Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / arch / powerpc / platforms / pseries / hvcserver.c
diff --git a/kernel/arch/powerpc/platforms/pseries/hvcserver.c b/kernel/arch/powerpc/platforms/pseries/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 <linux/string.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 <rsa@us.ibm.com>");
+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;
+       }
+}
+
+/**
+ * hvcs_free_partner_info - free pi allocated by hvcs_get_partner_info
+ * @head: list_head pointer for an allocated list of partner info structs to
+ *     free.
+ *
+ * This function is used to free the partner info list that was returned by
+ * calling hvcs_get_partner_info().
+ */
+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);
+}
+
+/**
+ * hvcs_get_partner_info - Get all of the partner info for a vty-server adapter
+ * @unit_address: The unit_address of the vty-server adapter for which this
+ *     function is fetching partner info.
+ * @head: An initialized list_head pointer to an empty list to use to return the
+ *     list of partner info fetched from the hypervisor to the caller.
+ * @pi_buff: A page sized buffer pre-allocated prior to calling this function
+ *     that is to be used to be used by firmware as an iterator to keep track
+ *     of the partner info retrieval.
+ *
+ * This function returns non-zero on success, or if there is no partner info.
+ *
+ * The pi_buff is pre-allocated prior to calling this function because this
+ * function may be called with a spin_lock held and kmalloc of a page is not
+ * recommended as GFP_ATOMIC.
+ *
+ * The first long of this buffer is used to store a partner unit address.  The
+ * second long is used to store a partner partition ID and starting at
+ * pi_buff[2] is the 79 character Converged Location Code (diff size than the
+ * unsigned longs, hence the casting mumbo jumbo you see later).
+ *
+ * Invocation of this function should always be followed by an invocation of
+ * hvcs_free_partner_info() using a pointer to the SAME list head instance
+ * that was passed as a parameter to this function.
+ */
+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 = be64_to_cpu(pi_buff[0]);
+               last_p_unit_address = be64_to_cpu(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 */
+               strlcpy(&next_partner_info->location_code[0],
+                       (char *)&pi_buff[2],
+                       sizeof(next_partner_info->location_code));
+
+               list_add_tail(&(next_partner_info->node), head);
+               next_partner_info = NULL;
+
+       } while (more);
+
+       return 0;
+}
+EXPORT_SYMBOL(hvcs_get_partner_info);
+
+/**
+ * hvcs_register_connection - establish a connection between this vty-server and
+ *     a vty.
+ * @unit_address: The unit address of the vty-server adapter that is to be
+ *     establish a connection.
+ * @p_partition_ID: The partition ID of the vty adapter that is to be connected.
+ * @p_unit_address: The unit address of the vty adapter to which the vty-server
+ *     is to be connected.
+ *
+ * If this function is called once and -EINVAL is returned it may
+ * indicate that the partner info needs to be refreshed for the
+ * target unit address at which point the caller must invoke
+ * hvcs_get_partner_info() and then call this function again.  If,
+ * for a second time, -EINVAL is returned then it indicates that
+ * there is probably already a partner connection registered to a
+ * different vty-server adapter.  It is also possible that a second
+ * -EINVAL may indicate that one of the parms is not valid, for
+ * instance if the link was removed between the vty-server adapter
+ * and the vty adapter that you are trying to open.  Don't shoot the
+ * messenger.  Firmware implemented it this way.
+ */
+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);
+
+/**
+ * hvcs_free_connection - free the connection between a vty-server and vty
+ * @unit_address: The unit address of the vty-server that is to have its
+ *     connection severed.
+ *
+ * This function is used to free the partner connection between a vty-server
+ * adapter and a vty adapter.
+ *
+ * If -EBUSY is returned continue to call this function until 0 is returned.
+ */
+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);