[PATCH v2 09/21] ipmi: kcs_bmc: Split out kcs_bmc_cdev_ipmi

Zev Weiss
2021-04-09T03:56:01Z

On Fri, Mar 19, 2021 at 01:27:40AM CDT, Andrew Jeffery wrote:
>Take steps towards defining a coherent API to separate the KCS device
>drivers from the userspace interface. Decreasing the coupling will
>improve the separation of concerns and enable the introduction of
>alternative userspace interfaces.
>
>For now, simply split the chardev logic out to a separate file. The code
>continues to build into the same module.
>
>Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
>---
> drivers/char/ipmi/Makefile | 2 +-
> drivers/char/ipmi/kcs_bmc.c | 423 +------------------------
> drivers/char/ipmi/kcs_bmc.h | 10 +-
> drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 428 ++++++++++++++++++++++++++
> 4 files changed, 451 insertions(+), 412 deletions(-)
> create mode 100644 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
>
>diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
>index 0822adc2ec41..a302bc865370 100644
>--- a/drivers/char/ipmi/Makefile
>+++ b/drivers/char/ipmi/Makefile
>@@ -22,7 +22,7 @@ obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o
> obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o
> obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
> obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o
>-obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o
>+obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o kcs_bmc_cdev_ipmi.o
> obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
> obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o
> obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o
>diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
>index c4336c1f2d6d..ef5c48ffe74a 100644
>--- a/drivers/char/ipmi/kcs_bmc.c
>+++ b/drivers/char/ipmi/kcs_bmc.c
>@@ -3,446 +3,51 @@
> * 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 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc)
>+u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc)
> {
> return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.idr);
> }
>+EXPORT_SYMBOL(kcs_bmc_read_data);
>
>-static inline void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data)
>+void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data)
> {
> kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.odr, data);
> }
>+EXPORT_SYMBOL(kcs_bmc_write_data);
>
>-static inline u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc)
>+u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc)
> {
> return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.str);
> }
>+EXPORT_SYMBOL(kcs_bmc_read_status);
>
>-static inline void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data)
>+void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data)
> {
> kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.str, data);
> }
>+EXPORT_SYMBOL(kcs_bmc_write_status);
>
>-static void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
>+void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
> {
> kcs_bmc->io_updateb(kcs_bmc, kcs_bmc->ioreg.str, mask, val);
> }
>+EXPORT_SYMBOL(kcs_bmc_update_status);
>
>-static inline void set_state(struct kcs_bmc *kcs_bmc, u8 state)
>-{
>- kcs_bmc_update_status(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);
>- kcs_bmc_read_data(kcs_bmc);
>- 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;
>- fallthrough;
>-
>- case KCS_PHASE_WRITE_DATA:
>- if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
>- set_state(kcs_bmc, WRITE_STATE);
>- kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
>- kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
>- kcs_bmc_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++] =
>- kcs_bmc_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 = kcs_bmc_read_data(kcs_bmc);
>- if (data != KCS_CMD_READ_BYTE) {
>- set_state(kcs_bmc, ERROR_STATE);
>- kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
>- break;
>- }
>-
>- if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len) {
>- kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
>- kcs_bmc->phase = KCS_PHASE_IDLE;
>- break;
>- }
>-
>- kcs_bmc_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);
>- kcs_bmc_read_data(kcs_bmc);
>- 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);
>- kcs_bmc_read_data(kcs_bmc);
>- 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);
>- kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
>-
>- cmd = kcs_bmc_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_ipmi_event(struct kcs_bmc *kcs_bmc);

This declaration looks a bit out of place here; should it be in
kcs_bmc.h instead?

> 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 = kcs_bmc_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;
>+ return kcs_bmc_ipmi_event(kcs_bmc);
> }
> 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);
>- kcs_bmc_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:
>- kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, KCS_STATUS_SMS_ATN);
>- break;
>-
>- case IPMI_BMC_IOCTL_CLEAR_SMS_ATN:
>- kcs_bmc_update_status(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_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel);

Similarly here.

