freebsd-skq/sys/dev/nvme/nvme.c
Warner Losh 8423f5d4c1 nvme: use config_intrhook_drain to avoid removable card races
nvme drives are configured early in boot. However, a number of the configuration
steps takes which take a while, so we defer those to a config intrhook that runs
before the root filesystem is mounted. At the same time, the PCI hot plug wakes
up and tests the status of the card. It may decide that the card has gone away
and deletes the child. As part of that process nvme_detach is called. If this
call happens after the config_intrhook starts to run, but before it is finished,
there's a race where we can tear down the device's soft state while the
config_intrhook is still using it. Use the new config_intrhook_drain to
disestablish the hook. Either it will be removed w/o running, or the routine
will wait for it to finish. This closes the race and allows safe hotplug at any
time, even very early in boot.

Sponsored by:		Netflix, Inc
Reviewed by:		jhb, mav
Differential Revision:	https://reviews.freebsd.org/D29006
2021-03-11 09:45:10 -07:00

367 lines
9.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (C) 2012-2014 Intel Corporation
* All rights reserved.
*
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/module.h>
#include <vm/uma.h>
#include "nvme_private.h"
struct nvme_consumer {
uint32_t id;
nvme_cons_ns_fn_t ns_fn;
nvme_cons_ctrlr_fn_t ctrlr_fn;
nvme_cons_async_fn_t async_fn;
nvme_cons_fail_fn_t fail_fn;
};
struct nvme_consumer nvme_consumer[NVME_MAX_CONSUMERS];
#define INVALID_CONSUMER_ID 0xFFFF
int32_t nvme_retry_count;
MALLOC_DEFINE(M_NVME, "nvme", "nvme(4) memory allocations");
devclass_t nvme_devclass;
static void
nvme_init(void)
{
uint32_t i;
for (i = 0; i < NVME_MAX_CONSUMERS; i++)
nvme_consumer[i].id = INVALID_CONSUMER_ID;
}
SYSINIT(nvme_register, SI_SUB_DRIVERS, SI_ORDER_SECOND, nvme_init, NULL);
static void
nvme_uninit(void)
{
}
SYSUNINIT(nvme_unregister, SI_SUB_DRIVERS, SI_ORDER_SECOND, nvme_uninit, NULL);
int
nvme_shutdown(device_t dev)
{
struct nvme_controller *ctrlr;
ctrlr = DEVICE2SOFTC(dev);
nvme_ctrlr_shutdown(ctrlr);
return (0);
}
void
nvme_dump_command(struct nvme_command *cmd)
{
printf(
"opc:%x f:%x cid:%x nsid:%x r2:%x r3:%x mptr:%jx prp1:%jx prp2:%jx cdw:%x %x %x %x %x %x\n",
cmd->opc, cmd->fuse, cmd->cid, le32toh(cmd->nsid),
cmd->rsvd2, cmd->rsvd3,
(uintmax_t)le64toh(cmd->mptr), (uintmax_t)le64toh(cmd->prp1), (uintmax_t)le64toh(cmd->prp2),
le32toh(cmd->cdw10), le32toh(cmd->cdw11), le32toh(cmd->cdw12),
le32toh(cmd->cdw13), le32toh(cmd->cdw14), le32toh(cmd->cdw15));
}
void
nvme_dump_completion(struct nvme_completion *cpl)
{
uint8_t p, sc, sct, m, dnr;
uint16_t status;
status = le16toh(cpl->status);
p = NVME_STATUS_GET_P(status);
sc = NVME_STATUS_GET_SC(status);
sct = NVME_STATUS_GET_SCT(status);
m = NVME_STATUS_GET_M(status);
dnr = NVME_STATUS_GET_DNR(status);
printf("cdw0:%08x sqhd:%04x sqid:%04x "
"cid:%04x p:%x sc:%02x sct:%x m:%x dnr:%x\n",
le32toh(cpl->cdw0), le16toh(cpl->sqhd), le16toh(cpl->sqid),
cpl->cid, p, sc, sct, m, dnr);
}
int
nvme_attach(device_t dev)
{
struct nvme_controller *ctrlr = DEVICE2SOFTC(dev);
int status;
