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author | Haiyue Wang <haiyue.wang@linux.intel.com> | 2018-02-02 10:16:10 +0800 |
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committer | Corey Minyard <cminyard@mvista.com> | 2018-02-26 09:21:28 -0600 |
commit | 20d60f61c58e8c937f3653819816dd203e6e3cb4 (patch) | |
tree | 1c3bd754e43f96688297f23953f0d25309f6412d /drivers/char/ipmi/kcs_bmc.c | |
parent | e1171aca7da6407c0e65ffb1f38509ee4486a3e7 (diff) | |
download | linux-stable-20d60f61c58e8c937f3653819816dd203e6e3cb4.tar.gz linux-stable-20d60f61c58e8c937f3653819816dd203e6e3cb4.tar.bz2 linux-stable-20d60f61c58e8c937f3653819816dd203e6e3cb4.zip |
ipmi: add a KCS IPMI BMC driver
Provides a device driver for the KCS (Keyboard Controller Style)
IPMI interface which meets the requirement of the BMC (Baseboard
Management Controllers) side for handling the IPMI request from
host system software.
Signed-off-by: Haiyue Wang <haiyue.wang@linux.intel.com>
[Removed the selectability of IPMI_KCS_BMC, as it doesn't do much
good to have it by itself.]
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Diffstat (limited to 'drivers/char/ipmi/kcs_bmc.c')
-rw-r--r-- | drivers/char/ipmi/kcs_bmc.c | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c new file mode 100644 index 000000000000..3a3498afa427 --- /dev/null +++ b/drivers/char/ipmi/kcs_bmc.c @@ -0,0 +1,464 @@ +// 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 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; + + 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 = 0; + u8 status; + + spin_lock_irqsave(&kcs_bmc->lock, flags); + + if (!kcs_bmc->running) { + kcs_force_abort(kcs_bmc); + ret = -ENODEV; + goto out_unlock; + } + + status = read_status(kcs_bmc) & (KCS_STATUS_IBF | KCS_STATUS_CMD_DAT); + + switch (status) { + case KCS_STATUS_IBF | KCS_STATUS_CMD_DAT: + kcs_bmc_handle_cmd(kcs_bmc); + break; + + case KCS_STATUS_IBF: + kcs_bmc_handle_data(kcs_bmc); + break; + + default: + ret = -ENODATA; + break; + } + +out_unlock: + spin_unlock_irqrestore(&kcs_bmc->lock, flags); + + return ret; +} +EXPORT_SYMBOL(kcs_bmc_handle_event); + +static inline struct kcs_bmc *file_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 = file_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 unsigned int kcs_bmc_poll(struct file *filp, poll_table *wait) +{ + struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp); + unsigned int mask = 0; + + poll_wait(filp, &kcs_bmc->queue, wait); + + spin_lock_irq(&kcs_bmc->lock); + if (kcs_bmc->data_in_avail) + mask |= POLLIN; + spin_unlock_irq(&kcs_bmc->lock); + + return mask; +} + +static ssize_t kcs_bmc_read(struct file *filp, char *buf, + size_t count, loff_t *offset) +{ + struct kcs_bmc *kcs_bmc = file_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 *buf, + size_t count, loff_t *offset) +{ + struct kcs_bmc *kcs_bmc = file_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 = file_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 = file_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; + + dev_set_name(dev, "ipmi-kcs%u", channel); + + 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); + if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer) + return NULL; + + kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR; + kcs_bmc->miscdev.name = dev_name(dev); + 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"); |