1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2015-2018, Intel Corporation.
6 #define pr_fmt(fmt) "kcs-bmc: " fmt
8 #include <linux/errno.h>
10 #include <linux/ipmi_bmc.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/poll.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
19 #define KCS_MSG_BUFSIZ 1000
21 #define KCS_ZERO_DATA 0
24 /* IPMI 2.0 - Table 9-1, KCS Interface Status Register Bits */
25 #define KCS_STATUS_STATE(state) (state << 6)
26 #define KCS_STATUS_STATE_MASK GENMASK(7, 6)
27 #define KCS_STATUS_CMD_DAT BIT(3)
28 #define KCS_STATUS_SMS_ATN BIT(2)
29 #define KCS_STATUS_IBF BIT(1)
30 #define KCS_STATUS_OBF BIT(0)
32 /* IPMI 2.0 - Table 9-2, KCS Interface State Bits */
40 /* IPMI 2.0 - Table 9-3, KCS Interface Control Codes */
41 #define KCS_CMD_GET_STATUS_ABORT 0x60
42 #define KCS_CMD_WRITE_START 0x61
43 #define KCS_CMD_WRITE_END 0x62
44 #define KCS_CMD_READ_BYTE 0x68
46 static inline u8 read_data(struct kcs_bmc *kcs_bmc)
48 return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.idr);
51 static inline void write_data(struct kcs_bmc *kcs_bmc, u8 data)
53 kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.odr, data);
56 static inline u8 read_status(struct kcs_bmc *kcs_bmc)
58 return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.str);
61 static inline void write_status(struct kcs_bmc *kcs_bmc, u8 data)
63 kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.str, data);
66 static void update_status_bits(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
68 u8 tmp = read_status(kcs_bmc);
73 write_status(kcs_bmc, tmp);
76 static inline void set_state(struct kcs_bmc *kcs_bmc, u8 state)
78 update_status_bits(kcs_bmc, KCS_STATUS_STATE_MASK,
79 KCS_STATUS_STATE(state));
82 static void kcs_force_abort(struct kcs_bmc *kcs_bmc)
84 set_state(kcs_bmc, ERROR_STATE);
86 write_data(kcs_bmc, KCS_ZERO_DATA);
88 kcs_bmc->phase = KCS_PHASE_ERROR;
89 kcs_bmc->data_in_avail = false;
90 kcs_bmc->data_in_idx = 0;
93 static void kcs_bmc_handle_data(struct kcs_bmc *kcs_bmc)
97 switch (kcs_bmc->phase) {
98 case KCS_PHASE_WRITE_START:
99 kcs_bmc->phase = KCS_PHASE_WRITE_DATA;
102 case KCS_PHASE_WRITE_DATA:
103 if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
104 set_state(kcs_bmc, WRITE_STATE);
105 write_data(kcs_bmc, KCS_ZERO_DATA);
106 kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
109 kcs_force_abort(kcs_bmc);
110 kcs_bmc->error = KCS_LENGTH_ERROR;
114 case KCS_PHASE_WRITE_END_CMD:
115 if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
116 set_state(kcs_bmc, READ_STATE);
117 kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
119 kcs_bmc->phase = KCS_PHASE_WRITE_DONE;
120 kcs_bmc->data_in_avail = true;
121 wake_up_interruptible(&kcs_bmc->queue);
123 kcs_force_abort(kcs_bmc);
124 kcs_bmc->error = KCS_LENGTH_ERROR;
129 if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len)
130 set_state(kcs_bmc, IDLE_STATE);
132 data = read_data(kcs_bmc);
133 if (data != KCS_CMD_READ_BYTE) {
134 set_state(kcs_bmc, ERROR_STATE);
135 write_data(kcs_bmc, KCS_ZERO_DATA);
