linux-stable/drivers/char/ipmi/kcs_bmc.c
Nicholas Mc Guire 42c7c6ef1e ipmi: kcs_bmc: handle devm_kasprintf() failure case
devm_kasprintf() may return NULL if internal allocation failed so this
assignment is not safe. Moved the error exit path and added the !NULL
which then allows the devres manager to take care of cleanup.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Fixes: cd2315d471 ("ipmi: kcs_bmc: don't change device name")
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Haiyue Wang <haiyue.wang@linux.intel.com>
2019-02-09 19:48:42 -06:00

458 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2015-2018, Intel Corporation.
*/
#define pr_fmt(fmt) "kcs-bmc: " fmt
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/ipmi_bmc.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include "kcs_bmc.h"
#define DEVICE_NAME "ipmi-kcs"
#define KCS_MSG_BUFSIZ 1000
#define KCS_ZERO_DATA 0
/* IPMI 2.0 - Table 9-1, KCS Interface Status Register Bits */
#define KCS_STATUS_STATE(state) (state << 6)
#define KCS_STATUS_STATE_MASK GENMASK(7, 6)
#define KCS_STATUS_CMD_DAT BIT(3)
#define KCS_STATUS_SMS_ATN BIT(2)
#define KCS_STATUS_IBF BIT(1)
#define KCS_STATUS_OBF BIT(0)
/* IPMI 2.0 - Table 9-2, KCS Interface State Bits */
enum kcs_states {
IDLE_STATE = 0,
READ_STATE = 1,
WRITE_STATE = 2,
ERROR_STATE = 3,
};
/* IPMI 2.0 - Table 9-3, KCS Interface Control Codes */
#define KCS_CMD_GET_STATUS_ABORT 0x60
#define KCS_CMD_WRITE_START 0x61
#define KCS_CMD_WRITE_END 0x62
#define KCS_CMD_READ_BYTE 0x68
static inline u8 read_data(struct kcs_bmc *kcs_bmc)
{
return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.idr);
}
static inline void write_data(struct kcs_bmc *kcs_bmc, u8 data)
{
kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.odr, data);
}
static inline u8 read_status(struct kcs_bmc *kcs_bmc)
{
return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.str);
}
static inline void write_status(struct kcs_bmc *kcs_bmc, u8 data)
{
kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.str, data);
}
static void update_status_bits(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
{
u8 tmp = read_status(kcs_bmc);
tmp &= ~mask;
tmp |= val & mask;
write_status(kcs_bmc, tmp);
}
static inline void set_state(struct kcs_bmc *kcs_bmc, u8 state)
{
update_status_bits(kcs_bmc, KCS_STATUS_STATE_MASK,
KCS_STATUS_STATE(state));
}
static void kcs_force_abort(struct kcs_bmc *kcs_bmc)
{
set_state(kcs_bmc, ERROR_STATE);
read_data(kcs_bmc);
write_data(kcs_bmc, KCS_ZERO_DATA);
kcs_bmc->phase = KCS_PHASE_ERROR;
kcs_bmc->data_in_avail = false;
kcs_bmc->data_in_idx = 0;
}
static void kcs_bmc_handle_data(struct kcs_bmc *kcs_bmc)
{
u8 data;
switch (kcs_bmc->phase) {
case KCS_PHASE_WRITE_START:
kcs_bmc->phase = KCS_PHASE_WRITE_DATA;
/* fall through */
case KCS_PHASE_WRITE_DATA:
if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
set_state(kcs_bmc, WRITE_STATE);
write_data(kcs_bmc, KCS_ZERO_DATA);
kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
read_data(kcs_bmc);
} else {
kcs_force_abort(kcs_bmc);
kcs_bmc->error = KCS_LENGTH_ERROR;
}
break;
case KCS_PHASE_WRITE_END_CMD:
if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
set_state(kcs_bmc, READ_STATE);
kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
read_data(kcs_bmc);
kcs_bmc->phase = KCS_PHASE_WRITE_DONE;
kcs_bmc->data_in_avail = true;
wake_up_interruptible(&kcs_bmc->queue);
