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/*
* Copyright (c) 2006 Ondrej Palkovsky
* Copyright (c) 2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup genericipc
* @{
*/
/**
* @file
* @brief IRQ notification framework.
*
* This framework allows applications to register to receive a notification
* when interrupt is detected. The application may provide a simple 'top-half'
* handler as part of its registration, which can perform simple operations
* (read/write port/memory, add information to notification ipc message).
*
* The structure of a notification message is as follows:
* - METHOD: method as registered by the SYS_IPC_REGISTER_IRQ syscall
* - ARG1: payload modified by a 'top-half' handler
* - ARG2: payload modified by a 'top-half' handler
* - ARG3: payload modified by a 'top-half' handler
* - ARG4: payload modified by a 'top-half' handler
* - ARG5: payload modified by a 'top-half' handler
* - in_phone_hash: interrupt counter (may be needed to assure correct order
* in multithreaded drivers)
*
* Note on synchronization for ipc_irq_register(), ipc_irq_unregister(),
* ipc_irq_cleanup() and IRQ handlers:
*
* By always taking all of the uspace IRQ hash table lock, IRQ structure lock
* and answerbox lock, we can rule out race conditions between the
* registration functions and also the cleanup function. Thus the observer can
* either see the IRQ structure present in both the hash table and the
* answerbox list or absent in both. Views in which the IRQ structure would be
* linked in the hash table but not in the answerbox list, or vice versa, are
* not possible.
*
* By always taking the hash table lock and the IRQ structure lock, we can
* rule out a scenario in which we would free up an IRQ structure, which is
* still referenced by, for example, an IRQ handler. The locking scheme forces
* us to lock the IRQ structure only after any progressing IRQs on that
* structure are finished. Because we hold the hash table lock, we prevent new
* IRQs from taking new references to the IRQ structure.
*/
#include <arch.h>
#include <mm/slab.h>
#include <errno.h>
#include <ddi/irq.h>
#include <ipc/ipc.h>
#include <ipc/irq.h>
#include <syscall/copy.h>
#include <console/console.h>
#include <print.h>
/** Free the top-half pseudocode.
*
* @param code Pointer to the top-half pseudocode.
*/
static void code_free(irq_code_t *code)
{
if (code) {
free(code->cmds);
free(code);
}
}
/** Copy the top-half pseudocode from userspace into the kernel.
*
* @param ucode Userspace address of the top-half pseudocode.
*
* @return Kernel address of the copied pseudocode.
*/
static irq_code_t *code_from_uspace(irq_code_t *ucode)
{
irq_code_t *code;
irq_cmd_t *ucmds;
int rc;
code = malloc(sizeof(*code), 0);
rc = copy_from_uspace(code, ucode, sizeof(*code));
if (rc != 0) {
free(code);
return NULL;
}
if (code->cmdcount > IRQ_MAX_PROG_SIZE) {
free(code);
return NULL;
}
ucmds = code->cmds;
code->cmds = malloc(sizeof(code->cmds[0]) * code->cmdcount, 0);
rc = copy_from_uspace(code->cmds, ucmds,
sizeof(code->cmds[0]) * code->cmdcount);
if (rc != 0) {
free(code->cmds);
free(code);
return NULL;
}
return code;
}
/** Register an answerbox as a receiving end for IRQ notifications.
*
* @param box Receiving answerbox.
* @param inr IRQ number.
* @param devno Device number.
* @param method Method to be associated with the notification.
* @param ucode Uspace pointer to top-half pseudocode.
*
* @return EBADMEM, ENOENT or EEXISTS on failure or 0 on success.
*
*/
int ipc_irq_register(answerbox_t *box, inr_t inr, devno_t devno,
unative_t method, irq_code_t *ucode)
{
ipl_t ipl;
irq_code_t *code;
irq_t *irq;
link_t *hlp;
unative_t key[] = {
(unative_t) inr,
(unative_t) devno
};
if (ucode) {
code = code_from_uspace(ucode);
if (!code)
return EBADMEM;
} else {
code = NULL;
}
/*
* Allocate and populate the IRQ structure.
*/
irq = malloc(sizeof(irq_t), 0);
irq_initialize(irq);
irq->devno = devno;
irq->inr = inr;
irq->claim = ipc_irq_top_half_claim;
irq->handler = ipc_irq_top_half_handler;
irq->notif_cfg.notify = true;
irq->notif_cfg.answerbox = box;
irq->notif_cfg.method = method;
irq->notif_cfg.code = code;
irq->notif_cfg.counter = 0;
/*
* Enlist the IRQ structure in the uspace IRQ hash table and the
* answerbox's list.
