Date:	Sun,  6 Feb 2011 11:51:07 +0100
From:	Geert Uytterhoeven <geert@...ux-m68k.org>
To:	linux-m68k@...r.kernel.org, linux-kernel@...r.kernel.org,
	cz-bobek-lists-aranym@...ts.bobek.cz
Cc:	Roman Zippel <zippel@...ux-m68k.org>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	Petr Stehlik <pstehlik@...hics.cz>
Subject: [PATCH 2/4] m68k/atari: ARAnyM - Add support for block access

From: Roman Zippel <zippel@...ux-m68k.org>

Signed-off-by: Roman Zippel <zippel@...ux-m68k.org>
[geert] Cleanups and updates
Signed-off-by: Geert Uytterhoeven <geert@...ux-m68k.org>
Cc: Petr Stehlik <pstehlik@...hics.cz>

---
Changelog:
  - Wrap natfeat calls

    Add wrappers with proper prototypes for the natfeat calls in nfblock.
    This fixes the problem where sector_t was pushed on the stack as a 64-bit
    value if CONFIG_LBDAF=y, while all parameters of the nf_call() varargs
    function are 32-bit.

  - Update for v2.6.31 block layer changes,
  - nfblock needs <linux/slab.h>,
  - Make needlessly global functions static,
  - Make struct block_device_operations const,
  - Use pr_*(),
  - Propagate error code from register_blkdev().
---
 arch/m68k/Kconfig       |    8 ++
 arch/m68k/emu/Makefile  |    2 +
 arch/m68k/emu/nfblock.c |  195 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 205 insertions(+), 0 deletions(-)
 create mode 100644 arch/m68k/emu/nfblock.c

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index f668a58..2c890b5 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 34cfa34..fc4f77a 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 0000000..48e50f8
--- /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");
-- 
1.7.0.4

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