_logical_map(cpu_count) = hwid;
+
+ early_map_cpu_to_node(cpu_count, of_node_to_nid(dn));
next:
cpu_count++;
}
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
index 57f57fd..54bb209 100644
--- a/arch/arm64/mm/Makefile
+++ b/arch/arm64/mm/Makefile
@@ -4,6 +4,7 @@ obj-y := dma-mapping.o extable.o fault.o init.o \
context.o proc.o pageattr.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM64_PTDUMP) += dump.o
+obj-$(CONFIG_NUMA) += numa.o

obj-$(CONFIG_KASAN) += kasan_init.o
KASAN_SANITIZE_kasan_init.o := n
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index f3b061e..c39c670 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -37,6 +37,7 @@

#include <asm/fixmap.h>
#include <asm/memory.h>
+#include <asm/numa.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
@@ -77,6 +78,21 @@ static phys_addr_t __init max_zone_dma_phys(void)
return min(offset + (1ULL << 32), memblock_end_of_DRAM());
}

+#ifdef CONFIG_NUMA
+
+static void __init zone_sizes_init(unsigned long min, unsigned long max)
+{
+ unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
+
+ if (IS_ENABLED(CONFIG_ZONE_DMA))
+ max_zone_pfns[ZONE_DMA] = PFN_DOWN(max_zone_dma_phys());
+ max_zone_pfns[ZONE_NORMAL] = max;
+
+ free_area_init_nodes(max_zone_pfns);
+}
+
+#else
+
static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
struct memblock_region *reg;
@@ -117,6 +133,8 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
free_area_init_node(0, zone_size, min, zhole_size);
}

+#endif /* CONFIG_NUMA */
+
#ifdef CONFIG_HAVE_ARCH_PFN_VALID
int pfn_valid(unsigned long pfn)
{
@@ -133,10 +151,15 @@ static void __init arm64_memory_present(void)
static void __init arm64_memory_present(void)
{
struct memblock_region *reg;
+ int nid = 0;

- for_each_memblock(memory, reg)
- memory_present(0, memblock_region_memory_base_pfn(reg),
- memblock_region_memory_end_pfn(reg));
+ for_each_memblock(memory, reg) {
+#ifdef CONFIG_NUMA
+ nid = reg->nid;
+#endif
+ memory_present(nid, memblock_region_memory_base_pfn(reg),
+ memblock_region_memory_end_pfn(reg));
+ }
}
#endif

@@ -181,7 +204,6 @@ void __init arm64_memblock_init(void)
dma_contiguous_reserve(arm64_dma_phys_limit);

memblock_allow_resize();
- memblock_dump_all();
}

void __init bootmem_init(void)
@@ -193,6 +215,9 @@ void __init bootmem_init(void)

early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);

+ max_pfn = max_low_pfn = max;
+
+ arm64_numa_init();
/*
* Sparsemem tries to allocate bootmem in memory_present(), so must be
* done after the fixed reservations.
@@ -203,7 +228,6 @@ void __init bootmem_init(void)
zone_sizes_init(min, max);

high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
- max_pfn = max_low_pfn = max;
}

#ifndef CONFIG_SPARSEMEM_VMEMMAP
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 58faeaa..44e3854 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -463,6 +463,7 @@ void __init paging_init(void)
zero_page = early_alloc(PAGE_SIZE);

bootmem_init();
+ memblock_dump_all();

empty_zero_page = virt_to_page(zero_page);

diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
new file mode 100644
index 0000000..604e886
--- /dev/null
+++ b/arch/arm64/mm/numa.c
@@ -0,0 +1,403 @@
+/*
+ * NUMA support, based on the x86 implementation.
+ *
+ * Copyright (C) 2015 Cavium Inc.
+ * Author: Ganapatrao Kulkarni <***@cavium.com>
+ *
+ * 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 <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
+EXPORT_SYMBOL(node_data);
+nodemask_t numa_nodes_parsed __initdata;
+static int cpu_to_node_map[NR_CPUS] = { [0 ... NR_CPUS-1] = NUMA_NO_NODE };
+
+static int numa_off;
+static int numa_distance_cnt;
+static u8 *numa_distance;
+
+static __init int numa_parse_early_param(char *opt)
+{
+ if (!opt)
+ return -EINVAL;
+ if (!strncmp(opt, "off", 3)) {
+ pr_info("%s\n", "NUMA turned off");
+ numa_off = 1;
+ }
+ return 0;
+}
+early_param("numa", numa_parse_early_param);
+
+cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
+EXPORT_SYMBOL(node_to_cpumask_map);
+
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+
+/*
+ * Returns a pointer to the bitmask of CPUs on Node 'node'.
+ */
+const struct cpumask *cpumask_of_node(int node)
+{
+ if (WARN_ON(node >= nr_node_ids))
+ return cpu_none_mask;
+
+ if (WARN_ON(node_to_cpumask_map[node] == NULL))
+ return cpu_online_mask;
+
+ return node_to_cpumask_map[node];
+}
+EXPORT_SYMBOL(cpumask_of_node);
+
+#endif
+
+static void map_cpu_to_node(unsigned int cpu, int nid)
+{
+ set_cpu_numa_node(cpu, nid);
+ if (nid >= 0)
+ cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
+}
+
+static void unmap_cpu_to_node(unsigned int cpu)
+{
+ int nid = cpu_to_node(cpu);
+
+ if (nid >= 0)
+ cpumask_clear_cpu(cpu, node_to_cpumask_map[nid]);
+ set_cpu_numa_node(cpu, NUMA_NO_NODE);
+}
+
+void numa_clear_node(unsigned int cpu)
+{
+ unmap_cpu_to_node(cpu);
+}
+
+/*
+ * Allocate node_to_cpumask_map based on number of available nodes
+ * Requires node_possible_map to be valid.
+ *
+ * Note: cpumask_of_node() is not valid until after this is done.
+ * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
+ */
+static void __init setup_node_to_cpumask_map(void)
+{
+ unsigned int cpu;
+ int node;
+
+ /* setup nr_node_ids if not done yet */
+ if (nr_node_ids == MAX_NUMNODES)
+ setup_nr_node_ids();
+
+ /* allocate and clear the mapping */
+ for (node = 0; node < nr_node_ids; node++) {
+ alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
+ cpumask_clear(node_to_cpumask_map[node]);
+ }
+
+ for_each_possible_cpu(cpu)
+ set_cpu_numa_node(cpu, NUMA_NO_NODE);
+
+ /* cpumask_of_node() will now work */
+ pr_debug("NUMA: Node to cpumask map for %d nodes\n", nr_node_ids);
+}
+
+/*
+ * Set the cpu to node and mem mapping
+ */
+void numa_store_cpu_info(unsigned int cpu)
+{
+ map_cpu_to_node(cpu, numa_off ? 0 : cpu_to_node_map[cpu]);
+}
+
+void __init early_map_cpu_to_node(unsigned int cpu, int nid)
+{
+ /* fallback to node 0 */
+ if (nid < 0 || nid >= MAX_NUMNODES)
+ nid = 0;
+
+ cpu_to_node_map[cpu] = nid;
+}
+
+/**
+ * numa_add_memblk - Set node id to memblk
+ * @nid: NUMA node ID of the new memblk
+ * @start: Start address of the new memblk
+ * @size: Size of the new memblk
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int __init numa_add_memblk(int nid, u64 start, u64 size)
+{
+ int ret;
+
+ ret = memblock_set_node(start, size, &memblock.memory, nid);
+ if (ret < 0) {
+ pr_err("NUMA: memblock [0x%llx - 0x%llx] failed to add on node %d\n",
+ start, (start + size - 1), nid);
+ return ret;
+ }
+
+ node_set(nid, numa_nodes_parsed);
+ pr_info("NUMA: Adding memblock [0x%llx - 0x%llx] on node %d\n",
+ start, (start + size - 1), nid);
+ return ret;
+}
+EXPORT_SYMBOL(numa_add_memblk);
+
+/**
+ * Initialize NODE_DATA for a node on the local memory
+ */
+static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
+{
+ const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
+ u64 nd_pa;
+ void *nd;
+ int tnid;
+
+ pr_info("NUMA: Initmem setup node %d [mem %#010Lx-%#010Lx]\n",
+ nid, start_pfn << PAGE_SHIFT,
+ (end_pfn << PAGE_SHIFT) - 1);
+
+ nd_pa = memblock_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
+ nd = __va(nd_pa);
+
+ /* report and initialize */
+ pr_info("NUMA: NODE_DATA [mem %#010Lx-%#010Lx]\n",
+ nd_pa, nd_pa + nd_size - 1);
+ tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
+ if (tnid != nid)
+ pr_info("NUMA: NODE_DATA(%d) on node %d\n", nid, tnid);
+
+ node_data[nid] = nd;
+ memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
+ NODE_DATA(nid)->node_id = nid;
+ NODE_DATA(nid)->node_start_pfn = start_pfn;
+ NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
+}
+
+/**
+ * numa_free_distance
+ *
+ * The current table is freed.
+ */
+void __init numa_free_distance(void)
+{
+ size_t size;
+
+ if (!numa_distance)
+ return;
+
+ size = numa_distance_cnt * numa_distance_cnt *
+ sizeof(numa_distance[0]);
+
+ memblock_free(__pa(numa_distance), size);
+ numa_distance_cnt = 0;
+ numa_distance = NULL;
+}
+
+/**
+ *
+ * Create a new NUMA distance table.
+ *
+ */
+static int __init numa_alloc_distance(void)
+{
+ size_t size;
+ u64 phys;
+ int i, j;
+
+ size = nr_node_ids * nr_node_ids * sizeof(numa_distance[0]);
+ phys = memblock_find_in_range(0, PFN_PHYS(max_pfn),
+ size, PAGE_SIZE);
+ if (WARN_ON(!phys))
+ return -ENOMEM;
+
+ memblock_reserve(phys, size);
+
+ numa_distance = __va(phys);
+ numa_distance_cnt = nr_node_ids;
+
+ /* fill with the default distances */
+ for (i = 0; i < numa_distance_cnt; i++)
+ for (j = 0; j < numa_distance_cnt; j++)
+ numa_distance[i * numa_distance_cnt + j] = i == j ?
+ LOCAL_DISTANCE : REMOTE_DISTANCE;
+
+ pr_debug("NUMA: Initialized distance table, cnt=%d\n",
+ numa_distance_cnt);
+
+ return 0;
+}
+
+/**
+ * numa_set_distance - Set inter node NUMA distance from node to node.
+ * @from: the 'from' node to set distance
+ * @to: the 'to' node to set distance
+ * @distance: NUMA distance
+ *
+ * Set the distance from node @from to @to to @distance.
+ * If distance table doesn't exist, a warning is printed.
+ *
+ * If @from or @to is higher than the highest known node or lower than zero
+ * or @distance doesn't make sense, the call is ignored.
+ *
+ */
+void __init numa_set_distance(int from, int to, int distance)
+{
+ if (!numa_distance) {
+ pr_warn_once("NUMA: Warning: distance table not allocated yet\n");
+ return;
+ }
+
+ if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
+ from < 0 || to < 0) {
+ pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
+ from, to, distance);
+ return;
+ }
+
+ if ((u8)distance != distance ||
+ (from == to && distance != LOCAL_DISTANCE)) {
+ pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
+ from, to, distance);
+ return;
+ }
+
+ numa_distance[from * numa_distance_cnt + to] = distance;
+}
+EXPORT_SYMBOL(numa_set_distance);
+
+/**
+ * Return NUMA distance @from to @to
+ */
+int __node_distance(int from, int to)
+{
+ if (from >= numa_distance_cnt || to >= numa_distance_cnt)
+ return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
+ return numa_distance[from * numa_distance_cnt + to];
+}
+EXPORT_SYMBOL(__node_distance);
+
+static int __init numa_register_nodes(void)
+{
+ int nid;
+ struct memblock_region *mblk;
+
+ /* Check that valid nid is set to memblks */
+ for_each_memblock(memory, mblk)
+ if (mblk->nid == NUMA_NO_NODE || mblk->nid >= MAX_NUMNODES) {
+ pr_warn("NUMA: Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
+ mblk->nid, mblk->base,
+ mblk->base + mblk->size - 1);
+ return -EINVAL;
+ }
+
+ /* Finally register nodes. */
+ for_each_node_mask(nid, numa_nodes_parsed) {
+ unsigned long start_pfn, end_pfn;
+
+ get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
+ setup_node_data(nid, start_pfn, end_pfn);
+ node_set_online(nid);
+ }
+
+ /* Setup online nodes to actual nodes*/
+ node_possible_map = numa_nodes_parsed;
+
+ return 0;
+}
+
+static int __init numa_init(int (*init_func)(void))
+{
+ int ret;
+
+ nodes_clear(numa_nodes_parsed);
+ nodes_clear(node_possible_map);
+ nodes_clear(node_online_map);
+ numa_free_distance();
+
+ ret = numa_alloc_distance();
+ if (ret < 0)
+ return ret;
+
+ ret = init_func();
+ if (ret < 0)
+ return ret;
+
+ if (nodes_empty(numa_nodes_parsed))
+ return -EINVAL;
+
+ ret = numa_register_nodes();
+ if (ret < 0)
+ return ret;
+
+ setup_node_to_cpumask_map();
+
+ /* init boot processor */
+ cpu_to_node_map[0] = 0;
+ map_cpu_to_node(0, 0);
+
+ return 0;
+}
+
+/**
+ * dummy_numa_init - Fallback dummy NUMA init
+ *
+ * Used if there's no underlying NUMA architecture, NUMA initialization
+ * fails, or NUMA is disabled on the command line.
+ *
+ * Must online at least one node (node 0) and add memory blocks that cover all
+ * allowed memory. It is unlikely that this function fails.
+ */
+static int __init dummy_numa_init(void)
+{
+ int ret;
+ struct memblock_region *mblk;
+
+ pr_info("%s\n", "No NUMA configuration found");
+ pr_info("NUMA: Faking a node at [mem %#018Lx-%#018Lx]\n",
+ 0LLU, PFN_PHYS(max_pfn) - 1);
+
+ for_each_memblock(memory, mblk) {
+ ret = numa_add_memblk(0, mblk->base, mblk->size);
+ if (!ret)
+ continue;
+
+ pr_err("NUMA init failed\n");
+ return ret;
+ }
+
+ numa_off = 1;
+ return 0;
+}
+
+/**
+ * arm64_numa_init - Initialize NUMA
+ *
+ * Try each configured NUMA initialization method until one succeeds. The
+ * last fallback is dummy single node config encomapssing whole memory.
+ */
+void __init arm64_numa_init(void)
+{
+ if (!numa_off) {
+ if (!numa_init(of_numa_init))
+ return;
+ }
+
+ numa_init(dummy_numa_init);
+}

--
1.8.3.1

Will Deacon

2016-02-23 10:26:14 UTC

[...]

Post by David Daney
diff --git a/arch/arm64/include/asm/mmzone.h b/arch/arm64/include/asm/mmzone.h
new file mode 100644
index 0000000..a0de9e6
--- /dev/null
+++ b/arch/arm64/include/asm/mmzone.h
@@ -0,0 +1,12 @@
+#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 */

What happened to the patch cleaning this up in generic code?

Will

David Daney

2016-02-23 17:35:06 UTC

[...]

What happened to the patch cleaning this up in generic code?

As per 0/5 :

v11:
- Dropped cleanup patches for other architectures, they will be
submitted as a separate set after more testing.

The "cleanup patches" were not building on x86, which is a bit of a
problem. I believe I have corrected that issue, but would like to do
a little more build testing on all the other architectures that are
effected.

I probably should have supplied more detail as to my plan of attack
for these. To make review more manageable, I would like to consider
the arm64 patches separately. The parties interested in getting arm64
NUMA working can proceed without waiting for the cleanups to be fully
tested and acknowledged. I am working on testing the cleanups on each
architecture touched, and will resubmit them as a separate patch set
this week. I think splitting them like this will streamline the
process of getting to the eventual goal of having both arm64 NUMA and
the cleanups merged.

David.

