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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/char/ipmi/ipmi_smic_sm.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/char/ipmi/ipmi_smic_sm.c')
-rw-r--r-- | drivers/char/ipmi/ipmi_smic_sm.c | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/drivers/char/ipmi/ipmi_smic_sm.c b/drivers/char/ipmi/ipmi_smic_sm.c new file mode 100644 index 000000000..466a5aac5 --- /dev/null +++ b/drivers/char/ipmi/ipmi_smic_sm.c @@ -0,0 +1,580 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * ipmi_smic_sm.c + * + * The state-machine driver for an IPMI SMIC driver + * + * It started as a copy of Corey Minyard's driver for the KSC interface + * and the kernel patch "mmcdev-patch-245" by HP + * + * modified by: Hannes Schulz <schulz@schwaar.com> + * ipmi@schwaar.com + * + * + * Corey Minyard's driver for the KSC interface has the following + * copyright notice: + * Copyright 2002 MontaVista Software Inc. + * + * the kernel patch "mmcdev-patch-245" by HP has the following + * copyright notice: + * (c) Copyright 2001 Grant Grundler (c) Copyright + * 2001 Hewlett-Packard Company + */ + +#include <linux/kernel.h> /* For printk. */ +#include <linux/string.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/ipmi_msgdefs.h> /* for completion codes */ +#include "ipmi_si_sm.h" + +/* smic_debug is a bit-field + * SMIC_DEBUG_ENABLE - turned on for now + * SMIC_DEBUG_MSG - commands and their responses + * SMIC_DEBUG_STATES - state machine +*/ +#define SMIC_DEBUG_STATES 4 +#define SMIC_DEBUG_MSG 2 +#define SMIC_DEBUG_ENABLE 1 + +static int smic_debug = 1; +module_param(smic_debug, int, 0644); +MODULE_PARM_DESC(smic_debug, "debug bitmask, 1=enable, 2=messages, 4=states"); + +enum smic_states { + SMIC_IDLE, + SMIC_START_OP, + SMIC_OP_OK, + SMIC_WRITE_START, + SMIC_WRITE_NEXT, + SMIC_WRITE_END, + SMIC_WRITE2READ, + SMIC_READ_START, + SMIC_READ_NEXT, + SMIC_READ_END, + SMIC_HOSED +}; + +#define MAX_SMIC_READ_SIZE 80 +#define MAX_SMIC_WRITE_SIZE 80 +#define SMIC_MAX_ERROR_RETRIES 3 + +/* Timeouts in microseconds. */ +#define SMIC_RETRY_TIMEOUT (2*USEC_PER_SEC) + +/* SMIC Flags Register Bits */ +#define SMIC_RX_DATA_READY 0x80 +#define SMIC_TX_DATA_READY 0x40 + +/* + * SMIC_SMI and SMIC_EVM_DATA_AVAIL are only used by + * a few systems, and then only by Systems Management + * Interrupts, not by the OS. Always ignore these bits. + * + */ +#define SMIC_SMI 0x10 +#define SMIC_EVM_DATA_AVAIL 0x08 +#define SMIC_SMS_DATA_AVAIL 0x04 +#define SMIC_FLAG_BSY 0x01 + +/* SMIC Error Codes */ +#define EC_NO_ERROR 0x00 +#define EC_ABORTED 0x01 +#define EC_ILLEGAL_CONTROL 0x02 +#define EC_NO_RESPONSE 0x03 +#define EC_ILLEGAL_COMMAND 0x04 +#define EC_BUFFER_FULL 0x05 + +struct si_sm_data { + enum smic_states state; + struct si_sm_io *io; + unsigned char write_data[MAX_SMIC_WRITE_SIZE]; + int write_pos; + int write_count; + int orig_write_count; + unsigned char read_data[MAX_SMIC_READ_SIZE]; + int read_pos; + int truncated; + unsigned int error_retries; + long smic_timeout; +}; + +static unsigned int init_smic_data(struct si_sm_data *smic, + struct si_sm_io *io) +{ + smic->state = SMIC_IDLE; + smic->io = io; + smic->write_pos = 0; + smic->write_count = 0; + smic->orig_write_count = 0; + smic->read_pos = 0; + smic->error_retries = 0; + smic->truncated = 0; + smic->smic_timeout = SMIC_RETRY_TIMEOUT; + + /* We use 3 bytes of I/O. */ + return 3; +} + +static int start_smic_transaction(struct si_sm_data *smic, + unsigned char *data, unsigned int size) +{ + unsigned int i; + + if (size < 2) + return IPMI_REQ_LEN_INVALID_ERR; + if (size > MAX_SMIC_WRITE_SIZE) + return IPMI_REQ_LEN_EXCEEDED_ERR; + + if ((smic->state != SMIC_IDLE) && (smic->state != SMIC_HOSED)) + return IPMI_NOT_IN_MY_STATE_ERR; + + if (smic_debug & SMIC_DEBUG_MSG) { + printk(KERN_DEBUG "start_smic_transaction -"); + for (i = 0; i < size; i++) + printk(" %02x", (unsigned char) data[i]); + printk("\n"); + } + smic->error_retries = 0; + memcpy(smic->write_data, data, size); + smic->write_count = size; + smic->orig_write_count = size; + smic->write_pos = 0; + smic->read_pos = 0; + smic->state = SMIC_START_OP; + smic->smic_timeout = SMIC_RETRY_TIMEOUT; + return 0; +} + +static int smic_get_result(struct si_sm_data *smic, + unsigned char *data, unsigned int length) +{ + int i; + + if (smic_debug & SMIC_DEBUG_MSG) { + printk(KERN_DEBUG "smic_get result -"); + for (i = 0; i < smic->read_pos; i++) + printk(" %02x", smic->read_data[i]); + printk("\n"); + } + if (length < smic->read_pos) { + smic->read_pos = length; + smic->truncated = 1; + } + memcpy(data, smic->read_data, smic->read_pos); + + if ((length >= 3) && (smic->read_pos < 3)) { + data[2] = IPMI_ERR_UNSPECIFIED; + smic->read_pos = 3; + } + if (smic->truncated) { + data[2] = IPMI_ERR_MSG_TRUNCATED; + smic->truncated = 0; + } + return smic->read_pos; +} + +static inline unsigned char read_smic_flags(struct si_sm_data *smic) +{ + return smic->io->inputb(smic->io, 2); +} + +static inline unsigned char read_smic_status(struct si_sm_data *smic) +{ + return smic->io->inputb(smic->io, 1); +} + +static inline unsigned char read_smic_data(struct si_sm_data *smic) +{ + return smic->io->inputb(smic->io, 0); +} + +static inline void write_smic_flags(struct si_sm_data *smic, + unsigned char flags) +{ + smic->io->outputb(smic->io, 2, flags); +} + +static inline void write_smic_control(struct si_sm_data *smic, + unsigned char control) +{ + smic->io->outputb(smic->io, 1, control); +} + +static inline void write_si_sm_data(struct si_sm_data *smic, + unsigned char data) +{ + smic->io->outputb(smic->io, 0, data); +} + +static inline void start_error_recovery(struct si_sm_data *smic, char *reason) +{ + (smic->error_retries)++; + if (smic->error_retries > SMIC_MAX_ERROR_RETRIES) { + if (smic_debug & SMIC_DEBUG_ENABLE) + printk(KERN_WARNING + "ipmi_smic_drv: smic hosed: %s\n", reason); + smic->state = SMIC_HOSED; + } else { + smic->write_count = smic->orig_write_count; + smic->write_pos = 0; + smic->read_pos = 0; + smic->state = SMIC_START_OP; + smic->smic_timeout = SMIC_RETRY_TIMEOUT; + } +} + +static inline void write_next_byte(struct si_sm_data *smic) +{ + write_si_sm_data(smic, smic->write_data[smic->write_pos]); + (smic->write_pos)++; + (smic->write_count)--; +} + +static inline void read_next_byte(struct si_sm_data *smic) +{ + if (smic->read_pos >= MAX_SMIC_READ_SIZE) { + read_smic_data(smic); + smic->truncated = 1; + } else { + smic->read_data[smic->read_pos] = read_smic_data(smic); + smic->read_pos++; + } +} + +/* SMIC Control/Status Code Components */ +#define SMIC_GET_STATUS 0x00 /* Control form's name */ +#define SMIC_READY 0x00 /* Status form's name */ +#define SMIC_WR_START 0x01 /* Unified Control/Status names... */ +#define SMIC_WR_NEXT 0x02 +#define SMIC_WR_END 0x03 +#define SMIC_RD_START 0x04 +#define SMIC_RD_NEXT 0x05 +#define SMIC_RD_END 0x06 +#define SMIC_CODE_MASK 0x0f + +#define SMIC_CONTROL 0x00 +#define SMIC_STATUS 0x80 +#define SMIC_CS_MASK 0x80 + +#define SMIC_SMS 0x40 +#define SMIC_SMM 0x60 +#define SMIC_STREAM_MASK 0x60 + +/* SMIC Control Codes */ +#define SMIC_CC_SMS_GET_STATUS (SMIC_CONTROL|SMIC_SMS|SMIC_GET_STATUS) +#define SMIC_CC_SMS_WR_START (SMIC_CONTROL|SMIC_SMS|SMIC_WR_START) +#define SMIC_CC_SMS_WR_NEXT (SMIC_CONTROL|SMIC_SMS|SMIC_WR_NEXT) +#define SMIC_CC_SMS_WR_END (SMIC_CONTROL|SMIC_SMS|SMIC_WR_END) +#define SMIC_CC_SMS_RD_START (SMIC_CONTROL|SMIC_SMS|SMIC_RD_START) +#define SMIC_CC_SMS_RD_NEXT (SMIC_CONTROL|SMIC_SMS|SMIC_RD_NEXT) +#define SMIC_CC_SMS_RD_END (SMIC_CONTROL|SMIC_SMS|SMIC_RD_END) + +#define SMIC_CC_SMM_GET_STATUS (SMIC_CONTROL|SMIC_SMM|SMIC_GET_STATUS) +#define SMIC_CC_SMM_WR_START (SMIC_CONTROL|SMIC_SMM|SMIC_WR_START) +#define SMIC_CC_SMM_WR_NEXT (SMIC_CONTROL|SMIC_SMM|SMIC_WR_NEXT) +#define SMIC_CC_SMM_WR_END (SMIC_CONTROL|SMIC_SMM|SMIC_WR_END) +#define SMIC_CC_SMM_RD_START (SMIC_CONTROL|SMIC_SMM|SMIC_RD_START) +#define SMIC_CC_SMM_RD_NEXT (SMIC_CONTROL|SMIC_SMM|SMIC_RD_NEXT) +#define SMIC_CC_SMM_RD_END (SMIC_CONTROL|SMIC_SMM|SMIC_RD_END) + +/* SMIC Status Codes */ +#define SMIC_SC_SMS_READY (SMIC_STATUS|SMIC_SMS|SMIC_READY) +#define SMIC_SC_SMS_WR_START (SMIC_STATUS|SMIC_SMS|SMIC_WR_START) +#define SMIC_SC_SMS_WR_NEXT (SMIC_STATUS|SMIC_SMS|SMIC_WR_NEXT) +#define SMIC_SC_SMS_WR_END (SMIC_STATUS|SMIC_SMS|SMIC_WR_END) +#define SMIC_SC_SMS_RD_START (SMIC_STATUS|SMIC_SMS|SMIC_RD_START) +#define SMIC_SC_SMS_RD_NEXT (SMIC_STATUS|SMIC_SMS|SMIC_RD_NEXT) +#define SMIC_SC_SMS_RD_END (SMIC_STATUS|SMIC_SMS|SMIC_RD_END) + +#define SMIC_SC_SMM_READY (SMIC_STATUS|SMIC_SMM|SMIC_READY) +#define SMIC_SC_SMM_WR_START (SMIC_STATUS|SMIC_SMM|SMIC_WR_START) +#define SMIC_SC_SMM_WR_NEXT (SMIC_STATUS|SMIC_SMM|SMIC_WR_NEXT) +#define SMIC_SC_SMM_WR_END (SMIC_STATUS|SMIC_SMM|SMIC_WR_END) +#define SMIC_SC_SMM_RD_START (SMIC_STATUS|SMIC_SMM|SMIC_RD_START) +#define SMIC_SC_SMM_RD_NEXT (SMIC_STATUS|SMIC_SMM|SMIC_RD_NEXT) +#define SMIC_SC_SMM_RD_END (SMIC_STATUS|SMIC_SMM|SMIC_RD_END) + +/* these are the control/status codes we actually use + SMIC_CC_SMS_GET_STATUS 0x40 + SMIC_CC_SMS_WR_START 0x41 + SMIC_CC_SMS_WR_NEXT 0x42 + SMIC_CC_SMS_WR_END 0x43 + SMIC_CC_SMS_RD_START 0x44 + SMIC_CC_SMS_RD_NEXT 0x45 + SMIC_CC_SMS_RD_END 0x46 + + SMIC_SC_SMS_READY 0xC0 + SMIC_SC_SMS_WR_START 0xC1 + SMIC_SC_SMS_WR_NEXT 0xC2 + SMIC_SC_SMS_WR_END 0xC3 + SMIC_SC_SMS_RD_START 0xC4 + SMIC_SC_SMS_RD_NEXT 0xC5 + SMIC_SC_SMS_RD_END 0xC6 +*/ + +static enum si_sm_result smic_event(struct si_sm_data *smic, long time) +{ + unsigned char status; + unsigned char flags; + unsigned char data; + + if (smic->state == SMIC_HOSED) { + init_smic_data(smic, smic->io); + return SI_SM_HOSED; + } + if (smic->state != SMIC_IDLE) { + if (smic_debug & SMIC_DEBUG_STATES) + printk(KERN_DEBUG + "smic_event - smic->smic_timeout = %ld," + " time = %ld\n", + smic->smic_timeout, time); + /* + * FIXME: smic_event is sometimes called with time > + * SMIC_RETRY_TIMEOUT + */ + if (time < SMIC_RETRY_TIMEOUT) { + smic->smic_timeout -= time; + if (smic->smic_timeout < 0) { + start_error_recovery(smic, "smic timed out."); + return SI_SM_CALL_WITH_DELAY; + } + } + } + flags = read_smic_flags(smic); + if (flags & SMIC_FLAG_BSY) + return SI_SM_CALL_WITH_DELAY; + + status = read_smic_status(smic); + if (smic_debug & SMIC_DEBUG_STATES) + printk(KERN_DEBUG + "smic_event - state = %d, flags = 0x%02x," + " status = 0x%02x\n", + smic->state, flags, status); + + switch (smic->state) { + case SMIC_IDLE: + /* in IDLE we check for available messages */ + if (flags & SMIC_SMS_DATA_AVAIL) + return SI_SM_ATTN; + return SI_SM_IDLE; + + case SMIC_START_OP: + /* sanity check whether smic is really idle */ + write_smic_control(smic, SMIC_CC_SMS_GET_STATUS); + write_smic_flags(smic, flags | SMIC_FLAG_BSY); + smic->state = SMIC_OP_OK; + break; + + case SMIC_OP_OK: + if (status != SMIC_SC_SMS_READY) { + /* this should not happen */ + start_error_recovery(smic, + "state = SMIC_OP_OK," + " status != SMIC_SC_SMS_READY"); + return SI_SM_CALL_WITH_DELAY; + } + /* OK so far; smic is idle let us start ... */ + write_smic_control(smic, SMIC_CC_SMS_WR_START); + write_next_byte(smic); + write_smic_flags(smic, flags | SMIC_FLAG_BSY); + smic->state = SMIC_WRITE_START; + break; + + case SMIC_WRITE_START: + if (status != SMIC_SC_SMS_WR_START) { + start_error_recovery(smic, + "state = SMIC_WRITE_START, " + "status != SMIC_SC_SMS_WR_START"); + return SI_SM_CALL_WITH_DELAY; + } + /* + * we must not issue WR_(NEXT|END) unless + * TX_DATA_READY is set + * */ + if (flags & SMIC_TX_DATA_READY) { + if (smic->write_count == 1) { + /* last byte */ + write_smic_control(smic, SMIC_CC_SMS_WR_END); + smic->state = SMIC_WRITE_END; + } else { + write_smic_control(smic, SMIC_CC_SMS_WR_NEXT); + smic->state = SMIC_WRITE_NEXT; + } + write_next_byte(smic); + write_smic_flags(smic, flags | SMIC_FLAG_BSY); + } else + return SI_SM_CALL_WITH_DELAY; + break; + + case SMIC_WRITE_NEXT: + if (status != SMIC_SC_SMS_WR_NEXT) { + start_error_recovery(smic, + "state = SMIC_WRITE_NEXT, " + "status != SMIC_SC_SMS_WR_NEXT"); + return SI_SM_CALL_WITH_DELAY; + } + /* this is the same code as in SMIC_WRITE_START */ + if (flags & SMIC_TX_DATA_READY) { + if (smic->write_count == 1) { + write_smic_control(smic, SMIC_CC_SMS_WR_END); + smic->state = SMIC_WRITE_END; + } else { + write_smic_control(smic, SMIC_CC_SMS_WR_NEXT); + smic->state = SMIC_WRITE_NEXT; + } + write_next_byte(smic); + write_smic_flags(smic, flags | SMIC_FLAG_BSY); + } else + return SI_SM_CALL_WITH_DELAY; + break; + + case SMIC_WRITE_END: + if (status != SMIC_SC_SMS_WR_END) { + start_error_recovery(smic, + "state = SMIC_WRITE_END, " + "status != SMIC_SC_SMS_WR_END"); + return SI_SM_CALL_WITH_DELAY; + } + /* data register holds an error code */ + data = read_smic_data(smic); + if (data != 0) { + if (smic_debug & SMIC_DEBUG_ENABLE) + printk(KERN_DEBUG + "SMIC_WRITE_END: data = %02x\n", data); + start_error_recovery(smic, + "state = SMIC_WRITE_END, " + "data != SUCCESS"); + return