*/
ipl = interrupts_disable();
spinlock_lock(&irq_uspace_hash_table_lock);
hlp = hash_table_find(&irq_uspace_hash_table, key);
if (hlp) {
irq_t *hirq __attribute__((unused))
= hash_table_get_instance(hlp, irq_t, link);
/* hirq is locked */
spinlock_unlock(&hirq->lock);
code_free(code);
spinlock_unlock(&irq_uspace_hash_table_lock);
free(irq);
interrupts_restore(ipl);
return EEXISTS;
}
spinlock_lock(&irq->lock); /* Not really necessary, but paranoid */
spinlock_lock(&box->irq_lock);
hash_table_insert(&irq_uspace_hash_table, key, &irq->link);
list_append(&irq->notif_cfg.link, &box->irq_head);
spinlock_unlock(&box->irq_lock);
spinlock_unlock(&irq->lock);
spinlock_unlock(&irq_uspace_hash_table_lock);
interrupts_restore(ipl);
return EOK;
}
/** Unregister task from IRQ notification.
*
* @param box Answerbox associated with the notification.
* @param inr IRQ number.
* @param devno Device number.
*/
int ipc_irq_unregister(answerbox_t *box, inr_t inr, devno_t devno)
{
ipl_t ipl;
unative_t key[] = {
(unative_t) inr,
(unative_t) devno
};
link_t *lnk;
irq_t *irq;
ipl = interrupts_disable();
spinlock_lock(&irq_uspace_hash_table_lock);
lnk = hash_table_find(&irq_uspace_hash_table, key);
if (!lnk) {
spinlock_unlock(&irq_uspace_hash_table_lock);
interrupts_restore(ipl);
return ENOENT;
}
irq = hash_table_get_instance(lnk, irq_t, link);
/* irq is locked */
spinlock_lock(&box->irq_lock);
ASSERT(irq->notif_cfg.answerbox == box);
/* Free up the pseudo code and associated structures. */
code_free(irq->notif_cfg.code);
/* Remove the IRQ from the answerbox's list. */
list_remove(&irq->notif_cfg.link);
/*
* We need to drop the IRQ lock now because hash_table_remove() will try
* to reacquire it. That basically violates the natural locking order,
* but a deadlock in hash_table_remove() is prevented by the fact that
* we already held the IRQ lock and didn't drop the hash table lock in
* the meantime.
*/
spinlock_unlock(&irq->lock);
/* Remove the IRQ from the uspace IRQ hash table. */
hash_table_remove(&irq_uspace_hash_table, key, 2);
spinlock_unlock(&irq_uspace_hash_table_lock);
spinlock_unlock(&box->irq_lock);
/* Free up the IRQ structure. */
free(irq);
interrupts_restore(ipl);
return EOK;
}
/** Disconnect all IRQ notifications from an answerbox.
*
* This function is effective because the answerbox contains
* list of all irq_t structures that are registered to
* send notifications to it.
*
* @param box Answerbox for which we want to carry out the cleanup.
*/
void ipc_irq_cleanup(answerbox_t *box)
{
ipl_t ipl;
loop:
ipl = interrupts_disable();
spinlock_lock(&irq_uspace_hash_table_lock);
spinlock_lock(&box->irq_lock);
while (box->irq_head.next != &box->irq_head) {
link_t *cur = box->irq_head.next;
irq_t *irq;
DEADLOCK_PROBE_INIT(p_irqlock);
unative_t key[2];
irq = list_get_instance(cur, irq_t, notif_cfg.link);
if (!spinlock_trylock(&irq->lock)) {
/*
* Avoid deadlock by trying again.
*/
spinlock_unlock(&box->irq_lock);
spinlock_unlock(&irq_uspace_hash_table_lock);
interrupts_restore(ipl);
DEADLOCK_PROBE(p_irqlock, DEADLOCK_THRESHOLD);
goto loop;
}
key[0] = irq->inr;
key[1] = irq->devno;
ASSERT(irq->notif_cfg.answerbox == box);
/* Unlist from the answerbox. */
list_remove(&irq->notif_cfg.link);
/* Free up the pseudo code and associated structures. */
code_free(irq->notif_cfg.code);
/*
* We need to drop the IRQ lock now because hash_table_remove()
* will try to reacquire it. That basically violates the natural
* locking order, but a deadlock in hash_table_remove() is
* prevented by the fact that we already held the IRQ lock and
* didn't drop the hash table lock in the meantime.
*/
spinlock_unlock(&irq->lock);
/* Remove from the hash table. */
hash_table_remove(&irq_uspace_hash_table, key, 2);
free(irq);
}
spinlock_unlock(&box->irq_lock);
spinlock_unlock(&irq_uspace_hash_table_lock);
interrupts_restore(ipl);
}
/** Add a call to the proper answerbox queue.
*
* Assume irq->lock is locked.
*
* @param irq IRQ structure referencing the target answerbox.
* @param call IRQ notification call.
*/
static void send_call(irq_t *irq, call_t *call)
{
spinlock_lock(&irq->notif_cfg.answerbox->irq_lock);
list_append(&call->link, &irq->notif_cfg.answerbox->irq_notifs);
spinlock_unlock(&irq->notif_cfg.answerbox->irq_lock);
waitq_wakeup(&irq->notif_cfg.answerbox->wq, WAKEUP_FIRST);
}
/** Apply the top-half pseudo code to find out whether to accept the IRQ or not.
