--- /dev/null
+// 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");
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2015-2018, Intel Corporation.
+
+#ifndef __KCS_BMC_H__
+#define __KCS_BMC_H__
+
+#include <linux/miscdevice.h>
+
+/* Different phases of the KCS BMC module :
+ * KCS_PHASE_IDLE :
+ * BMC should not be expecting nor sending any data.
+ * KCS_PHASE_WRITE_START :
+ * BMC is receiving a WRITE_START command from system software.
+ * KCS_PHASE_WRITE_DATA :
+ * BMC is receiving a data byte from system software.
+ * KCS_PHASE_WRITE_END_CMD :
+ * BMC is waiting a last data byte from system software.
+ * KCS_PHASE_WRITE_DONE :
+ * BMC has received the whole request from system software.
+ * KCS_PHASE_WAIT_READ :
+ * BMC is waiting the response from the upper IPMI service.
+ * KCS_PHASE_READ :
+ * BMC is transferring the response to system software.
+ * KCS_PHASE_ABORT_ERROR1 :
+ * BMC is waiting error status request from system software.
+ * KCS_PHASE_ABORT_ERROR2 :
+ * BMC is waiting for idle status afer error from system software.
+ * KCS_PHASE_ERROR :
+ * BMC has detected a protocol violation at the interface level.
+ */
+enum kcs_phases {
+ KCS_PHASE_IDLE,
+
+ KCS_PHASE_WRITE_START,
+ KCS_PHASE_WRITE_DATA,
+ KCS_PHASE_WRITE_END_CMD,
+ KCS_PHASE_WRITE_DONE,
+
+ KCS_PHASE_WAIT_READ,
+ KCS_PHASE_READ,
+
+ KCS_PHASE_ABORT_ERROR1,
+ KCS_PHASE_ABORT_ERROR2,
+ KCS_PHASE_ERROR
+};
+
+/* IPMI 2.0 - Table 9-4, KCS Interface Status Codes */
+enum kcs_errors {
+ KCS_NO_ERROR = 0x00,
+ KCS_ABORTED_BY_COMMAND = 0x01,
+ KCS_ILLEGAL_CONTROL_CODE = 0x02,
+ KCS_LENGTH_ERROR = 0x06,
+ KCS_UNSPECIFIED_ERROR = 0xFF
+};
+
+/* IPMI 2.0 - 9.5, KCS Interface Registers
+ * @idr : Input Data Register
+ * @odr : Output Data Register
+ * @str : Status Register
+ */
+struct kcs_ioreg {
+ u32 idr;
+ u32 odr;
+ u32 str;
+};
+
+struct kcs_bmc {
+ spinlock_t lock;
+
+ u32 channel;
+ int running;
+
+ /* Setup by BMC KCS controller driver */
+ struct kcs_ioreg ioreg;
+ u8 (*io_inputb)(struct kcs_bmc *kcs_bmc, u32 reg);
+ void (*io_outputb)(struct kcs_bmc *kcs_bmc, u32 reg, u8 b);
+
+ enum kcs_phases phase;
+ enum kcs_errors error;
+
+ wait_queue_head_t queue;
+ bool data_in_avail;
+ int data_in_idx;
+ u8 *data_in;
+
+ int data_out_idx;
+ int data_out_len;
+ u8 *data_out;
+
+ struct mutex mutex;
+ u8 *kbuffer;
+
+ struct miscdevice miscdev;
+
+ unsigned long priv[];
+};
+
+static inline void *kcs_bmc_priv(struct kcs_bmc *kcs_bmc)
+{
+ return kcs_bmc->priv;
+}
+
+int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc);
+struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv,
+ u32 channel);
+#endif
projects / platform / kernel / linux-starfive.git / commitdiff