freebsd-dev/sys/dev/ipmi/ipmi_kcs.c
Jonathan T. Looney 1524298754 The current IPMI KCS code is waiting 100us for all transitions (roughly
between each byte either sent or received). However, most transitions
actually complete in 2-3 microseconds.

By polling the status register with a delay of 4us with exponential
backoff, the performance of most IPMI operations is significantly
improved:
  - A BMC update on a Supermicro x9 or x11 motherboard goes from ~1 hour
    to ~6-8 minutes.
  - An ipmitool sensor list time improves by a factor of 4.

Testing showed no significant improvements on a modern server by using
a lower delay.

The changes should also generally reduce the total amount of CPU or
I/O bandwidth used for a given IPMI operation.

Submitted by:	Loic Prylli <lprylli@netflix.com>
Reviewed by:	jhb
MFC after:	2 weeks
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D20527
2019-06-12 16:06:31 +00:00

639 lines
14 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2006 IronPort Systems Inc. <ambrisko@ironport.com>
* 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/systm.h>
#include <sys/bus.h>
#include <sys/condvar.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/rman.h>
#include <sys/selinfo.h>
#include <machine/bus.h>
#ifdef LOCAL_MODULE
#include <ipmi.h>
#include <ipmivars.h>
#else
#include <sys/ipmi.h>
#include <dev/ipmi/ipmivars.h>
#endif
#define POLLING_DELAY_MIN 4 /* Waits are 2-3 usecs on typical systems */
#define POLLING_DELAY_MAX 256
static void kcs_clear_obf(struct ipmi_softc *, int);
static void kcs_error(struct ipmi_softc *);
static int kcs_wait_for_ibf(struct ipmi_softc *, bool);
static int kcs_wait_for_obf(struct ipmi_softc *, bool);
static int
kcs_wait(struct ipmi_softc *sc, int value, int mask)
{
int status, start = ticks;
int delay_usec = POLLING_DELAY_MIN;
status = INB(sc, KCS_CTL_STS);
while (ticks - start < MAX_TIMEOUT && (status & mask) != value) {
/*
* The wait delay is increased exponentially to avoid putting
* significant load on I/O bus.
*/
DELAY(delay_usec);
status = INB(sc, KCS_CTL_STS);
if (delay_usec < POLLING_DELAY_MAX)
delay_usec *= 2;
}
return (status);
}
static int
kcs_wait_for_ibf(struct ipmi_softc *sc, bool level)
{
return (kcs_wait(sc, level ? KCS_STATUS_IBF : 0, KCS_STATUS_IBF));
}
static int
kcs_wait_for_obf(struct ipmi_softc *sc, bool level)
{
return (kcs_wait(sc, level ? KCS_STATUS_OBF : 0, KCS_STATUS_OBF));
}
static void
kcs_clear_obf(struct ipmi_softc *sc, int status)
{
int data;
/* Clear OBF */
if (status & KCS_STATUS_OBF) {
data = INB(sc, KCS_DATA);
}
}
static void
kcs_error(struct ipmi_softc *sc)
{
int retry, status;
u_char data;
for (retry = 0; retry < 2; retry++) {
/* Wait for IBF = 0 */
status = kcs_wait_for_ibf(sc, 0);
/* ABORT */
OUTB(sc, KCS_CTL_STS, KCS_CONTROL_GET_STATUS_ABORT);
/* Wait for IBF = 0 */
status = kcs_wait_for_ibf(sc, 0);
/* Clear OBF */
kcs_clear_obf(sc, status);
if (status & KCS_STATUS_OBF) {
data = INB(sc, KCS_DATA);
if (data != 0)
device_printf(sc->ipmi_dev,
"KCS Error Data %02x\n", data);
}
/* 0x00 to DATA_IN */
OUTB(sc, KCS_DATA, 0x00);
/* Wait for IBF = 0 */
status = kcs_wait_for_ibf(sc, 0);
if (KCS_STATUS_STATE(status) == KCS_STATUS_STATE_READ) {
/* Wait for OBF = 1 */
status = kcs_wait_for_obf(sc, 1);
/* Read error status */
data = INB(sc, KCS_DATA);
if (data != 0 && (data != 0xff || bootverbose))
device_printf(sc->ipmi_dev, "KCS error: %02x\n",
data);
/* Write READ into Data_in */
OUTB(sc, KCS_DATA, KCS_DATA_IN_READ);
/* Wait for IBF = 0 */
status = kcs_wait_for_ibf(sc, 0);
}
/* IDLE STATE */
if (KCS_STATUS_STATE(status) == KCS_STATUS_STATE_IDLE) {
/* Wait for OBF = 1 */
status = kcs_wait_for_obf(sc, 1);
/* Clear OBF */
kcs_clear_obf(sc, status);
return;
}
}
device_printf(sc->ipmi_dev, "KCS: Error retry exhausted\n");
}
/*
* Start to write a request. Waits for IBF to clear and then sends the
* WR_START command.
