// 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_obj(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);
