tape_3590.c

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/*
 *  drivers/s390/char/tape_3590.c
 *    tape device discipline for 3590 tapes.
 *
 *    Copyright (C) IBM Corp. 2001,2006
 *    Author(s): Stefan Bader <[e-mail]>
 *		 Michael Holzheu <[e-mail]>
 *		 Martin Schwidefsky <[e-mail]>
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/bio.h>

#define TAPE_DBF_AREA	tape_3590_dbf

#include "tape.h"
#include "tape_std.h"
#include "tape_3590.h"

/*
 * Pointer to debug area.
 */
debug_info_t *TAPE_DBF_AREA = NULL;
EXPORT_SYMBOL(TAPE_DBF_AREA);

/*******************************************************************
 * Error Recovery fuctions:
 * - Read Opposite:		 implemented
 * - Read Device (buffered) log: BRA
 * - Read Library log:		 BRA
 * - Swap Devices:		 BRA
 * - Long Busy:			 BRA
 * - Special Intercept:		 BRA
 * - Read Alternate:		 implemented
 *******************************************************************/

#define PRINTK_HEADER "TAPE_3590: "

static const char *tape_3590_msg[TAPE_3590_MAX_MSG] = {
	[0x00] = "",
	[0x10] = "Lost Sense",
	[0x11] = "Assigned Elsewhere",
	[0x12] = "Allegiance Reset",
	[0x13] = "Shared Access Violation",
	[0x20] = "Command Reject",
	[0x21] = "Configuration Error",
	[0x22] = "Protection Exception",
	[0x23] = "Write Protect",
	[0x24] = "Write Length",
	[0x25] = "Read-Only Format",
	[0x31] = "Beginning of Partition",
	[0x33] = "End of Partition",
	[0x34] = "End of Data",
	[0x35] = "Block not found",
	[0x40] = "Device Intervention",
	[0x41] = "Loader Intervention",
	[0x42] = "Library Intervention",
	[0x50] = "Write Error",
	[0x51] = "Erase Error",
	[0x52] = "Formatting Error",
	[0x53] = "Read Error",
	[0x54] = "Unsupported Format",
	[0x55] = "No Formatting",
	[0x56] = "Positioning lost",
	[0x57] = "Read Length",
	[0x60] = "Unsupported Medium",
	[0x61] = "Medium Length Error",
	[0x62] = "Medium removed",
	[0x64] = "Load Check",
	[0x65] = "Unload Check",
	[0x70] = "Equipment Check",
	[0x71] = "Bus out Check",
	[0x72] = "Protocol Error",
	[0x73] = "Interface Error",
	[0x74] = "Overrun",
	[0x75] = "Halt Signal",
	[0x90] = "Device fenced",
	[0x91] = "Device Path fenced",
	[0xa0] = "Volume misplaced",
	[0xa1] = "Volume inaccessible",
	[0xa2] = "Volume in input",
	[0xa3] = "Volume ejected",
	[0xa4] = "All categories reserved",
	[0xa5] = "Duplicate Volume",
	[0xa6] = "Library Manager Offline",
	[0xa7] = "Library Output Station full",
	[0xa8] = "Vision System non-operational",
	[0xa9] = "Library Manager Equipment Check",
	[0xaa] = "Library Equipment Check",
	[0xab] = "All Library Cells full",
	[0xac] = "No Cleaner Volumes in Library",
	[0xad] = "I/O Station door open",
	[0xae] = "Subsystem environmental alert",
};

/*
 * 3590 IOCTL Overload
 */
static int
tape_3590_ioctl(struct tape_device *device, unsigned int cmd, unsigned long arg)
{
	switch (cmd) {
	case TAPE390_DISPLAY: {
		struct display_struct disp;

		if (copy_from_user(&disp, (char __user *) arg, sizeof(disp)))
			return -EFAULT;

		return tape_std_display(device, &disp);
	}
	default:
		return -EINVAL;	/* no additional ioctls */
	}
}

/*
 * SENSE Medium: Get Sense data about medium state
 */
static int
tape_3590_sense_medium(struct tape_device *device)
{
	struct tape_request *request;

	request = tape_alloc_request(1, 128);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_MSEN;
	tape_ccw_end(request->cpaddr, MEDIUM_SENSE, 128, request->cpdata);
	return tape_do_io_free(device, request);
}

/*
 * MTTELL: Tell block. Return the number of block relative to current file.
 */
static int
tape_3590_mttell(struct tape_device *device, int mt_count)
{
	__u64 block_id;
	int rc;

	rc = tape_std_read_block_id(device, &block_id);
	if (rc)
		return rc;
	return block_id >> 32;
}

