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-rw-r--r--arch/s390/hypfs/hypfs_diag0c.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/arch/s390/hypfs/hypfs_diag0c.c b/arch/s390/hypfs/hypfs_diag0c.c
new file mode 100644
index 0000000000..9a2786079e
--- /dev/null
+++ b/arch/s390/hypfs/hypfs_diag0c.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hypervisor filesystem for Linux on s390
+ *
+ * Diag 0C implementation
+ *
+ * Copyright IBM Corp. 2014
+ */
+
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <asm/diag.h>
+#include <asm/hypfs.h>
+#include "hypfs.h"
+
+#define DBFS_D0C_HDR_VERSION 0
+
+/*
+ * Get hypfs_diag0c_entry from CPU vector and store diag0c data
+ */
+static void diag0c_fn(void *data)
+{
+ diag_stat_inc(DIAG_STAT_X00C);
+ diag_amode31_ops.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;
+
+ cpus_read_lock();
+ cpu_count = num_online_cpus();
+ cpu_vec = kmalloc_array(num_possible_cpus(), sizeof(*cpu_vec),
+ GFP_KERNEL);
+ if (!cpu_vec)
+ goto fail_unlock_cpus;
+ /* Note: Diag 0c needs 8 byte alignment and real storage */
+ diag0c_data = kzalloc(struct_size(diag0c_data, entry, cpu_count),
+ 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);
+ cpus_read_unlock();
+ return diag0c_data;
+
+fail_kfree_cpu_vec:
+ kfree(cpu_vec);
+fail_unlock_cpus:
+ cpus_read_unlock();
+ 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));
+ store_tod_clock_ext((union tod_clock *)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;
+ hypfs_dbfs_create_file(&dbfs_file_0c);
+ return 0;
+}
+
+/*
+ * Shutdown diag 0c interface for z/VM
+ */
+void hypfs_diag0c_exit(void)
+{
+ if (!MACHINE_IS_VM)
+ return;
+ hypfs_dbfs_remove_file(&dbfs_file_0c);
+}