status = nvme_ctrlr_construct(ctrlr, dev);
if (status != 0) {
nvme_ctrlr_destruct(ctrlr, dev);
return (status);
}
ctrlr->config_hook.ich_func = nvme_ctrlr_start_config_hook;
ctrlr->config_hook.ich_arg = ctrlr;
if (config_intrhook_establish(&ctrlr->config_hook) != 0)
return (ENOMEM);
return (0);
}
int
nvme_detach(device_t dev)
{
struct nvme_controller *ctrlr = DEVICE2SOFTC(dev);
config_intrhook_drain(&ctrlr->config_hook);
nvme_ctrlr_destruct(ctrlr, dev);
return (0);
}
static void
nvme_notify(struct nvme_consumer *cons,
struct nvme_controller *ctrlr)
{
struct nvme_namespace *ns;
void *ctrlr_cookie;
int cmpset, ns_idx;
/*
* The consumer may register itself after the nvme devices
* have registered with the kernel, but before the
* driver has completed initialization. In that case,
* return here, and when initialization completes, the
* controller will make sure the consumer gets notified.
*/
if (!ctrlr->is_initialized)
return;
cmpset = atomic_cmpset_32(&ctrlr->notification_sent, 0, 1);
if (cmpset == 0)
return;
if (cons->ctrlr_fn != NULL)
ctrlr_cookie = (*cons->ctrlr_fn)(ctrlr);
else
ctrlr_cookie = (void *)(uintptr_t)0xdeadc0dedeadc0de;
ctrlr->cons_cookie[cons->id] = ctrlr_cookie;
/* ctrlr_fn has failed. Nothing to notify here any more. */
if (ctrlr_cookie == NULL)
return;
if (ctrlr->is_failed) {
ctrlr->cons_cookie[cons->id] = NULL;
if (cons->fail_fn != NULL)
(*cons->fail_fn)(ctrlr_cookie);
/*
* Do not notify consumers about the namespaces of a
* failed controller.
*/
return;
}
for (ns_idx = 0; ns_idx < min(ctrlr->cdata.nn, NVME_MAX_NAMESPACES); ns_idx++) {
ns = &ctrlr->ns[ns_idx];
if (ns->data.nsze == 0)
continue;
if (cons->ns_fn != NULL)
ns->cons_cookie[cons->id] =
(*cons->ns_fn)(ns, ctrlr_cookie);
}
}
void
nvme_notify_new_controller(struct nvme_controller *ctrlr)
{
int i;
for (i = 0; i < NVME_MAX_CONSUMERS; i++) {
if (nvme_consumer[i].id != INVALID_CONSUMER_ID) {
nvme_notify(&nvme_consumer[i], ctrlr);
}
}
}
static void
nvme_notify_new_consumer(struct nvme_consumer *cons)
{
device_t *devlist;
struct nvme_controller *ctrlr;
int dev_idx, devcount;
if (devclass_get_devices(nvme_devclass, &devlist, &devcount))
return;
for (dev_idx = 0; dev_idx < devcount; dev_idx++) {
ctrlr = DEVICE2SOFTC(devlist[dev_idx]);
nvme_notify(cons, ctrlr);
}
free(devlist, M_TEMP);
}
void
nvme_notify_async_consumers(struct nvme_controller *ctrlr,
const struct nvme_completion *async_cpl,
uint32_t log_page_id, void *log_page_buffer,
uint32_t log_page_size)
{
struct nvme_consumer *cons;
void *ctrlr_cookie;
uint32_t i;
for (i = 0; i < NVME_MAX_CONSUMERS; i++) {
cons = &nvme_consumer[i];
if (cons->id != INVALID_CONSUMER_ID && cons->async_fn != NULL &&
(ctrlr_cookie = ctrlr->cons_cookie[i]) != NULL) {
(*cons->async_fn)(ctrlr_cookie, async_cpl,
log_page_id, log_page_buffer, log_page_size);
}
}
}
void
nvme_notify_fail_consumers(struct nvme_controller *ctrlr)
{
struct nvme_consumer *cons;
void *ctrlr_cookie;
uint32_t i;
/*
* This controller failed during initialization (i.e. IDENTIFY
* command failed or timed out). Do not notify any nvme
* consumers of the failure here, since the consumer does not
* even know about the controller yet.