David Daney

2016-02-23 17:40:21 UTC

+ Bjorn Helgaas

Bjorn,

I Inadvertently omitted you from the list of recipients. There is an
arm64 PCI bit in here that may be of interest...

Post by David Daney
Attempt to get the memory and CPU NUMA node via of_numa. If that
fails, default the dummy NUMA node and map all memory and CPUs to node
0.
---
arch/arm64/Kconfig | 26 +++
arch/arm64/include/asm/mmzone.h | 12 ++
arch/arm64/include/asm/numa.h | 45 +++++
arch/arm64/include/asm/topology.h | 10 +
arch/arm64/kernel/pci.c | 10 +
arch/arm64/kernel/setup.c | 4 +
arch/arm64/kernel/smp.c | 4 +
arch/arm64/mm/Makefile | 1 +
arch/arm64/mm/init.c | 34 +++-
arch/arm64/mm/mmu.c | 1 +
arch/arm64/mm/numa.c | 403 ++++++++++++++++++++++++++++++++++++++
11 files changed, 545 insertions(+), 5 deletions(-)
create mode 100644 arch/arm64/include/asm/mmzone.h
create mode 100644 arch/arm64/include/asm/numa.h
create mode 100644 arch/arm64/mm/numa.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a969970..9f0972a 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -74,6 +74,7 @@ config ARM64
select HAVE_HW_BREAKPOINT if PERF_EVENTS
select HAVE_IRQ_TIME_ACCOUNTING
select HAVE_MEMBLOCK
+ select HAVE_MEMBLOCK_NODE_MAP if NUMA
select HAVE_PATA_PLATFORM
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
@@ -96,6 +97,7 @@ config ARM64
select SYSCTL_EXCEPTION_TRACE
select HAVE_CONTEXT_TRACKING
select HAVE_ARM_SMCCC
+ select OF_NUMA if NUMA && OF
help
ARM 64-bit (AArch64) Linux support.
@@ -545,6 +547,30 @@ config HOTPLUG_CPU
Say Y here to experiment with turning CPUs off and on. CPUs
can be controlled through /sys/devices/system/cpu.
+# Common NUMA Features
+config NUMA
+ bool "Numa Memory Allocation and Scheduler Support"
+ depends on SMP
+ 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
+
source kernel/Kconfig.preempt
source kernel/Kconfig.hz
diff --git a/arch/arm64/include/asm/mmzone.h b/arch/arm64/include/asm/mmzone.h
new file mode 100644
index 0000000..a0de9e6
--- /dev/null
+++ b/arch/arm64/include/asm/mmzone.h
@@ -0,0 +1,12 @@
+#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/arm64/include/asm/numa.h b/arch/arm64/include/asm/numa.h
new file mode 100644
index 0000000..e9b4f29
--- /dev/null
+++ b/arch/arm64/include/asm/numa.h
@@ -0,0 +1,45 @@
+#ifndef __ASM_NUMA_H
+#define __ASM_NUMA_H
+
+#include <asm/topology.h>
+
+#ifdef CONFIG_NUMA
+
+/* currently, arm64 implements flat NUMA topology */
+#define parent_node(node) (node)
+
+int __node_distance(int from, int to);
+#define node_distance(a, b) __node_distance(a, b)
+
+extern nodemask_t numa_nodes_parsed __initdata;
+
+/* Mappings between node number and cpus on that node. */
+extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
+void numa_clear_node(unsigned int cpu);
+
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+const struct cpumask *cpumask_of_node(int node);
+#else
+/* Returns a pointer to the cpumask of CPUs on Node 'node'. */
+static inline const struct cpumask *cpumask_of_node(int node)
+{
+ return node_to_cpumask_map[node];
+}
+#endif
+
+void __init arm64_numa_init(void);
+int __init numa_add_memblk(int nodeid, u64 start, u64 end);
+void __init numa_set_distance(int from, int to, int distance);
+void __init numa_free_distance(void);
+void __init early_map_cpu_to_node(unsigned int cpu, int nid);
+void numa_store_cpu_info(unsigned int cpu);
+
+#else /* CONFIG_NUMA */
+
+static inline void numa_store_cpu_info(unsigned int cpu) { }
+static inline void arm64_numa_init(void) { }
+static inline void early_map_cpu_to_node(unsigned int cpu, int nid) { }
+
+#endif /* CONFIG_NUMA */
+
+#endif /* __ASM_NUMA_H */
diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h
index a3e9d6f..8b57339 100644
--- a/arch/arm64/include/asm/topology.h
+++ b/arch/arm64/include/asm/topology.h
@@ -22,6 +22,16 @@ void init_cpu_topology(void);
void store_cpu_topology(unsigned int cpuid);
const struct cpumask *cpu_coregroup_mask(int cpu);
+#ifdef CONFIG_NUMA
+
+struct pci_bus;
+int pcibus_to_node(struct pci_bus *bus);
+#define cpumask_of_pcibus(bus) (pcibus_to_node(bus) == -1 ? \
+ cpu_all_mask : \
+ cpumask_of_node(pcibus_to_node(bus)))
+
+#endif /* CONFIG_NUMA */
+
#include <asm-generic/topology.h>
#endif /* _ASM_ARM_TOPOLOGY_H */
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index b3d098b..65e6b7d 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -76,6 +76,16 @@ int raw_pci_write(unsigned int domain, unsigned int bus,
return -ENXIO;
}
+#ifdef CONFIG_NUMA
+
+int pcibus_to_node(struct pci_bus *bus)
+{
+ return dev_to_node(&bus->dev);
+}
+EXPORT_SYMBOL(pcibus_to_node);
+
+#endif
+
#ifdef CONFIG_ACPI
/* Root bridge scanning */
struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 8119479..d9b9761 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -53,6 +53,7 @@
#include <asm/cpufeature.h>
#include <asm/cpu_ops.h>
#include <asm/kasan.h>
+#include <asm/numa.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp_plat.h>
@@ -372,6 +373,9 @@ static int __init topology_init(void)
{
int i;
+ for_each_online_node(i)
+ register_one_node(i);
+
for_each_possible_cpu(i) {
struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
cpu->hotpluggable = 1;
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index b1adc51..46c45c8 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -45,6 +45,7 @@
#include <asm/cputype.h>
#include <asm/cpu_ops.h>
#include <asm/mmu_context.h>
+#include <asm/numa.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
@@ -125,6 +126,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
static void smp_store_cpu_info(unsigned int cpuid)
{
store_cpu_topology(cpuid);
+ numa_store_cpu_info(cpuid);
}
/*
@@ -518,6 +520,8 @@ static void __init of_parse_and_init_cpus(void)
pr_debug("cpu logical map 0x%llx\n", hwid);
cpu_logical_map(cpu_count) = hwid;
+
+ early_map_cpu_to_node(cpu_count, of_node_to_nid(dn));
cpu_count++;
}
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
index 57f57fd..54bb209 100644
--- a/arch/arm64/mm/Makefile
+++ b/arch/arm64/mm/Makefile
@@ -4,6 +4,7 @@ obj-y := dma-mapping.o extable.o fault.o init.o \
context.o proc.o pageattr.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM64_PTDUMP) += dump.o
+obj-$(CONFIG_NUMA) += numa.o
obj-$(CONFIG_KASAN) += kasan_init.o
KASAN_SANITIZE_kasan_init.o := n
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index f3b061e..c39c670 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -37,6 +37,7 @@
#include <asm/fixmap.h>
#include <asm/memory.h>
+#include <asm/numa.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
@@ -77,6 +78,21 @@ static phys_addr_t __init max_zone_dma_phys(void)
return min(offset + (1ULL << 32), memblock_end_of_DRAM());
}
+#ifdef CONFIG_NUMA
+
+static void __init zone_sizes_init(unsigned long min, unsigned long max)
+{
+ unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
+
+ if (IS_ENABLED(CONFIG_ZONE_DMA))
+ max_zone_pfns[ZONE_DMA] = PFN_DOWN(max_zone_dma_phys());
+ max_zone_pfns[ZONE_NORMAL] = max;
+
+ free_area_init_nodes(max_zone_pfns);
+}
+
+#else
+
static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
struct memblock_region *reg;
@@ -117,6 +133,8 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
free_area_init_node(0, zone_size, min, zhole_size);
}
+#endif /* CONFIG_NUMA */
+
#ifdef CONFIG_HAVE_ARCH_PFN_VALID
int pfn_valid(unsigned long pfn)
{
@@ -133,10 +151,15 @@ static void __init arm64_memory_present(void)
static void __init arm64_memory_present(void)
{
struct memblock_region *reg;
+ int nid = 0;
- for_each_memblock(memory, reg)
- memory_present(0, memblock_region_memory_base_pfn(reg),
- memblock_region_memory_end_pfn(reg));
+ for_each_memblock(memory, reg) {
+#ifdef CONFIG_NUMA
+ nid = reg->nid;
+#endif
+ memory_present(nid, memblock_region_memory_base_pfn(reg),
+ memblock_region_memory_end_pfn(reg));
+ }
}
#endif
@@ -181,7 +204,6 @@ void __init arm64_memblock_init(void)
dma_contiguous_reserve(arm64_dma_phys_limit);
memblock_allow_resize();
- memblock_dump_all();
}
void __init bootmem_init(void)
@@ -193,6 +215,9 @@ void __init bootmem_init(void)
early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
+ max_pfn = max_low_pfn = max;
+
+ arm64_numa_init();
/*
* Sparsemem tries to allocate bootmem in memory_present(), so must be
* done after the fixed reservations.
@@ -203,7 +228,6 @@ void __init bootmem_init(void)
zone_sizes_init(min, max);
high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
- max_pfn = max_low_pfn = max;
}
#ifndef CONFIG_SPARSEMEM_VMEMMAP
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 58faeaa..44e3854 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -463,6 +463,7 @@ void __init paging_init(void)
zero_page = early_alloc(PAGE_SIZE);
bootmem_init();
+ memblock_dump_all();
empty_zero_page = virt_to_page(zero_page);
diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
new file mode 100644
index 0000000..604e886