> 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;
>+ return kcs_bmc_ipmi_alloc(dev, sizeof_priv, channel);
> }
> EXPORT_SYMBOL(kcs_bmc_alloc);
>
>diff --git a/drivers/char/ipmi/kcs_bmc.h b/drivers/char/ipmi/kcs_bmc.h
>index 970f53892f2d..febea0c8deb4 100644
>--- a/drivers/char/ipmi/kcs_bmc.h
>+++ b/drivers/char/ipmi/kcs_bmc.h
>@@ -104,6 +104,12 @@ static inline void *kcs_bmc_priv(struct kcs_bmc *kcs_bmc)
> }
>
> int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc);
>-struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv,
>- u32 channel);
>+struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel);
>+
>+u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc);
>+void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data);
>+u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc);
>+void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data);
>+void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val);
>+
> #endif /* __KCS_BMC_H__ */
>diff --git a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
>new file mode 100644
>index 000000000000..82c77994e481
>--- /dev/null
>+++ b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
>@@ -0,0 +1,428 @@
>+// 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 void set_state(struct kcs_bmc *kcs_bmc, u8 state)
>+{
>+ kcs_bmc_update_status(kcs_bmc, KCS_STATUS_STATE_MASK,
>+ KCS_STATUS_STATE(state));
>+}
>+
>+static void kcs_bmc_ipmi_force_abort(struct kcs_bmc *kcs_bmc)
>+{
>+ set_state(kcs_bmc, ERROR_STATE);
>+ kcs_bmc_read_data(kcs_bmc);
>+ 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_ipmi_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;
>+ fallthrough;
>+
>+ case KCS_PHASE_WRITE_DATA:
>+ if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
>+ set_state(kcs_bmc, WRITE_STATE);
>+ kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
>+ kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
>+ kcs_bmc_read_data(kcs_bmc);
>+ } else {
>+ kcs_bmc_ipmi_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++] =
>+ kcs_bmc_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_bmc_ipmi_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 = kcs_bmc_read_data(kcs_bmc);
>+ if (data != KCS_CMD_READ_BYTE) {
>+ set_state(kcs_bmc, ERROR_STATE);
>+ kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
>+ break;
>+ }
>+
>+ if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len) {
>+ kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
>+ kcs_bmc->phase = KCS_PHASE_IDLE;
>+ break;
>+ }
>+
>+ kcs_bmc_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);
>+ kcs_bmc_read_data(kcs_bmc);
>+ 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);
>+ kcs_bmc_read_data(kcs_bmc);
>+ kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
>+ kcs_bmc->phase = KCS_PHASE_IDLE;
>+ break;
>+
>+ default:
>+ kcs_bmc_ipmi_force_abort(kcs_bmc);
>+ break;
>+ }
>+}
>+
>+static void kcs_bmc_ipmi_handle_cmd(struct kcs_bmc *kcs_bmc)
>+{
>+ u8 cmd;
>+
>+ set_state(kcs_bmc, WRITE_STATE);
>+ kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
>+
>+ cmd = kcs_bmc_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_bmc_ipmi_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_bmc_ipmi_force_abort(kcs_bmc);
>+ kcs_bmc->error = KCS_ILLEGAL_CONTROL_CODE;
>+ break;
>+ }
>+}
>+
>+int kcs_bmc_ipmi_event(struct kcs_bmc *kcs_bmc);

Another instance...

>+int kcs_bmc_ipmi_event(struct kcs_bmc *kcs_bmc)
>+{
>+ unsigned long flags;
>+ int ret = -ENODATA;
>+ u8 status;
>+
>+ spin_lock_irqsave(&kcs_bmc->lock, flags);
>+
>+ status = kcs_bmc_read_status(kcs_bmc);
>+ if (status & KCS_STATUS_IBF) {
>+ if (!kcs_bmc->running)
>+ kcs_bmc_ipmi_force_abort(kcs_bmc);
>+ else if (status & KCS_STATUS_CMD_DAT)
>+ kcs_bmc_ipmi_handle_cmd(kcs_bmc);
>+ else
>+ kcs_bmc_ipmi_handle_data(kcs_bmc);
>+
>+ ret = 0;
>+ }
>+
>+ spin_unlock_irqrestore(&kcs_bmc->lock, flags);
>+
>+ return ret;
>+}
>+EXPORT_SYMBOL(kcs_bmc_ipmi_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_ipmi_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_ipmi_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_ipmi_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_bmc_ipmi_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_ipmi_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);
>+ kcs_bmc_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_ipmi_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:
>+ kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, KCS_STATUS_SMS_ATN);
>+ break;
>+
>+ case IPMI_BMC_IOCTL_CLEAR_SMS_ATN:
>+ kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, 0);
>+ break;
>+
>+ case IPMI_BMC_IOCTL_FORCE_ABORT:
>+ kcs_bmc_ipmi_force_abort(kcs_bmc);
>+ break;
>+
>+ default:
>+ ret = -EINVAL;
>+ break;
>+ }
>+
>+ spin_unlock_irq(&kcs_bmc->lock);
>+
>+ return ret;
>+}
>+
>+static int kcs_bmc_ipmi_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_bmc_ipmi_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_ipmi_open,
>+ .read = kcs_bmc_ipmi_read,
>+ .write = kcs_bmc_ipmi_write,
>+ .release = kcs_bmc_ipmi_release,
>+ .poll = kcs_bmc_ipmi_poll,
>+ .unlocked_ioctl = kcs_bmc_ipmi_ioctl,
>+};
>+
>+struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel);

Here too.

>+struct kcs_bmc *kcs_bmc_ipmi_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_ipmi_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");
>--
>2.27.0
>