139 if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len) {
140 write_data(kcs_bmc, KCS_ZERO_DATA);
141 kcs_bmc->phase = KCS_PHASE_IDLE;
146 kcs_bmc->data_out[kcs_bmc->data_out_idx++]);
149 case KCS_PHASE_ABORT_ERROR1:
150 set_state(kcs_bmc, READ_STATE);
152 write_data(kcs_bmc, kcs_bmc->error);
153 kcs_bmc->phase = KCS_PHASE_ABORT_ERROR2;
156 case KCS_PHASE_ABORT_ERROR2:
157 set_state(kcs_bmc, IDLE_STATE);
159 write_data(kcs_bmc, KCS_ZERO_DATA);
160 kcs_bmc->phase = KCS_PHASE_IDLE;
164 kcs_force_abort(kcs_bmc);
169 static void kcs_bmc_handle_cmd(struct kcs_bmc *kcs_bmc)
173 set_state(kcs_bmc, WRITE_STATE);
174 write_data(kcs_bmc, KCS_ZERO_DATA);
176 cmd = read_data(kcs_bmc);
178 case KCS_CMD_WRITE_START:
179 kcs_bmc->phase = KCS_PHASE_WRITE_START;
180 kcs_bmc->error = KCS_NO_ERROR;
181 kcs_bmc->data_in_avail = false;
182 kcs_bmc->data_in_idx = 0;
185 case KCS_CMD_WRITE_END:
186 if (kcs_bmc->phase != KCS_PHASE_WRITE_DATA) {
187 kcs_force_abort(kcs_bmc);
191 kcs_bmc->phase = KCS_PHASE_WRITE_END_CMD;
194 case KCS_CMD_GET_STATUS_ABORT:
195 if (kcs_bmc->error == KCS_NO_ERROR)
196 kcs_bmc->error = KCS_ABORTED_BY_COMMAND;
198 kcs_bmc->phase = KCS_PHASE_ABORT_ERROR1;
199 kcs_bmc->data_in_avail = false;
200 kcs_bmc->data_in_idx = 0;
204 kcs_force_abort(kcs_bmc);
205 kcs_bmc->error = KCS_ILLEGAL_CONTROL_CODE;
210 int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc)
216 spin_lock_irqsave(&kcs_bmc->lock, flags);
218 status = read_status(kcs_bmc);
219 if (status & KCS_STATUS_IBF) {
220 if (!kcs_bmc->running)
221 kcs_force_abort(kcs_bmc);
222 else if (status & KCS_STATUS_CMD_DAT)
223 kcs_bmc_handle_cmd(kcs_bmc);
225 kcs_bmc_handle_data(kcs_bmc);
230 spin_unlock_irqrestore(&kcs_bmc->lock, flags);
234 EXPORT_SYMBOL(kcs_bmc_handle_event);
236 static inline struct kcs_bmc *to_kcs_bmc(struct file *filp)
238 return container_of(filp->private_data, struct kcs_bmc, miscdev);
241 static int kcs_bmc_open(struct inode *inode, struct file *filp)
243 struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
246 spin_lock_irq(&kcs_bmc->lock);
247 if (!kcs_bmc->running)
248 kcs_bmc->running = 1;
251 spin_unlock_irq(&kcs_bmc->lock);
256 static __poll_t kcs_bmc_poll(struct file *filp, poll_table *wait)
258 struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
261 poll_wait(filp, &kcs_bmc->queue, wait);
263 spin_lock_irq(&kcs_bmc->lock);
264 if (kcs_bmc->data_in_avail)
266 spin_unlock_irq(&kcs_bmc->lock);
271 static ssize_t kcs_bmc_read(struct file *filp, char __user *buf,
272 size_t count, loff_t *ppos)
274 struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
279 if (!(filp->f_flags & O_NONBLOCK))
280 wait_event_interruptible(kcs_bmc->queue,
281 kcs_bmc->data_in_avail);
283 mutex_lock(&kcs_bmc->mutex);
285 spin_lock_irq(&kcs_bmc->lock);
286 data_avail = kcs_bmc->data_in_avail;
288 data_len = kcs_bmc->data_in_idx;
289 memcpy(kcs_bmc->kbuffer, kcs_bmc->data_in, data_len);
291 spin_unlock_irq(&kcs_bmc->lock);
298 if (count < data_len) {
299 pr_err("channel=%u with too large data : %zu\n",
300 kcs_bmc->channel, data_len);
302 spin_lock_irq(&kcs_bmc->lock);