*/
static int
kcs_start_write(struct ipmi_softc *sc)
{
int retry, status;
for (retry = 0; retry < 10; retry++) {
/* Wait for IBF = 0 */
status = kcs_wait_for_ibf(sc, 0);
if (status & KCS_STATUS_IBF)
return (0);
/* Clear OBF */
kcs_clear_obf(sc, status);
/* Write start to command */
OUTB(sc, KCS_CTL_STS, KCS_CONTROL_WRITE_START);
/* Wait for IBF = 0 */
status = kcs_wait_for_ibf(sc, 0);
if (status & KCS_STATUS_IBF)
return (0);
if (KCS_STATUS_STATE(status) == KCS_STATUS_STATE_WRITE)
break;
DELAY(1000000);
}
if (KCS_STATUS_STATE(status) != KCS_STATUS_STATE_WRITE)
/* error state */
return (0);
/* Clear OBF */
kcs_clear_obf(sc, status);
return (1);
}
/*
* Write a byte of the request message, excluding the last byte of the
* message which requires special handling.
*/
static int
kcs_write_byte(struct ipmi_softc *sc, u_char data)
{
int status;
/* Data to Data */
OUTB(sc, KCS_DATA, data);
/* Wait for IBF = 0 */
status = kcs_wait_for_ibf(sc, 0);
if (status & KCS_STATUS_IBF)
return (0);
if (KCS_STATUS_STATE(status) != KCS_STATUS_STATE_WRITE)
return (0);
/* Clear OBF */
kcs_clear_obf(sc, status);
return (1);
}
/*
* Write the last byte of a request message.
*/
static int
kcs_write_last_byte(struct ipmi_softc *sc, u_char data)
{
int status;
/* Write end to command */
OUTB(sc, KCS_CTL_STS, KCS_CONTROL_WRITE_END);
/* Wait for IBF = 0 */
status = kcs_wait_for_ibf(sc, 0);
if (status & KCS_STATUS_IBF)
return (0);
if (KCS_STATUS_STATE(status) != KCS_STATUS_STATE_WRITE)
/* error state */
return (0);
/* Clear OBF */
kcs_clear_obf(sc, status);
/* Send data byte to DATA. */
OUTB(sc, KCS_DATA, data);
return (1);
}
/*
* Read one byte of the reply message.
*/
static int
kcs_read_byte(struct ipmi_softc *sc, u_char *data)
{
int status;
u_char dummy;
/* Wait for IBF = 0 */
status = kcs_wait_for_ibf(sc, 0);
/* Read State */
if (KCS_STATUS_STATE(status) == KCS_STATUS_STATE_READ) {
/* Wait for OBF = 1 */
status = kcs_wait_for_obf(sc, 1);
if ((status & KCS_STATUS_OBF) == 0)
return (0);
/* Read Data_out */
*data = INB(sc, KCS_DATA);
/* Write READ into Data_in */
OUTB(sc, KCS_DATA, KCS_DATA_IN_READ);
return (1);
}
/* Idle State */
if (KCS_STATUS_STATE(status) == KCS_STATUS_STATE_IDLE) {
/* Wait for OBF = 1*/
status = kcs_wait_for_obf(sc, 1);
if ((status & KCS_STATUS_OBF) == 0)
return (0);
/* Read Dummy */
dummy = INB(sc, KCS_DATA);
return (2);
}
/* Error State */
return (0);
}
/*
* Send a request message and collect the reply. Returns true if we
* succeed.
