NetBSD/sys/kern/subr_kcpuset.c

544 lines
12 KiB
C

/* $NetBSD: subr_kcpuset.c,v 1.11 2014/05/19 20:39:23 rmind Exp $ */
/*-
* Copyright (c) 2011 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Mindaugas Rasiukevicius.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Kernel CPU set implementation.
*
* Interface can be used by kernel subsystems as a unified dynamic CPU
* bitset implementation handling many CPUs. Facility also supports early
* use by MD code on boot, as it fixups bitsets on further boot.
*
* TODO:
* - Handle "reverse" bitset on fixup/grow.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_kcpuset.c,v 1.11 2014/05/19 20:39:23 rmind Exp $");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/atomic.h>
#include <sys/sched.h>
#include <sys/kcpuset.h>
#include <sys/pool.h>
/* Number of CPUs to support. */
#define KC_MAXCPUS roundup2(MAXCPUS, 32)
/*
* Structure of dynamic CPU set in the kernel.
*/
struct kcpuset {
uint32_t bits[0];
};
typedef struct kcpuset_impl {
/* Reference count. */
u_int kc_refcnt;
/* Next to free, if non-NULL (used when multiple references). */
struct kcpuset * kc_next;
/* Actual variable-sized field of bits. */
struct kcpuset kc_field;
} kcpuset_impl_t;
#define KC_BITS_OFF (offsetof(struct kcpuset_impl, kc_field))
#define KC_GETSTRUCT(b) ((kcpuset_impl_t *)((char *)(b) - KC_BITS_OFF))
#define KC_GETCSTRUCT(b) ((const kcpuset_impl_t *)((const char *)(b) - KC_BITS_OFF))
/* Sizes of a single bitset. */
#define KC_SHIFT 5
#define KC_MASK 31
/* An array of noted early kcpuset creations and data. */
#define KC_SAVE_NITEMS 8
/* Structures for early boot mechanism (must be statically initialised). */
static kcpuset_t ** kc_noted_early[KC_SAVE_NITEMS];
static uint32_t kc_bits_early[KC_SAVE_NITEMS];
static int kc_last_idx = 0;
static bool kc_initialised = false;
#define KC_BITSIZE_EARLY sizeof(kc_bits_early[0])
#define KC_NFIELDS_EARLY 1
/*
* The size of whole bitset fields and amount of fields.
* The whole size must statically initialise for early case.
*/
static size_t kc_bitsize __read_mostly = KC_BITSIZE_EARLY;
static size_t kc_nfields __read_mostly = KC_NFIELDS_EARLY;
static pool_cache_t kc_cache __read_mostly;
static kcpuset_t * kcpuset_create_raw(bool);
/*
* kcpuset_sysinit: initialize the subsystem, transfer early boot cases
* to dynamically allocated sets.
*/
void
kcpuset_sysinit(void)
{
kcpuset_t *kc_dynamic[KC_SAVE_NITEMS], *kcp;
int i, s;
/* Set a kcpuset_t sizes. */
kc_nfields = (KC_MAXCPUS >> KC_SHIFT);
kc_bitsize = sizeof(uint32_t) * kc_nfields;
KASSERT(kc_nfields != 0 && kc_bitsize != 0);
kc_cache = pool_cache_init(sizeof(kcpuset_impl_t) + kc_bitsize,
coherency_unit, 0, 0, "kcpuset", NULL, IPL_NONE, NULL, NULL, NULL);
/* First, pre-allocate kcpuset entries. */
for (i = 0; i < kc_last_idx; i++) {
kcp = kcpuset_create_raw(true);
kc_dynamic[i] = kcp;
}
/*
* Prepare to convert all early noted kcpuset uses to dynamic sets.
* All processors, except the one we are currently running (primary),
* must not be spinned yet. Since MD facilities can use kcpuset,
* raise the IPL to high.
*/
KASSERT(mp_online == false);
s = splhigh();
for (i = 0; i < kc_last_idx; i++) {
/*
* Transfer the bits from early static storage to the kcpuset.
*/
KASSERT(kc_bitsize >= KC_BITSIZE_EARLY);
memcpy(kc_dynamic[i], &kc_bits_early[i], KC_BITSIZE_EARLY);
/*
* Store the new pointer, pointing to the allocated kcpuset.
* Note: we are not in an interrupt context and it is the only
* CPU running - thus store is safe (e.g. no need for pointer
* variable to be volatile).
*/
*kc_noted_early[i] = kc_dynamic[i];
}
kc_initialised = true;
kc_last_idx = 0;
splx(s);
}
/*
* kcpuset_early_ptr: note an early boot use by saving the pointer and
* returning a pointer to a static, temporary bit field.
*/
static kcpuset_t *
kcpuset_early_ptr(kcpuset_t **kcptr)
{
kcpuset_t *kcp;
int s;
s = splhigh();
if (kc_last_idx < KC_SAVE_NITEMS) {
/*
* Save the pointer, return pointer to static early field.
* Need to zero it out.
