Files
linux/drivers/acpi/numa/srat.c
Kai Huang 1e1cd49ded ACPI: NUMA: Only parse CFMWS at boot when CXL_ACPI is on
On CXL platforms, the Static Resource Affinity Table (SRAT) may not
cover memory affinity information for all the CXL memory regions.  Since
each CXL memory region is enumerated via a CXL Fixed Memory Window
Structure (CFMWS), during early boot the kernel parses the CFMWS tables
to find all CXL memory regions and sets a NUMA node for each of them.
This memory affinity information of CXL memory regions is later used by
the CXL ACPI driver.

The CFMWS table doesn't provide the memory affinity information either.
Currently the kernel assigns a 'faked' NUMA node for each CXL memory
region, starting from the next node of the highest node that is
enumerated via the SRAT.  This can potentially increase the maximum NUMA
node ID of the platform ('nr_node_ids') a lot.  E.g., on a GNR platform
with 4 NUMA nodes and 18 CFMWS tables, this bumps the 'nr_node_ids' to
22.

Increasing the 'nr_node_ids' has side effects.  For instance, it is
widely used by the kernel for "highest possible NUMA node" based memory
allocations.  It also impacts userspace ABIs, e.g., some NUMA memory
related system calls such as 'get_mempolicy' which requires 'maxnode'
not being smaller than the 'nr_node_ids'.

Currently parsing CFMWS tables and assigning faked NUMA node at boot is
done unconditionally.  However, if the CXL ACPI driver is not enabled,
there will be no user of such memory affinity information of CXL memory
regions.

Change to only parsing the CFMWS tables at boot when CXL_ACPI is enabled
in Kconfig to avoid the unnecessary cost of bumping up 'nr_node_ids'.

E.g., on the aforementioned GNR platform, the "Slab" in /proc/meminfo is
reduced with this change (when CXL_ACPI is off):

	w/ this change		w/o

Slab	900488 kB		923660 kB

Signed-off-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260308222313.14014-1-kai.huang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-03-16 10:11:25 -07:00

