diff options
author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2015-02-09 14:49:10 +0100 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-02-10 16:38:58 +0100 |
commit | 34c0dad752294f373a0720840f59e186788ba227 (patch) | |
tree | 4d9da02c1edf8c5b4cf57016164747bfabd6faee /arch/s390/hypfs/hypfs_diag0c.c | |
parent | 45cce4ccafe3cddc924ef5221d22b9853fc9a13c (diff) | |
download | linux-34c0dad752294f373a0720840f59e186788ba227.tar.bz2 |
s390/hypfs: Add diagnose 0c support
With this feature, you can read the CPU performance metrics provided by the
z/VM diagnose 0C. This then allows to get the management time for each
online CPU of the guest where the diagnose is executed.
The new debugfs file /sys/kernel/debug/s390_hypfs/diag_0c exports the
diag0C binary data to user space via an open/read/close interface.
The binary data consists out of a header structure followed by an
array that contains the diagnose 0c data for each online CPU.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/hypfs/hypfs_diag0c.c')
-rw-r--r-- | arch/s390/hypfs/hypfs_diag0c.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/s390/hypfs/hypfs_diag0c.c b/arch/s390/hypfs/hypfs_diag0c.c new file mode 100644 index 000000000000..d4c0d3717543 --- /dev/null +++ b/arch/s390/hypfs/hypfs_diag0c.c @@ -0,0 +1,139 @@ +/* + * Hypervisor filesystem for Linux on s390 + * + * Diag 0C implementation + * + * Copyright IBM Corp. 2014 + */ + +#include <linux/slab.h> +#include <linux/cpu.h> +#include <asm/hypfs.h> +#include "hypfs.h" + +#define DBFS_D0C_HDR_VERSION 0 + +/* + * Execute diagnose 0c in 31 bit mode + */ +static void diag0c(struct hypfs_diag0c_entry *entry) +{ + asm volatile ( +#ifdef CONFIG_64BIT + " sam31\n" + " diag %0,%0,0x0c\n" + " sam64\n" +#else + " diag %0,%0,0x0c\n" +#endif + : /* no output register */ + : "a" (entry) + : "memory"); +} + +/* + * Get hypfs_diag0c_entry from CPU vector and store diag0c data + */ +static void diag0c_fn(void *data) +{ + diag0c(((void **) data)[smp_processor_id()]); +} + +/* + * Allocate buffer and store diag 0c data + */ +static void *diag0c_store(unsigned int *count) +{ + struct hypfs_diag0c_data *diag0c_data; + unsigned int cpu_count, cpu, i; + void **cpu_vec; + + get_online_cpus(); + cpu_count = num_online_cpus(); + cpu_vec = kmalloc(sizeof(*cpu_vec) * num_possible_cpus(), GFP_KERNEL); + if (!cpu_vec) + goto fail_put_online_cpus; + /* Note: Diag 0c needs 8 byte alignment and real storage */ + diag0c_data = kzalloc(sizeof(struct hypfs_diag0c_hdr) + + cpu_count * sizeof(struct hypfs_diag0c_entry), + GFP_KERNEL | GFP_DMA); + if (!diag0c_data) + goto fail_kfree_cpu_vec; + i = 0; + /* Fill CPU vector for each online CPU */ + for_each_online_cpu(cpu) { + diag0c_data->entry[i].cpu = cpu; + cpu_vec[cpu] = &diag0c_data->entry[i++]; + } + /* Collect data all CPUs */ + on_each_cpu(diag0c_fn, cpu_vec, 1); + *count = cpu_count; + kfree(cpu_vec); + put_online_cpus(); + return diag0c_data; + +fail_kfree_cpu_vec: + kfree(cpu_vec); +fail_put_online_cpus: + put_online_cpus(); + return ERR_PTR(-ENOMEM); +} + +/* + * Hypfs DBFS callback: Free diag 0c data + */ +static void dbfs_diag0c_free(const void *data) +{ + kfree(data); +} + +/* + * Hypfs DBFS callback: Create diag 0c data + */ +static int dbfs_diag0c_create(void **data, void **data_free_ptr, size_t *size) +{ + struct hypfs_diag0c_data *diag0c_data; + unsigned int count; + + diag0c_data = diag0c_store(&count); + if (IS_ERR(diag0c_data)) + return PTR_ERR(diag0c_data); + memset(&diag0c_data->hdr, 0, sizeof(diag0c_data->hdr)); + get_tod_clock_ext(diag0c_data->hdr.tod_ext); + diag0c_data->hdr.len = count * sizeof(struct hypfs_diag0c_entry); + diag0c_data->hdr.version = DBFS_D0C_HDR_VERSION; + diag0c_data->hdr.count = count; + *data = diag0c_data; + *data_free_ptr = diag0c_data; + *size = diag0c_data->hdr.len + sizeof(struct hypfs_diag0c_hdr); + return 0; +} + +/* + * Hypfs DBFS file structure + */ +static struct hypfs_dbfs_file dbfs_file_0c = { + .name = "diag_0c", + .data_create = dbfs_diag0c_create, + .data_free = dbfs_diag0c_free, +}; + +/* + * Initialize diag 0c interface for z/VM + */ +int __init hypfs_diag0c_init(void) +{ + if (!MACHINE_IS_VM) + return 0; + return hypfs_dbfs_create_file(&dbfs_file_0c); +} + +/* + * Shutdown diag 0c interface for z/VM + */ +void hypfs_diag0c_exit(void) +{ + if (!MACHINE_IS_VM) + return; + hypfs_dbfs_remove_file(&dbfs_file_0c); +} |