*/
kc_noted_early[kc_last_idx] = kcptr;
kcp = (kcpuset_t *)&kc_bits_early[kc_last_idx];
kc_last_idx++;
memset(kcp, 0, KC_BITSIZE_EARLY);
KASSERT(kc_bitsize == KC_BITSIZE_EARLY);
} else {
panic("kcpuset(9): all early-use entries exhausted; "
"increase KC_SAVE_NITEMS\n");
}
splx(s);
return kcp;
}
/*
* Routines to create or destroy the CPU set.
* Early boot case is handled.
*/
static kcpuset_t *
kcpuset_create_raw(bool zero)
{
kcpuset_impl_t *kc;
kc = pool_cache_get(kc_cache, PR_WAITOK);
kc->kc_refcnt = 1;
kc->kc_next = NULL;
if (zero) {
memset(&kc->kc_field, 0, kc_bitsize);
}
/* Note: return pointer to the actual field of bits. */
KASSERT((uint8_t *)kc + KC_BITS_OFF == (uint8_t *)&kc->kc_field);
return &kc->kc_field;
}
void
kcpuset_create(kcpuset_t **retkcp, bool zero)
{
if (__predict_false(!kc_initialised)) {
/* Early boot use - special case. */
*retkcp = kcpuset_early_ptr(retkcp);
return;
}
*retkcp = kcpuset_create_raw(zero);
}
void
kcpuset_clone(kcpuset_t **retkcp, const kcpuset_t *kcp)
{
kcpuset_create(retkcp, false);
memcpy(*retkcp, kcp, kc_bitsize);
}
void
kcpuset_destroy(kcpuset_t *kcp)
{
kcpuset_impl_t *kc;
KASSERT(kc_initialised);
KASSERT(kcp != NULL);
do {
kc = KC_GETSTRUCT(kcp);
kcp = kc->kc_next;
pool_cache_put(kc_cache, kc);
} while (kcp);
}
/*
* Routines to reference/unreference the CPU set.
* Note: early boot case is not supported by these routines.
*/
void
kcpuset_use(kcpuset_t *kcp)
{
kcpuset_impl_t *kc = KC_GETSTRUCT(kcp);
KASSERT(kc_initialised);
atomic_inc_uint(&kc->kc_refcnt);
}
void
kcpuset_unuse(kcpuset_t *kcp, kcpuset_t **lst)
{
kcpuset_impl_t *kc = KC_GETSTRUCT(kcp);
KASSERT(kc_initialised);
KASSERT(kc->kc_refcnt > 0);
if (atomic_dec_uint_nv(&kc->kc_refcnt) != 0) {
return;
}
KASSERT(kc->kc_next == NULL);
if (lst == NULL) {
kcpuset_destroy(kcp);
return;
}
kc->kc_next = *lst;
*lst = kcp;
}
/*
* Routines to transfer the CPU set from / to userspace.
* Note: early boot case is not supported by these routines.
*/
int
kcpuset_copyin(const cpuset_t *ucp, kcpuset_t *kcp, size_t len)
{
kcpuset_impl_t *kc __diagused = KC_GETSTRUCT(kcp);
KASSERT(kc_initialised);
KASSERT(kc->kc_refcnt > 0);
KASSERT(kc->kc_next == NULL);
if (len > kc_bitsize) { /* XXX */
return EINVAL;
}
return copyin(ucp, kcp, len);
}
int
kcpuset_copyout(kcpuset_t *kcp, cpuset_t *ucp, size_t len)
{
kcpuset_impl_t *kc __diagused = KC_GETSTRUCT(kcp);
KASSERT(kc_initialised);
KASSERT(kc->kc_refcnt > 0);
KASSERT(kc->kc_next == NULL);
if (len > kc_bitsize) { /* XXX */
return EINVAL;
}
return copyout(kcp, ucp, len);
}
void
kcpuset_export_u32(const kcpuset_t *kcp, uint32_t *bitfield, size_t len)
{
size_t rlen = MIN(kc_bitsize, len);
KASSERT(kcp != NULL);
memcpy(bitfield, kcp->bits, rlen);
}
/*
* Routines to change bit field - zero, fill, copy, set, unset, etc.
