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[POWERPC] spufs: add support for nonschedulable contexts
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This adds two new flags to spu_create:

SPU_CREATE_NONSCHED: create a context that is never moved
away from an SPE once it has started running. This flag
can only be used by tasks with the CAP_SYS_NICE capability.

SPU_CREATE_ISOLATED: create a nonschedulable context that
enters isolation mode upon first run. This requires the
SPU_CREATE_NONSCHED flag.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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Mark Nutter authored and Paul Mackerras committed Oct 25, 2006
1 parent cc21a66 commit 5737edd
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Showing 7 changed files with 103 additions and 7 deletions.
22 changes: 22 additions & 0 deletions arch/powerpc/platforms/cell/spufs/file.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1531,3 +1531,25 @@ struct tree_descr spufs_dir_contents[] = {
{ "object-id", &spufs_object_id_ops, 0666, },
{},
};

struct tree_descr spufs_dir_nosched_contents[] = {
{ "mem", &spufs_mem_fops, 0666, },
{ "mbox", &spufs_mbox_fops, 0444, },
{ "ibox", &spufs_ibox_fops, 0444, },
{ "wbox", &spufs_wbox_fops, 0222, },
{ "mbox_stat", &spufs_mbox_stat_fops, 0444, },
{ "ibox_stat", &spufs_ibox_stat_fops, 0444, },
{ "wbox_stat", &spufs_wbox_stat_fops, 0444, },
{ "signal1", &spufs_signal1_fops, 0666, },
{ "signal2", &spufs_signal2_fops, 0666, },
{ "signal1_type", &spufs_signal1_type, 0666, },
{ "signal2_type", &spufs_signal2_type, 0666, },
{ "mss", &spufs_mss_fops, 0666, },
{ "mfc", &spufs_mfc_fops, 0666, },
{ "cntl", &spufs_cntl_fops, 0666, },
{ "npc", &spufs_npc_ops, 0666, },
{ "psmap", &spufs_psmap_fops, 0666, },
{ "phys-id", &spufs_id_ops, 0666, },
{ "object-id", &spufs_object_id_ops, 0666, },
{},
};
5 changes: 4 additions & 1 deletion arch/powerpc/platforms/cell/spufs/hw_ops.c
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Original file line number Diff line number Diff line change
Expand Up @@ -219,8 +219,11 @@ static char *spu_hw_get_ls(struct spu_context *ctx)

static void spu_hw_runcntl_write(struct spu_context *ctx, u32 val)
{
eieio();
spin_lock_irq(&ctx->spu->register_lock);
if (val & SPU_RUNCNTL_ISOLATE)
out_be64(&ctx->spu->priv2->spu_privcntl_RW, 4LL);
out_be32(&ctx->spu->problem->spu_runcntl_RW, val);
spin_unlock_irq(&ctx->spu->register_lock);
}

static void spu_hw_runcntl_stop(struct spu_context *ctx)
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17 changes: 16 additions & 1 deletion arch/powerpc/platforms/cell/spufs/inode.c
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Original file line number Diff line number Diff line change
Expand Up @@ -258,7 +258,12 @@ spufs_mkdir(struct inode *dir, struct dentry *dentry, unsigned int flags,

inode->i_op = &spufs_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
if (flags & SPU_CREATE_NOSCHED)
ret = spufs_fill_dir(dentry, spufs_dir_nosched_contents,
mode, ctx);
else
ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);

if (ret)
goto out_free_ctx;