704 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* acpi_numa.c - ACPI NUMA support
*
* Copyright (C) 2002 Takayoshi Kochi <t-kochi@bq.jp.nec.com>
*/
#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/memory.h>
#include <linux/numa.h>
#include <linux/nodemask.h>
#include <linux/topology.h>
#include <linux/numa_memblks.h>
#include <linux/string_choices.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;
static int acpi_numa __initdata;
static int last_real_pxm;
void __init disable_srat(void)
{
acpi_numa = -1;
}
int pxm_to_node(int pxm)
{
if (pxm < 0 || pxm >= MAX_PXM_DOMAINS || numa_off)
return NUMA_NO_NODE;
return pxm_to_node_map[pxm];
}
EXPORT_SYMBOL(pxm_to_node);
int node_to_pxm(int node)
{
if (node < 0)
return PXM_INVAL;
return node_to_pxm_map[node];
}
EXPORT_SYMBOL_GPL(node_to_pxm);
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) {
node = first_unset_node(nodes_found_map);
if (node >= MAX_NUMNODES)
return NUMA_NO_NODE;
__acpi_map_pxm_to_node(pxm, node);
node_set(node, nodes_found_map);
}
return node;
}
EXPORT_SYMBOL(acpi_map_pxm_to_node);
#ifdef CONFIG_NUMA_EMU
/*
* Take max_nid - 1 fake-numa nodes into account in both
* pxm_to_node_map()/node_to_pxm_map[] tables.
*/
int __init fix_pxm_node_maps(int max_nid)
{
static int pxm_to_node_map_copy[MAX_PXM_DOMAINS] __initdata
= { [0 ... MAX_PXM_DOMAINS - 1] = NUMA_NO_NODE };
static int node_to_pxm_map_copy[MAX_NUMNODES] __initdata
= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };
int i, j, index = -1, count = 0;
nodemask_t nodes_to_enable;
if (numa_off)
return -1;
/* no or incomplete node/PXM mapping set, nothing to do */
if (srat_disabled())
return 0;
/* find fake nodes PXM mapping */
for (i = 0; i < MAX_NUMNODES; i++) {
if (node_to_pxm_map[i] != PXM_INVAL) {
for (j = 0; j <= max_nid; j++) {
if ((emu_nid_to_phys[j] == i) &&
WARN(node_to_pxm_map_copy[j] != PXM_INVAL,
"Node %d is already binded to PXM %d\n",
j, node_to_pxm_map_copy[j]))
return -1;
if (emu_nid_to_phys[j] == i) {
node_to_pxm_map_copy[j] =
node_to_pxm_map[i];
if (j > index)
index = j;
count++;
}
}
}
}
if (index == -1) {
pr_debug("No node/PXM mapping has been set\n");
/* nothing more to be done */
return 0;
}
if (WARN(index != max_nid, "%d max nid when expected %d\n",
index, max_nid))
return -1;
nodes_clear(nodes_to_enable);
/* map phys nodes not used for fake nodes */
for (i = 0; i < MAX_NUMNODES; i++) {
if (node_to_pxm_map[i] != PXM_INVAL) {
for (j = 0; j <= max_nid; j++)
if (emu_nid_to_phys[j] == i)
break;
/* fake nodes PXM mapping has been done */
if (j <= max_nid)
continue;
/* find first hole */
for (j = 0;
j < MAX_NUMNODES &&
node_to_pxm_map_copy[j] != PXM_INVAL;
j++)
;
if (WARN(j == MAX_NUMNODES,
"Number of nodes exceeds MAX_NUMNODES\n"))
return -1;
node_to_pxm_map_copy[j] = node_to_pxm_map[i];
node_set(j, nodes_to_enable);
count++;
}
}
/* creating reverse mapping in pxm_to_node_map[] */
for (i = 0; i < MAX_NUMNODES; i++)
if (node_to_pxm_map_copy[i] != PXM_INVAL &&
pxm_to_node_map_copy[node_to_pxm_map_copy[i]] == NUMA_NO_NODE)
pxm_to_node_map_copy[node_to_pxm_map_copy[i]] = i;
/* overwrite with new mapping */
for (i = 0; i < MAX_NUMNODES; i++) {
node_to_pxm_map[i] = node_to_pxm_map_copy[i];
pxm_to_node_map[i] = pxm_to_node_map_copy[i];
}
/* enable other nodes found in PXM for hotplug */
nodes_or(numa_nodes_parsed, nodes_to_enable, numa_nodes_parsed);
pr_debug("found %d total number of nodes\n", count);
return 0;
}
#endif
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,
str_enabled_disabled(p->flags & ACPI_SRAT_CPU_ENABLED));
}
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,
str_enabled_disabled(p->flags & ACPI_SRAT_MEM_ENABLED),
(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,
str_enabled_disabled(p->flags & ACPI_SRAT_CPU_ENABLED));
}
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,
