1 files changed, 239 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/hvcserver.c b/arch/powerpc/platforms/pseries/hvcserver.c
new file mode 100644
index 000000000..d48c9c7ce
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/hvcserver.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * hvcserver.c
+ * Copyright (C) 2004 Ryan S Arnold, IBM Corporation
+ *
+ * PPC64 virtual I/O console server support.
+ */
+
+#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:
+		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;
+
+	/* invalid parameters */
+	if (!head || !pi_buff)
+		return -EINVAL;
+
+	memset(pi_buff, 0x00, PAGE_SIZE);
+	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 */
+		strscpy(&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);