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// SPDX-License-Identifier: GPL-2.0
/*
* GXP eventfd
*
* Copyright (C) 202d Google LLC
*/
#include <linux/eventfd.h>
#include <linux/refcount.h>
#include <linux/slab.h>
#include "gxp-eventfd.h"
struct gxp_eventfd {
struct eventfd_ctx *ctx;
refcount_t refcount;
};
struct gxp_eventfd *gxp_eventfd_create(int fd)
{
struct gxp_eventfd *efd;
int err;
efd = kmalloc(sizeof(*efd), GFP_KERNEL);
if (!efd)
return ERR_PTR(-ENOMEM);
efd->ctx = eventfd_ctx_fdget(fd);
if (IS_ERR(efd->ctx)) {
err = PTR_ERR(efd->ctx);
goto error;
}
refcount_set(&efd->refcount, 1);
return efd;
error:
kfree(efd);
return ERR_PTR(err);
}
bool gxp_eventfd_get(struct gxp_eventfd *eventfd)
{
return refcount_inc_not_zero(&eventfd->refcount);
}
bool gxp_eventfd_put(struct gxp_eventfd *eventfd)
{
bool refcount_is_zero;
refcount_is_zero = refcount_dec_and_test(&eventfd->refcount);
if (refcount_is_zero) {
eventfd_ctx_put(eventfd->ctx);
kfree(eventfd);
}
return refcount_is_zero;
}
bool gxp_eventfd_signal(struct gxp_eventfd *eventfd)
{
bool ret;
ret = gxp_eventfd_get(eventfd);
if (ret)
eventfd_signal(eventfd->ctx, 1);
gxp_eventfd_put(eventfd);
return ret;
}
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