str_enabled_disabled(p->flags & ACPI_SRAT_GICC_ENABLED));
}
break;
case ACPI_SRAT_TYPE_GENERIC_AFFINITY:
{
struct acpi_srat_generic_affinity *p =
(struct acpi_srat_generic_affinity *)header;
if (p->device_handle_type == 1) {
/*
* For pci devices this may be the only place they
* are assigned a proximity domain
*/
pr_debug("SRAT Generic Initiator(Seg:%u BDF:%u) in proximity domain %d %s\n",
*(u16 *)(&p->device_handle[0]),
*(u16 *)(&p->device_handle[2]),
p->proximity_domain,
str_enabled_disabled(p->flags & ACPI_SRAT_GENERIC_AFFINITY_ENABLED));
} else {
/*
* In this case we can rely on the device having a
* proximity domain reference
*/
pr_debug("SRAT Generic Initiator(HID=%.8s UID=%.4s) in proximity domain %d %s\n",
(char *)(&p->device_handle[0]),
(char *)(&p->device_handle[8]),
p->proximity_domain,
str_enabled_disabled(p->flags & ACPI_SRAT_GENERIC_AFFINITY_ENABLED));
}
}
break;
case ACPI_SRAT_TYPE_RINTC_AFFINITY:
{
struct acpi_srat_rintc_affinity *p =
(struct acpi_srat_rintc_affinity *)header;
pr_debug("SRAT Processor (acpi id[0x%04x]) in proximity domain %d %s\n",
p->acpi_processor_uid,
p->proximity_domain,
str_enabled_disabled(p->flags & ACPI_SRAT_RINTC_ENABLED));
}
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");
disable_srat();
}
int __init srat_disabled(void)
{
return acpi_numa < 0;
}
__weak int __init numa_fill_memblks(u64 start, u64 end)
{
return NUMA_NO_MEMBLK;
}
/*
* 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.
*/
static int __init acpi_parse_slit(struct acpi_table_header *table)
{
struct acpi_table_slit *slit = (struct acpi_table_slit *)table;
int i, j;
if (!slit_valid(slit)) {
pr_info("SLIT table looks invalid. Not used.\n");
return -EINVAL;
}
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]);
}
}
return 0;
}
static int parsed_numa_memblks __initdata;
static int __init
acpi_parse_memory_affinity(union acpi_subtable_headers *header,
const unsigned long table_end)
{
struct acpi_srat_mem_affinity *ma;
u64 start, end;
u32 hotpluggable;
int node, pxm;
ma = (struct acpi_srat_mem_affinity *)header;
acpi_table_print_srat_entry(&header->common);
if (srat_disabled())
return 0;
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)
return 0;
hotpluggable = IS_ENABLED(CONFIG_MEMORY_HOTPLUG) &&
(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE);
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) {
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));
parsed_numa_memblks++;
return 0;
out_err_bad_srat:
/* Just disable SRAT, but do not fail and ignore errors. */
bad_srat();
return 0;
}
static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
void *arg, const unsigned long table_end)
{
struct acpi_cedt_cfmws *cfmws;
int *fake_pxm = arg;
u64 start, end, align;
int node;
int err;
cfmws = (struct acpi_cedt_cfmws *)header;
start = cfmws->base_hpa;
end = cfmws->base_hpa + cfmws->window_size;
/* Align memblock size to CFMW regions if possible */
align = 1UL << __ffs(start | end);
if (align >= SZ_256M) {
err = memory_block_advise_max_size(align);
if (err)
pr_warn("CFMWS: memblock size advise failed (%d)\n", err);
} else
pr_err("CFMWS: [BIOS BUG] base/size alignment violates spec\n");
/*
* The SRAT may have already described NUMA details for all,
* or a portion of, this CFMWS HPA range. Extend the memblks
* found for any portion of the window to cover the entire
* window.
*/
if (!numa_fill_memblks(start, end))
return 0;
/* No SRAT description. Create a new node. */
node = acpi_map_pxm_to_node(*fake_pxm);
if (node == NUMA_NO_NODE) {
pr_err("ACPI NUMA: Too many proximity domains while processing CFMWS.\n");
return -EINVAL;
}
if (numa_add_reserved_memblk(node, start, end) < 0) {
/* CXL driver must handle the NUMA_NO_NODE case */
pr_warn("ACPI NUMA: Failed to add memblk for CFMWS node %d [mem %#llx-%#llx]\n",
node, start, end);
}
node_set(node, numa_nodes_parsed);
