cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cfutill.c (2861B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (C) ST-Ericsson AB 2010
      4 * Author:	Sjur Brendeland
      5 */
      6
      7#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
      8
      9#include <linux/kernel.h>
     10#include <linux/types.h>
     11#include <linux/slab.h>
     12#include <linux/errno.h>
     13#include <net/caif/caif_layer.h>
     14#include <net/caif/cfsrvl.h>
     15#include <net/caif/cfpkt.h>
     16
     17#define container_obj(layr) ((struct cfsrvl *) layr)
     18#define UTIL_PAYLOAD  0x00
     19#define UTIL_CMD_BIT  0x80
     20#define UTIL_REMOTE_SHUTDOWN 0x82
     21#define UTIL_FLOW_OFF 0x81
     22#define UTIL_FLOW_ON  0x80
     23
     24static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
     25static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
     26
     27struct cflayer *cfutill_create(u8 channel_id, struct dev_info *dev_info)
     28{
     29	struct cfsrvl *util = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
     30	if (!util)
     31		return NULL;
     32	caif_assert(offsetof(struct cfsrvl, layer) == 0);
     33	cfsrvl_init(util, channel_id, dev_info, true);
     34	util->layer.receive = cfutill_receive;
     35	util->layer.transmit = cfutill_transmit;
     36	snprintf(util->layer.name, CAIF_LAYER_NAME_SZ, "util1");
     37	return &util->layer;
     38}
     39
     40static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt)
     41{
     42	u8 cmd = -1;
     43	struct cfsrvl *service = container_obj(layr);
     44	caif_assert(layr != NULL);
     45	caif_assert(layr->up != NULL);
     46	caif_assert(layr->up->receive != NULL);
     47	caif_assert(layr->up->ctrlcmd != NULL);
     48	if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
     49		pr_err("Packet is erroneous!\n");
     50		cfpkt_destroy(pkt);
     51		return -EPROTO;
     52	}
     53
     54	switch (cmd) {
     55	case UTIL_PAYLOAD:
     56		return layr->up->receive(layr->up, pkt);
     57	case UTIL_FLOW_OFF:
     58		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
     59		cfpkt_destroy(pkt);
     60		return 0;
     61	case UTIL_FLOW_ON:
     62		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
     63		cfpkt_destroy(pkt);
     64		return 0;
     65	case UTIL_REMOTE_SHUTDOWN:	/* Remote Shutdown Request */
     66		pr_err("REMOTE SHUTDOWN REQUEST RECEIVED\n");
     67		layr->ctrlcmd(layr, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, 0);
     68		service->open = false;
     69		cfpkt_destroy(pkt);
     70		return 0;
     71	default:
     72		cfpkt_destroy(pkt);
     73		pr_warn("Unknown service control %d (0x%x)\n", cmd, cmd);
     74		return -EPROTO;
     75	}
     76}
     77
     78static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt)
     79{
     80	u8 zero = 0;
     81	struct caif_payload_info *info;
     82	int ret;
     83	struct cfsrvl *service = container_obj(layr);
     84	caif_assert(layr != NULL);
     85	caif_assert(layr->dn != NULL);
     86	caif_assert(layr->dn->transmit != NULL);
     87
     88	if (!cfsrvl_ready(service, &ret)) {
     89		cfpkt_destroy(pkt);
     90		return ret;
     91	}
     92
     93	cfpkt_add_head(pkt, &zero, 1);
     94	/* Add info for MUX-layer to route the packet out. */
     95	info = cfpkt_info(pkt);
     96	info->channel_id = service->layer.id;
     97	/*
     98	 * To optimize alignment, we add up the size of CAIF header before
     99	 * payload.
    100	 */
    101	info->hdr_len = 1;
    102	info->dev_info = &service->dev_info;
    103	return layr->dn->transmit(layr->dn, pkt);
    104}