*/
static int
kcs_polled_request(struct ipmi_softc *sc, struct ipmi_request *req)
{
u_char *cp, data;
int i, state;
IPMI_IO_LOCK(sc);
/* Send the request. */
if (!kcs_start_write(sc)) {
device_printf(sc->ipmi_dev, "KCS: Failed to start write\n");
goto fail;
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: WRITE_START... ok\n");
#endif
if (!kcs_write_byte(sc, req->ir_addr)) {
device_printf(sc->ipmi_dev, "KCS: Failed to write address\n");
goto fail;
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: Wrote address: %02x\n", req->ir_addr);
#endif
if (req->ir_requestlen == 0) {
if (!kcs_write_last_byte(sc, req->ir_command)) {
device_printf(sc->ipmi_dev,
"KCS: Failed to write command\n");
goto fail;
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: Wrote command: %02x\n",
req->ir_command);
#endif
} else {
if (!kcs_write_byte(sc, req->ir_command)) {
device_printf(sc->ipmi_dev,
"KCS: Failed to write command\n");
goto fail;
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: Wrote command: %02x\n",
req->ir_command);
#endif
cp = req->ir_request;
for (i = 0; i < req->ir_requestlen - 1; i++) {
if (!kcs_write_byte(sc, *cp++)) {
device_printf(sc->ipmi_dev,
"KCS: Failed to write data byte %d\n",
i + 1);
goto fail;
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: Wrote data: %02x\n",
cp[-1]);
#endif
}
if (!kcs_write_last_byte(sc, *cp)) {
device_printf(sc->ipmi_dev,
"KCS: Failed to write last dta byte\n");
goto fail;
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: Wrote last data: %02x\n",
*cp);
#endif
}
/* Read the reply. First, read the NetFn/LUN. */
if (kcs_read_byte(sc, &data) != 1) {
device_printf(sc->ipmi_dev, "KCS: Failed to read address\n");
goto fail;
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: Read address: %02x\n", data);
#endif
if (data != IPMI_REPLY_ADDR(req->ir_addr)) {
device_printf(sc->ipmi_dev, "KCS: Reply address mismatch\n");
goto fail;
}
/* Next we read the command. */
if (kcs_read_byte(sc, &data) != 1) {
device_printf(sc->ipmi_dev, "KCS: Failed to read command\n");
goto fail;
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: Read command: %02x\n", data);
#endif
if (data != req->ir_command) {
device_printf(sc->ipmi_dev, "KCS: Command mismatch\n");
goto fail;
}
/* Next we read the completion code. */
if (kcs_read_byte(sc, &req->ir_compcode) != 1) {
if (bootverbose) {
device_printf(sc->ipmi_dev,
"KCS: Failed to read completion code\n");
}
goto fail;
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: Read completion code: %02x\n",
req->ir_compcode);
#endif
/* Finally, read the reply from the BMC. */
i = 0;
for (;;) {
state = kcs_read_byte(sc, &data);
if (state == 0) {
device_printf(sc->ipmi_dev,
"KCS: Read failed on byte %d\n", i + 1);
goto fail;
}
if (state == 2)
break;
if (i < req->ir_replybuflen) {
req->ir_reply[i] = data;
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: Read data %02x\n",
data);
} else {
device_printf(sc->ipmi_dev,
"KCS: Read short %02x byte %d\n", data, i + 1);
#endif
}
i++;
}
IPMI_IO_UNLOCK(sc);
req->ir_replylen = i;
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: READ finished (%d bytes)\n", i);
if (req->ir_replybuflen < i)
#else
if (req->ir_replybuflen < i && req->ir_replybuflen != 0)
#endif
device_printf(sc->ipmi_dev,
"KCS: Read short: %zd buffer, %d actual\n",
req->ir_replybuflen, i);
return (1);
fail:
kcs_error(sc);
IPMI_IO_UNLOCK(sc);
return (0);
}
static void
kcs_loop(void *arg)
{
struct ipmi_softc *sc = arg;
struct ipmi_request *req;
int i, ok;
IPMI_LOCK(sc);