} else {
kcs_force_abort(kcs_bmc);
kcs_bmc->error = KCS_LENGTH_ERROR;
}
break;
case KCS_PHASE_READ:
if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len)
set_state(kcs_bmc, IDLE_STATE);
data = read_data(kcs_bmc);
if (data != KCS_CMD_READ_BYTE) {
set_state(kcs_bmc, ERROR_STATE);
write_data(kcs_bmc, KCS_ZERO_DATA);
break;
}
if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len) {
write_data(kcs_bmc, KCS_ZERO_DATA);
kcs_bmc->phase = KCS_PHASE_IDLE;
break;
}
write_data(kcs_bmc,
kcs_bmc->data_out[kcs_bmc->data_out_idx++]);
break;
case KCS_PHASE_ABORT_ERROR1:
set_state(kcs_bmc, READ_STATE);
read_data(kcs_bmc);
write_data(kcs_bmc, kcs_bmc->error);
kcs_bmc->phase = KCS_PHASE_ABORT_ERROR2;
break;
case KCS_PHASE_ABORT_ERROR2:
set_state(kcs_bmc, IDLE_STATE);
read_data(kcs_bmc);
write_data(kcs_bmc, KCS_ZERO_DATA);
kcs_bmc->phase = KCS_PHASE_IDLE;
break;
default:
kcs_force_abort(kcs_bmc);
break;
}
}
static void kcs_bmc_handle_cmd(struct kcs_bmc *kcs_bmc)
{
u8 cmd;
set_state(kcs_bmc, WRITE_STATE);
write_data(kcs_bmc, KCS_ZERO_DATA);
cmd = read_data(kcs_bmc);
switch (cmd) {
case KCS_CMD_WRITE_START:
kcs_bmc->phase = KCS_PHASE_WRITE_START;
kcs_bmc->error = KCS_NO_ERROR;
kcs_bmc->data_in_avail = false;
kcs_bmc->data_in_idx = 0;
break;
case KCS_CMD_WRITE_END:
if (kcs_bmc->phase != KCS_PHASE_WRITE_DATA) {
kcs_force_abort(kcs_bmc);
break;
}
kcs_bmc->phase = KCS_PHASE_WRITE_END_CMD;
break;
case KCS_CMD_GET_STATUS_ABORT:
if (kcs_bmc->error == KCS_NO_ERROR)
kcs_bmc->error = KCS_ABORTED_BY_COMMAND;
kcs_bmc->phase = KCS_PHASE_ABORT_ERROR1;
kcs_bmc->data_in_avail = false;
kcs_bmc->data_in_idx = 0;
break;
default:
kcs_force_abort(kcs_bmc);
kcs_bmc->error = KCS_ILLEGAL_CONTROL_CODE;
break;
}
}
int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc)
{
unsigned long flags;
int ret = -ENODATA;
u8 status;
spin_lock_irqsave(&kcs_bmc->lock, flags);
status = read_status(kcs_bmc);
if (status & KCS_STATUS_IBF) {
if (!kcs_bmc->running)
kcs_force_abort(kcs_bmc);
else if (status & KCS_STATUS_CMD_DAT)
kcs_bmc_handle_cmd(kcs_bmc);
else
kcs_bmc_handle_data(kcs_bmc);
ret = 0;
}
spin_unlock_irqrestore(&kcs_bmc->lock, flags);
return ret;
}
EXPORT_SYMBOL(kcs_bmc_handle_event);
static inline struct kcs_bmc *to_kcs_bmc(struct file *filp)
{
return container_of(filp->private_data, struct kcs_bmc, miscdev);
}
static int kcs_bmc_open(struct inode *inode, struct file *filp)
{
struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
int ret = 0;
spin_lock_irq(&kcs_bmc->lock);
if (!kcs_bmc->running)
kcs_bmc->running = 1;
else
ret = -EBUSY;
spin_unlock_irq(&kcs_bmc->lock);
return ret;
}
static __poll_t kcs_bmc_poll(struct file *filp, poll_table *wait)
{
struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
__poll_t mask = 0;
poll_wait(filp, &kcs_bmc->queue, wait);
spin_lock_irq(&kcs_bmc->lock);
if (kcs_bmc->data_in_avail)
mask |= EPOLLIN;
spin_unlock_irq(&kcs_bmc->lock);
return mask;
}
static ssize_t kcs_bmc_read(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
bool data_avail;
size_t data_len;
ssize_t ret;
if (!(filp->f_flags & O_NONBLOCK))
wait_event_interruptible(kcs_bmc->queue,
kcs_bmc->data_in_avail);
mutex_lock(&kcs_bmc->mutex);
spin_lock_irq(&kcs_bmc->lock);
data_avail = kcs_bmc->data_in_avail;
if (data_avail) {
data_len = kcs_bmc->data_in_idx;
memcpy(kcs_bmc->kbuffer, kcs_bmc->data_in, data_len);
}
spin_unlock_irq(&kcs_bmc->lock);
