linux/arch/powerpc/platforms/cell/spufs/hw_ops.c
Arnd Bergmann 3a843d7cd3 [PATCH] spufs: fix mailbox polling
Handling mailbox interrupts was broken in multiple respects,
the combination of which was hiding the bugs most of the time.

- The ibox interrupt mask was open initially even though there
  are no waiters on a newly created SPU.

- Acknowledging the mailbox interrupt did not work because
  it is level triggered and the mailbox data is never retrieved
  from inside the interrupt handler.

- The interrupt handler delivered interrupts with a disabled
  mask if another interrupt is triggered for the same class
  but a different mask.

- The poll function did not enable the interrupt if it had not
  been enabled, so we might run into the poll timeout if none of
  the other bugs saved us and no signal was delivered.

We probably still have a similar problem with blocking
read/write on mailbox files, but that will result in extra
wakeup in the worst case, not in incorrect behaviour.

Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09 14:53:01 +11:00

262 lines
6.9 KiB
C

/* hw_ops.c - query/set operations on active SPU context.
*
* Copyright (C) IBM 2005
* Author: Mark Nutter <mnutter@us.ibm.com>
*
* 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/poll.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"
static int spu_hw_mbox_read(struct spu_context *ctx, u32 * data)
{
struct spu *spu = ctx->spu;
struct spu_problem __iomem *prob = spu->problem;
u32 mbox_stat;
int ret = 0;
spin_lock_irq(&spu->register_lock);
mbox_stat = in_be32(&prob->mb_stat_R);
if (mbox_stat & 0x0000ff) {
*data = in_be32(&prob->pu_mb_R);
ret = 4;
}
spin_unlock_irq(&spu->register_lock);
return ret;
}
static u32 spu_hw_mbox_stat_read(struct spu_context *ctx)
{
return in_be32(&ctx->spu->problem->mb_stat_R);
}
static unsigned int spu_hw_mbox_stat_poll(struct spu_context *ctx,
unsigned int events)
{
struct spu *spu = ctx->spu;
struct spu_priv1 __iomem *priv1 = spu->priv1;
int ret = 0;
u32 stat;
spin_lock_irq(&spu->register_lock);
stat = in_be32(&spu->problem->mb_stat_R);
/* if the requested event is there, return the poll
mask, otherwise enable the interrupt to get notified,
but first mark any pending interrupts as done so
we don't get woken up unnecessarily */
if (events & (POLLIN | POLLRDNORM)) {
if (stat & 0xff0000)
ret |= POLLIN | POLLRDNORM;
else {
out_be64(&priv1->int_stat_class2_RW, 0x1);
out_be64(&priv1->int_mask_class2_RW,
in_be64(&priv1->int_mask_class2_RW) | 0x1);
}
}
if (events & (POLLOUT | POLLWRNORM)) {
if (stat & 0x00ff00)
ret = POLLOUT | POLLWRNORM;
else {
out_be64(&priv1->int_stat_class2_RW, 0x10);
out_be64(&priv1->int_mask_class2_RW,
in_be64(&priv1->int_mask_class2_RW) | 0x10);
}
}
spin_unlock_irq(&spu->register_lock);
return ret;
}
static int spu_hw_ibox_read(struct spu_context *ctx, u32 * data)
{
struct spu *spu = ctx->spu;
struct spu_problem __iomem *prob = spu->problem;
struct spu_priv1 __iomem *priv1 = spu->priv1;
struct spu_priv2 __iomem *priv2 = spu->priv2;
int ret;
spin_lock_irq(&spu->register_lock);
if (in_be32(&prob->mb_stat_R) & 0xff0000) {
/* read the first available word */
*data = in_be64(&priv2->puint_mb_R);
ret = 4;
} else {
/* make sure we get woken up by the interrupt */
out_be64(&priv1->int_mask_class2_RW,
in_be64(&priv1->int_mask_class2_RW) | 0x1);
ret = 0;
}
spin_unlock_irq(&spu->register_lock);
return ret;
}
static int spu_hw_wbox_write(struct spu_context *ctx, u32 data)
{
struct spu *spu = ctx->spu;
