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/arch/ppc64/kernel/hvcserver.c

https://bitbucket.org/evzijst/gittest
C | 249 lines | 121 code | 25 blank | 103 comment | 13 complexity | 777eb10cd5054fe368340c5e93fdcb85 MD5 | raw file
  1/*
  2 * hvcserver.c
  3 * Copyright (C) 2004 Ryan S Arnold, IBM Corporation
  4 *
  5 * PPC64 virtual I/O console server support.
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License as published by
  9 * the Free Software Foundation; either version 2 of the License, or
 10 * (at your option) any later version.
 11 *
 12 * This program is distributed in the hope that it will be useful,
 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15 * GNU General Public License for more details.
 16 *
 17 * You should have received a copy of the GNU General Public License
 18 * along with this program; if not, write to the Free Software
 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 20 */
 21
 22#include <linux/kernel.h>
 23#include <linux/list.h>
 24#include <linux/module.h>
 25#include <asm/hvcall.h>
 26#include <asm/hvcserver.h>
 27#include <asm/io.h>
 28
 29#define HVCS_ARCH_VERSION "1.0.0"
 30
 31MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>");
 32MODULE_DESCRIPTION("IBM hvcs ppc64 API");
 33MODULE_LICENSE("GPL");
 34MODULE_VERSION(HVCS_ARCH_VERSION);
 35
 36/*
 37 * Convert arch specific return codes into relevant errnos.  The hvcs
 38 * functions aren't performance sensitive, so this conversion isn't an
 39 * issue.
 40 */
 41int hvcs_convert(long to_convert)
 42{
 43	switch (to_convert) {
 44		case H_Success:
 45			return 0;
 46		case H_Parameter:
 47			return -EINVAL;
 48		case H_Hardware:
 49			return -EIO;
 50		case H_Busy:
 51		case H_LongBusyOrder1msec:
 52		case H_LongBusyOrder10msec:
 53		case H_LongBusyOrder100msec:
 54		case H_LongBusyOrder1sec:
 55		case H_LongBusyOrder10sec:
 56		case H_LongBusyOrder100sec:
 57			return -EBUSY;
 58		case H_Function: /* fall through */
 59		default:
 60			return -EPERM;
 61	}
 62}
 63
 64/**
 65 * hvcs_free_partner_info - free pi allocated by hvcs_get_partner_info
 66 * @head: list_head pointer for an allocated list of partner info structs to
 67 *	free.
 68 *
 69 * This function is used to free the partner info list that was returned by
 70 * calling hvcs_get_partner_info().
 71 */
 72int hvcs_free_partner_info(struct list_head *head)
 73{
 74	struct hvcs_partner_info *pi;
 75	struct list_head *element;
 76
 77	if (!head)
 78		return -EINVAL;
 79
 80	while (!list_empty(head)) {
 81		element = head->next;
 82		pi = list_entry(element, struct hvcs_partner_info, node);
 83		list_del(element);
 84		kfree(pi);
 85	}
 86
 87	return 0;
 88}
 89EXPORT_SYMBOL(hvcs_free_partner_info);
 90
 91/* Helper function for hvcs_get_partner_info */
 92int hvcs_next_partner(uint32_t unit_address,
 93		unsigned long last_p_partition_ID,
 94		unsigned long last_p_unit_address, unsigned long *pi_buff)
 95
 96{
 97	long retval;
 98	retval = plpar_hcall_norets(H_VTERM_PARTNER_INFO, unit_address,
 99			last_p_partition_ID,
100				last_p_unit_address, virt_to_phys(pi_buff));
101	return hvcs_convert(retval);
102}
103
104/**
105 * hvcs_get_partner_info - Get all of the partner info for a vty-server adapter
106 * @unit_address: The unit_address of the vty-server adapter for which this
107 *	function is fetching partner info.
108 * @head: An initialized list_head pointer to an empty list to use to return the
109 *	list of partner info fetched from the hypervisor to the caller.
110 * @pi_buff: A page sized buffer pre-allocated prior to calling this function
111 *	that is to be used to be used by firmware as an iterator to keep track
112 *	of the partner info retrieval.
113 *
114 * This function returns non-zero on success, or if there is no partner info.
115 *
116 * The pi_buff is pre-allocated prior to calling this function because this
117 * function may be called with a spin_lock held and kmalloc of a page is not
118 * recommended as GFP_ATOMIC.
119 *
120 * The first long of this buffer is used to store a partner unit address.  The
121 * second long is used to store a partner partition ID and starting at
122 * pi_buff[2] is the 79 character Converged Location Code (diff size than the
123 * unsigned longs, hence the casting mumbo jumbo you see later).