SI_SM_CALL_WITH_DELAY; + } else + smic->state = SMIC_WRITE2READ; + break; + + case SMIC_WRITE2READ: + /* + * we must wait for RX_DATA_READY to be set before we + * can continue + */ + if (flags & SMIC_RX_DATA_READY) { + write_smic_control(smic, SMIC_CC_SMS_RD_START); + write_smic_flags(smic, flags | SMIC_FLAG_BSY); + smic->state = SMIC_READ_START; + } else + return SI_SM_CALL_WITH_DELAY; + break; + + case SMIC_READ_START: + if (status != SMIC_SC_SMS_RD_START) { + start_error_recovery(smic, + "state = SMIC_READ_START, " + "status != SMIC_SC_SMS_RD_START"); + return SI_SM_CALL_WITH_DELAY; + } + if (flags & SMIC_RX_DATA_READY) { + read_next_byte(smic); + write_smic_control(smic, SMIC_CC_SMS_RD_NEXT); + write_smic_flags(smic, flags | SMIC_FLAG_BSY); + smic->state = SMIC_READ_NEXT; + } else + return SI_SM_CALL_WITH_DELAY; + break; + + case SMIC_READ_NEXT: + switch (status) { + /* + * smic tells us that this is the last byte to be read + * --> clean up + */ + case SMIC_SC_SMS_RD_END: + read_next_byte(smic); + write_smic_control(smic, SMIC_CC_SMS_RD_END); + write_smic_flags(smic, flags | SMIC_FLAG_BSY); + smic->state = SMIC_READ_END; + break; + case SMIC_SC_SMS_RD_NEXT: + if (flags & SMIC_RX_DATA_READY) { + read_next_byte(smic); + write_smic_control(smic, SMIC_CC_SMS_RD_NEXT); + write_smic_flags(smic, flags | SMIC_FLAG_BSY); + smic->state = SMIC_READ_NEXT; + } else + return SI_SM_CALL_WITH_DELAY; + break; + default: + start_error_recovery( + smic, + "state = SMIC_READ_NEXT, " + "status != SMIC_SC_SMS_RD_(NEXT|END)"); + return SI_SM_CALL_WITH_DELAY; + } + break; + + case SMIC_READ_END: + if (status != SMIC_SC_SMS_READY) { + start_error_recovery(smic, + "state = SMIC_READ_END, " + "status != SMIC_SC_SMS_READY"); + return SI_SM_CALL_WITH_DELAY; + } + data = read_smic_data(smic); + /* data register holds an error code */ + if (data != 0) { + if (smic_debug & SMIC_DEBUG_ENABLE) + printk(KERN_DEBUG + "SMIC_READ_END: data = %02x\n", data); + start_error_recovery(smic, + "state = SMIC_READ_END, " + "data != SUCCESS"); + return SI_SM_CALL_WITH_DELAY; + } else { + smic->state = SMIC_IDLE; + return SI_SM_TRANSACTION_COMPLETE; + } + + case SMIC_HOSED: + init_smic_data(smic, smic->io); + return SI_SM_HOSED; + + default: + if (smic_debug & SMIC_DEBUG_ENABLE) { + printk(KERN_DEBUG "smic->state = %d\n", smic->state); + start_error_recovery(smic, "state = UNKNOWN"); + return SI_SM_CALL_WITH_DELAY; + } + } + smic->smic_timeout = SMIC_RETRY_TIMEOUT; + return SI_SM_CALL_WITHOUT_DELAY; +} + +static int smic_detect(struct si_sm_data *smic) +{ + /* + * It's impossible for the SMIC fnags register to be all 1's, + * (assuming a properly functioning, self-initialized BMC) + * but that's what you get from reading a bogus address, so we + * test that first. + */ + if (read_smic_flags(smic) == 0xff) + return 1; + + return 0; +} + +static void smic_cleanup(struct si_sm_data *kcs) +{ +} + +static int smic_size(void) +{ + return sizeof(struct si_sm_data); +} + +const struct si_sm_handlers smic_smi_handlers = { + .init_data = init_smic_data, + .start_transaction = start_smic_transaction, + .get_result = smic_get_result, + .event = smic_event, + .detect = smic_detect, + .cleanup = smic_cleanup, + .size = smic_size, +}; |