struct spu_problem __iomem *prob = spu->problem;
struct spu_priv1 __iomem *priv1 = spu->priv1;
int ret;
spin_lock_irq(&spu->register_lock);
if (in_be32(&prob->mb_stat_R) & 0x00ff00) {
/* we have space to write wbox_data to */
out_be32(&prob->spu_mb_W, data);
ret = 4;
} else {
/* make sure we get woken up by the interrupt when space
becomes available */
out_be64(&priv1->int_mask_class2_RW,
in_be64(&priv1->int_mask_class2_RW) | 0x10);
ret = 0;
}
spin_unlock_irq(&spu->register_lock);
return ret;
}
static u32 spu_hw_signal1_read(struct spu_context *ctx)
{
return in_be32(&ctx->spu->problem->signal_notify1);
}
static void spu_hw_signal1_write(struct spu_context *ctx, u32 data)
{
out_be32(&ctx->spu->problem->signal_notify1, data);
}
static u32 spu_hw_signal2_read(struct spu_context *ctx)
{
return in_be32(&ctx->spu->problem->signal_notify1);
}
static void spu_hw_signal2_write(struct spu_context *ctx, u32 data)
{
out_be32(&ctx->spu->problem->signal_notify2, data);
}
static void spu_hw_signal1_type_set(struct spu_context *ctx, u64 val)
{
struct spu *spu = ctx->spu;
struct spu_priv2 __iomem *priv2 = spu->priv2;
u64 tmp;
spin_lock_irq(&spu->register_lock);
tmp = in_be64(&priv2->spu_cfg_RW);
if (val)
tmp |= 1;
else
tmp &= ~1;
out_be64(&priv2->spu_cfg_RW, tmp);
spin_unlock_irq(&spu->register_lock);
}
static u64 spu_hw_signal1_type_get(struct spu_context *ctx)
{
return ((in_be64(&ctx->spu->priv2->spu_cfg_RW) & 1) != 0);
}
static void spu_hw_signal2_type_set(struct spu_context *ctx, u64 val)
{
struct spu *spu = ctx->spu;
struct spu_priv2 __iomem *priv2 = spu->priv2;
u64 tmp;
spin_lock_irq(&spu->register_lock);
tmp = in_be64(&priv2->spu_cfg_RW);
if (val)
tmp |= 2;
else
tmp &= ~2;
out_be64(&priv2->spu_cfg_RW, tmp);
spin_unlock_irq(&spu->register_lock);
}
static u64 spu_hw_signal2_type_get(struct spu_context *ctx)
{
return ((in_be64(&ctx->spu->priv2->spu_cfg_RW) & 2) != 0);
}
static u32 spu_hw_npc_read(struct spu_context *ctx)
{
return in_be32(&ctx->spu->problem->spu_npc_RW);
}
static void spu_hw_npc_write(struct spu_context *ctx, u32 val)
{
out_be32(&ctx->spu->problem->spu_npc_RW, val);
}
static u32 spu_hw_status_read(struct spu_context *ctx)
{
return in_be32(&ctx->spu->problem->spu_status_R);
}
static char *spu_hw_get_ls(struct spu_context *ctx)
{
return ctx->spu->local_store;
}
static void spu_hw_runcntl_write(struct spu_context *ctx, u32 val)
{
eieio();
out_be32(&ctx->spu->problem->spu_runcntl_RW, val);
}
static void spu_hw_runcntl_stop(struct spu_context *ctx)
{
spin_lock_irq(&ctx->spu->register_lock);
out_be32(&ctx->spu->problem->spu_runcntl_RW, SPU_RUNCNTL_STOP);
while (in_be32(&ctx->spu->problem->spu_status_R) & SPU_STATUS_RUNNING)
cpu_relax();
spin_unlock_irq(&ctx->spu->register_lock);
}
struct spu_context_ops spu_hw_ops = {
.mbox_read = spu_hw_mbox_read,
.mbox_stat_read = spu_hw_mbox_stat_read,
.mbox_stat_poll = spu_hw_mbox_stat_poll,
.ibox_read = spu_hw_ibox_read,
.wbox_write = spu_hw_wbox_write,
.signal1_read = spu_hw_signal1_read,
.signal1_write = spu_hw_signal1_write,
.signal2_read = spu_hw_signal2_read,
.signal2_write = spu_hw_signal2_write,
.signal1_type_set = spu_hw_signal1_type_set,
.signal1_type_get = spu_hw_signal1_type_get,
.signal2_type_set = spu_hw_signal2_type_set,
.signal2_type_get = spu_hw_signal2_type_get,
.npc_read = spu_hw_npc_read,
.npc_write = spu_hw_npc_write,
.status_read = spu_hw_status_read,
.get_ls = spu_hw_get_ls,
.runcntl_write = spu_hw_runcntl_write,
.runcntl_stop = spu_hw_runcntl_stop,
};