linux/drivers/acpi/numa.c
Linus Torvalds f67e3fb489 device-dax for 5.1
* Replace the /sys/class/dax device model with /sys/bus/dax, and include
   a compat driver so distributions can opt-in to the new ABI.
 
 * Allow for an alternative driver for the device-dax address-range
 
 * Introduce the 'kmem' driver to hotplug / assign a device-dax
   address-range to the core-mm.
 
 * Arrange for the device-dax target-node to be onlined so that the newly
   added memory range can be uniquely referenced by numa apis.
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Merge tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull device-dax updates from Dan Williams:
 "New device-dax infrastructure to allow persistent memory and other
  "reserved" / performance differentiated memories, to be assigned to
  the core-mm as "System RAM".

  Some users want to use persistent memory as additional volatile
  memory. They are willing to cope with potential performance
  differences, for example between DRAM and 3D Xpoint, and want to use
  typical Linux memory management apis rather than a userspace memory
  allocator layered over an mmap() of a dax file. The administration
  model is to decide how much Persistent Memory (pmem) to use as System
  RAM, create a device-dax-mode namespace of that size, and then assign
  it to the core-mm. The rationale for device-dax is that it is a
  generic memory-mapping driver that can be layered over any "special
  purpose" memory, not just pmem. On subsequent boots udev rules can be
  used to restore the memory assignment.

  One implication of using pmem as RAM is that mlock() no longer keeps
  data off persistent media. For this reason it is recommended to enable
  NVDIMM Security (previously merged for 5.0) to encrypt pmem contents
  at rest. We considered making this recommendation an actively enforced
  requirement, but in the end decided to leave it as a distribution /
  administrator policy to allow for emulation and test environments that
  lack security capable NVDIMMs.

  Summary:

   - Replace the /sys/class/dax device model with /sys/bus/dax, and
     include a compat driver so distributions can opt-in to the new ABI.

   - Allow for an alternative driver for the device-dax address-range

   - Introduce the 'kmem' driver to hotplug / assign a device-dax
     address-range to the core-mm.

   - Arrange for the device-dax target-node to be onlined so that the
     newly added memory range can be uniquely referenced by numa apis"

NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because
we currently have special - and very annoying rules in the kernel about
accessing PMEM only with the "MC safe" accessors, because machine checks
inside the regular repeat string copy functions can be fatal in some
(not described) circumstances.

And apparently the PMEM modules can cause that a lot more than regular
RAM.  The argument is that this happens because PMEM doesn't necessarily
get scrubbed at boot like RAM does, but that is planned to be added for
the user space tooling.

Quoting Dan from another email:
 "The exposure can be reduced in the volatile-RAM case by scanning for
  and clearing errors before it is onlined as RAM. The userspace tooling
  for that can be in place before v5.1-final. There's also runtime
  notifications of errors via acpi_nfit_uc_error_notify() from
  background scrubbers on the DIMM devices. With that mechanism the
  kernel could proactively clear newly discovered poison in the volatile
  case, but that would be additional development more suitable for v5.2.

  I understand the concern, and the need to highlight this issue by
  tapping the brakes on feature development, but I don't see PMEM as RAM
  making the situation worse when the exposure is also there via DAX in
  the PMEM case. Volatile-RAM is arguably a safer use case since it's
  possible to repair pages where the persistent case needs active
  application coordination"

* tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  device-dax: "Hotplug" persistent memory for use like normal RAM
  mm/resource: Let walk_system_ram_range() search child resources
  mm/memory-hotplug: Allow memory resources to be children
  mm/resource: Move HMM pr_debug() deeper into resource code
  mm/resource: Return real error codes from walk failures
  device-dax: Add a 'modalias' attribute to DAX 'bus' devices
  device-dax: Add a 'target_node' attribute
  device-dax: Auto-bind device after successful new_id
  acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node
  device-dax: Add /sys/class/dax backwards compatibility
  device-dax: Add support for a dax override driver
  device-dax: Move resource pinning+mapping into the common driver
  device-dax: Introduce bus + driver model
  device-dax: Start defining a dax bus model
  device-dax: Remove multi-resource infrastructure
  device-dax: Kill dax_region base
  device-dax: Kill dax_region ida
2019-03-16 13:05:32 -07:00

