m68k/atari: ARAnyM - Add support for block access

[geert: Cleanups and updates]

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Petr Stehlik <pstehlik@sophics.cz>

3 files changed, 205 insertions, 0 deletions

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index f668a5802a4a..2c890b56c96e 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -247,6 +247,14 @@ config NATFEAT
           This option enables support for ARAnyM native features, such as
           access to a disk image as /dev/hda.
 
+config NFBLOCK
+        tristate "NatFeat block device support"
+        depends on BLOCK && NATFEAT
+        help
+          Say Y to include support for the ARAnyM NatFeat block device
+          which allows direct access to the hard drives without using
+          the hardware emulation.
+
 comment "Processor type"
 
 config M68020
diff --git a/arch/m68k/emu/Makefile b/arch/m68k/emu/Makefile
index 34cfa348ca2b..fc4f77a3d35c 100644
--- a/arch/m68k/emu/Makefile
+++ b/arch/m68k/emu/Makefile
@@ -3,3 +3,5 @@
 #
 
 obj-y                   += natfeat.o
+
+obj-$(CONFIG_NFBLOCK)   += nfblock.o
diff --git a/arch/m68k/emu/nfblock.c b/arch/m68k/emu/nfblock.c
new file mode 100644
index 000000000000..48e50f8c1c7e
--- /dev/null
+++ b/arch/m68k/emu/nfblock.c
@@ -0,0 +1,195 @@
+/*
+ * ARAnyM block device driver
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/genhd.h>
+#include <linux/blkdev.h>
+#include <linux/hdreg.h>
+#include <linux/slab.h>
+
+#include <asm/natfeat.h>
+
+static long nfhd_id;
+
+enum {
+        /* emulation entry points */
+        NFHD_READ_WRITE = 10,
+        NFHD_GET_CAPACITY = 14,
+
+        /* skip ACSI devices */
+        NFHD_DEV_OFFSET = 8,
+};
+
+static inline s32 nfhd_read_write(u32 major, u32 minor, u32 rwflag, u32 recno,
+                                  u32 count, u32 buf)
+{
+        return nf_call(nfhd_id + NFHD_READ_WRITE, major, minor, rwflag, recno,
+                       count, buf);
+}
+
+static inline s32 nfhd_get_capacity(u32 major, u32 minor, u32 *blocks,
+                                    u32 *blocksize)
+{
+        return nf_call(nfhd_id + NFHD_GET_CAPACITY, major, minor, blocks,
+                       blocksize);
+}
+
+static LIST_HEAD(nfhd_list);
+
+static int major_num;
+module_param(major_num, int, 0);
+
+struct nfhd_device {
+        struct list_head list;
+        int id;
+        u32 blocks, bsize;
+        int bshift;
+        struct request_queue *queue;
+        struct gendisk *disk;
+};
+
+static int nfhd_make_request(struct request_queue *queue, struct bio *bio)
+{
+        struct nfhd_device *dev = queue->queuedata;
+        struct bio_vec *bvec;
+        int i, dir, len, shift;
+        sector_t sec = bio->bi_sector;
+
+        dir = bio_data_dir(bio);
+        shift = dev->bshift;
+        bio_for_each_segment(bvec, bio, i) {
+                len = bvec->bv_len;
+                len >>= 9;
+                nfhd_read_write(dev->id, 0, dir, sec >> shift, len >> shift,
+                                bvec_to_phys(bvec));
+                sec += len;
+        }
+        bio_endio(bio, 0);
+        return 0;
+}
+
+static int nfhd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+{
+        struct nfhd_device *dev = bdev->bd_disk->private_data;
+
+        geo->cylinders = dev->blocks >> (6 - dev->bshift);
+        geo->heads = 4;
+        geo->sectors = 16;
+
+        return 0;
+}
+
+static const struct block_device_operations nfhd_ops = {
+        .owner  = THIS_MODULE,
+        .getgeo = nfhd_getgeo,
+};
+
+static int __init nfhd_init_one(int id, u32 blocks, u32 bsize)
+{
+        struct nfhd_device *dev;
+        int dev_id = id - NFHD_DEV_OFFSET;
+
+        pr_info("nfhd%u: found device with %u blocks (%u bytes)\n", dev_id,
+                blocks, bsize);
+
+        if (bsize < 512 || (bsize & (bsize - 1))) {
+                pr_warn("nfhd%u: invalid block size\n", dev_id);
+                return -EINVAL;
+        }
+
+        dev = kmalloc(sizeof(struct nfhd_device), GFP_KERNEL);
+        if (!dev)
+                goto out;
+
+        dev->id = id;
+        dev->blocks = blocks;
+        dev->bsize = bsize;
+        dev->bshift = ffs(bsize) - 10;
+
+        dev->queue = blk_alloc_queue(GFP_KERNEL);
+        if (dev->queue == NULL)
+                goto free_dev;
+
+        dev->queue->queuedata = dev;
+        blk_queue_make_request(dev->queue, nfhd_make_request);
+        blk_queue_logical_block_size(dev->queue, bsize);
+
+        dev->disk = alloc_disk(16);
+        if (!dev->disk)
+                goto free_queue;
+
+        dev->disk->major = major_num;
+        dev->disk->first_minor = dev_id * 16;
+        dev->disk->fops = &nfhd_ops;
+        dev->disk->private_data = dev;
+        sprintf(dev->disk->disk_name, "nfhd%u", dev_id);
+        set_capacity(dev->disk, (sector_t)blocks * (bsize / 512));
+        dev->disk->queue = dev->queue;
+
+        add_disk(dev->disk);
+
+        list_add_tail(&dev->list, &nfhd_list);
+
+        return 0;
+
+free_queue:
+        blk_cleanup_queue(dev->queue);
+free_dev:
+        kfree(dev);
+out:
+        return -ENOMEM;
+}
+
+static int __init nfhd_init(void)
+{
+        u32 blocks, bsize;
+        int i;
+
+        nfhd_id = nf_get_id("XHDI");
+        if (!nfhd_id)
+                return -ENODEV;
+
+        major_num = register_blkdev(major_num, "nfhd");
+        if (major_num <= 0) {
+                pr_warn("nfhd: unable to get major number\n");
+                return major_num;
+        }
+
+        for (i = NFHD_DEV_OFFSET; i < 24; i++) {
+                if (nfhd_get_capacity(i, 0, &blocks, &bsize))
+                        continue;
+                nfhd_init_one(i, blocks, bsize);
+        }
+
+        return 0;
+}
+
+static void __exit nfhd_exit(void)
+{
+        struct nfhd_device *dev, *next;
+
+        list_for_each_entry_safe(dev, next, &nfhd_list, list) {
+                list_del(&dev->list);
+                del_gendisk(dev->disk);
+                put_disk(dev->disk);
+                blk_cleanup_queue(dev->queue);
+                kfree(dev);
+        }
+        unregister_blkdev(major_num, "nfhd");
+}
+
+module_init(nfhd_init);
+module_exit(nfhd_exit);
+
+MODULE_LICENSE("GPL");