/*
 * MTSEEK: seek to the specified block.
 */
static int
tape_3590_mtseek(struct tape_device *device, int count)
{
	struct tape_request *request;

	DBF_EVENT(6, "xsee id: %x\n", count);
	request = tape_alloc_request(3, 4);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_LBL;
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	*(__u32 *) request->cpdata = count;
	tape_ccw_cc(request->cpaddr + 1, LOCATE, 4, request->cpdata);
	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
	return tape_do_io_free(device, request);
}

/*
 * Read Opposite Error Recovery Function:
 * Used, when Read Forward does not work
 */
static void
tape_3590_read_opposite(struct tape_device *device,
			struct tape_request *request)
{
	struct tape_3590_disc_data *data;

	/*
	 * We have allocated 4 ccws in tape_std_read, so we can now
	 * transform the request to a read backward, followed by a
	 * forward space block.
	 */
	request->op = TO_RBA;
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	data = device->discdata;
	tape_ccw_cc_idal(request->cpaddr + 1, data->read_back_op,
			 device->char_data.idal_buf);
	tape_ccw_cc(request->cpaddr + 2, FORSPACEBLOCK, 0, NULL);
	tape_ccw_end(request->cpaddr + 3, NOP, 0, NULL);
	DBF_EVENT(6, "xrop ccwg\n");
}

/*
 * Read Attention Msg
 * This should be done after an interrupt with attention bit (0x80)
 * in device state.
 *
 * After a "read attention message" request there are two possible
 * results:
 *
 * 1. A unit check is presented, when attention sense is present (e.g. when
 * a medium has been unloaded). The attention sense comes then
 * together with the unit check. The recovery action is either "retry"
 * (in case there is an attention message pending) or "permanent error".
 *
 * 2. The attention msg is written to the "read subsystem data" buffer.
 * In this case we probably should print it to the console.
 */
static int
tape_3590_read_attmsg(struct tape_device *device)
{
	struct tape_request *request;
	char *buf;

	request = tape_alloc_request(3, 4096);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_READ_ATTMSG;
	buf = request->cpdata;
	buf[0] = PREP_RD_SS_DATA;
	buf[6] = RD_ATTMSG;	/* read att msg */
	tape_ccw_cc(request->cpaddr, PERFORM_SS_FUNC, 12, buf);
	tape_ccw_cc(request->cpaddr + 1, READ_SS_DATA, 4096 - 12, buf + 12);
	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
	return tape_do_io_free(device, request);
}

/*
 * These functions are used to schedule follow-up actions from within an
 * interrupt context (like unsolicited interrupts).
 */
struct work_handler_data {
	struct tape_device *device;
	enum tape_op        op;
	struct work_struct  work;
};

static void
tape_3590_work_handler(void *data)
{
	struct work_handler_data *p = data;

	switch (p->op) {
	case TO_MSEN:
		tape_3590_sense_medium(p->device);
		break;
	case TO_READ_ATTMSG:
		tape_3590_read_attmsg(p->device);
		break;
	default:
		DBF_EVENT(3, "T3590: work handler undefined for "
			  "operation 0x%02x\n", p->op);
	}
	tape_put_device(p->device);
	kfree(p);
}

static int
tape_3590_schedule_work(struct tape_device *device, enum tape_op op)
{
	struct work_handler_data *p;

	if ((p = kzalloc(sizeof(*p), GFP_ATOMIC)) == NULL)
		return -ENOMEM;

	INIT_WORK(&p->work, tape_3590_work_handler, p);

	p->device = tape_get_device_reference(device);
	p->op = op;

	schedule_work(&p->work);
	return 0;
}

#ifdef CONFIG_S390_TAPE_BLOCK
/*
 * Tape Block READ
 */
static struct tape_request *
tape_3590_bread(struct tape_device *device, struct request *req)
{
	struct tape_request *request;
	struct ccw1 *ccw;
	int count = 0, start_block, i;
	unsigned off;
	char *dst;
	struct bio_vec *bv;
	struct bio *bio;