504 lines
13 KiB
C

/*
* acpi_numa.c - ACPI NUMA support
*
* Copyright (C) 2002 Takayoshi Kochi <t-kochi@bq.jp.nec.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
*/
#define pr_fmt(fmt) "ACPI: " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/acpi.h>
#include <linux/memblock.h>
#include <linux/numa.h>
#include <linux/nodemask.h>
#include <linux/topology.h>
static nodemask_t nodes_found_map = NODE_MASK_NONE;
/* maps to convert between proximity domain and logical node ID */
static int pxm_to_node_map[MAX_PXM_DOMAINS]
= { [0 ... MAX_PXM_DOMAINS - 1] = NUMA_NO_NODE };
static int node_to_pxm_map[MAX_NUMNODES]
= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };
unsigned char acpi_srat_revision __initdata;
int acpi_numa __initdata;
int pxm_to_node(int pxm)
{
if (pxm < 0)
return NUMA_NO_NODE;
return pxm_to_node_map[pxm];
}
int node_to_pxm(int node)
{
if (node < 0)
return PXM_INVAL;
return node_to_pxm_map[node];
}
static void __acpi_map_pxm_to_node(int pxm, int node)
{
if (pxm_to_node_map[pxm] == NUMA_NO_NODE || node < pxm_to_node_map[pxm])
pxm_to_node_map[pxm] = node;
if (node_to_pxm_map[node] == PXM_INVAL || pxm < node_to_pxm_map[node])
node_to_pxm_map[node] = pxm;
}
int acpi_map_pxm_to_node(int pxm)
{
int node;
if (pxm < 0 || pxm >= MAX_PXM_DOMAINS || numa_off)
return NUMA_NO_NODE;
node = pxm_to_node_map[pxm];
if (node == NUMA_NO_NODE) {
if (nodes_weight(nodes_found_map) >= MAX_NUMNODES)
return NUMA_NO_NODE;
node = first_unset_node(nodes_found_map);
__acpi_map_pxm_to_node(pxm, node);
node_set(node, nodes_found_map);
}
return node;
}
EXPORT_SYMBOL(acpi_map_pxm_to_node);
/**
* acpi_map_pxm_to_online_node - Map proximity ID to online node
* @pxm: ACPI proximity ID
*
* This is similar to acpi_map_pxm_to_node(), but always returns an online
* node. When the mapped node from a given proximity ID is offline, it
* looks up the node distance table and returns the nearest online node.
*
* ACPI device drivers, which are called after the NUMA initialization has
* completed in the kernel, can call this interface to obtain their device
* NUMA topology from ACPI tables. Such drivers do not have to deal with
* offline nodes. A node may be offline when a device proximity ID is
* unique, SRAT memory entry does not exist, or NUMA is disabled, ex.
* "numa=off" on x86.
*/
int acpi_map_pxm_to_online_node(int pxm)
{
int node, min_node;
node = acpi_map_pxm_to_node(pxm);
if (node == NUMA_NO_NODE)
node = 0;
min_node = node;
if (!node_online(node)) {
int min_dist = INT_MAX, dist, n;
for_each_online_node(n) {
dist = node_distance(node, n);
if (dist < min_dist) {
min_dist = dist;
min_node = n;
}
}
}
return min_node;
}
EXPORT_SYMBOL(acpi_map_pxm_to_online_node);
static void __init
acpi_table_print_srat_entry(struct acpi_subtable_header *header)
{
switch (header->type) {
case ACPI_SRAT_TYPE_CPU_AFFINITY:
{
struct acpi_srat_cpu_affinity *p =
(struct acpi_srat_cpu_affinity *)header;
pr_debug("SRAT Processor (id[0x%02x] eid[0x%02x]) in proximity domain %d %s\n",
p->apic_id, p->local_sapic_eid,
p->proximity_domain_lo,
(p->flags & ACPI_SRAT_CPU_ENABLED) ?
"enabled" : "disabled");
}
break;
case ACPI_SRAT_TYPE_MEMORY_AFFINITY:
{
struct acpi_srat_mem_affinity *p =
(struct acpi_srat_mem_affinity *)header;
pr_debug("SRAT Memory (0x%llx length 0x%llx) in proximity domain %d %s%s%s\n",
(unsigned long long)p->base_address,
(unsigned long long)p->length,
p->proximity_domain,
(p->flags & ACPI_SRAT_MEM_ENABLED) ?
"enabled" : "disabled",
(p->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) ?
" hot-pluggable" : "",
(p->flags & ACPI_SRAT_MEM_NON_VOLATILE) ?
" non-volatile" : "");
}
break;
case ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY:
{
struct acpi_srat_x2apic_cpu_affinity *p =
(struct acpi_srat_x2apic_cpu_affinity *)header;
pr_debug("SRAT Processor (x2apicid[0x%08x]) in proximity domain %d %s\n",
p->apic_id,
p->proximity_domain,
