arch/powerpc/platforms/pseries/hvcserver.c - linux - Git at Google

 // 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: /* 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;

 	/* 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 */
 		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);
	// 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: /* 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;

	/* 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 */
	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);