while ((req = ipmi_dequeue_request(sc)) != NULL) {
IPMI_UNLOCK(sc);
ok = 0;
for (i = 0; i < 3 && !ok; i++)
ok = kcs_polled_request(sc, req);
if (ok)
req->ir_error = 0;
else
req->ir_error = EIO;
IPMI_LOCK(sc);
ipmi_complete_request(sc, req);
}
IPMI_UNLOCK(sc);
kproc_exit(0);
}
static int
kcs_startup(struct ipmi_softc *sc)
{
return (kproc_create(kcs_loop, sc, &sc->ipmi_kthread, 0, 0, "%s: kcs",
device_get_nameunit(sc->ipmi_dev)));
}
static int
kcs_driver_request(struct ipmi_softc *sc, struct ipmi_request *req, int timo)
{
int i, ok;
ok = 0;
for (i = 0; i < 3 && !ok; i++)
ok = kcs_polled_request(sc, req);
if (ok)
req->ir_error = 0;
else
req->ir_error = EIO;
return (req->ir_error);
}
int
ipmi_kcs_attach(struct ipmi_softc *sc)
{
int status;
/* Setup function pointers. */
sc->ipmi_startup = kcs_startup;
sc->ipmi_enqueue_request = ipmi_polled_enqueue_request;
sc->ipmi_driver_request = kcs_driver_request;
sc->ipmi_driver_requests_polled = 1;
/* See if we can talk to the controller. */
status = INB(sc, KCS_CTL_STS);
if (status == 0xff) {
device_printf(sc->ipmi_dev, "couldn't find it\n");
return (ENXIO);
}
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "KCS: initial state: %02x\n", status);
#endif
if (status & KCS_STATUS_OBF ||
KCS_STATUS_STATE(status) != KCS_STATUS_STATE_IDLE)
kcs_error(sc);
return (0);
}
/*
* Determine the alignment automatically for a PCI attachment. In this case,
* any unused bytes will return 0x00 when read. We make use of the C/D bit
* in the CTL_STS register to try to start a GET_STATUS transaction. When
* we write the command, that bit should be set, so we should get a non-zero
* value back when we read CTL_STS if the offset we are testing is the CTL_STS
* register.
*/
int
ipmi_kcs_probe_align(struct ipmi_softc *sc)
{
int data, status;
sc->ipmi_io_spacing = 1;
retry:
#ifdef KCS_DEBUG
device_printf(sc->ipmi_dev, "Trying KCS align %d... ", sc->ipmi_io_spacing);
#endif
/* Wait for IBF = 0 */
status = INB(sc, KCS_CTL_STS);
while (status & KCS_STATUS_IBF) {
DELAY(100);
status = INB(sc, KCS_CTL_STS);
}
OUTB(sc, KCS_CTL_STS, KCS_CONTROL_GET_STATUS_ABORT);
/* Wait for IBF = 0 */
status = INB(sc, KCS_CTL_STS);
while (status & KCS_STATUS_IBF) {
DELAY(100);
status = INB(sc, KCS_CTL_STS);
}
/* If we got 0x00 back, then this must not be the CTL_STS register. */
if (status == 0) {
#ifdef KCS_DEBUG
printf("failed\n");
#endif
sc->ipmi_io_spacing <<= 1;
if (sc->ipmi_io_spacing > 4)
return (0);
goto retry;
}
#ifdef KCS_DEBUG
printf("ok\n");
#endif
/* Finish out the transaction. */
/* Clear OBF */
if (status & KCS_STATUS_OBF)
data = INB(sc, KCS_DATA);
/* 0x00 to DATA_IN */
OUTB(sc, KCS_DATA, 0);
/* Wait for IBF = 0 */
status = INB(sc, KCS_CTL_STS);
while (status & KCS_STATUS_IBF) {
DELAY(100);
status = INB(sc, KCS_CTL_STS);
}
if (KCS_STATUS_STATE(status) == KCS_STATUS_STATE_READ) {
/* Wait for IBF = 1 */
while (!(status & KCS_STATUS_OBF)) {
DELAY(100);
status = INB(sc, KCS_CTL_STS);
}
/* Read error status. */
data = INB(sc, KCS_DATA);
/* Write dummy READ to DATA_IN. */
OUTB(sc, KCS_DATA, KCS_DATA_IN_READ);
/* Wait for IBF = 0 */
status = INB(sc, KCS_CTL_STS);
while (status & KCS_STATUS_IBF) {
DELAY(100);
status = INB(sc, KCS_CTL_STS);
}
}
if (KCS_STATUS_STATE(status) == KCS_STATUS_STATE_IDLE) {
/* Wait for IBF = 1 */
while (!(status & KCS_STATUS_OBF)) {
DELAY(100);
status = INB(sc, KCS_CTL_STS);
}
/* Clear OBF */
if (status & KCS_STATUS_OBF)
data = INB(sc, KCS_DATA);
} else
device_printf(sc->ipmi_dev, "KCS probe: end state %x\n",
KCS_STATUS_STATE(status));
return (1);
}