usb: gadget: f_mtp: Avoid race between mtp_read and mtp_function_disable

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / net / caif / cfdbgl.c

/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:	Sjur Brendeland
 * License terms: GNU General Public License (GPL) version 2
 */

#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__

#include <linux/stddef.h>
#include <linux/slab.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfsrvl.h>
#include <net/caif/cfpkt.h>

#define container_obj(layr) ((struct cfsrvl *) layr)

static int cfdbgl_receive(struct cflayer *layr, struct cfpkt *pkt);
static int cfdbgl_transmit(struct cflayer *layr, struct cfpkt *pkt);

struct cflayer *cfdbgl_create(u8 channel_id, struct dev_info *dev_info)
{
	struct cfsrvl *dbg = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
	if (!dbg)
		return NULL;
	caif_assert(offsetof(struct cfsrvl, layer) == 0);
	cfsrvl_init(dbg, channel_id, dev_info, false);
	dbg->layer.receive = cfdbgl_receive;
	dbg->layer.transmit = cfdbgl_transmit;
	snprintf(dbg->layer.name, CAIF_LAYER_NAME_SZ - 1, "dbg%d", channel_id);
	return &dbg->layer;
}

static int cfdbgl_receive(struct cflayer *layr, struct cfpkt *pkt)
{
	return layr->up->receive(layr->up, pkt);
}

static int cfdbgl_transmit(struct cflayer *layr, struct cfpkt *pkt)
{
	struct cfsrvl *service = container_obj(layr);
	struct caif_payload_info *info;
	int ret;

	if (!cfsrvl_ready(service, &ret)) {
		cfpkt_destroy(pkt);
		return ret;
	}

	/* Add info for MUX-layer to route the packet out */
	info = cfpkt_info(pkt);
	info->channel_id = service->layer.id;
	info->dev_info = &service->dev_info;

	return layr->dn->transmit(layr->dn, pkt);
}