--- /dev/null
+++ b/arch/arm64/mm/numa.c
@@ -0,0 +1,403 @@
+/*
+ * NUMA support, based on the x86 implementation.
+ *
+ * Copyright (C) 2015 Cavium Inc.
+ *
+ * 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 <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
+EXPORT_SYMBOL(node_data);
+nodemask_t numa_nodes_parsed __initdata;
+static int cpu_to_node_map[NR_CPUS] = { [0 ... NR_CPUS-1] = NUMA_NO_NODE };
+
+static int numa_off;
+static int numa_distance_cnt;
+static u8 *numa_distance;
+
+static __init int numa_parse_early_param(char *opt)
+{
+ if (!opt)
+ return -EINVAL;
+ if (!strncmp(opt, "off", 3)) {
+ pr_info("%s\n", "NUMA turned off");
+ numa_off = 1;
+ }
+ return 0;
+}
+early_param("numa", numa_parse_early_param);
+
+cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
+EXPORT_SYMBOL(node_to_cpumask_map);
+
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+
+/*
+ * Returns a pointer to the bitmask of CPUs on Node 'node'.
+ */
+const struct cpumask *cpumask_of_node(int node)
+{
+ if (WARN_ON(node >= nr_node_ids))
+ return cpu_none_mask;
+
+ if (WARN_ON(node_to_cpumask_map[node] == NULL))
+ return cpu_online_mask;
+
+ return node_to_cpumask_map[node];
+}
+EXPORT_SYMBOL(cpumask_of_node);
+
+#endif
+
+static void map_cpu_to_node(unsigned int cpu, int nid)
+{
+ set_cpu_numa_node(cpu, nid);
+ if (nid >= 0)
+ cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
+}
+
+static void unmap_cpu_to_node(unsigned int cpu)
+{
+ int nid = cpu_to_node(cpu);
+
+ if (nid >= 0)
+ cpumask_clear_cpu(cpu, node_to_cpumask_map[nid]);
+ set_cpu_numa_node(cpu, NUMA_NO_NODE);
+}
+
+void numa_clear_node(unsigned int cpu)
+{
+ unmap_cpu_to_node(cpu);
+}
+
+/*
+ * Allocate node_to_cpumask_map based on number of available nodes
+ * Requires node_possible_map to be valid.
+ *
+ * Note: cpumask_of_node() is not valid until after this is done.
+ * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
+ */
+static void __init setup_node_to_cpumask_map(void)
+{
+ unsigned int cpu;
+ int node;
+
+ /* setup nr_node_ids if not done yet */
+ if (nr_node_ids == MAX_NUMNODES)
+ setup_nr_node_ids();
+
+ /* allocate and clear the mapping */
+ for (node = 0; node < nr_node_ids; node++) {
+ alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
+ cpumask_clear(node_to_cpumask_map[node]);
+ }
+
+ for_each_possible_cpu(cpu)
+ set_cpu_numa_node(cpu, NUMA_NO_NODE);
+
+ /* cpumask_of_node() will now work */
+ pr_debug("NUMA: Node to cpumask map for %d nodes\n", nr_node_ids);
+}
+
+/*
+ * Set the cpu to node and mem mapping
+ */
+void numa_store_cpu_info(unsigned int cpu)
+{
+ map_cpu_to_node(cpu, numa_off ? 0 : cpu_to_node_map[cpu]);
+}
+
+void __init early_map_cpu_to_node(unsigned int cpu, int nid)
+{
+ /* fallback to node 0 */
+ if (nid < 0 || nid >= MAX_NUMNODES)
+ nid = 0;
+
+ cpu_to_node_map[cpu] = nid;
+}
+
+/**
+ * numa_add_memblk - Set node id to memblk
+ *
+ * 0 on success, -errno on failure.
+ */
+int __init numa_add_memblk(int nid, u64 start, u64 size)
+{
+ int ret;
+
+ ret = memblock_set_node(start, size, &memblock.memory, nid);
+ if (ret < 0) {
+ pr_err("NUMA: memblock [0x%llx - 0x%llx] failed to add on node %d\n",
+ start, (start + size - 1), nid);
+ return ret;
+ }
+
+ node_set(nid, numa_nodes_parsed);
+ pr_info("NUMA: Adding memblock [0x%llx - 0x%llx] on node %d\n",
+ start, (start + size - 1), nid);
+ return ret;
+}
+EXPORT_SYMBOL(numa_add_memblk);
+
+/**
+ * Initialize NODE_DATA for a node on the local memory
+ */
+static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
+{
+ const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
+ u64 nd_pa;
+ void *nd;
+ int tnid;
+
+ pr_info("NUMA: Initmem setup node %d [mem %#010Lx-%#010Lx]\n",
+ nid, start_pfn << PAGE_SHIFT,
+ (end_pfn << PAGE_SHIFT) - 1);
+
+ nd_pa = memblock_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
+ nd = __va(nd_pa);
+
+ /* report and initialize */
+ pr_info("NUMA: NODE_DATA [mem %#010Lx-%#010Lx]\n",
+ nd_pa, nd_pa + nd_size - 1);
+ tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
+ if (tnid != nid)
+ pr_info("NUMA: NODE_DATA(%d) on node %d\n", nid, tnid);
+
+ node_data[nid] = nd;
+ memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
+ NODE_DATA(nid)->node_id = nid;
+ NODE_DATA(nid)->node_start_pfn = start_pfn;
+ NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
+}
+
+/**
+ * numa_free_distance
+ *
+ * The current table is freed.
+ */
+void __init numa_free_distance(void)
+{
+ size_t size;
+
+ if (!numa_distance)
+ return;
+
+ size = numa_distance_cnt * numa_distance_cnt *
+ sizeof(numa_distance[0]);
+
+ memblock_free(__pa(numa_distance), size);
+ numa_distance_cnt = 0;
+ numa_distance = NULL;
+}
+
+/**
+ *
+ * Create a new NUMA distance table.
+ *
+ */
+static int __init numa_alloc_distance(void)
+{
+ size_t size;
+ u64 phys;
+ int i, j;
+
+ size = nr_node_ids * nr_node_ids * sizeof(numa_distance[0]);
+ phys = memblock_find_in_range(0, PFN_PHYS(max_pfn),
+ size, PAGE_SIZE);
+ if (WARN_ON(!phys))
+ return -ENOMEM;
+
+ memblock_reserve(phys, size);
+
+ numa_distance = __va(phys);
+ numa_distance_cnt = nr_node_ids;
+
+ /* fill with the default distances */
+ for (i = 0; i < numa_distance_cnt; i++)
+ for (j = 0; j < numa_distance_cnt; j++)
+ numa_distance[i * numa_distance_cnt + j] = i == j ?
+ LOCAL_DISTANCE : REMOTE_DISTANCE;
+
+ pr_debug("NUMA: Initialized distance table, cnt=%d\n",
+ numa_distance_cnt);
+
+ return 0;
+}
+
+/**
+ * numa_set_distance - Set inter node NUMA distance from node to node.
+ *
+ * If distance table doesn't exist, a warning is printed.
+ *
+ *
+ */
+void __init numa_set_distance(int from, int to, int distance)
+{
+ if (!numa_distance) {
+ pr_warn_once("NUMA: Warning: distance table not allocated yet\n");
+ return;
+ }
+
+ if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
+ from < 0 || to < 0) {
+ pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
+ from, to, distance);
+ return;
+ }
+
+ if ((u8)distance != distance ||
+ (from == to && distance != LOCAL_DISTANCE)) {
+ pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
+ from, to, distance);
+ return;
+ }
+
+ numa_distance[from * numa_distance_cnt + to] = distance;
+}
+EXPORT_SYMBOL(numa_set_distance);
+
+/**
+ */
+int __node_distance(int from, int to)
+{
+ if (from >= numa_distance_cnt || to >= numa_distance_cnt)
+ return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
+ return numa_distance[from * numa_distance_cnt + to];
+}
+EXPORT_SYMBOL(__node_distance);
+
+static int __init numa_register_nodes(void)
+{
+ int nid;
+ struct memblock_region *mblk;
+
+ /* Check that valid nid is set to memblks */
+ for_each_memblock(memory, mblk)
+ if (mblk->nid == NUMA_NO_NODE || mblk->nid >= MAX_NUMNODES) {
+ pr_warn("NUMA: Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
+ mblk->nid, mblk->base,
+ mblk->base + mblk->size - 1);
+ return -EINVAL;
+ }
+
+ /* Finally register nodes. */
+ for_each_node_mask(nid, numa_nodes_parsed) {
+ unsigned long start_pfn, end_pfn;
+
+ get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
+ setup_node_data(nid, start_pfn, end_pfn);
+ node_set_online(nid);
+ }
+
+ /* Setup online nodes to actual nodes*/
+ node_possible_map = numa_nodes_parsed;
+
+ return 0;
+}
+
+static int __init numa_init(int (*init_func)(void))
+{
+ int ret;
+
+ nodes_clear(numa_nodes_parsed);
+ nodes_clear(node_possible_map);
+ nodes_clear(node_online_map);
+ numa_free_distance();
+
+ ret = numa_alloc_distance();
+ if (ret < 0)
+ return ret;
+
+ ret = init_func();
+ if (ret < 0)
+ return ret;
+
+ if (nodes_empty(numa_nodes_parsed))
+ return -EINVAL;
+
+ ret = numa_register_nodes();
+ if (ret < 0)
+ return ret;
+
+ setup_node_to_cpumask_map();
+
+ /* init boot processor */
+ cpu_to_node_map[0] = 0;
+ map_cpu_to_node(0, 0);
+
+ return 0;
+}
+
+/**
+ * dummy_numa_init - Fallback dummy NUMA init
+ *
+ * Used if there's no underlying NUMA architecture, NUMA initialization
+ * fails, or NUMA is disabled on the command line.
+ *
+ * Must online at least one node (node 0) and add memory blocks that cover all
+ * allowed memory. It is unlikely that this function fails.
+ */
+static int __init dummy_numa_init(void)
+{
+ int ret;
+ struct memblock_region *mblk;
+
+ pr_info("%s\n", "No NUMA configuration found");
+ pr_info("NUMA: Faking a node at [mem %#018Lx-%#018Lx]\n",
+ 0LLU, PFN_PHYS(max_pfn) - 1);
+
+ for_each_memblock(memory, mblk) {
+ ret = numa_add_memblk(0, mblk->base, mblk->size);
+ if (!ret)
+ continue;
+
+ pr_err("NUMA init failed\n");
+ return ret;
+ }
+
+ numa_off = 1;
+ return 0;
+}
+
+/**
+ * arm64_numa_init - Initialize NUMA
+ *
+ * Try each configured NUMA initialization method until one succeeds. The
+ * last fallback is dummy single node config encomapssing whole memory.
+ */
+void __init arm64_numa_init(void)
+{
+ if (!numa_off) {
+ if (!numa_init(of_numa_init))
+ return;
+ }
+
+ numa_init(dummy_numa_init);
+}

