1/* ------------------------------------------------------------
  2 * iSeries_vscsi.c
  3 * (C) Copyright IBM Corporation 1994, 2003
  4 * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
  5 *          Santiago Leon (santil@us.ibm.com)
  6 *          Dave Boutcher (sleddog@us.ibm.com)
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License as published by
 10 * the Free Software Foundation; either version 2 of the License, or
 11 * (at your option) any later version.
 12 *
 13 * This program is distributed in the hope that it will be useful,
 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 * GNU General Public License for more details.
 17 *
 18 * You should have received a copy of the GNU General Public License
 19 * along with this program; if not, write to the Free Software
 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 21 * USA
 22 *
 23 * ------------------------------------------------------------
 24 * iSeries-specific functions of the SCSI host adapter for Virtual I/O devices
 25 *
 26 * This driver allows the Linux SCSI peripheral drivers to directly
 27 * access devices in the hosting partition, either on an iSeries
 28 * hypervisor system or a converged hypervisor system.
 29 */
 30
 31#include <asm/iseries/vio.h>
 32#include <asm/iseries/hv_lp_event.h>
 33#include <asm/iseries/hv_types.h>
 34#include <asm/iseries/hv_lp_config.h>
 35#include <asm/vio.h>
 36#include <linux/device.h>
 37#include "ibmvscsi.h"
 38
 39/* global variables */
 40static struct ibmvscsi_host_data *single_host_data;
 41
 42/* ------------------------------------------------------------
 43 * Routines for direct interpartition interaction
 44 */
 45struct srp_lp_event {
 46	struct HvLpEvent lpevt;	/* 0x00-0x17          */
 47	u32 reserved1;		/* 0x18-0x1B; unused  */
 48	u16 version;		/* 0x1C-0x1D; unused  */
 49	u16 subtype_rc;		/* 0x1E-0x1F; unused  */
 50	struct viosrp_crq crq;	/* 0x20-0x3F          */
 51};
 52
 53/** 
 54 * standard interface for handling logical partition events.
 55 */
 56static void iseriesvscsi_handle_event(struct HvLpEvent *lpevt)
 57{
 58	struct srp_lp_event *evt = (struct srp_lp_event *)lpevt;
 59
 60	if (!evt) {
 61		printk(KERN_ERR "ibmvscsi: received null event\n");
 62		return;
 63	}
 64
 65	if (single_host_data == NULL) {
 66		printk(KERN_ERR
 67		       "ibmvscsi: received event, no adapter present\n");
 68		return;
 69	}
 70
 71	ibmvscsi_handle_crq(&evt->crq, single_host_data);
 72}
 73
 74/* ------------------------------------------------------------
 75 * Routines for driver initialization
 76 */
 77static int iseriesvscsi_init_crq_queue(struct crq_queue *queue,
 78				       struct ibmvscsi_host_data *hostdata,
 79				       int max_requests)
 80{
 81	int rc;
 82
 83	single_host_data = hostdata;
 84	rc = viopath_open(viopath_hostLp, viomajorsubtype_scsi, max_requests);
 85	if (rc < 0) {
 86		printk("viopath_open failed with rc %d in open_event_path\n",
 87		       rc);
 88		goto viopath_open_failed;
 89	}
 90
 91	rc = vio_setHandler(viomajorsubtype_scsi, iseriesvscsi_handle_event);
 92	if (rc < 0) {
 93		printk("vio_setHandler failed with rc %d in open_event_path\n",
 94		       rc);
 95		goto vio_setHandler_failed;
 96	}
 97	return 0;
 98
 99      vio_setHandler_failed:
100	viopath_close(viopath_hostLp, viomajorsubtype_scsi, max_requests);
101      viopath_open_failed:
102	return -1;
103}
104
105static void iseriesvscsi_release_crq_queue(struct crq_queue *queue,
106					   struct ibmvscsi_host_data *hostdata,
107					   int max_requests)
108{
109	vio_clearHandler(viomajorsubtype_scsi);
110	viopath_close(viopath_hostLp, viomajorsubtype_scsi, max_requests);
111}
112
113/**
114 * reset_crq_queue: - resets a crq after a failure
115 * @queue:	crq_queue to initialize and register
116 * @hostdata:	ibmvscsi_host_data of host
117 *
118 * no-op for iSeries
119 */
120static int iseriesvscsi_reset_crq_queue(struct crq_queue *queue,
121					struct ibmvscsi_host_data *hostdata)
122{
123	return 0;
124}
125
126/**
127 * reenable_crq_queue: - reenables a crq after a failure
128 * @queue:	crq_queue to initialize and register
129 * @hostdata:	ibmvscsi_host_data of host
130 *
131 * no-op for iSeries
132 */
133static int iseriesvscsi_reenable_crq_queue(struct crq_queue *queue,
134					   struct ibmvscsi_host_data *hostdata)
135{
136	return 0;
137}
138
139/**
140 * iseriesvscsi_send_crq: - Send a CRQ
141 * @hostdata:	the adapter
142 * @word1:	the first 64 bits of the data
143 * @word2:	the second 64 bits of the data
144 */
145static int iseriesvscsi_send_crq(struct ibmvscsi_host_data *hostdata,
146				 u64 word1, u64 word2)
147{
148	single_host_data = hostdata;
149	return HvCallEvent_signalLpEventFast(viopath_hostLp,
150					     HvLpEvent_Type_VirtualIo,
151					     viomajorsubtype_scsi,
152					     HvLpEvent_AckInd_NoAck,
153					     HvLpEvent_AckType_ImmediateAck,
154					     viopath_sourceinst(viopath_hostLp),
155					     viopath_targetinst(viopath_hostLp),
156					     0,
157					     VIOVERSION << 16, word1, word2, 0,
158					     0);
159}
160
161static int iseriesvscsi_resume(struct ibmvscsi_host_data *hostdata)
162{
163	return 0;
164}
165
166struct ibmvscsi_ops iseriesvscsi_ops = {
167	.init_crq_queue = iseriesvscsi_init_crq_queue,
168	.release_crq_queue = iseriesvscsi_release_crq_queue,
169	.reset_crq_queue = iseriesvscsi_reset_crq_queue,
170	.reenable_crq_queue = iseriesvscsi_reenable_crq_queue,
171	.send_crq = iseriesvscsi_send_crq,
172	.resume = iseriesvscsi_resume,
173};