303 kcs_force_abort(kcs_bmc);
304 spin_unlock_irq(&kcs_bmc->lock);
310 if (copy_to_user(buf, kcs_bmc->kbuffer, data_len)) {
317 spin_lock_irq(&kcs_bmc->lock);
318 if (kcs_bmc->phase == KCS_PHASE_WRITE_DONE) {
319 kcs_bmc->phase = KCS_PHASE_WAIT_READ;
320 kcs_bmc->data_in_avail = false;
321 kcs_bmc->data_in_idx = 0;
325 spin_unlock_irq(&kcs_bmc->lock);
328 mutex_unlock(&kcs_bmc->mutex);
333 static ssize_t kcs_bmc_write(struct file *filp, const char __user *buf,
334 size_t count, loff_t *ppos)
336 struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
339 /* a minimum response size '3' : netfn + cmd + ccode */
340 if (count < 3 || count > KCS_MSG_BUFSIZ)
343 mutex_lock(&kcs_bmc->mutex);
345 if (copy_from_user(kcs_bmc->kbuffer, buf, count)) {
350 spin_lock_irq(&kcs_bmc->lock);
351 if (kcs_bmc->phase == KCS_PHASE_WAIT_READ) {
352 kcs_bmc->phase = KCS_PHASE_READ;
353 kcs_bmc->data_out_idx = 1;
354 kcs_bmc->data_out_len = count;
355 memcpy(kcs_bmc->data_out, kcs_bmc->kbuffer, count);
356 write_data(kcs_bmc, kcs_bmc->data_out[0]);
361 spin_unlock_irq(&kcs_bmc->lock);
364 mutex_unlock(&kcs_bmc->mutex);
369 static long kcs_bmc_ioctl(struct file *filp, unsigned int cmd,
372 struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
375 spin_lock_irq(&kcs_bmc->lock);
378 case IPMI_BMC_IOCTL_SET_SMS_ATN:
379 update_status_bits(kcs_bmc, KCS_STATUS_SMS_ATN,
383 case IPMI_BMC_IOCTL_CLEAR_SMS_ATN:
384 update_status_bits(kcs_bmc, KCS_STATUS_SMS_ATN,
388 case IPMI_BMC_IOCTL_FORCE_ABORT:
389 kcs_force_abort(kcs_bmc);
397 spin_unlock_irq(&kcs_bmc->lock);
402 static int kcs_bmc_release(struct inode *inode, struct file *filp)
404 struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
406 spin_lock_irq(&kcs_bmc->lock);
407 kcs_bmc->running = 0;
408 kcs_force_abort(kcs_bmc);
409 spin_unlock_irq(&kcs_bmc->lock);
414 static const struct file_operations kcs_bmc_fops = {
415 .owner = THIS_MODULE,
416 .open = kcs_bmc_open,
417 .read = kcs_bmc_read,
418 .write = kcs_bmc_write,
419 .release = kcs_bmc_release,
420 .poll = kcs_bmc_poll,
421 .unlocked_ioctl = kcs_bmc_ioctl,
424 struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel)
426 struct kcs_bmc *kcs_bmc;
428 kcs_bmc = devm_kzalloc(dev, sizeof(*kcs_bmc) + sizeof_priv, GFP_KERNEL);
432 dev_set_name(dev, "ipmi-kcs%u", channel);
434 spin_lock_init(&kcs_bmc->lock);
435 kcs_bmc->channel = channel;
437 mutex_init(&kcs_bmc->mutex);
438 init_waitqueue_head(&kcs_bmc->queue);
440 kcs_bmc->data_in = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
441 kcs_bmc->data_out = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
442 kcs_bmc->kbuffer = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
443 if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer)
446 kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
447 kcs_bmc->miscdev.name = dev_name(dev);
448 kcs_bmc->miscdev.fops = &kcs_bmc_fops;
452 EXPORT_SYMBOL(kcs_bmc_alloc);
454 MODULE_LICENSE("GPL v2");
455 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
456 MODULE_DESCRIPTION("KCS BMC to handle the IPMI request from system software");