	DBF_EVENT(6, "xBREDid:");
	start_block = req->sector >> TAPEBLOCK_HSEC_S2B;
	DBF_EVENT(6, "start_block = %i\n", start_block);

	rq_for_each_bio(bio, req) {
		bio_for_each_segment(bv, bio, i) {
			count += bv->bv_len >> (TAPEBLOCK_HSEC_S2B + 9);
		}
	}
	request = tape_alloc_request(2 + count + 1, 4);
	if (IS_ERR(request))
		return request;
	request->op = TO_BLOCK;
	*(__u32 *) request->cpdata = start_block;
	ccw = request->cpaddr;
	ccw = tape_ccw_cc(ccw, MODE_SET_DB, 1, device->modeset_byte);

	/*
	 * We always setup a nop after the mode set ccw. This slot is
	 * used in tape_std_check_locate to insert a locate ccw if the
	 * current tape position doesn't match the start block to be read.
	 */
	ccw = tape_ccw_cc(ccw, NOP, 0, NULL);

	rq_for_each_bio(bio, req) {
		bio_for_each_segment(bv, bio, i) {
			dst = page_address(bv->bv_page) + bv->bv_offset;
			for (off = 0; off < bv->bv_len;
			     off += TAPEBLOCK_HSEC_SIZE) {
				ccw->flags = CCW_FLAG_CC;
				ccw->cmd_code = READ_FORWARD;
				ccw->count = TAPEBLOCK_HSEC_SIZE;
				set_normalized_cda(ccw, (void *) __pa(dst));
				ccw++;
				dst += TAPEBLOCK_HSEC_SIZE;
			}
			if (off > bv->bv_len)
				BUG();
		}
	}
	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
	DBF_EVENT(6, "xBREDccwg\n");
	return request;
}

static void
tape_3590_free_bread(struct tape_request *request)
{
	struct ccw1 *ccw;

	/* Last ccw is a nop and doesn't need clear_normalized_cda */
	for (ccw = request->cpaddr; ccw->flags & CCW_FLAG_CC; ccw++)
		if (ccw->cmd_code == READ_FORWARD)
			clear_normalized_cda(ccw);
	tape_free_request(request);
}

/*
 * check_locate is called just before the tape request is passed to
 * the common io layer for execution. It has to check the current
 * tape position and insert a locate ccw if it doesn't match the
 * start block for the request.
 */
static void
tape_3590_check_locate(struct tape_device *device, struct tape_request *request)
{
	__u32 *start_block;

	start_block = (__u32 *) request->cpdata;
	if (*start_block != device->blk_data.block_position) {
		/* Add the start offset of the file to get the real block. */
		*start_block += device->bof;
		tape_ccw_cc(request->cpaddr + 1, LOCATE, 4, request->cpdata);
	}
}
#endif

/*
 * The done handler is called at device/channel end and wakes up the sleeping
 * process
 */
static int
tape_3590_done(struct tape_device *device, struct tape_request *request)
{
	struct tape_3590_med_sense *sense;

	DBF_EVENT(6, "%s done\n", tape_op_verbose[request->op]);

	switch (request->op) {
	case TO_BSB:
	case TO_BSF:
	case TO_DSE:
	case TO_FSB:
	case TO_FSF:
	case TO_LBL:
	case TO_RFO:
	case TO_RBA:
	case TO_REW:
	case TO_WRI:
	case TO_WTM:
	case TO_BLOCK:
	case TO_LOAD:
		tape_med_state_set(device, MS_LOADED);
		break;
	case TO_RUN:
		tape_med_state_set(device, MS_UNLOADED);
		break;
	case TO_MSEN:
		sense = (struct tape_3590_med_sense *) request->cpdata;
		if (sense->masst == MSENSE_UNASSOCIATED)
			tape_med_state_set(device, MS_UNLOADED);
		if (sense->masst == MSENSE_ASSOCIATED_MOUNT)
			tape_med_state_set(device, MS_LOADED);
		break;
	case TO_RBI:	/* RBI seems to succeed even without medium loaded. */
	case TO_NOP:	/* Same to NOP. */
	case TO_READ_CONFIG:
	case TO_READ_ATTMSG:
	case TO_DIS:
	case TO_ASSIGN:
	case TO_UNASSIGN:
		break;
	case TO_SIZE:
		break;
	}
	return TAPE_IO_SUCCESS;
}

/*
 * This fuction is called, when error recovery was successfull
 */
static inline int
tape_3590_erp_succeded(struct tape_device *device, struct tape_request *request)
{
	DBF_EVENT(3, "Error Recovery successfull for %s\n",
		  tape_op_verbose[request->op]);
	return tape_3590_done(device, request);
}

/*
 * This fuction is called, when error recovery was not successfull
 */
static inline int
tape_3590_erp_failed(struct tape_device *device, struct tape_request *request,