*
* @param irq IRQ structure.
*
* @return IRQ_ACCEPT if the interrupt is accepted by the
* pseudocode. IRQ_DECLINE otherwise.
*/
irq_ownership_t ipc_irq_top_half_claim(irq_t *irq)
{
unsigned int i;
unative_t dstval;
irq_code_t *code = irq->notif_cfg.code;
unative_t *scratch = irq->notif_cfg.scratch;
if (!irq->notif_cfg.notify)
return IRQ_DECLINE;
if (!code)
return IRQ_DECLINE;
for (i = 0; i < code->cmdcount; i++) {
unsigned int srcarg = code->cmds[i].srcarg;
unsigned int dstarg = code->cmds[i].dstarg;
if (srcarg >= IPC_CALL_LEN)
break;
if (dstarg >= IPC_CALL_LEN)
break;
switch (code->cmds[i].cmd) {
case CMD_PIO_READ_8:
dstval = pio_read_8((ioport8_t *) code->cmds[i].addr);
if (dstarg)
scratch[dstarg] = dstval;
break;
case CMD_PIO_READ_16:
dstval = pio_read_16((ioport16_t *) code->cmds[i].addr);
if (dstarg)
scratch[dstarg] = dstval;
break;
case CMD_PIO_READ_32:
dstval = pio_read_32((ioport32_t *) code->cmds[i].addr);
if (dstarg)
scratch[dstarg] = dstval;
break;
case CMD_PIO_WRITE_8:
pio_write_8((ioport8_t *) code->cmds[i].addr,
(uint8_t) code->cmds[i].value);
break;
case CMD_PIO_WRITE_16:
pio_write_16((ioport16_t *) code->cmds[i].addr,
(uint16_t) code->cmds[i].value);
break;
case CMD_PIO_WRITE_32:
pio_write_32((ioport32_t *) code->cmds[i].addr,
(uint32_t) code->cmds[i].value);
break;
case CMD_BTEST:
if (srcarg && dstarg) {
dstval = scratch[srcarg] & code->cmds[i].value;
scratch[dstarg] = dstval;
}
break;
case CMD_PREDICATE:
if (srcarg && !scratch[srcarg]) {
i += code->cmds[i].value;
continue;
}
break;
case CMD_ACCEPT:
return IRQ_ACCEPT;
break;
case CMD_DECLINE:
default:
return IRQ_DECLINE;
}
}
return IRQ_DECLINE;
}
/* IRQ top-half handler.
*
* We expect interrupts to be disabled and the irq->lock already held.
*
* @param irq IRQ structure.
*/
void ipc_irq_top_half_handler(irq_t *irq)
{
ASSERT(irq);
if (irq->notif_cfg.answerbox) {
call_t *call;
call = ipc_call_alloc(FRAME_ATOMIC);
if (!call)
return;
call->flags |= IPC_CALL_NOTIF;
/* Put a counter to the message */
call->priv = ++irq->notif_cfg.counter;
/* Set up args */
IPC_SET_METHOD(call->data, irq->notif_cfg.method);
IPC_SET_ARG1(call->data, irq->notif_cfg.scratch[1]);
IPC_SET_ARG2(call->data, irq->notif_cfg.scratch[2]);
IPC_SET_ARG3(call->data, irq->notif_cfg.scratch[3]);
IPC_SET_ARG4(call->data, irq->notif_cfg.scratch[4]);
IPC_SET_ARG5(call->data, irq->notif_cfg.scratch[5]);
send_call(irq, call);
}
}
/** Send notification message.
*
* @param irq IRQ structure.
* @param a1 Driver-specific payload argument.
* @param a2 Driver-specific payload argument.
* @param a3 Driver-specific payload argument.
* @param a4 Driver-specific payload argument.
* @param a5 Driver-specific payload argument.
*/
void ipc_irq_send_msg(irq_t *irq, unative_t a1, unative_t a2, unative_t a3,
unative_t a4, unative_t a5)
{
call_t *call;
spinlock_lock(&irq->lock);
if (irq->notif_cfg.answerbox) {
call = ipc_call_alloc(FRAME_ATOMIC);
if (!call) {
spinlock_unlock(&irq->lock);
return;
}
call->flags |= IPC_CALL_NOTIF;
/* Put a counter to the message */
call->priv = ++irq->notif_cfg.counter;
IPC_SET_METHOD(call->data, irq->notif_cfg.method);
IPC_SET_ARG1(call->data, a1);
IPC_SET_ARG2(call->data, a2);
IPC_SET_ARG3(call->data, a3);
IPC_SET_ARG4(call->data, a4);
IPC_SET_ARG5(call->data, a5);
send_call(irq, call);
}
spinlock_unlock(&irq->lock);
}
/** @}
*/