Will Deacon

2016-02-26 18:53:40 UTC

Post by David Daney
Attempt to get the memory and CPU NUMA node via of_numa. If that
fails, default the dummy NUMA node and map all memory and CPUs to node
0.

[...]

Post by David Daney
@@ -133,10 +151,15 @@ static void __init arm64_memory_present(void)
static void __init arm64_memory_present(void)
{
struct memblock_region *reg;
+ int nid = 0;
- for_each_memblock(memory, reg)
- memory_present(0, memblock_region_memory_base_pfn(reg),
- memblock_region_memory_end_pfn(reg));
+ for_each_memblock(memory, reg) {
+#ifdef CONFIG_NUMA
+ nid = reg->nid;
+#endif
+ memory_present(nid, memblock_region_memory_base_pfn(reg),
+ memblock_region_memory_end_pfn(reg));
+ }
}
#endif
@@ -181,7 +204,6 @@ void __init arm64_memblock_init(void)
dma_contiguous_reserve(arm64_dma_phys_limit);
memblock_allow_resize();
- memblock_dump_all();
}
void __init bootmem_init(void)
@@ -193,6 +215,9 @@ void __init bootmem_init(void)
early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
+ max_pfn = max_low_pfn = max;
+
+ arm64_numa_init();
/*
* Sparsemem tries to allocate bootmem in memory_present(), so must be
* done after the fixed reservations.
@@ -203,7 +228,6 @@ void __init bootmem_init(void)
zone_sizes_init(min, max);
high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
- max_pfn = max_low_pfn = max;
}
#ifndef CONFIG_SPARSEMEM_VMEMMAP
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 58faeaa..44e3854 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -463,6 +463,7 @@ void __init paging_init(void)
zero_page = early_alloc(PAGE_SIZE);
bootmem_init();
+ memblock_dump_all();
empty_zero_page = virt_to_page(zero_page);
diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
new file mode 100644
index 0000000..604e886
--- /dev/null
+++ b/arch/arm64/mm/numa.c
@@ -0,0 +1,403 @@
+/*
+ * NUMA support, based on the x86 implementation.
+ *
+ * Copyright (C) 2015 Cavium Inc.
+ *
+ * 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 <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
+EXPORT_SYMBOL(node_data);
+nodemask_t numa_nodes_parsed __initdata;
+static int cpu_to_node_map[NR_CPUS] = { [0 ... NR_CPUS-1] = NUMA_NO_NODE };
+
+static int numa_off;
+static int numa_distance_cnt;
+static u8 *numa_distance;
+
+static __init int numa_parse_early_param(char *opt)
+{
+ if (!opt)
+ return -EINVAL;
+ if (!strncmp(opt, "off", 3)) {
+ pr_info("%s\n", "NUMA turned off");
+ numa_off = 1;
+ }
+ return 0;
+}
+early_param("numa", numa_parse_early_param);

Curious, but when is this option actually useful?

