forked from Minki/linux
36d46a5907
It's cumbersome and error-prone to keep adding fixed IRQ numbers, and for proper device wakeup support for the virtio/vhost-user support we need to have different IRQs for each device. Even if in theory two IRQs (with and without wake) might be sufficient, it's much easier to reason about it when we have dynamic number assignment. It also makes it easier to add new devices that may dynamically exist or depending on the configuration, etc. Add support for this, up to 64 IRQs (the same limit as epoll FDs we have right now). Since it's not easy to port all the existing places to dynamic allocation (some data is statically initialized) keep the low numbers are reserved for the existing hard-coded IRQ numbers. Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
123 lines
2.5 KiB
C
123 lines
2.5 KiB
C
/* Copyright (C) 2005 - 2008 Jeff Dike <jdike@{linux.intel,addtoit}.com> */
|
|
|
|
/* Much of this ripped from drivers/char/hw_random.c, see there for other
|
|
* copyright.
|
|
*
|
|
* This software may be used and distributed according to the terms
|
|
* of the GNU General Public License, incorporated herein by reference.
|
|
*/
|
|
#include <linux/sched/signal.h>
|
|
#include <linux/module.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/hw_random.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/uaccess.h>
|
|
#include <init.h>
|
|
#include <irq_kern.h>
|
|
#include <os.h>
|
|
|
|
/*
|
|
* core module information
|
|
*/
|
|
#define RNG_MODULE_NAME "hw_random"
|
|
|
|
/* Changed at init time, in the non-modular case, and at module load
|
|
* time, in the module case. Presumably, the module subsystem
|
|
* protects against a module being loaded twice at the same time.
|
|
*/
|
|
static int random_fd = -1;
|
|
static struct hwrng hwrng = { 0, };
|
|
static DECLARE_COMPLETION(have_data);
|
|
|
|
static int rng_dev_read(struct hwrng *rng, void *buf, size_t max, bool block)
|
|
{
|
|
int ret;
|
|
|
|
for (;;) {
|
|
ret = os_read_file(random_fd, buf, max);
|
|
if (block && ret == -EAGAIN) {
|
|
add_sigio_fd(random_fd);
|
|
|
|
ret = wait_for_completion_killable(&have_data);
|
|
|
|
ignore_sigio_fd(random_fd);
|
|
deactivate_fd(random_fd, RANDOM_IRQ);
|
|
|
|
if (ret < 0)
|
|
break;
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ret != -EAGAIN ? ret : 0;
|
|
}
|
|
|
|
static irqreturn_t random_interrupt(int irq, void *data)
|
|
{
|
|
complete(&have_data);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/*
|
|
* rng_init - initialize RNG module
|
|
*/
|
|
static int __init rng_init (void)
|
|
{
|
|
int err;
|
|
|
|
err = os_open_file("/dev/random", of_read(OPENFLAGS()), 0);
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
random_fd = err;
|
|
err = um_request_irq(RANDOM_IRQ, random_fd, IRQ_READ, random_interrupt,
|
|
0, "random", NULL);
|
|
if (err < 0)
|
|
goto err_out_cleanup_hw;
|
|
|
|
sigio_broken(random_fd, 1);
|
|
hwrng.name = RNG_MODULE_NAME;
|
|
hwrng.read = rng_dev_read;
|
|
hwrng.quality = 1024;
|
|
|
|
err = hwrng_register(&hwrng);
|
|
if (err) {
|
|
pr_err(RNG_MODULE_NAME " registering failed (%d)\n", err);
|
|
goto err_out_cleanup_hw;
|
|
}
|
|
out:
|
|
return err;
|
|
|
|
err_out_cleanup_hw:
|
|
os_close_file(random_fd);
|
|
random_fd = -1;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* rng_cleanup - shutdown RNG module
|
|
*/
|
|
|
|
static void cleanup(void)
|
|
{
|
|
free_irq_by_fd(random_fd);
|
|
os_close_file(random_fd);
|
|
}
|
|
|
|
static void __exit rng_cleanup(void)
|
|
{
|
|
hwrng_unregister(&hwrng);
|
|
os_close_file(random_fd);
|
|
}
|
|
|
|
module_init (rng_init);
|
|
module_exit (rng_cleanup);
|
|
__uml_exitcall(cleanup);
|
|
|
|
MODULE_DESCRIPTION("UML Host Random Number Generator (RNG) driver");
|
|
MODULE_LICENSE("GPL");
|