path: root/drivers/infiniband/hw/qib/qib_sdma.c

/*
 * Copyright (c) 2012 Intel Corporation. All rights reserved.
 * Copyright (c) 2007 - 2012 QLogic Corporation. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/spinlock.h>
#include <linux/netdevice.h>
#include <linux/moduleparam.h>

#include "qib.h"
#include "qib_common.h"

/* default pio off, sdma on */
static ushort sdma_descq_cnt = 256;
module_param_named(sdma_descq_cnt, sdma_descq_cnt, ushort, S_IRUGO);
MODULE_PARM_DESC(sdma_descq_cnt, "Number of SDMA descq entries");

/*
 * Bits defined in the send DMA descriptor.
 */
#define SDMA_DESC_LAST          (1ULL << 11)
#define SDMA_DESC_FIRST         (1ULL << 12)
#define SDMA_DESC_DMA_HEAD      (1ULL << 13)
#define SDMA_DESC_USE_LARGE_BUF (1ULL << 14)
#define SDMA_DESC_INTR          (1ULL << 15)
#define SDMA_DESC_COUNT_LSB     16
#define SDMA_DESC_GEN_LSB       30

char *qib_sdma_state_names[] = {
	[qib_sdma_state_s00_hw_down]          = "s00_HwDown",
	[qib_sdma_state_s10_hw_start_up_wait] = "s10_HwStartUpWait",
	[qib_sdma_state_s20_idle]             = "s20_Idle",
	[qib_sdma_state_s30_sw_clean_up_wait] = "s30_SwCleanUpWait",
	[qib_sdma_state_s40_hw_clean_up_wait] = "s40_HwCleanUpWait",
	[qib_sdma_state_s50_hw_halt_wait]     = "s50_HwHaltWait",
	[qib_sdma_state_s99_running]          = "s99_Running",
};

char *qib_sdma_event_names[] = {
	[qib_sdma_event_e00_go_hw_down]   = "e00_GoHwDown",
	[qib_sdma_event_e10_go_hw_start]  = "e10_GoHwStart",
	[qib_sdma_event_e20_hw_started]   = "e20_HwStarted",
	[qib_sdma_event_e30_go_running]   = "e30_GoRunning",
	[qib_sdma_event_e40_sw_cleaned]   = "e40_SwCleaned",
	[qib_sdma_event_e50_hw_cleaned]   = "e50_HwCleaned",
	[qib_sdma_event_e60_hw_halted]    = "e60_HwHalted",
	[qib_sdma_event_e70_go_idle]      = "e70_GoIdle",
	[qib_sdma_event_e7220_err_halted] = "e7220_ErrHalted",
	[qib_sdma_event_e7322_err_halted] = "e7322_ErrHalted",
	[qib_sdma_event_e90_timer_tick]   = "e90_TimerTick",
};

/* declare all statics here rather than keep sorting */
static int alloc_sdma(struct qib_pportdata *);
static void sdma_complete(struct kref *);
static void sdma_finalput(struct qib_sdma_state *);
static void sdma_get(struct qib_sdma_state *);
static void sdma_put(struct qib_sdma_state *);
static void sdma_set_state(struct qib_pportdata *, enum qib_sdma_states);
static void sdma_start_sw_clean_up(struct qib_pportdata *);
static void sdma_sw_clean_up_task(unsigned long);
static void unmap_desc(struct qib_pportdata *, unsigned);

static void sdma_get(struct qib_sdma_state *ss)
{
	kref_get(&ss->kref);
}

static void sdma_complete(struct kref *kref)
{
	struct qib_sdma_state *ss =
		container_of(kref, struct qib_sdma_state, kref);

	complete(&ss->comp);
}

static void sdma_put(struct qib_sdma_state *ss)
{
	kref_put(&ss->kref, sdma_complete);
}

static void sdma_finalput(struct qib_sdma_state *ss)
{
	sdma_put(ss);
	wait_for_completion(&ss->comp);
}

/*
 * Complete all the sdma requests on the active list, in the correct
 * order, and with appropriate processing.   Called when cleaning up
 * after sdma shutdown, and when new sdma requests are submitted for
 * a link that is down.   This matches what is done for requests
 * that complete normally, it's just the full list.
 *
 * Must be called with sdma_lock held
 */
static void clear_sdma_activelist(struct qib_pportdata *ppd)
{
	struct qib_sdma_txreq *txp, *txp_next;

	list_for_each_entry_safe(txp, txp_next, &ppd->sdma_activelist, list) {
		list_del_init(&txp->list);
		if (txp->flags & QIB_SDMA_TXREQ_F_FREEDESC) {
			unsigned idx;

			idx = txp->start_idx;
			while (idx != txp->next_descq_idx) {
				unmap_desc(ppd, idx);
				if (++idx == ppd->sdma_descq_cnt)
					idx = 0;
			}
		}
		if (txp->callback)
			(*txp->callback)(txp, QIB_SDMA_TXREQ_S_ABORTED);
	}
}

static void sdma_sw_clean_up_task(unsigned long opaque)
{
	struct qib_pportdata *ppd = (struct qib_pportdata *) opaque;
	unsigned long