backing_ops.c

/* backing_ops.c - query/set operations on saved SPU context.
 *
 * Copyright (C) IBM 2005
 * Author: Mark Nutter <mnutter@us.ibm.com>
 *
 * These register operations allow SPUFS to operate on saved
 * SPU contexts rather than hardware.
 *
 * 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.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>

#include <asm/io.h>
#include <asm/spu.h>
#include <asm/spu_csa.h>
#include <asm/mmu_context.h>
#include "spufs.h"

/*
 * Reads/writes to various problem and priv2 registers require
 * state changes, i.e.  generate SPU events, modify channel
 * counts, etc.
 */

static void gen_spu_event(struct spu_context *ctx, u32 event)
{
	u64 ch0_cnt;
	u64 ch0_data;
	u64 ch1_data;

	ch0_cnt = ctx->csa.spu_chnlcnt_RW[0];
	ch0_data = ctx->csa.spu_chnldata_RW[0];
	ch1_data = ctx->csa.spu_chnldata_RW[1];
	ctx->csa.spu_chnldata_RW[0] |= event;
	if ((ch0_cnt == 0) && !(ch0_data & event) && (ch1_data & event)) {
		ctx->csa.spu_chnlcnt_RW[0] = 1;
	}
}

static int spu_backing_mbox_read(struct spu_context *ctx, u32 * data)
{
	u32 mbox_stat;
	int ret = 0;

	spin_lock(&ctx->csa.register_lock);
	mbox_stat = ctx->csa.prob.mb_stat_R;
	if (mbox_stat & 0x0000ff) {
		/* Read the first available word.
		 * Implementation note: the depth
		 * of pu_mb_R is currently 1.
		 */
		*data = ctx->csa.prob.pu_mb_R;
		ctx->csa.prob.mb_stat_R &= ~(0x0000ff);
		ctx->csa.spu_chnlcnt_RW[28] = 1;
		gen_spu_event(ctx, MFC_PU_MAILBOX_AVAILABLE_EVENT);
		ret = 4;
	}
	spin_unlock(&ctx->csa.register_lock);
	return ret;
}

static u32 spu_backing_mbox_stat_read(struct spu_context *ctx)
{
	return ctx->csa.prob.mb_stat_R;
}

static int spu_backing_ibox_read(struct spu_context *ctx, u32 * data)
{
	int ret;

	spin_lock(&ctx->csa.register_lock);
	if (ctx->csa.prob.mb_stat_R & 0xff0000) {
		/* Read the first available word.
		 * Implementation note: the depth
		 * of puint_mb_R is currently 1.
		 */
		*data = ctx->csa.priv2.puint_mb_R;
		ctx->csa.prob.mb_stat_R &= ~(0xff0000);
		ctx->csa.spu_chnlcnt_RW[30] = 1;
		gen_spu_event(ctx, MFC_PU_INT_MAILBOX_AVAILABLE_EVENT);
		ret = 4;
	} else {
		/* make sure we get woken up by the interrupt */
		ctx->csa.priv1.int_mask_class2_RW |= 0x1UL;
		ret = 0;
	}
	spin_unlock(&ctx->csa.register_lock);
	return ret;
}

static int spu_backing_wbox_write(struct spu_context *ctx, u32 data)
{
	int ret;

	spin_lock(&ctx->csa.register_lock);
	if ((ctx->csa.prob.mb_stat_R) & 0x00ff00) {
		int slot = ctx->csa.spu_chnlcnt_RW[29];
		int avail = (ctx->csa.prob.mb_stat_R & 0x00ff00) >> 8;

		/* We have space to write wbox_data.
		 * Implementation note: the depth
		 * of spu_mb_W is currently 4.
		 */
		BUG_ON(avail != (4 - slot));
		ctx->csa.spu_mailbox_data[slot] = data;
		ctx->csa.spu_chnlcnt_RW[29] = ++slot;
		ctx->csa.prob.mb_stat_R = (((4 - slot) & 0xff) << 8);
		gen_spu_event(ctx, MFC_SPU_MAILBOX_WRITTEN_EVENT);
		ret = 4;
	} else {
		/* make sure we get woken up by the interrupt when space
		   becomes available */
		ctx->csa.priv1.int_mask_class2_RW |= 0x10;
		ret = 0;
	}
	spin_unlock(&ctx->csa.register_lock);
	return ret;
}

