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Diffstat (limited to '')
-rw-r--r-- | arch/s390/hypfs/hypfs_vm.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/s390/hypfs/hypfs_vm.c b/arch/s390/hypfs/hypfs_vm.c new file mode 100644 index 0000000000..3db40ad853 --- /dev/null +++ b/arch/s390/hypfs/hypfs_vm.c @@ -0,0 +1,141 @@ +// 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); +} |