124 *
125 * Invocation of this function should always be followed by an invocation of
126 * hvcs_free_partner_info() using a pointer to the SAME list head instance
127 * that was passed as a parameter to this function.
128 */
129int hvcs_get_partner_info(uint32_t unit_address, struct list_head *head,
130		unsigned long *pi_buff)
131{
132	/*
133	 * Dealt with as longs because of the hcall interface even though the
134	 * values are uint32_t.
135	 */
136	unsigned long	last_p_partition_ID;
137	unsigned long	last_p_unit_address;
138	struct hvcs_partner_info *next_partner_info = NULL;
139	int more = 1;
140	int retval;
141
142	memset(pi_buff, 0x00, PAGE_SIZE);
143	/* invalid parameters */
144	if (!head || !pi_buff)
145		return -EINVAL;
146
147	last_p_partition_ID = last_p_unit_address = ~0UL;
148	INIT_LIST_HEAD(head);
149
150	do {
151		retval = hvcs_next_partner(unit_address, last_p_partition_ID,
152				last_p_unit_address, pi_buff);
153		if (retval) {
154			/*
155			 * Don't indicate that we've failed if we have
156			 * any list elements.
157			 */
158			if (!list_empty(head))
159				return 0;
160			return retval;
161		}
162
163		last_p_partition_ID = pi_buff[0];
164		last_p_unit_address = pi_buff[1];
165
166		/* This indicates that there are no further partners */
167		if (last_p_partition_ID == ~0UL
168				&& last_p_unit_address == ~0UL)
169			break;
170
171		/* This is a very small struct and will be freed soon in
172		 * hvcs_free_partner_info(). */
173		next_partner_info = kmalloc(sizeof(struct hvcs_partner_info),
174				GFP_ATOMIC);
175
176		if (!next_partner_info) {
177			printk(KERN_WARNING "HVCONSOLE: kmalloc() failed to"
178				" allocate partner info struct.\n");
179			hvcs_free_partner_info(head);
180			return -ENOMEM;
181		}
182
183		next_partner_info->unit_address
184			= (unsigned int)last_p_unit_address;
185		next_partner_info->partition_ID
186			= (unsigned int)last_p_partition_ID;
187
188		/* copy the Null-term char too */
189		strncpy(&next_partner_info->location_code[0],
190			(char *)&pi_buff[2],
191			strlen((char *)&pi_buff[2]) + 1);
192
193		list_add_tail(&(next_partner_info->node), head);
194		next_partner_info = NULL;
195
196	} while (more);
197
198	return 0;
199}
200EXPORT_SYMBOL(hvcs_get_partner_info);
201
202/**
203 * hvcs_register_connection - establish a connection between this vty-server and
204 *	a vty.
205 * @unit_address: The unit address of the vty-server adapter that is to be
206 *	establish a connection.
207 * @p_partition_ID: The partition ID of the vty adapter that is to be connected.
208 * @p_unit_address: The unit address of the vty adapter to which the vty-server
209 *	is to be connected.
210 *
211 * If this function is called once and -EINVAL is returned it may
212 * indicate that the partner info needs to be refreshed for the
213 * target unit address at which point the caller must invoke
214 * hvcs_get_partner_info() and then call this function again.  If,
215 * for a second time, -EINVAL is returned then it indicates that
216 * there is probably already a partner connection registered to a
217 * different vty-server adapter.  It is also possible that a second
218 * -EINVAL may indicate that one of the parms is not valid, for
219 * instance if the link was removed between the vty-server adapter
220 * and the vty adapter that you are trying to open.  Don't shoot the
221 * messenger.  Firmware implemented it this way.
222 */
223int hvcs_register_connection( uint32_t unit_address,
224		uint32_t p_partition_ID, uint32_t p_unit_address)
225{
226	long retval;
227	retval = plpar_hcall_norets(H_REGISTER_VTERM, unit_address,
228				p_partition_ID, p_unit_address);
229	return hvcs_convert(retval);
230}
231EXPORT_SYMBOL(hvcs_register_connection);
232
233/**
234 * hvcs_free_connection - free the connection between a vty-server and vty
235 * @unit_address: The unit address of the vty-server that is to have its
236 *	connection severed.
237 *
238 * This function is used to free the partner connection between a vty-server
239 * adapter and a vty adapter.
240 *
241 * If -EBUSY is returned continue to call this function until 0 is returned.
242 */
243int hvcs_free_connection(uint32_t unit_address)
244{
245	long retval;
246	retval = plpar_hcall_norets(H_FREE_VTERM, unit_address);
247	return hvcs_convert(retval);
248}
249EXPORT_SYMBOL(hvcs_free_connection);