(p->flags & ACPI_SRAT_CPU_ENABLED) ?
"enabled" : "disabled");
}
break;
case ACPI_SRAT_TYPE_GICC_AFFINITY:
{
struct acpi_srat_gicc_affinity *p =
(struct acpi_srat_gicc_affinity *)header;
pr_debug("SRAT Processor (acpi id[0x%04x]) in proximity domain %d %s\n",
p->acpi_processor_uid,
p->proximity_domain,
(p->flags & ACPI_SRAT_GICC_ENABLED) ?
"enabled" : "disabled");
}
break;
default:
pr_warn("Found unsupported SRAT entry (type = 0x%x)\n",
header->type);
break;
}
}
/*
* A lot of BIOS fill in 10 (= no distance) everywhere. This messes
* up the NUMA heuristics which wants the local node to have a smaller
* distance than the others.
* Do some quick checks here and only use the SLIT if it passes.
*/
static int __init slit_valid(struct acpi_table_slit *slit)
{
int i, j;
int d = slit->locality_count;
for (i = 0; i < d; i++) {
for (j = 0; j < d; j++) {
u8 val = slit->entry[d*i + j];
if (i == j) {
if (val != LOCAL_DISTANCE)
return 0;
} else if (val <= LOCAL_DISTANCE)
return 0;
}
}
return 1;
}
void __init bad_srat(void)
{
pr_err("SRAT: SRAT not used.\n");
acpi_numa = -1;
}
int __init srat_disabled(void)
{
return acpi_numa < 0;
}
#if defined(CONFIG_X86) || defined(CONFIG_ARM64)
/*
* Callback for SLIT parsing. pxm_to_node() returns NUMA_NO_NODE for
* I/O localities since SRAT does not list them. I/O localities are
* not supported at this point.
*/
void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
{
int i, j;
for (i = 0; i < slit->locality_count; i++) {
const int from_node = pxm_to_node(i);
if (from_node == NUMA_NO_NODE)
continue;
for (j = 0; j < slit->locality_count; j++) {
const int to_node = pxm_to_node(j);
if (to_node == NUMA_NO_NODE)
continue;
numa_set_distance(from_node, to_node,
slit->entry[slit->locality_count * i + j]);
}
}
}
/*
* Default callback for parsing of the Proximity Domain <-> Memory
* Area mappings
*/
int __init
acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
{
u64 start, end;
u32 hotpluggable;
int node, pxm;
if (srat_disabled())
goto out_err;
if (ma->header.length < sizeof(struct acpi_srat_mem_affinity)) {
pr_err("SRAT: Unexpected header length: %d\n",
ma->header.length);
goto out_err_bad_srat;
}
if ((ma->flags & ACPI_SRAT_MEM_ENABLED) == 0)
goto out_err;
hotpluggable = ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE;
if (hotpluggable && !IS_ENABLED(CONFIG_MEMORY_HOTPLUG))
goto out_err;
start = ma->base_address;
end = start + ma->length;
pxm = ma->proximity_domain;
if (acpi_srat_revision <= 1)
pxm &= 0xff;
node = acpi_map_pxm_to_node(pxm);
if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
pr_err("SRAT: Too many proximity domains.\n");
goto out_err_bad_srat;
}
if (numa_add_memblk(node, start, end) < 0) {
pr_err("SRAT: Failed to add memblk to node %u [mem %#010Lx-%#010Lx]\n",
node, (unsigned long long) start,
(unsigned long long) end - 1);
goto out_err_bad_srat;
}
node_set(node, numa_nodes_parsed);
pr_info("SRAT: Node %u PXM %u [mem %#010Lx-%#010Lx]%s%s\n",
node, pxm,
(unsigned long long) start, (unsigned long long) end - 1,
hotpluggable ? " hotplug" : "",
ma->flags & ACPI_SRAT_MEM_NON_VOLATILE ? " non-volatile" : "");
/* Mark hotplug range in memblock. */
if (hotpluggable && memblock_mark_hotplug(start, ma->length))
pr_warn("SRAT: Failed to mark hotplug range [mem %#010Lx-%#010Lx] in memblock\n",
(unsigned long long)start, (unsigned long long)end - 1);
max_possible_pfn = max(max_possible_pfn, PFN_UP(end - 1));
return 0;
out_err_bad_srat:
bad_srat();
out_err:
return -EINVAL;
}
#endif /* defined(CONFIG_X86) || defined (CONFIG_ARM64) */
static int __init acpi_parse_slit(struct acpi_table_header *table)
{
struct acpi_table_slit *slit = (struct acpi_table_slit *)table;
if (!slit_valid(slit)) {
pr_info("SLIT table looks invalid. Not used.\n");
return -EINVAL;
}
acpi_numa_slit_init(slit);
return 0;
}
void __init __weak
acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)
{
pr_warn("Found unsupported x2apic [0x%08x] SRAT entry\n", pa->apic_id);