/* Set the next available fake_pxm value */
(*fake_pxm)++;
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(union acpi_subtable_headers *header,
const unsigned long end)
{
struct acpi_srat_x2apic_cpu_affinity *processor_affinity;
processor_affinity = (struct acpi_srat_x2apic_cpu_affinity *)header;
acpi_table_print_srat_entry(&header->common);
/* let architecture-dependent part to do it */
acpi_numa_x2apic_affinity_init(processor_affinity);
return 0;
}
static int __init
acpi_parse_processor_affinity(union acpi_subtable_headers *header,
const unsigned long end)
{
struct acpi_srat_cpu_affinity *processor_affinity;
processor_affinity = (struct acpi_srat_cpu_affinity *)header;
acpi_table_print_srat_entry(&header->common);
/* let architecture-dependent part to do it */
acpi_numa_processor_affinity_init(processor_affinity);
return 0;
}
static int __init
acpi_parse_gicc_affinity(union acpi_subtable_headers *header,
const unsigned long end)
{
struct acpi_srat_gicc_affinity *processor_affinity;
processor_affinity = (struct acpi_srat_gicc_affinity *)header;
acpi_table_print_srat_entry(&header->common);
/* let architecture-dependent part to do it */
acpi_numa_gicc_affinity_init(processor_affinity);
return 0;
}
#if defined(CONFIG_X86) || defined(CONFIG_ARM64)
static int __init
acpi_parse_gi_affinity(union acpi_subtable_headers *header,
const unsigned long end)
{
struct acpi_srat_generic_affinity *gi_affinity;
int node;
gi_affinity = (struct acpi_srat_generic_affinity *)header;
if (!gi_affinity)
return -EINVAL;
acpi_table_print_srat_entry(&header->common);
if (!(gi_affinity->flags & ACPI_SRAT_GENERIC_AFFINITY_ENABLED))
return -EINVAL;
node = acpi_map_pxm_to_node(gi_affinity->proximity_domain);
if (node == NUMA_NO_NODE) {
pr_err("SRAT: Too many proximity domains.\n");
return -EINVAL;
}
node_set(node, numa_nodes_parsed);
node_set_state(node, N_GENERIC_INITIATOR);
return 0;
}
#else
static int __init
acpi_parse_gi_affinity(union acpi_subtable_headers *header,
const unsigned long end)
{
return 0;
}
#endif /* defined(CONFIG_X86) || defined (CONFIG_ARM64) */
static int __init
acpi_parse_rintc_affinity(union acpi_subtable_headers *header,
const unsigned long end)
{
struct acpi_srat_rintc_affinity *rintc_affinity;
rintc_affinity = (struct acpi_srat_rintc_affinity *)header;
acpi_table_print_srat_entry(&header->common);
/* let architecture-dependent part to do it */
acpi_numa_rintc_affinity_init(rintc_affinity);
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 i, fake_pxm, 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[5];
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;
srat_proc[3].id = ACPI_SRAT_TYPE_GENERIC_AFFINITY;
srat_proc[3].handler = acpi_parse_gi_affinity;
srat_proc[4].id = ACPI_SRAT_TYPE_RINTC_AFFINITY;
srat_proc[4].handler = acpi_parse_rintc_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);
/*
* CXL Fixed Memory Window Structures (CFMWS) must be parsed
* after the SRAT. Create NUMA Nodes for CXL memory ranges that
* are defined in the CFMWS and not already defined in the SRAT.
* Initialize a fake_pxm as the first available PXM to emulate.
*/
/* fake_pxm is the next unused PXM value after SRAT parsing */
for (i = 0, fake_pxm = -1; i < MAX_NUMNODES; i++) {
if (node_to_pxm_map[i] > fake_pxm)
fake_pxm = node_to_pxm_map[i];
}
last_real_pxm = fake_pxm;
fake_pxm++;
/* No need to expand numa nodes if CXL is disabled */
if (IS_ENABLED(CONFIG_CXL_ACPI))
acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, acpi_parse_cfmws,
&fake_pxm);
if (cnt < 0)
return cnt;
else if (!parsed_numa_memblks)
return -ENOENT;
return 0;
}
bool acpi_node_backed_by_real_pxm(int nid)
{
int pxm = node_to_pxm(nid);
return pxm <= last_real_pxm;
}
EXPORT_SYMBOL_GPL(acpi_node_backed_by_real_pxm);
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 pxm_to_node(pxm);
}
EXPORT_SYMBOL(acpi_get_node);