hvcserver.c

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/*
 * hvcserver.c
 * Copyright (C) 2004 Ryan S Arnold, IBM Corporation
 *
 * PPC64 virtual I/O console server support.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <asm/hvcall.h>
#include <asm/hvcserver.h>
#include <asm/io.h>

#define HVCS_ARCH_VERSION "1.0.0"

MODULE_AUTHOR("Ryan S. Arnold <[email protected]>");
MODULE_DESCRIPTION("IBM hvcs ppc64 API");
MODULE_LICENSE("GPL");
MODULE_VERSION(HVCS_ARCH_VERSION);

/*
 * Convert arch specific return codes into relevant errnos.  The hvcs
 * functions aren't performance sensitive, so this conversion isn't an
 * issue.
 */
static int hvcs_convert(long to_convert)
{
    switch (to_convert) {
        case H_SUCCESS:
            return 0;
        case H_PARAMETER:
            return -EINVAL;
        case H_HARDWARE:
            return -EIO;
        case H_BUSY:
        case H_LONG_BUSY_ORDER_1_MSEC:
        case H_LONG_BUSY_ORDER_10_MSEC:
        case H_LONG_BUSY_ORDER_100_MSEC:
        case H_LONG_BUSY_ORDER_1_SEC:
        case H_LONG_BUSY_ORDER_10_SEC:
        case H_LONG_BUSY_ORDER_100_SEC:
            return -EBUSY;
        case H_FUNCTION: /* fall through */
        default:
            return -EPERM;
    }
}

int hvcs_free_partner_info(struct list_head *head)
{
    struct hvcs_partner_info *pi;
    struct list_head *element;

    if (!head)
        return -EINVAL;

    while (!list_empty(head)) {
        element = head->next;
        pi = list_entry(element, struct hvcs_partner_info, node);
        list_del(element);
        kfree(pi);
    }

    return 0;
}
EXPORT_SYMBOL(hvcs_free_partner_info);

/* Helper function for hvcs_get_partner_info */
static int hvcs_next_partner(uint32_t unit_address,
        unsigned long last_p_partition_ID,
        unsigned long last_p_unit_address, unsigned long *pi_buff)

{
    long retval;
    retval = plpar_hcall_norets(H_VTERM_PARTNER_INFO, unit_address,
            last_p_partition_ID,
                last_p_unit_address, virt_to_phys(pi_buff));
    return hvcs_convert(retval);
}

int hvcs_get_partner_info(uint32_t unit_address, struct list_head *head,
        unsigned long *pi_buff)
{
    /*
     * Dealt with as longs because of the hcall interface even though the
     * values are uint32_t.
     */
    unsigned long   last_p_partition_ID;
    unsigned long   last_p_unit_address;
    struct hvcs_partner_info *next_partner_info = NULL;
    int more = 1;
    int retval;

    memset(pi_buff, 0x00, PAGE_SIZE);
    /* invalid parameters */
    if (!head || !pi_buff)
        return -EINVAL;

    last_p_partition_ID = last_p_unit_address = ~0UL;
    INIT_LIST_HEAD(head);

    do {
        retval = hvcs_next_partner(unit_address, last_p_partition_ID,
                last_p_unit_address, pi_buff);
        if (retval) {
            /*
             * Don't indicate that we've failed if we have
             * any list elements.
             */
            if (!list_empty(head))
                return 0;
            return retval;
        }

        last_p_partition_ID = pi_buff[0];
        last_p_unit_address = pi_buff[1];

        /* This indicates that there are no further partners */
        if (last_p_partition_ID == ~0UL
                && last_p_unit_address == ~0UL)
            break;

        /* This is a very small struct and will be freed soon in
         * hvcs_free_partner_info(). */
        next_partner_info = kmalloc(sizeof(struct hvcs_partner_info),
                GFP_ATOMIC);

        if (!next_partner_info) {
            printk(KERN_WARNING "HVCONSOLE: kmalloc() failed to"
                " allocate partner info struct.\n");
            hvcs_free_partner_info(head);
            return -ENOMEM;
        }

        next_partner_info->unit_address
            = (unsigned int)last_p_unit_address;
        next_partner_info->partition_ID
            = (unsigned int)last_p_partition_ID;

        /* copy the Null-term char too */
        strncpy(&next_partner_info->location_code[0],
            (char *)&pi_buff[2],
            strlen((char *)&pi_buff[2]) + 1);

        list_add_tail(&(next_partner_info->node), head);
        next_partner_info = NULL;

    } while (more);

    return 0;
}
EXPORT_SYMBOL(hvcs_get_partner_info);

int hvcs_register_connection( uint32_t unit_address,
        uint32_t p_partition_ID, uint32_t p_unit_address)
{
    long retval;
    retval = plpar_hcall_norets(H_REGISTER_VTERM, unit_address,
                p_partition_ID, p_unit_address);
    return hvcs_convert(retval);
}
EXPORT_SYMBOL(hvcs_register_connection);

int hvcs_free_connection(uint32_t unit_address)
{
    long retval;
    retval = plpar_hcall_norets(H_FREE_VTERM, unit_address);
    return hvcs_convert(retval);
}
EXPORT_SYMBOL(hvcs_free_connection);