Post by David Daney
+
+cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
+EXPORT_SYMBOL(node_to_cpumask_map);
+
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+
+/*
+ * Returns a pointer to the bitmask of CPUs on Node 'node'.
+ */
+const struct cpumask *cpumask_of_node(int node)
+{
+ if (WARN_ON(node >= nr_node_ids))
+ return cpu_none_mask;
+
+ if (WARN_ON(node_to_cpumask_map[node] == NULL))
+ return cpu_online_mask;
+
+ return node_to_cpumask_map[node];
+}
+EXPORT_SYMBOL(cpumask_of_node);
+
+#endif
+
+static void map_cpu_to_node(unsigned int cpu, int nid)
+{
+ set_cpu_numa_node(cpu, nid);
+ if (nid >= 0)
+ cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
+}
+
+static void unmap_cpu_to_node(unsigned int cpu)
+{
+ int nid = cpu_to_node(cpu);
+
+ if (nid >= 0)
+ cpumask_clear_cpu(cpu, node_to_cpumask_map[nid]);
+ set_cpu_numa_node(cpu, NUMA_NO_NODE);
+}

How do you end up with negative nids this late in the game?

Post by David Daney
+
+void numa_clear_node(unsigned int cpu)
+{
+ unmap_cpu_to_node(cpu);

Why don't you just inline this function?

Post by David Daney
+}
+
+/*
+ * Allocate node_to_cpumask_map based on number of available nodes
+ * Requires node_possible_map to be valid.
+ *
+ * Note: cpumask_of_node() is not valid until after this is done.
+ * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
+ */
+static void __init setup_node_to_cpumask_map(void)
+{
+ unsigned int cpu;
+ int node;
+
+ /* setup nr_node_ids if not done yet */
+ if (nr_node_ids == MAX_NUMNODES)
+ setup_nr_node_ids();
+
+ /* allocate and clear the mapping */
+ for (node = 0; node < nr_node_ids; node++) {
+ alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
+ cpumask_clear(node_to_cpumask_map[node]);
+ }
+
+ for_each_possible_cpu(cpu)
+ set_cpu_numa_node(cpu, NUMA_NO_NODE);
+
+ /* cpumask_of_node() will now work */
+ pr_debug("NUMA: Node to cpumask map for %d nodes\n", nr_node_ids);
+}
+
+/*
+ * Set the cpu to node and mem mapping
+ */
+void numa_store_cpu_info(unsigned int cpu)
+{
+ map_cpu_to_node(cpu, numa_off ? 0 : cpu_to_node_map[cpu]);
+}
+
+void __init early_map_cpu_to_node(unsigned int cpu, int nid)
+{
+ /* fallback to node 0 */
+ if (nid < 0 || nid >= MAX_NUMNODES)
+ nid = 0;
+
+ cpu_to_node_map[cpu] = nid;
+}
+
+/**
+ * numa_add_memblk - Set node id to memblk
+ *
+ * 0 on success, -errno on failure.
+ */
+int __init numa_add_memblk(int nid, u64 start, u64 size)
+{
+ int ret;
+
+ ret = memblock_set_node(start, size, &memblock.memory, nid);
+ if (ret < 0) {
+ pr_err("NUMA: memblock [0x%llx - 0x%llx] failed to add on node %d\n",
+ start, (start + size - 1), nid);
+ return ret;
+ }
+
+ node_set(nid, numa_nodes_parsed);
+ pr_info("NUMA: Adding memblock [0x%llx - 0x%llx] on node %d\n",
+ start, (start + size - 1), nid);
+ return ret;
+}
+EXPORT_SYMBOL(numa_add_memblk);

But this is marked __init... (and you've done this elsewhere in the patch
too).

Will

David Daney

2016-02-26 19:51:47 UTC

On 02/26/2016 10:53 AM, Will Deacon wrote:
[...]

Post by David Daney
diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
new file mode 100644
index 0000000..604e886
--- /dev/null
+++ b/arch/arm64/mm/numa.c
@@ -0,0 +1,403 @@

[...]

Post by David Daney
+
+static int numa_off;
+static int numa_distance_cnt;
+static u8 *numa_distance;
+
+static __init int numa_parse_early_param(char *opt)
+{
+ if (!opt)
+ return -EINVAL;
+ if (!strncmp(opt, "off", 3)) {
+ pr_info("%s\n", "NUMA turned off");
+ numa_off = 1;
+ }
+ return 0;
+}
+early_param("numa", numa_parse_early_param);

Curious, but when is this option actually useful?

Good point. I will remove that bit, it was used as an aid in debugging
while bringing up the patch set.

How do you end up with negative nids this late in the game?

It might be possible with some of the hot plugging code. It is a little
paranoia programming.

If you really don't like it, we can remove it.

Post by David Daney
+
+void numa_clear_node(unsigned int cpu)
+{
+ unmap_cpu_to_node(cpu);

Why don't you just inline this function?

Good point, I will do that.

[...]

Post by David Daney
+int __init numa_add_memblk(int nid, u64 start, u64 size)
+{
+ int ret;
+
+ ret = memblock_set_node(start, size, &memblock.memory, nid);
+ if (ret < 0) {
+ pr_err("NUMA: memblock [0x%llx - 0x%llx] failed to add on node %d\n",
+ start, (start + size - 1), nid);
+ return ret;
+ }
+
+ node_set(nid, numa_nodes_parsed);
+ pr_info("NUMA: Adding memblock [0x%llx - 0x%llx] on node %d\n",
+ start, (start + size - 1), nid);
+ return ret;
+}
+EXPORT_SYMBOL(numa_add_memblk);

But this is marked __init... (and you've done this elsewhere in the patch
too).

I will fix these.

Post by Will Deacon
Will

Robert Richter

2016-02-29 10:13:12 UTC

Post by David Daney
+static __init int numa_parse_early_param(char *opt)
+{
+ if (!opt)
+ return -EINVAL;
+ if (!strncmp(opt, "off", 3)) {
+ pr_info("%s\n", "NUMA turned off");
+ numa_off = 1;
+ }
+ return 0;
+}
+early_param("numa", numa_parse_early_param);

Curious, but when is this option actually useful?

Good point. I will remove that bit, it was used as an aid in debugging
while bringing up the patch set.

this is handy in debugging new platforms.
this boot argument option forces to boot as single node dummy system
adding all resources to node0.

This is used to disable numa in a numa enabled kernel esp. for
debugging/enabling/booting single node systems. Same kernel parameter
as for x86 and other archs. Should not being removed.

-Robert

Robert Richter

2016-02-29 17:34:59 UTC

If you move this before the remaining initializers, you will need to
clean this up on error. So better move it back after
numa_register_nodes() as it was in v10. This should work since
distances are used not earlier than numa is enabled.

-Robert

Post by David Daney
+
+ ret = init_func();
+ if (ret < 0)
+ return ret;
+
+ if (nodes_empty(numa_nodes_parsed))
+ return -EINVAL;
+
+ ret = numa_register_nodes();
+ if (ret < 0)
+ return ret;
+
+ setup_node_to_cpumask_map();
+
+ /* init boot processor */
+ cpu_to_node_map[0] = 0;
+ map_cpu_to_node(0, 0);
+
+ return 0;
+}

David Daney

2016-02-29 23:43:13 UTC

^^^^^^^^^^^^^
Cleanup for any previous numa_alloc_distance()

Post by David Daney
+
+ ret = numa_alloc_distance();
+ if (ret < 0)
+ return ret;

If you move this before the remaining initializers, you will need to
clean this up on error.

Yes, we do this. See above.

Post by Robert Richter
So better move it back after
numa_register_nodes() as it was in v10. This should work since
distances are used not earlier than numa is enabled.

I moved it here for a reason.

The init_func (of_numa_init() in this case) makes callbacks that use the
numa_distance object. We need to allocate it before using it.
Allocating it after calling the init_func() is too late.

Post by Robert Richter
-Robert

Robert Richter

2016-03-01 12:21:40 UTC

Post by David Daney
+static int __init numa_init(int (*init_func)(void))
+{
+ int ret;
+
+ nodes_clear(numa_nodes_parsed);
+ nodes_clear(node_possible_map);
+ nodes_clear(node_online_map);
+ numa_free_distance();

^^^^^^^^^^^^^
Cleanup for any previous numa_alloc_distance()

Post by David Daney
+
+ ret = numa_alloc_distance();
+ if (ret < 0)
+ return ret;

If you move this before the remaining initializers, you will need to
clean this up on error.

Yes, we do this. See above.

Post by Robert Richter
So better move it back after
numa_register_nodes() as it was in v10. This should work since
distances are used not earlier than numa is enabled.

