/*
 * Copyright (c) 2001 by David Brownell
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* this file is part of ehci-hcd.c */

/*-------------------------------------------------------------------------*/

/*
 * There's basically three types of memory:
 *      - data used only by the HCD ... kmalloc is fine
 *      - async and periodic schedules, shared by HC and HCD ... these
 *        need to use dma_pool or dma_alloc_coherent
 *      - driver buffers, read/written by HC ... single shot DMA mapped
 *
 * There's also "register" data (e.g. PCI or SOC), which is memory mapped.
 * No memory seen by this driver is pageable.
 */

/*-------------------------------------------------------------------------*/

/* Allocate the key transfer structures from the previously allocated pool */

static inline void ehci_qtd_init(struct ehci_hcd *ehci, struct ehci_qtd *qtd,
                                  dma_addr_t dma)
{
        memset (qtd, 0, sizeof *qtd);
        qtd->qtd_dma = dma;
        qtd->hw_token = cpu_to_le32 (QTD_STS_HALT);
        qtd->hw_next = EHCI_LIST_END(ehci);
        qtd->hw_alt_next = EHCI_LIST_END(ehci);
        INIT_LIST_HEAD (&qtd->qtd_list);
}

static struct ehci_qtd *ehci_qtd_alloc (struct ehci_hcd *ehci, gfp_t flags)
{
        struct ehci_qtd         *qtd;
        dma_addr_t              dma;

        qtd = dma_pool_alloc (ehci->qtd_pool, flags, &dma);
        if (qtd != NULL) {
                ehci_qtd_init(ehci, qtd, dma);
        }
        return qtd;
}

static inline void ehci_qtd_free (struct ehci_hcd *ehci, struct ehci_qtd *qtd)
{
        dma_pool_free (ehci->qtd_pool, qtd, qtd->qtd_dma);
}


static void qh_destroy(struct ehci_qh *qh)
{
        struct ehci_hcd *ehci = qh->ehci;

        /* clean qtds first, and know this is not linked */
        if (!list_empty (&qh->qtd_list) || qh->qh_next.ptr) {
                ehci_dbg (ehci, "unused qh not empty!\n");
                BUG ();
        }
        if (qh->dummy)
                ehci_qtd_free (ehci, qh->dummy);
        dma_pool_free (ehci->qh_pool, qh, qh->qh_dma);
}

static struct ehci_qh *ehci_qh_alloc (struct ehci_hcd *ehci, gfp_t flags)
{
        struct ehci_qh          *qh;
        dma_addr_t              dma;

        qh = (struct ehci_qh *)
                dma_pool_alloc (ehci->qh_pool, flags, &dma);
        if (!qh)
                return qh;

        memset (qh, 0, sizeof *qh);
        qh->refcount = 1;
        qh->ehci = ehci;
        qh->qh_dma = dma;
        // INIT_LIST_HEAD (&qh->qh_list);
        INIT_LIST_HEAD (&qh->qtd_list);

        /* dummy td enables safe urb queuing */
        qh->dummy = ehci_qtd_alloc (ehci, flags);
        if (qh->dummy == NULL) {
                ehci_dbg (ehci, "no dummy td\n");
                dma_pool_free (ehci->qh_pool, qh, qh->qh_dma);
                qh = NULL;
        }
        return qh;
}

/* to share a qh (cpu threads, or hc) */
static inline struct ehci_qh *qh_get (struct ehci_qh *qh)
{
        WARN_ON(!qh->refcount);
        qh->refcount++;
        return qh;
}

static inline void qh_put (struct ehci_qh *qh)
{
        if (!--qh->refcount)
                qh_destroy(qh);
}

/*-------------------------------------------------------------------------*/

/* The queue heads and transfer descriptors are managed from pools tied
 * to each of the "per device" structures.
 * This is the initialisation and cleanup code.
 */

static void ehci_mem_cleanup (struct ehci_hcd *ehci)
{
        if (ehci->async)
                qh_put (ehci->async);
        ehci->async = NULL;

        /* DMA consistent memory and pools */
        if (ehci->qtd_pool)
                dma_pool_destroy (ehci->qtd_pool);
        ehci->qtd_pool = NULL;

        if (ehci->qh_pool) {
                dma_pool_destroy (ehci->qh_pool);
                ehci->qh_pool = NULL;
        }

        if (ehci->itd_pool)
                dma_pool_destroy (ehci->itd_pool);
        ehci->itd_pool = NULL;

        if (ehci->sitd_pool)
                dma_pool_destroy (ehci->sitd_pool);
        ehci->sitd_pool = NULL;

        if (ehci->periodic)
                dma_free_coherent (ehci_to_hcd(ehci)->self.controller,
                        ehci->periodic_size * sizeof (u32),
                        ehci->periodic, ehci->periodic_dma);
        ehci->periodic = NULL;

        /* shadow periodic table */
        kfree(ehci->pshadow);
        ehci->pshadow = NULL;
}

/* remember to add cleanup code (above) if you add anything here */
static int ehci_mem_init (struct ehci_hcd *ehci, gfp_t flags)
{
        int i;

        /* QTDs for control/bulk/intr transfers */
        ehci->qtd_pool = dma_pool_create ("ehci_qtd",
                        ehci_to_hcd(ehci)->self.controller,
                        sizeof (struct ehci_qtd),
                        32 /* byte alignment (for hw parts) */,
                        4096 /* can't cross 4K */);
        if (!ehci->qtd_pool) {
                goto fail;
        }

        /* QHs for control/bulk/intr transfers */
        ehci->qh_pool = dma_pool_create ("ehci_qh",
                        ehci_to_hcd(ehci)->self.controller,
                        sizeof (struct ehci_qh),
                        32 /* byte alignment (for hw parts) */,
                        4096 /* can't cross 4K */);
        if (!ehci->qh_pool) {
                goto fail;
        }
        ehci->async = ehci_qh_alloc (ehci, flags);
        if (!ehci->async) {
                goto fail;
        }

        /* ITD for high speed ISO transfers */
        ehci->itd_pool = dma_pool_create ("ehci_itd",
                        ehci_to_hcd(ehci)->self.controller,
                        sizeof (struct ehci_itd),
                        32 /* byte alignment (for hw parts) */,
                        4096 /* can't cross 4K */);
        if (!ehci->itd_pool) {
                goto fail;
        }

        /* SITD for full/low speed split ISO transfers */
        ehci->sitd_pool = dma_pool_create ("ehci_sitd",
                        ehci_to_hcd(ehci)->self.controller,
                        sizeof (struct ehci_sitd),
                        32 /* byte alignment (for hw parts) */,
                        4096 /* can't cross 4K */);
        if (!ehci->sitd_pool) {
                goto fail;
        }

        /* Hardware periodic table */
        ehci->periodic = (__le32 *)
                dma_alloc_coherent (ehci_to_hcd(ehci)->self.controller,
                        ehci->periodic_size * sizeof(__le32),
                        &ehci->periodic_dma, 0);
        if (ehci->periodic == NULL) {
                goto fail;
        }
        for (i = 0; i < ehci->periodic_size; i++)
                ehci->periodic [i] = EHCI_LIST_END(ehci);

        /* software shadow of hardware table */
        ehci->pshadow = kcalloc(ehci->periodic_size, sizeof(void *), flags);
        if (ehci->pshadow != NULL)
                return 0;

fail:
        ehci_dbg (ehci, "couldn't init memory\n");
        ehci_mem_cleanup (ehci);
        return -ENOMEM;
}