*/
if (!ctrlr->is_initialized)
return;
for (i = 0; i < NVME_MAX_CONSUMERS; i++) {
cons = &nvme_consumer[i];
if (cons->id != INVALID_CONSUMER_ID &&
(ctrlr_cookie = ctrlr->cons_cookie[i]) != NULL) {
ctrlr->cons_cookie[i] = NULL;
if (cons->fail_fn != NULL)
cons->fail_fn(ctrlr_cookie);
}
}
}
void
nvme_notify_ns(struct nvme_controller *ctrlr, int nsid)
{
struct nvme_consumer *cons;
struct nvme_namespace *ns;
void *ctrlr_cookie;
uint32_t i;
KASSERT(nsid <= NVME_MAX_NAMESPACES,
("%s: Namespace notification to nsid %d exceeds range\n",
device_get_nameunit(ctrlr->dev), nsid));
if (!ctrlr->is_initialized)
return;
ns = &ctrlr->ns[nsid - 1];
for (i = 0; i < NVME_MAX_CONSUMERS; i++) {
cons = &nvme_consumer[i];
if (cons->id != INVALID_CONSUMER_ID && cons->ns_fn != NULL &&
(ctrlr_cookie = ctrlr->cons_cookie[i]) != NULL)
ns->cons_cookie[i] = (*cons->ns_fn)(ns, ctrlr_cookie);
}
}
struct nvme_consumer *
nvme_register_consumer(nvme_cons_ns_fn_t ns_fn, nvme_cons_ctrlr_fn_t ctrlr_fn,
nvme_cons_async_fn_t async_fn,
nvme_cons_fail_fn_t fail_fn)
{
int i;
/*
* TODO: add locking around consumer registration.
*/
for (i = 0; i < NVME_MAX_CONSUMERS; i++)
if (nvme_consumer[i].id == INVALID_CONSUMER_ID) {
nvme_consumer[i].id = i;
nvme_consumer[i].ns_fn = ns_fn;
nvme_consumer[i].ctrlr_fn = ctrlr_fn;
nvme_consumer[i].async_fn = async_fn;
nvme_consumer[i].fail_fn = fail_fn;
nvme_notify_new_consumer(&nvme_consumer[i]);
return (&nvme_consumer[i]);
}
printf("nvme(4): consumer not registered - no slots available\n");
return (NULL);
}
void
nvme_unregister_consumer(struct nvme_consumer *consumer)
{
consumer->id = INVALID_CONSUMER_ID;
}
void
nvme_completion_poll_cb(void *arg, const struct nvme_completion *cpl)
{
struct nvme_completion_poll_status *status = arg;
/*
* Copy status into the argument passed by the caller, so that
* the caller can check the status to determine if the
* the request passed or failed.
*/
memcpy(&status->cpl, cpl, sizeof(*cpl));
atomic_store_rel_int(&status->done, 1);
}
static int
nvme_modevent(module_t mod __unused, int type __unused, void *argp __unused)
{
return (0);
}
static moduledata_t nvme_mod = {
"nvme",
nvme_modevent,
0
};
DECLARE_MODULE(nvme, nvme_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
MODULE_VERSION(nvme, 1);
MODULE_DEPEND(nvme, cam, 1, 1, 1);