diff options
Diffstat (limited to 'arch/s390/hypfs/hypfs_diag.c')
-rw-r--r-- | arch/s390/hypfs/hypfs_diag.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/arch/s390/hypfs/hypfs_diag.c b/arch/s390/hypfs/hypfs_diag.c new file mode 100644 index 0000000000..279b7bba4d --- /dev/null +++ b/arch/s390/hypfs/hypfs_diag.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Hypervisor filesystem for Linux on s390. Diag 204 and 224 + * implementation. + * + * Copyright IBM Corp. 2006, 2008 + * Author(s): Michael Holzheu <holzheu@de.ibm.com> + */ + +#define KMSG_COMPONENT "hypfs" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <asm/diag.h> +#include <asm/ebcdic.h> +#include "hypfs_diag.h" +#include "hypfs.h" + +#define DBFS_D204_HDR_VERSION 0 + +static enum diag204_sc diag204_store_sc; /* used subcode for store */ +static enum diag204_format diag204_info_type; /* used diag 204 data format */ + +static void *diag204_buf; /* 4K aligned buffer for diag204 data */ +static int diag204_buf_pages; /* number of pages for diag204 data */ + +static struct dentry *dbfs_d204_file; + +enum diag204_format diag204_get_info_type(void) +{ + return diag204_info_type; +} + +static void diag204_set_info_type(enum diag204_format type) +{ + diag204_info_type = type; +} + +/* Diagnose 204 functions */ +/* + * For the old diag subcode 4 with simple data format we have to use real + * memory. If we use subcode 6 or 7 with extended data format, we can (and + * should) use vmalloc, since we need a lot of memory in that case. Currently + * up to 93 pages! + */ + +static void diag204_free_buffer(void) +{ + vfree(diag204_buf); + diag204_buf = NULL; +} + +void *diag204_get_buffer(enum diag204_format fmt, int *pages) +{ + if (diag204_buf) { + *pages = diag204_buf_pages; + return diag204_buf; + } + if (fmt == DIAG204_INFO_SIMPLE) { + *pages = 1; + } else {/* DIAG204_INFO_EXT */ + *pages = diag204((unsigned long)DIAG204_SUBC_RSI | + (unsigned long)DIAG204_INFO_EXT, 0, NULL); + if (*pages <= 0) + return ERR_PTR(-EOPNOTSUPP); + } + diag204_buf = __vmalloc_node(array_size(*pages, PAGE_SIZE), + PAGE_SIZE, GFP_KERNEL, NUMA_NO_NODE, + __builtin_return_address(0)); + if (!diag204_buf) + return ERR_PTR(-ENOMEM); + diag204_buf_pages = *pages; + return diag204_buf; +} + +/* + * diag204_probe() has to find out, which type of diagnose 204 implementation + * we have on our machine. Currently there are three possible scanarios: + * - subcode 4 + simple data format (only one page) + * - subcode 4-6 + extended data format + * - subcode 4-7 + extended data format + * + * Subcode 5 is used to retrieve the size of the data, provided by subcodes + * 6 and 7. Subcode 7 basically has the same function as subcode 6. In addition + * to subcode 6 it provides also information about secondary cpus. + * In order to get as much information as possible, we first try + * subcode 7, then 6 and if both fail, we use subcode 4. + */ + +static int diag204_probe(void) +{ + void *buf; + int pages, rc; + + buf = diag204_get_buffer(DIAG204_INFO_EXT, &pages); + if (!IS_ERR(buf)) { + if (diag204((unsigned long)DIAG204_SUBC_STIB7 | + (unsigned long)DIAG204_INFO_EXT, pages, buf) >= 0) { + diag204_store_sc = DIAG204_SUBC_STIB7; + diag204_set_info_type(DIAG204_INFO_EXT); + goto out; + } + if (diag204((unsigned long)DIAG204_SUBC_STIB6 | + (unsigned long)DIAG204_INFO_EXT, pages, buf) >= 0) { + diag204_store_sc = DIAG204_SUBC_STIB6; + diag204_set_info_type(DIAG204_INFO_EXT); + goto out; + } + diag204_free_buffer(); + } + + /* subcodes 6 and 7 failed, now try subcode 4 */ + + buf = diag204_get_buffer(DIAG204_INFO_SIMPLE, &pages); + if (IS_ERR(buf)) { + rc = PTR_ERR(buf); + goto fail_alloc; + } + if (diag204((unsigned long)DIAG204_SUBC_STIB4 | + (unsigned long)DIAG204_INFO_SIMPLE, pages, buf) >= 0) { + diag204_store_sc = DIAG204_SUBC_STIB4; + diag204_set_info_type(DIAG204_INFO_SIMPLE); + goto out; + } else { + rc = -EOPNOTSUPP; + goto fail_store; + } +out: + rc = 0; +fail_store: + diag204_free_buffer(); +fail_alloc: + return rc; +} + +int diag204_store(void *buf, int pages) +{ + int rc; + + rc = diag204((unsigned long)diag204_store_sc | + (unsigned long)diag204_get_info_type(), pages, buf); + return rc < 0 ? -EOPNOTSUPP : 0; +} + +struct dbfs_d204_hdr { + u64 len; /* Length of d204 buffer without header */ + u16 version; /* Version of header */ + u8 sc; /* Used subcode */ + char reserved[53]; +} __attribute__ ((packed)); + +struct dbfs_d204 { + struct dbfs_d204_hdr hdr; /* 64 byte header */ + char buf[]; /* d204 buffer */ +} __attribute__ ((packed)); + +static int dbfs_d204_create(void **data, void **data_free_ptr, size_t *size) +{ + struct dbfs_d204 *d204; + int rc, buf_size; + void *base; + + buf_size = PAGE_SIZE * (diag204_buf_pages + 1) + sizeof(d204->hdr); + base = vzalloc(buf_size); + if (!base) + return -ENOMEM; + d204 = PTR_ALIGN(base + sizeof(d204->hdr), PAGE_SIZE) - sizeof(d204->hdr); + rc = diag204_store(d204->buf, diag204_buf_pages); + if (rc) { + vfree(base); + return rc; + } + d204->hdr.version = DBFS_D204_HDR_VERSION; + d204->hdr.len = PAGE_SIZE * diag204_buf_pages; + d204->hdr.sc = diag204_store_sc; + *data = d204; + *data_free_ptr = base; + *size = d204->hdr.len + sizeof(struct dbfs_d204_hdr); + return 0; +} + +static struct hypfs_dbfs_file dbfs_file_d204 = { + .name = "diag_204", + .data_create = dbfs_d204_create, + .data_free = vfree, +}; + +__init int hypfs_diag_init(void) +{ + int rc; + + if (diag204_probe()) { + pr_info("The hardware system does not support hypfs\n"); + return -ENODATA; + } + + if (diag204_get_info_type() == DIAG204_INFO_EXT) + hypfs_dbfs_create_file(&dbfs_file_d204); + + rc = hypfs_diag_fs_init(); + if (rc) { + pr_err("The hardware system does not provide all functions required by hypfs\n"); + debugfs_remove(dbfs_d204_file); + } + return rc; +} + +void hypfs_diag_exit(void) +{ + debugfs_remove(dbfs_d204_file); + hypfs_diag_fs_exit(); + diag204_free_buffer(); + hypfs_dbfs_remove_file(&dbfs_file_d204); +} |