*/
void
kcpuset_zero(kcpuset_t *kcp)
{
KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_refcnt > 0);
KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_next == NULL);
memset(kcp, 0, kc_bitsize);
}
void
kcpuset_fill(kcpuset_t *kcp)
{
KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_refcnt > 0);
KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_next == NULL);
memset(kcp, ~0, kc_bitsize);
}
void
kcpuset_copy(kcpuset_t *dkcp, const kcpuset_t *skcp)
{
KASSERT(!kc_initialised || KC_GETSTRUCT(dkcp)->kc_refcnt > 0);
KASSERT(!kc_initialised || KC_GETSTRUCT(dkcp)->kc_next == NULL);
memcpy(dkcp, skcp, kc_bitsize);
}
void
kcpuset_set(kcpuset_t *kcp, cpuid_t i)
{
const size_t j = i >> KC_SHIFT;
KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_next == NULL);
KASSERT(j < kc_nfields);
kcp->bits[j] |= 1 << (i & KC_MASK);
}
void
kcpuset_clear(kcpuset_t *kcp, cpuid_t i)
{
const size_t j = i >> KC_SHIFT;
KASSERT(!kc_initialised || KC_GETCSTRUCT(kcp)->kc_next == NULL);
KASSERT(j < kc_nfields);
kcp->bits[j] &= ~(1 << (i & KC_MASK));
}
bool
kcpuset_isset(const kcpuset_t *kcp, cpuid_t i)
{
const size_t j = i >> KC_SHIFT;
KASSERT(kcp != NULL);
KASSERT(!kc_initialised || KC_GETCSTRUCT(kcp)->kc_refcnt > 0);
KASSERT(!kc_initialised || KC_GETCSTRUCT(kcp)->kc_next == NULL);
KASSERT(j < kc_nfields);
return ((1 << (i & KC_MASK)) & kcp->bits[j]) != 0;
}
bool
kcpuset_isotherset(const kcpuset_t *kcp, cpuid_t i)
{
const size_t j2 = i >> KC_SHIFT;
const uint32_t mask = ~(1 << (i & KC_MASK));
for (size_t j = 0; j < kc_nfields; j++) {
const uint32_t bits = kcp->bits[j];
if (bits && (j != j2 || (bits & mask) != 0)) {
return true;
}
}
return false;
}
bool
kcpuset_iszero(const kcpuset_t *kcp)
{
for (size_t j = 0; j < kc_nfields; j++) {
if (kcp->bits[j] != 0) {
return false;
}
}
return true;
}
bool
kcpuset_match(const kcpuset_t *kcp1, const kcpuset_t *kcp2)
{
return memcmp(kcp1, kcp2, kc_bitsize) == 0;
}
bool
kcpuset_intersecting_p(const kcpuset_t *kcp1, const kcpuset_t *kcp2)
{
for (size_t j = 0; j < kc_nfields; j++) {
if (kcp1->bits[j] & kcp2->bits[j])
return true;
}
return false;
}
cpuid_t
kcpuset_ffs(const kcpuset_t *kcp)
{
for (size_t j = 0; j < kc_nfields; j++) {
if (kcp->bits[j])
return 32 * j + ffs(kcp->bits[j]);
}
return 0;
}
cpuid_t
kcpuset_ffs_intersecting(const kcpuset_t *kcp1, const kcpuset_t *kcp2)
{
for (size_t j = 0; j < kc_nfields; j++) {
uint32_t bits = kcp1->bits[j] & kcp2->bits[j];
if (bits)
return 32 * j + ffs(bits);
}
return 0;
}
void
kcpuset_merge(kcpuset_t *kcp1, const kcpuset_t *kcp2)
{
for (size_t j = 0; j < kc_nfields; j++) {
kcp1->bits[j] |= kcp2->bits[j];
}
}
void
kcpuset_intersect(kcpuset_t *kcp1, const kcpuset_t *kcp2)
{
for (size_t j = 0; j < kc_nfields; j++) {
kcp1->bits[j] &= kcp2->bits[j];
}
}
void
kcpuset_remove(kcpuset_t *kcp1, const kcpuset_t *kcp2)
{
for (size_t j = 0; j < kc_nfields; j++) {
kcp1->bits[j] &= ~kcp2->bits[j];
}
}
int
kcpuset_countset(const kcpuset_t *kcp)
{
int count = 0;
for (size_t j = 0; j < kc_nfields; j++) {
count += popcount32(kcp->bits[j]);
}
return count;
}
/*
* Routines to set/clear the flags atomically.
*/
void
kcpuset_atomic_set(kcpuset_t *kcp, cpuid_t i)
{
const size_t j = i >> KC_SHIFT;
KASSERT(j < kc_nfields);
atomic_or_32(&kcp->bits[j], 1 << (i & KC_MASK));
}
void
kcpuset_atomic_clear(kcpuset_t *kcp, cpuid_t i)
{
const size_t j = i >> KC_SHIFT;
KASSERT(j < kc_nfields);
atomic_and_32(&kcp->bits[j], ~(1 << (i & KC_MASK)));
}
void
kcpuset_atomicly_intersect(kcpuset_t *kcp1, const kcpuset_t *kcp2)
{
for (size_t j = 0; j < kc_nfields; j++) {
if (kcp2->bits[j])
atomic_and_32(&kcp1->bits[j], kcp2->bits[j]);
}
}
void
kcpuset_atomicly_merge(kcpuset_t *kcp1, const kcpuset_t *kcp2)
{
for (size_t j = 0; j < kc_nfields; j++) {
if (kcp2->bits[j])
atomic_or_32(&kcp1->bits[j], kcp2->bits[j]);
}
}
void
kcpuset_atomicly_remove(kcpuset_t *kcp1, const kcpuset_t *kcp2)
{
for (size_t j = 0; j < kc_nfields; j++) {
if (kcp2->bits[j])
atomic_and_32(&kcp1->bits[j], ~kcp2->bits[j]);
}
}