I moved it here for a reason.
The init_func (of_numa_init() in this case) makes callbacks that use the
numa_distance object. We need to allocate it before using it. Allocating it
after calling the init_func() is too late.

Sounds reasonable and looks sane now.

Thanks,

-Robert

David Daney

2016-02-23 01:59:25 UTC

From: Ganapatrao Kulkarni <***@caviumnetworks.com>

Enable NUMA balancing for arm64 platforms.
Add pte, pmd protnone helpers for use by automatic NUMA balancing.

Reviewed-by: Robert Richter <***@cavium.com>
Signed-off-by: Ganapatrao Kulkarni <***@caviumnetworks.com>
Signed-off-by: David Daney <***@cavium.com>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/pgtable.h | 15 +++++++++++++++
2 files changed, 16 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9f0972a..6e22503 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -11,6 +11,7 @@ config ARM64
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_USE_CMPXCHG_LOCKREF
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_NUMA_BALANCING
select ARCH_WANT_OPTIONAL_GPIOLIB
select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
select ARCH_WANT_FRAME_POINTERS
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index bf464de..5af9db2 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -346,6 +346,21 @@ static inline pgprot_t mk_sect_prot(pgprot_t prot)
return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
}

+#ifdef CONFIG_NUMA_BALANCING
+/*
+ * See the comment in include/asm-generic/pgtable.h
+ */
+static inline int pte_protnone(pte_t pte)
+{
+ return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
+}
+
+static inline int pmd_protnone(pmd_t pmd)
+{
+ return pte_protnone(pmd_pte(pmd));
+}
+#endif
+
/*
* THP definitions.
*/

--
1.8.3.1

Will Deacon

2016-02-26 18:53:55 UTC

Post by David Daney
Enable NUMA balancing for arm64 platforms.
Add pte, pmd protnone helpers for use by automatic NUMA balancing.
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/pgtable.h | 15 +++++++++++++++
2 files changed, 16 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9f0972a..6e22503 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -11,6 +11,7 @@ config ARM64
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_USE_CMPXCHG_LOCKREF
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_NUMA_BALANCING
select ARCH_WANT_OPTIONAL_GPIOLIB
select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
select ARCH_WANT_FRAME_POINTERS
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index bf464de..5af9db2 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -346,6 +346,21 @@ static inline pgprot_t mk_sect_prot(pgprot_t prot)
return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
}
+#ifdef CONFIG_NUMA_BALANCING
+/*
+ * See the comment in include/asm-generic/pgtable.h
+ */
+static inline int pte_protnone(pte_t pte)
+{
+ return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
+}
+
+static inline int pmd_protnone(pmd_t pmd)
+{
+ return pte_protnone(pmd_pte(pmd));
+}
+#endif

Can these not be macros, like our other pte_* and pmd_* predicates in
this header file?

Will

David Daney

2016-02-26 19:26:18 UTC

Can these not be macros, like our other pte_* and pmd_* predicates in
this header file?

They probably could be. However there is precedence for the static
inline form:

$ git grep pte_protnone | grep '\.h' | grep -v return
arch/arm64/include/asm/pgtable.h:static inline int pte_protnone(pte_t pte)
arch/powerpc/include/asm/book3s/64/hash.h:static inline int
pte_protnone(pte_t pte)
arch/powerpc/include/asm/nohash/pgtable.h:static inline int
pte_protnone(pte_t pte)
arch/s390/include/asm/pgtable.h:static inline int pte_protnone(pte_t pte)
arch/x86/include/asm/pgtable.h:static inline int pte_protnone(pte_t pte)
include/asm-generic/pgtable.h:static inline int pte_protnone(pte_t pte)

Actually I am a little surprised that all the arm64 pte_* and pmd_*
things are not written as static inline to achieve added type safety.
The generated code should be identical.

Post by Will Deacon
Will

David Daney

2016-02-23 01:59:42 UTC

From: Ganapatrao Kulkarni <***@caviumnetworks.com>

ADD device tree node parsing for NUMA topology using device
"numa-node-id" property distance-map.

Reviewed-by: Robert Richter <***@cavium.com>
Signed-off-by: Ganapatrao Kulkarni <***@caviumnetworks.com>
Signed-off-by: David Daney <***@cavium.com>
---
drivers/of/Kconfig | 3 +
drivers/of/Makefile | 1 +
drivers/of/of_numa.c | 211 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 9 +++
4 files changed, 224 insertions(+)
create mode 100644 drivers/of/of_numa.c

diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index e2a4841..b3bec3a 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -112,4 +112,7 @@ config OF_OVERLAY
While this option is selected automatically when needed, you can
enable it manually to improve device tree unit test coverage.

+config OF_NUMA
+ bool
+
endif # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 156c072..bee3fa9 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -14,5 +14,6 @@ obj-$(CONFIG_OF_MTD) += of_mtd.o
obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
obj-$(CONFIG_OF_RESOLVE) += resolver.o
obj-$(CONFIG_OF_OVERLAY) += overlay.o
+obj-$(CONFIG_OF_NUMA) += of_numa.o

obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c
new file mode 100644
index 0000000..a691d06
--- /dev/null
+++ b/drivers/of/of_numa.c
@@ -0,0 +1,211 @@
+/*
+ * OF NUMA Parsing support.
+ *
+ * Copyright (C) 2015 - 2016 Cavium Inc.
+ * Author: Ganapatrao Kulkarni <***@cavium.com>
+ *
+ * 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 <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/nodemask.h>
+
+#include <asm/numa.h>
+
+/* define default numa node to 0 */
+#define DEFAULT_NODE 0
+
+/* Returns nid in the range [0..MAX_NUMNODES-1],
+ * or NUMA_NO_NODE if no valid numa-node-id entry found
+ * or DEFAULT_NODE if no numa-node-id entry exists
+ */
+static int of_numa_prop_to_nid(const __be32 *of_numa_prop, int length)
+{
+ int nid;
+
+ if (!of_numa_prop)
+ return DEFAULT_NODE;
+
+ if (length != sizeof(*of_numa_prop)) {
+ pr_warn("NUMA: Invalid of_numa_prop length %d found.\n",
+ length);
+ return NUMA_NO_NODE;
+ }
+
+ nid = of_read_number(of_numa_prop, 1);
+ if (nid >= MAX_NUMNODES) {
+ pr_warn("NUMA: Invalid numa node %d found.\n", nid);
+ return NUMA_NO_NODE;
+ }
+
+ return nid;
+}
+
+static int __init early_init_of_node_to_nid(unsigned long node)
+{
+ int length;
+ const __be32 *of_numa_prop;
+
+ of_numa_prop = of_get_flat_dt_prop(node, "numa-node-id", &length);
+
+ return of_numa_prop_to_nid(of_numa_prop, length);
+}
+
+/*
+ * Even though we connect cpus to numa domains later in SMP
+ * init, we need to know the node ids now for all cpus.
+*/
+static int __init early_init_parse_cpu_node(unsigned long node)
+{
+ int nid;
+ const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+
+ if (type == NULL)
+ return 0;
+
+ if (strcmp(type, "cpu") != 0)
+ return 0;
+
+ nid = early_init_of_node_to_nid(node);
+ if (nid == NUMA_NO_NODE)
+ return -EINVAL;
+
+ node_set(nid, numa_nodes_parsed);
+ return 0;
+}
+
+static int __init early_init_parse_memory_node(unsigned long node)
+{
+ const __be32 *reg, *endp;
+ int length;
+ int nid;
+ const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+
+ if (type == NULL)
+ return 0;
+
+ if (strcmp(type, "memory") != 0)
+ return 0;
+
+ nid = early_init_of_node_to_nid(node);
+ if (nid == NUMA_NO_NODE)
+ return -EINVAL;
+
+ reg = of_get_flat_dt_prop(node, "reg", &length);
+ endp = reg + (length / sizeof(__be32));
+
+ while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
+ u64 base, size;
+
+ base = dt_mem_next_cell(dt_root_addr_cells, &reg);
+ size = dt_mem_next_cell(dt_root_size_cells, &reg);
+ pr_debug("NUMA: base = %llx , node = %u\n",
+ base, nid);
+
+ if (numa_add_memblk(nid, base, size) < 0)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int __init early_init_parse_distance_map_v1(unsigned long node,
+ const char *uname)
+{
+ const __be32 *prop_dist_matrix;
+ int length = 0, i, matrix_count;
+ int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+
+ pr_info("NUMA: parsing numa-distance-map-v1\n");
+
+ prop_dist_matrix =
+ of_get_flat_dt_prop(node, "distance-matrix", &length);
+
+ if (!length) {
+ pr_err("NUMA: failed to parse distance-matrix\n");
+ return -ENODEV;
+ }
+
+ matrix_count = ((length / sizeof(__be32)) / (3 * nr_size_cells));
+
+ if ((matrix_count * sizeof(__be32) * 3 * nr_size_cells) != length) {
+ pr_warn("NUMA: invalid distance-matrix length %d\n", length);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < matrix_count; i++) {
+ u32 nodea, nodeb, distance;
+
+ nodea = dt_mem_next_cell(nr_size_cells, &prop_dist_matrix);
+ nodeb = dt_mem_next_cell(nr_size_cells, &prop_dist_matrix);
+ distance = dt_mem_next_cell(nr_size_cells, &prop_dist_matrix);
+ numa_set_distance(nodea, nodeb, distance);
+ pr_debug("NUMA: distance[node%d -> node%d] = %d\n",
+ nodea, nodeb, distance);
+
+ /* Set default distance of node B->A same as A->B */
+ if (nodeb > nodea)
+ numa_set_distance(nodeb, nodea, distance);
+ }
+
+ return 0;
+}
+
+static int __init early_init_parse_distance_map(unsigned long node,
+ const char *uname)
+{
+ if (strcmp(uname, "distance-map") != 0)
+ return 0;
+
+ if (of_flat_dt_is_compatible(node, "numa-distance-map-v1"))
+ return early_init_parse_distance_map_v1(node, uname);
+
+ pr_err("NUMA: invalid distance-map device node\n");
+ return -EINVAL;
+}
+
+static int __init early_init_of_scan_numa_map(unsigned long node,
+ const char *uname,
+ int depth, void *data)
+{
+ int ret;
+
+ ret = early_init_parse_cpu_node(node);
+ if (ret)
+ return ret;
+
+ ret = early_init_parse_memory_node(node);
+ if (ret)
+ return ret;
+
+ return early_init_parse_distance_map(node, uname);
+}
+
+int of_node_to_nid(struct device_node *device)
+{
+ const __be32 *of_numa_prop;
+ int length;
+
+ of_numa_prop = of_get_property(device, "numa-node-id", &length);
+ if (of_numa_prop)
+ return of_numa_prop_to_nid(of_numa_prop, length);
+
+ return NUMA_NO_NODE;
+}
+
+/* DT node mapping is done already early_init_of_scan_memory */
+int __init of_numa_init(void)
+{
+ return of_scan_flat_dt(early_init_of_scan_numa_map, NULL);
+}
diff --git a/include/linux/of.h b/include/linux/of.h
index dc6e396..fe67a4c 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -685,6 +685,15 @@ static inline int of_node_to_nid(struct device_node *device)
}
#endif

+#ifdef CONFIG_OF_NUMA
+extern int of_numa_init(void);
+#else
+static inline int of_numa_init(void)
+{
+ return -ENOSYS;
+}
+#endif
+
static inline struct device_node *of_find_matching_node(
struct device_node *from,
const struct of_device_id *matches)

--
1.8.3.1

Robert Richter

2016-02-29 17:30:10 UTC

Post by David Daney
ADD device tree node parsing for NUMA topology using device
"numa-node-id" property distance-map.
---
drivers/of/Kconfig | 3 +
drivers/of/Makefile | 1 +
drivers/of/of_numa.c | 211 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 9 +++
4 files changed, 224 insertions(+)
create mode 100644 drivers/of/of_numa.c
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index e2a4841..b3bec3a 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -112,4 +112,7 @@ config OF_OVERLAY
While this option is selected automatically when needed, you can
enable it manually to improve device tree unit test coverage.
+config OF_NUMA

In arch/arm64/Kconfig you now need to:

select OF_NUMA if NUMA && OF

This should depend here on OF and NUMA and enabled in that case. Why
moving that to arch code? This duplicates code as the same needs to be
implemented for every arch.

-Robert

Post by David Daney
+ bool
+
endif # OF

David Daney

2016-02-29 18:14:06 UTC

select OF_NUMA if NUMA && OF
This should depend here on OF and NUMA and enabled in that case. Why
moving that to arch code?

The dependency on of_numa.o is in the architecture specific code, so
that is where the Kconfig select should be too.

For new code, we try to avoid putting architecture specific things into
the core Kconfig files.

Since arm64 is the only architecture that is currently using this, we
don't want to select it for non-arm64 kernels that happen to select NUMA
&& OF.

I will restore the depends, as it is guard against errors in the
architecture specific Kconfig select statements, but I am going to leave
the NUMA && OF in the arm64/Kconfig for clarity.

Post by David Daney
This duplicates code as the same needs to be
implemented for every arch.

Better to duplicate a single Kconfig select statement a few times in
architecture specific Kconfig files, than force people to continuously
modify the depends in drivers/of/Kconfig

David.

Robert Richter

2016-02-29 19:45:38 UTC

select OF_NUMA if NUMA && OF
This should depend here on OF and NUMA and enabled in that case. Why
moving that to arch code?

The dependency on of_numa.o is in the architecture specific code, so that is
where the Kconfig select should be too.

If you grep for select in Kconfig files you will see that dependency
checkers in the form of select ... if ... are very rare. Since select
does not check for depends-on at all, defbool y is commonly used to
enable a config in case all dependencies match. If OF_NUMA only
supports ARM64, why not state this there? It is common to enable
certain configs in drivers/ only for a some archs.

For new code, we try to avoid putting architecture specific things into the
core Kconfig files.

But to avoid arch configs in generic Kconfigs, define HAVE_OF_NUMA,
add it as dependency to OF_NUMA and select it in arch/arm64/Kconfig.
OF_NUMA is then enabled with defbool y if all requirements are met.

This also addresses your concerns below.

-Robert

Since arm64 is the only architecture that is currently using this, we don't
want to select it for non-arm64 kernels that happen to select NUMA && OF.
I will restore the depends, as it is guard against errors in the
architecture specific Kconfig select statements, but I am going to leave the
NUMA && OF in the arm64/Kconfig for clarity.

Post by David Daney
This duplicates code as the same needs to be
implemented for every arch.

Better to duplicate a single Kconfig select statement a few times in
architecture specific Kconfig files, than force people to continuously
modify the depends in drivers/of/Kconfig

David Daney

2016-02-29 22:57:13 UTC

select OF_NUMA if NUMA && OF
This should depend here on OF and NUMA and enabled in that case. Why
moving that to arch code?

The dependency on of_numa.o is in the architecture specific code, so that is
where the Kconfig select should be too.

If you grep for select in Kconfig files you will see that dependency
checkers in the form of select ... if ... are very rare.

You are right...

$ find . -name Kconfig | xargs grep -e 'select.*if' | wc -l
1513
$ find . -name Kconfig | xargs grep -e 'select' | wc -l
14179

The 'if' variety is encountered in fewer than 11% of the cases.

That said, I am not sure if this type of statistic should be used to
evaluate code "goodness".

[...]

Post by Robert Richter
But to avoid arch configs in generic Kconfigs, define HAVE_OF_NUMA,
add it as dependency to OF_NUMA and select it in arch/arm64/Kconfig.
OF_NUMA is then enabled with defbool y if all requirements are met.

Really, what we want is NEEDS_OF_NUMA. That is exactly what "select
OF_NUMA" means.

There is no need to build a Rube Goldberg device out of these Kconfig
things. The "select OF_NUMA if NUMA && OF" is concise, allowed by the
Kconfig system and exactly expresses when the file should be compiled.

Unless there are other objections, I am going to use the the Kconfig
changes in the v12 form.

David.

David Daney

2016-02-23 02:00:02 UTC