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

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

diff --git a/arch/s390/hypfs/hypfs_diag.c b/arch/s390/hypfs/hypfs_diag.c
index 5b1acdb..1211bb1 100644 (file)
--- a/arch/s390/hypfs/hypfs_diag.c
+++ b/arch/s390/hypfs/hypfs_diag.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/vmalloc.h>
+#include <linux/mm.h>
 #include <asm/ebcdic.h>
 #include "hypfs.h"
 
@@ -22,6 +23,8 @@
 #define CPU_NAME_LEN 16                /* type name len of cpus in diag224 name table */
 #define TMP_SIZE 64            /* size of temporary buffers */
 
+#define DBFS_D204_HDR_VERSION  0
+
 /* diag 204 subcodes */
 enum diag204_sc {
        SUBC_STIB4 = 4,
@@ -47,6 +50,8 @@ static void *diag204_buf;             /* 4K aligned buffer for diag204 data */
 static void *diag204_buf_vmalloc;      /* vmalloc pointer for diag204 data */
 static int diag204_buf_pages;          /* number of pages for diag204 data */
 
+static struct dentry *dbfs_d204_file;
+
 /*
  * DIAG 204 data structures and member access functions.
  *
@@ -364,18 +369,21 @@ static void diag204_free_buffer(void)
        } else {
                free_pages((unsigned long) diag204_buf, 0);
        }
-       diag204_buf_pages = 0;
        diag204_buf = NULL;
 }
 
+static void *page_align_ptr(void *ptr)
+{
+       return (void *) PAGE_ALIGN((unsigned long) ptr);
+}
+
 static void *diag204_alloc_vbuf(int pages)
 {
        /* The buffer has to be page aligned! */
        diag204_buf_vmalloc = vmalloc(PAGE_SIZE * (pages + 1));
        if (!diag204_buf_vmalloc)
                return ERR_PTR(-ENOMEM);
-       diag204_buf = (void*)((unsigned long)diag204_buf_vmalloc
-                               & ~0xfffUL) + 0x1000;
+       diag204_buf = page_align_ptr(diag204_buf_vmalloc);
        diag204_buf_pages = pages;
        return diag204_buf;
 }
@@ -468,17 +476,26 @@ fail_alloc:
        return rc;
 }
 
+static int diag204_do_store(void *buf, int pages)
+{
+       int rc;
+
+       rc = diag204((unsigned long) diag204_store_sc |
+                    (unsigned long) diag204_info_type, pages, buf);
+       return rc < 0 ? -ENOSYS : 0;
+}
+
 static void *diag204_store(void)
 {
        void *buf;
-       int pages;
+       int pages, rc;
 
        buf = diag204_get_buffer(diag204_info_type, &pages);
        if (IS_ERR(buf))
                goto out;
-       if (diag204((unsigned long)diag204_store_sc |
-                   (unsigned long)diag204_info_type, pages, buf) < 0)
-               return ERR_PTR(-ENOSYS);
+       rc = diag204_do_store(buf, pages);
+       if (rc)
+               return ERR_PTR(rc);
 out:
        return buf;
 }
@@ -526,6 +543,92 @@ static int diag224_idx2name(int index, char *name)
        return 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));
+
+struct dbfs_d204_private {
+       struct dbfs_d204        *d204;  /* Aligned d204 data with header */
+       void                    *base;  /* Base pointer (needed for vfree) */
+};
+
+static int dbfs_d204_open(struct inode *inode, struct file *file)
+{
+       struct dbfs_d204_private *data;
+       struct dbfs_d204 *d204;
+       int rc, buf_size;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+       buf_size = PAGE_SIZE * (diag204_buf_pages + 1) + sizeof(d204->hdr);
+       data->base = vmalloc(buf_size);
+       if (!data->base) {
+               rc = -ENOMEM;
+               goto fail_kfree_data;
+       }
+       memset(data->base, 0, buf_size);
+       d204 = page_align_ptr(data->base + sizeof(d204->hdr))
+               - sizeof(d204->hdr);
+       rc = diag204_do_store(&d204->buf, diag204_buf_pages);
+       if (rc)
+               goto fail_vfree_base;
+       d204->hdr.version = DBFS_D204_HDR_VERSION;
+       d204->hdr.len = PAGE_SIZE * diag204_buf_pages;
+       d204->hdr.sc = diag204_store_sc;
+       data->d204 = d204;
+       file->private_data = data;
+       return nonseekable_open(inode, file);
+
+fail_vfree_base:
+       vfree(data->base);
+fail_kfree_data:
+       kfree(data);
+       return rc;
+}
+
+static int dbfs_d204_release(struct inode *inode, struct file *file)
+{
+       struct dbfs_d204_private *data = file->private_data;
+
+       vfree(data->base);
+       kfree(data);
+       return 0;
+}
+
+static ssize_t dbfs_d204_read(struct file *file, char __user *buf,
+                             size_t size, loff_t *ppos)
+{
+       struct dbfs_d204_private *data = file->private_data;
+
+       return simple_read_from_buffer(buf, size, ppos, data->d204,
+                                      data->d204->hdr.len +
+                                      sizeof(data->d204->hdr));
+}
+
+static const struct file_operations dbfs_d204_ops = {
+       .open           = dbfs_d204_open,
+       .read           = dbfs_d204_read,
+       .release        = dbfs_d204_release,
+};
+
+static int hypfs_dbfs_init(void)
+{
+       dbfs_d204_file = debugfs_create_file("diag_204", 0400, hypfs_dbfs_dir,
+                                            NULL, &dbfs_d204_ops);
+       if (IS_ERR(dbfs_d204_file))
+               return PTR_ERR(dbfs_d204_file);
+       return 0;
+}
+
 __init int hypfs_diag_init(void)
 {
        int rc;
@@ -540,11 +643,17 @@ __init int hypfs_diag_init(void)
                pr_err("The hardware system does not provide all "
                       "functions required by hypfs\n");
        }
+       if (diag204_info_type == INFO_EXT) {
+               rc = hypfs_dbfs_init();
+               if (rc)
+                       diag204_free_buffer();
+       }
        return rc;
 }
 
 void hypfs_diag_exit(void)
 {
+       debugfs_remove(dbfs_d204_file);
        diag224_delete_name_table();
        diag204_free_buffer();
 }