mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
163 lines
4.2 KiB
163 lines
4.2 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
|
|
/* |
|
* IBM ASM Service Processor Device Driver |
|
* |
|
* Copyright (C) IBM Corporation, 2004 |
|
* |
|
* Author: Max Asböck <[email protected]> |
|
*/ |
|
|
|
#include <linux/sched.h> |
|
#include <linux/slab.h> |
|
#include "ibmasm.h" |
|
#include "lowlevel.h" |
|
|
|
/* |
|
* ASM service processor event handling routines. |
|
* |
|
* Events are signalled to the device drivers through interrupts. |
|
* They have the format of dot commands, with the type field set to |
|
* sp_event. |
|
* The driver does not interpret the events, it simply stores them in a |
|
* circular buffer. |
|
*/ |
|
|
|
static void wake_up_event_readers(struct service_processor *sp) |
|
{ |
|
struct event_reader *reader; |
|
|
|
list_for_each_entry(reader, &sp->event_buffer->readers, node) |
|
wake_up_interruptible(&reader->wait); |
|
} |
|
|
|
/* |
|
* receive_event |
|
* Called by the interrupt handler when a dot command of type sp_event is |
|
* received. |
|
* Store the event in the circular event buffer, wake up any sleeping |
|
* event readers. |
|
* There is no reader marker in the buffer, therefore readers are |
|
* responsible for keeping up with the writer, or they will lose events. |
|
*/ |
|
void ibmasm_receive_event(struct service_processor *sp, void *data, unsigned int data_size) |
|
{ |
|
struct event_buffer *buffer = sp->event_buffer; |
|
struct ibmasm_event *event; |
|
unsigned long flags; |
|
|
|
data_size = min(data_size, IBMASM_EVENT_MAX_SIZE); |
|
|
|
spin_lock_irqsave(&sp->lock, flags); |
|
/* copy the event into the next slot in the circular buffer */ |
|
event = &buffer->events[buffer->next_index]; |
|
memcpy_fromio(event->data, data, data_size); |
|
event->data_size = data_size; |
|
event->serial_number = buffer->next_serial_number; |
|
|
|
/* advance indices in the buffer */ |
|
buffer->next_index = (buffer->next_index + 1) % IBMASM_NUM_EVENTS; |
|
buffer->next_serial_number++; |
|
spin_unlock_irqrestore(&sp->lock, flags); |
|
|
|
wake_up_event_readers(sp); |
|
} |
|
|
|
static inline int event_available(struct event_buffer *b, struct event_reader *r) |
|
{ |
|
return (r->next_serial_number < b->next_serial_number); |
|
} |
|
|
|
/* |
|
* get_next_event |
|
* Called by event readers (initiated from user space through the file |
|
* system). |
|
* Sleeps until a new event is available. |
|
*/ |
|
int ibmasm_get_next_event(struct service_processor *sp, struct event_reader *reader) |
|
{ |
|
struct event_buffer *buffer = sp->event_buffer; |
|
struct ibmasm_event *event; |
|
unsigned int index; |
|
unsigned long flags; |
|
|
|
reader->cancelled = 0; |
|
|
|
if (wait_event_interruptible(reader->wait, |
|
event_available(buffer, reader) || reader->cancelled)) |
|
return -ERESTARTSYS; |
|
|
|
if (!event_available(buffer, reader)) |
|
return 0; |
|
|
|
spin_lock_irqsave(&sp->lock, flags); |
|
|
|
index = buffer->next_index; |
|
event = &buffer->events[index]; |
|
while (event->serial_number < reader->next_serial_number) { |
|
index = (index + 1) % IBMASM_NUM_EVENTS; |
|
event = &buffer->events[index]; |
|
} |
|
memcpy(reader->data, event->data, event->data_size); |
|
reader->data_size = event->data_size; |
|
reader->next_serial_number = event->serial_number + 1; |
|
|
|
spin_unlock_irqrestore(&sp->lock, flags); |
|
|
|
return event->data_size; |
|
} |
|
|
|
void ibmasm_cancel_next_event(struct event_reader *reader) |
|
{ |
|
reader->cancelled = 1; |
|
wake_up_interruptible(&reader->wait); |
|
} |
|
|
|
void ibmasm_event_reader_register(struct service_processor *sp, struct event_reader *reader) |
|
{ |
|
unsigned long flags; |
|
|
|
reader->next_serial_number = sp->event_buffer->next_serial_number; |
|
init_waitqueue_head(&reader->wait); |
|
spin_lock_irqsave(&sp->lock, flags); |
|
list_add(&reader->node, &sp->event_buffer->readers); |
|
spin_unlock_irqrestore(&sp->lock, flags); |
|
} |
|
|
|
void ibmasm_event_reader_unregister(struct service_processor *sp, struct event_reader *reader) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&sp->lock, flags); |
|
list_del(&reader->node); |
|
spin_unlock_irqrestore(&sp->lock, flags); |
|
} |
|
|
|
int ibmasm_event_buffer_init(struct service_processor *sp) |
|
{ |
|
struct event_buffer *buffer; |
|
struct ibmasm_event *event; |
|
int i; |
|
|
|
buffer = kmalloc(sizeof(struct event_buffer), GFP_KERNEL); |
|
if (!buffer) |
|
return -ENOMEM; |
|
|
|
buffer->next_index = 0; |
|
buffer->next_serial_number = 1; |
|
|
|
event = buffer->events; |
|
for (i=0; i<IBMASM_NUM_EVENTS; i++, event++) |
|
event->serial_number = 0; |
|
|
|
INIT_LIST_HEAD(&buffer->readers); |
|
|
|
sp->event_buffer = buffer; |
|
|
|
return 0; |
|
} |
|
|
|
void ibmasm_event_buffer_exit(struct service_processor *sp) |
|
{ |
|
kfree(sp->event_buffer); |
|
}
|
|
|