spu_utils.h

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/*
 * utils.h: Utilities for SPU-side of the context switch operation.
 *
 * (C) Copyright IBM 2005
 *
 * 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, 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.
 */

#ifndef _SPU_CONTEXT_UTILS_H_
#define _SPU_CONTEXT_UTILS_H_

/*
 * 64-bit safe EA.
 */
typedef union {
    unsigned long long ull;
    unsigned int ui[2];
} addr64;

/*
 * 128-bit register template.
 */
typedef union {
    unsigned int slot[4];
    vector unsigned int v;
} spu_reg128v;

/*
 * DMA list structure.
 */
struct dma_list_elem {
    unsigned int size;
    unsigned int ea_low;
};

/*
 * Declare storage for 8-byte aligned DMA list.
 */
struct dma_list_elem dma_list[15] __attribute__ ((aligned(8)));

/*
 * External definition for storage
 * declared in crt0.
 */
extern spu_reg128v regs_spill[NR_SPU_SPILL_REGS];

/*
 * Compute LSCSA byte offset for a given field.
 */
static struct spu_lscsa *dummy = (struct spu_lscsa *)0;
#define LSCSA_BYTE_OFFSET(_field)  \
    ((char *)(&(dummy->_field)) - (char *)(&(dummy->gprs[0].slot[0])))
#define LSCSA_QW_OFFSET(_field)  (LSCSA_BYTE_OFFSET(_field) >> 4)

static inline void set_event_mask(void)
{
    unsigned int event_mask = 0;

    /* Save, Step 4:
     * Restore, Step 1:
     *    Set the SPU_RdEventMsk channel to zero to mask
     *    all events.
     */
    spu_writech(SPU_WrEventMask, event_mask);
}

static inline void set_tag_mask(void)
{
    unsigned int tag_mask = 1;

    /* Save, Step 5:
     * Restore, Step 2:
     *    Set the SPU_WrTagMsk channel to '01' to unmask
     *    only tag group 0.
     */
    spu_writech(MFC_WrTagMask, tag_mask);
}

static inline void build_dma_list(addr64 lscsa_ea)
{
    unsigned int ea_low;
    int i;

    /* Save, Step 6:
     * Restore, Step 3:
     *    Update the effective address for the CSA in the
     *    pre-canned DMA-list in local storage.
     */
    ea_low = lscsa_ea.ui[1];
    ea_low += LSCSA_BYTE_OFFSET(ls[16384]);

    for (i = 0; i < 15; i++, ea_low += 16384) {
        dma_list[i].size = 16384;
        dma_list[i].ea_low = ea_low;
    }
}

static inline void enqueue_putllc(addr64 lscsa_ea)
{
    unsigned int ls = 0;
    unsigned int size = 128;
    unsigned int tag_id = 0;
    unsigned int cmd = 0xB4;    /* PUTLLC */

    /* Save, Step 12:
     * Restore, Step 7:
     *    Send a PUTLLC (tag 0) command to the MFC using
     *    an effective address in the CSA in order to
     *    remove any possible lock-line reservation.
     */
    spu_writech(MFC_LSA, ls);
    spu_writech(MFC_EAH, lscsa_ea.ui[0]);
    spu_writech(MFC_EAL, lscsa_ea.ui[1]);
    spu_writech(MFC_Size, size);
    spu_writech(MFC_TagID, tag_id);
    spu_writech(MFC_Cmd, cmd);
}

static inline void set_tag_update(void)
{
    unsigned int update_any = 1;

    /* Save, Step 15:
     * Restore, Step 8:
     *    Write the MFC_TagUpdate channel with '01'.
     */
    spu_writech(MFC_WrTagUpdate, update_any);
}

static inline void read_tag_status(void)
{
    /* Save, Step 16:
     * Restore, Step 9:
     *    Read the MFC_TagStat channel data.
     */
    spu_readch(MFC_RdTagStat);
}

static inline void read_llar_status(void)
{
    /* Save, Step 17:
     * Restore, Step 10:
     *    Read the MFC_AtomicStat channel data.
     */
    spu_readch(MFC_RdAtomicStat);
}

#endif              /* _SPU_CONTEXT_UTILS_H_ */