if (!data_avail) {
ret = -EAGAIN;
goto out_unlock;
}
if (count < data_len) {
pr_err("channel=%u with too large data : %zu\n",
kcs_bmc->channel, data_len);
spin_lock_irq(&kcs_bmc->lock);
kcs_force_abort(kcs_bmc);
spin_unlock_irq(&kcs_bmc->lock);
ret = -EOVERFLOW;
goto out_unlock;
}
if (copy_to_user(buf, kcs_bmc->kbuffer, data_len)) {
ret = -EFAULT;
goto out_unlock;
}
ret = data_len;
spin_lock_irq(&kcs_bmc->lock);
if (kcs_bmc->phase == KCS_PHASE_WRITE_DONE) {
kcs_bmc->phase = KCS_PHASE_WAIT_READ;
kcs_bmc->data_in_avail = false;
kcs_bmc->data_in_idx = 0;
} else {
ret = -EAGAIN;
}
spin_unlock_irq(&kcs_bmc->lock);
out_unlock:
mutex_unlock(&kcs_bmc->mutex);
return ret;
}
static ssize_t kcs_bmc_write(struct file *filp, const char __user *buf,
size_t count, loff_t *ppos)
{
struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
ssize_t ret;
/* a minimum response size '3' : netfn + cmd + ccode */
if (count < 3 || count > KCS_MSG_BUFSIZ)
return -EINVAL;
mutex_lock(&kcs_bmc->mutex);
if (copy_from_user(kcs_bmc->kbuffer, buf, count)) {
ret = -EFAULT;
goto out_unlock;
}
spin_lock_irq(&kcs_bmc->lock);
if (kcs_bmc->phase == KCS_PHASE_WAIT_READ) {
kcs_bmc->phase = KCS_PHASE_READ;
kcs_bmc->data_out_idx = 1;
kcs_bmc->data_out_len = count;
memcpy(kcs_bmc->data_out, kcs_bmc->kbuffer, count);
write_data(kcs_bmc, kcs_bmc->data_out[0]);
ret = count;
} else {
ret = -EINVAL;
}
spin_unlock_irq(&kcs_bmc->lock);
out_unlock:
mutex_unlock(&kcs_bmc->mutex);
return ret;
}
static long kcs_bmc_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
long ret = 0;
spin_lock_irq(&kcs_bmc->lock);
switch (cmd) {
case IPMI_BMC_IOCTL_SET_SMS_ATN:
update_status_bits(kcs_bmc, KCS_STATUS_SMS_ATN,
KCS_STATUS_SMS_ATN);
break;
case IPMI_BMC_IOCTL_CLEAR_SMS_ATN:
update_status_bits(kcs_bmc, KCS_STATUS_SMS_ATN,
0);
break;
case IPMI_BMC_IOCTL_FORCE_ABORT:
kcs_force_abort(kcs_bmc);
break;
default:
ret = -EINVAL;
break;
}
spin_unlock_irq(&kcs_bmc->lock);
return ret;
}
static int kcs_bmc_release(struct inode *inode, struct file *filp)
{
struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
spin_lock_irq(&kcs_bmc->lock);
kcs_bmc->running = 0;
kcs_force_abort(kcs_bmc);
spin_unlock_irq(&kcs_bmc->lock);
return 0;
}
static const struct file_operations kcs_bmc_fops = {
.owner = THIS_MODULE,
.open = kcs_bmc_open,
.read = kcs_bmc_read,
.write = kcs_bmc_write,
.release = kcs_bmc_release,
.poll = kcs_bmc_poll,
.unlocked_ioctl = kcs_bmc_ioctl,
};
struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel)
{
struct kcs_bmc *kcs_bmc;
kcs_bmc = devm_kzalloc(dev, sizeof(*kcs_bmc) + sizeof_priv, GFP_KERNEL);
if (!kcs_bmc)
return NULL;
spin_lock_init(&kcs_bmc->lock);
kcs_bmc->channel = channel;
mutex_init(&kcs_bmc->mutex);
init_waitqueue_head(&kcs_bmc->queue);
kcs_bmc->data_in = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
kcs_bmc->data_out = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
kcs_bmc->kbuffer = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
kcs_bmc->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s%u",
DEVICE_NAME, channel);
if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer ||
!kcs_bmc->miscdev.name)
return NULL;
kcs_bmc->miscdev.fops = &kcs_bmc_fops;
return kcs_bmc;
}
EXPORT_SYMBOL(kcs_bmc_alloc);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
MODULE_DESCRIPTION("KCS BMC to handle the IPMI request from system software");