Merge branch 'docs-next' of git://git.lwn.net/linux-2.6

[pandora-kernel.git] / arch / s390 / hypfs / hypfs_vm.c

diff --git a/arch/s390/hypfs/hypfs_vm.c b/arch/s390/hypfs/hypfs_vm.c
index f0b0d31..ee5ab1a 100644 (file)
--- a/arch/s390/hypfs/hypfs_vm.c
+++ b/arch/s390/hypfs/hypfs_vm.c
@@ -10,14 +10,18 @@
 #include <linux/string.h>
 #include <linux/vmalloc.h>
 #include <asm/ebcdic.h>
+#include <asm/timex.h>
 #include "hypfs.h"
 
 #define NAME_LEN 8
+#define DBFS_D2FC_HDR_VERSION 0
 
 static char local_guest[] = "        ";
 static char all_guests[] = "*       ";
 static char *guest_query;
 
+static struct dentry *dbfs_d2fc_file;
+
 struct diag2fc_data {
        __u32 version;
        __u32 flags;
@@ -76,23 +80,26 @@ static int diag2fc(int size, char* query, void *addr)
                return -residual_cnt;
 }
 
-static struct diag2fc_data *diag2fc_store(char *query, int *count)
+/*
+ * Allocate buffer for "query" and store diag 2fc at "offset"
+ */
+static void *diag2fc_store(char *query, unsigned int *count, int offset)
 {
+       void *data;
        int size;
-       struct diag2fc_data *data;
 
        do {
                size = diag2fc(0, query, NULL);
                if (size < 0)
                        return ERR_PTR(-EACCES);
-               data = vmalloc(size);
+               data = vmalloc(size + offset);
                if (!data)
                        return ERR_PTR(-ENOMEM);
-               if (diag2fc(size, query, data) == 0)
+               if (diag2fc(size, query, data + offset) == 0)
                        break;
                vfree(data);
        } while (1);
-       *count = (size / sizeof(*data));
+       *count = (size / sizeof(struct diag2fc_data));
 
        return data;
 }
@@ -168,9 +175,10 @@ int hypfs_vm_create_files(struct super_block *sb, struct dentry *root)
 {
        struct dentry *dir, *file;
        struct diag2fc_data *data;
-       int rc, i, count = 0;
+       unsigned int count = 0;
+       int rc, i;
 
-       data = diag2fc_store(guest_query, &count);
+       data = diag2fc_store(guest_query, &count, 0);
        if (IS_ERR(data))
                return PTR_ERR(data);
 
@@ -218,8 +226,61 @@ failed:
        return rc;
 }
 
+struct dbfs_d2fc_hdr {
+       u64     len;            /* Length of d2fc buffer without header */
+       u16     version;        /* Version of header */
+       char    tod_ext[16];    /* 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_d2fc_open(struct inode *inode, struct file *file)
+{
+       struct dbfs_d2fc *data;
+       unsigned int count;
+
+       data = diag2fc_store(guest_query, &count, sizeof(data->hdr));
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+       get_clock_ext(data->hdr.tod_ext);
+       data->hdr.len = count * sizeof(struct diag2fc_data);
+       data->hdr.version = DBFS_D2FC_HDR_VERSION;
+       data->hdr.count = count;
+       memset(&data->hdr.reserved, 0, sizeof(data->hdr.reserved));
+       file->private_data = data;
+       return nonseekable_open(inode, file);
+}
+
+static int dbfs_d2fc_release(struct inode *inode, struct file *file)
+{
+       diag2fc_free(file->private_data);
+       return 0;
+}
+
+static ssize_t dbfs_d2fc_read(struct file *file, char __user *buf,
+                                   size_t size, loff_t *ppos)
+{
+       struct dbfs_d2fc *data = file->private_data;
+
+       return simple_read_from_buffer(buf, size, ppos, data, data->hdr.len +
+                                      sizeof(struct dbfs_d2fc_hdr));
+}
+
+static const struct file_operations dbfs_d2fc_ops = {
+       .open           = dbfs_d2fc_open,
+       .read           = dbfs_d2fc_read,
+       .release        = dbfs_d2fc_release,
+};
+
 int hypfs_vm_init(void)
 {
+       if (!MACHINE_IS_VM)
+               return 0;
        if (diag2fc(0, all_guests, NULL) > 0)
                guest_query = all_guests;
        else if (diag2fc(0, local_guest, NULL) > 0)
@@ -227,5 +288,17 @@ int hypfs_vm_init(void)
        else
                return -EACCES;
 
+       dbfs_d2fc_file = debugfs_create_file("diag_2fc", 0400, hypfs_dbfs_dir,
+                                            NULL, &dbfs_d2fc_ops);
+       if (IS_ERR(dbfs_d2fc_file))
+               return PTR_ERR(dbfs_d2fc_file);
+
        return 0;
 }
+
+void hypfs_vm_exit(void)
+{
+       if (!MACHINE_IS_VM)
+               return;
+       debugfs_remove(dbfs_d2fc_file);
+}