}
static int __init
acpi_parse_x2apic_affinity(struct acpi_subtable_header *header,
const unsigned long end)
{
struct acpi_srat_x2apic_cpu_affinity *processor_affinity;
processor_affinity = (struct acpi_srat_x2apic_cpu_affinity *)header;
if (!processor_affinity)
return -EINVAL;
acpi_table_print_srat_entry(header);
/* let architecture-dependent part to do it */
acpi_numa_x2apic_affinity_init(processor_affinity);
return 0;
}
static int __init
acpi_parse_processor_affinity(struct acpi_subtable_header *header,
const unsigned long end)
{
struct acpi_srat_cpu_affinity *processor_affinity;
processor_affinity = (struct acpi_srat_cpu_affinity *)header;
if (!processor_affinity)
return -EINVAL;
acpi_table_print_srat_entry(header);
/* let architecture-dependent part to do it */
acpi_numa_processor_affinity_init(processor_affinity);
return 0;
}
static int __init
acpi_parse_gicc_affinity(struct acpi_subtable_header *header,
const unsigned long end)
{
struct acpi_srat_gicc_affinity *processor_affinity;
processor_affinity = (struct acpi_srat_gicc_affinity *)header;
if (!processor_affinity)
return -EINVAL;
acpi_table_print_srat_entry(header);
/* let architecture-dependent part to do it */
acpi_numa_gicc_affinity_init(processor_affinity);
return 0;
}
static int __initdata parsed_numa_memblks;
static int __init
acpi_parse_memory_affinity(struct acpi_subtable_header * header,
const unsigned long end)
{
struct acpi_srat_mem_affinity *memory_affinity;
memory_affinity = (struct acpi_srat_mem_affinity *)header;
if (!memory_affinity)
return -EINVAL;
acpi_table_print_srat_entry(header);
/* let architecture-dependent part to do it */
if (!acpi_numa_memory_affinity_init(memory_affinity))
parsed_numa_memblks++;
return 0;
}
static int __init acpi_parse_srat(struct acpi_table_header *table)
{
struct acpi_table_srat *srat = (struct acpi_table_srat *)table;
acpi_srat_revision = srat->header.revision;
/* Real work done in acpi_table_parse_srat below. */
return 0;
}
static int __init
acpi_table_parse_srat(enum acpi_srat_type id,
acpi_tbl_entry_handler handler, unsigned int max_entries)
{
return acpi_table_parse_entries(ACPI_SIG_SRAT,
sizeof(struct acpi_table_srat), id,
handler, max_entries);
}
int __init acpi_numa_init(void)
{
int cnt = 0;
if (acpi_disabled)
return -EINVAL;
/*
* Should not limit number with cpu num that is from NR_CPUS or nr_cpus=
* SRAT cpu entries could have different order with that in MADT.
* So go over all cpu entries in SRAT to get apicid to node mapping.
*/
/* SRAT: System Resource Affinity Table */
if (!acpi_table_parse(ACPI_SIG_SRAT, acpi_parse_srat)) {
struct acpi_subtable_proc srat_proc[3];
memset(srat_proc, 0, sizeof(srat_proc));
srat_proc[0].id = ACPI_SRAT_TYPE_CPU_AFFINITY;
srat_proc[0].handler = acpi_parse_processor_affinity;
srat_proc[1].id = ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY;
srat_proc[1].handler = acpi_parse_x2apic_affinity;
srat_proc[2].id = ACPI_SRAT_TYPE_GICC_AFFINITY;
srat_proc[2].handler = acpi_parse_gicc_affinity;
acpi_table_parse_entries_array(ACPI_SIG_SRAT,
sizeof(struct acpi_table_srat),
srat_proc, ARRAY_SIZE(srat_proc), 0);
cnt = acpi_table_parse_srat(ACPI_SRAT_TYPE_MEMORY_AFFINITY,
acpi_parse_memory_affinity, 0);
}
/* SLIT: System Locality Information Table */
acpi_table_parse(ACPI_SIG_SLIT, acpi_parse_slit);
if (cnt < 0)
return cnt;
else if (!parsed_numa_memblks)
return -ENOENT;
return 0;
}
static int acpi_get_pxm(acpi_handle h)
{
unsigned long long pxm;
acpi_status status;
acpi_handle handle;
acpi_handle phandle = h;
do {
handle = phandle;
status = acpi_evaluate_integer(handle, "_PXM", NULL, &pxm);
if (ACPI_SUCCESS(status))
return pxm;
status = acpi_get_parent(handle, &phandle);
} while (ACPI_SUCCESS(status));
return -1;
}
int acpi_get_node(acpi_handle handle)
{
int pxm;
pxm = acpi_get_pxm(handle);
return acpi_map_pxm_to_node(pxm);
}
EXPORT_SYMBOL(acpi_get_node);