static u32 spu_backing_signal1_read(struct spu_context *ctx)
{
	return ctx->csa.spu_chnldata_RW[3];
}

static void spu_backing_signal1_write(struct spu_context *ctx, u32 data)
{
	spin_lock(&ctx->csa.register_lock);
	if (ctx->csa.priv2.spu_cfg_RW & 0x1)
		ctx->csa.spu_chnldata_RW[3] |= data;
	else
		ctx->csa.spu_chnldata_RW[3] = data;
	ctx->csa.spu_chnlcnt_RW[3] = 1;
	gen_spu_event(ctx, MFC_SIGNAL_1_EVENT);
	spin_unlock(&ctx->csa.register_lock);
}

static u32 spu_backing_signal2_read(struct spu_context *ctx)
{
	return ctx->csa.spu_chnldata_RW[4];
}

static void spu_backing_signal2_write(struct spu_context *ctx, u32 data)
{
	spin_lock(&ctx->csa.register_lock);
	if (ctx->csa.priv2.spu_cfg_RW & 0x2)
		ctx->csa.spu_chnldata_RW[4] |= data;
	else
		ctx->csa.spu_chnldata_RW[4] = data;
	ctx->csa.spu_chnlcnt_RW[4] = 1;
	gen_spu_event(ctx, MFC_SIGNAL_2_EVENT);
	spin_unlock(&ctx->csa.register_lock);
}

static void spu_backing_signal1_type_set(struct spu_context *ctx, u64 val)
{
	u64 tmp;

	spin_lock(&ctx->csa.register_lock);
	tmp = ctx->csa.priv2.spu_cfg_RW;
	if (val)
		tmp |= 1;
	else
		tmp &= ~1;
	ctx->csa.priv2.spu_cfg_RW = tmp;
	spin_unlock(&ctx->csa.register_lock);
}

static u64 spu_backing_signal1_type_get(struct spu_context *ctx)
{
	return ((ctx->csa.priv2.spu_cfg_RW & 1) != 0);
}

static void spu_backing_signal2_type_set(struct spu_context *ctx, u64 val)
{
	u64 tmp;

	spin_lock(&ctx->csa.register_lock);
	tmp = ctx->csa.priv2.spu_cfg_RW;
	if (val)
		tmp |= 2;
	else
		tmp &= ~2;
	ctx->csa.priv2.spu_cfg_RW = tmp;
	spin_unlock(&ctx->csa.register_lock);
}

static u64 spu_backing_signal2_type_get(struct spu_context *ctx)
{
	return ((ctx->csa.priv2.spu_cfg_RW & 2) != 0);
}

static u32 spu_backing_npc_read(struct spu_context *ctx)
{
	return ctx->csa.prob.spu_npc_RW;
}

static void spu_backing_npc_write(struct spu_context *ctx, u32 val)
{
	ctx->csa.prob.spu_npc_RW = val;
}

static u32 spu_backing_status_read(struct spu_context *ctx)
{
	return ctx->csa.prob.spu_status_R;
}

static char *spu_backing_get_ls(struct spu_context *ctx)
{
	return ctx->csa.lscsa->ls;
}

struct spu_context_ops spu_backing_ops = {
	.mbox_read = spu_backing_mbox_read,
	.mbox_stat_read = spu_backing_mbox_stat_read,
	.ibox_read = spu_backing_ibox_read,
	.wbox_write = spu_backing_wbox_write,
	.signal1_read = spu_backing_signal1_read,
	.signal1_write = spu_backing_signal1_write,
	.signal2_read = spu_backing_signal2_read,
	.signal2_write = spu_backing_signal2_write,
	.signal1_type_set = spu_backing_signal1_type_set,
	.signal1_type_get = spu_backing_signal1_type_get,
	.signal2_type_set = spu_backing_signal2_type_set,
	.signal2_type_get = spu_backing_signal2_type_get,
	.npc_read = spu_backing_npc_read,
	.npc_write = spu_backing_npc_write,
	.status_read = spu_backing_status_read,
	.get_ls = spu_backing_get_ls,
};