blob: 3db40ad853e008d206a44804fd63916a45827be9 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Hypervisor filesystem for Linux on s390. z/VM implementation.
*
* Copyright IBM Corp. 2006
* Author(s): Michael Holzheu <holzheu@de.ibm.com>
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <asm/extable.h>
#include <asm/diag.h>
#include <asm/ebcdic.h>
#include <asm/timex.h>
#include "hypfs_vm.h"
#include "hypfs.h"
#define DBFS_D2FC_HDR_VERSION 0
static char local_guest[] = " ";
static char all_guests[] = "* ";
static char *all_groups = all_guests;
char *diag2fc_guest_query;
static int diag2fc(int size, char* query, void *addr)
{
unsigned long residual_cnt;
unsigned long rc;
struct diag2fc_parm_list parm_list;
memcpy(parm_list.userid, query, DIAG2FC_NAME_LEN);
ASCEBC(parm_list.userid, DIAG2FC_NAME_LEN);
memcpy(parm_list.aci_grp, all_groups, DIAG2FC_NAME_LEN);
ASCEBC(parm_list.aci_grp, DIAG2FC_NAME_LEN);
parm_list.addr = (unsigned long)addr;
parm_list.size = size;
parm_list.fmt = 0x02;
rc = -1;
diag_stat_inc(DIAG_STAT_X2FC);
asm volatile(
" diag %0,%1,0x2fc\n"
"0: nopr %%r7\n"
EX_TABLE(0b,0b)
: "=d" (residual_cnt), "+d" (rc) : "0" (&parm_list) : "memory");
if ((rc != 0 ) && (rc != -2))
return rc;
else
return -residual_cnt;
}
/*
* Allocate buffer for "query" and store diag 2fc at "offset"
*/
void *diag2fc_store(char *query, unsigned int *count, int offset)
{
void *data;
int size;
do {
size = diag2fc(0, query, NULL);
if (size < 0)
return ERR_PTR(-EACCES);
data = vmalloc(size + offset);
if (!data)
return ERR_PTR(-ENOMEM);
if (diag2fc(size, query, data + offset) == 0)
break;
vfree(data);
} while (1);
*count = (size / sizeof(struct diag2fc_data));
return data;
}
void diag2fc_free(const void *data)
{
vfree(data);
}
struct dbfs_d2fc_hdr {
u64 len; /* Length of d2fc buffer without header */
u16 version; /* Version of header */
union tod_clock tod_ext; /* TOD clock for d2fc */
u64 count; /* Number of VM guests in d2fc buffer */
char reserved[30];
} __attribute__ ((packed));
struct dbfs_d2fc {
struct dbfs_d2fc_hdr hdr; /* 64 byte header */
char buf[]; /* d2fc buffer */
} __attribute__ ((packed));
static int dbfs_diag2fc_create(void **data, void **data_free_ptr, size_t *size)
{
struct dbfs_d2fc *d2fc;
unsigned int count;
d2fc = diag2fc_store(diag2fc_guest_query, &count, sizeof(d2fc->hdr));
if (IS_ERR(d2fc))
return PTR_ERR(d2fc);
store_tod_clock_ext(&d2fc->hdr.tod_ext);
d2fc->hdr.len = count * sizeof(struct diag2fc_data);
d2fc->hdr.version = DBFS_D2FC_HDR_VERSION;
d2fc->hdr.count = count;
memset(&d2fc->hdr.reserved, 0, sizeof(d2fc->hdr.reserved));
*data = d2fc;
*data_free_ptr = d2fc;
*size = d2fc->hdr.len + sizeof(struct dbfs_d2fc_hdr);
return 0;
}
static struct hypfs_dbfs_file dbfs_file_2fc = {
.name = "diag_2fc",
.data_create = dbfs_diag2fc_create,
.data_free = diag2fc_free,
};
int hypfs_vm_init(void)
{
if (!MACHINE_IS_VM)
return 0;
if (diag2fc(0, all_guests, NULL) > 0)
diag2fc_guest_query = all_guests;
else if (diag2fc(0, local_guest, NULL) > 0)
diag2fc_guest_query = local_guest;
else
return -EACCES;
hypfs_dbfs_create_file(&dbfs_file_2fc);
return 0;
}
void hypfs_vm_exit(void)
{
if (!MACHINE_IS_VM)
return;
hypfs_dbfs_remove_file(&dbfs_file_2fc);
}