Expand Down Expand Up @@ -307,6 +312,16 @@ static int spufs_create_context(struct inode *inode,
{
int ret;

ret = -EPERM;
if ((flags & SPU_CREATE_NOSCHED) &&
!capable(CAP_SYS_NICE))
goto out_unlock;

ret = -EINVAL;
if ((flags & (SPU_CREATE_NOSCHED | SPU_CREATE_ISOLATE))
== SPU_CREATE_ISOLATE)
goto out_unlock;

ret = spufs_mkdir(inode, dentry, flags, mode & S_IRWXUGO);
if (ret)
goto out_unlock;
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10 changes: 8 additions & 2 deletions arch/powerpc/platforms/cell/spufs/run.c
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Original file line number Diff line number Diff line change
Expand Up @@ -51,11 +51,17 @@ static inline int spu_stopped(struct spu_context *ctx, u32 * stat)
static inline int spu_run_init(struct spu_context *ctx, u32 * npc)
{
int ret;
unsigned long runcntl = SPU_RUNCNTL_RUNNABLE;

if ((ret = spu_acquire_runnable(ctx)) != 0)
return ret;
ctx->ops->npc_write(ctx, *npc);
ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);

if (ctx->flags & SPU_CREATE_ISOLATE)
runcntl |= SPU_RUNCNTL_ISOLATE;
else
ctx->ops->npc_write(ctx, *npc);

ctx->ops->runcntl_write(ctx, runcntl);
return 0;
}

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1 change: 1 addition & 0 deletions arch/powerpc/platforms/cell/spufs/spufs.h
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Original file line number Diff line number Diff line change
Expand Up @@ -135,6 +135,7 @@ struct spufs_inode_info {
container_of(inode, struct spufs_inode_info, vfs_inode)

extern struct tree_descr spufs_dir_contents[];
extern struct tree_descr spufs_dir_nosched_contents[];

/* system call implementation */
long spufs_run_spu(struct file *file,
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50 changes: 48 additions & 2 deletions arch/powerpc/platforms/cell/spufs/switch.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1916,6 +1916,51 @@ static void save_lscsa(struct spu_state *prev, struct spu *spu)
wait_spu_stopped(prev, spu); /* Step 57. */
}

static void force_spu_isolate_exit(struct spu *spu)
{
struct spu_problem __iomem *prob = spu->problem;
struct spu_priv2 __iomem *priv2 = spu->priv2;

/* Stop SPE execution and wait for completion. */
out_be32(&prob->spu_runcntl_RW, SPU_RUNCNTL_STOP);
iobarrier_rw();
POLL_WHILE_TRUE(in_be32(&prob->spu_status_R) & SPU_STATUS_RUNNING);

/* Restart SPE master runcntl. */
spu_mfc_sr1_set(spu, MFC_STATE1_MASTER_RUN_CONTROL_MASK);
iobarrier_w();

/* Initiate isolate exit request and wait for completion. */
out_be64(&priv2->spu_privcntl_RW, 4LL);
iobarrier_w();
out_be32(&prob->spu_runcntl_RW, 2);
iobarrier_rw();
POLL_WHILE_FALSE((in_be32(&prob->spu_status_R)
& SPU_STATUS_STOPPED_BY_STOP));

/* Reset load request to normal. */
out_be64(&priv2->spu_privcntl_RW, SPU_PRIVCNT_LOAD_REQUEST_NORMAL);
iobarrier_w();
}

/**
* stop_spu_isolate
* Check SPU run-control state and force isolated
* exit function as necessary.
*/
static void stop_spu_isolate(struct spu *spu)
{
struct spu_problem __iomem *prob = spu->problem;

if (in_be32(&prob->spu_status_R) & SPU_STATUS_ISOLATED_STATE) {
/* The SPU is in isolated state; the only way
* to get it out is to perform an isolated
* exit (clean) operation.
*/
force_spu_isolate_exit(spu);
}
}

static void harvest(struct spu_state *prev, struct spu *spu)
{
/*
Expand All @@ -1928,6 +1973,7 @@ static void harvest(struct spu_state *prev, struct spu *spu)
inhibit_user_access(prev, spu); /* Step 3. */
terminate_spu_app(prev, spu); /* Step 4. */
set_switch_pending(prev, spu); /* Step 5. */
stop_spu_isolate(spu); /* NEW. */
remove_other_spu_access(prev, spu); /* Step 6. */
suspend_mfc(prev, spu); /* Step 7. */
wait_suspend_mfc_complete(prev, spu); /* Step 8. */
Expand Down Expand Up @@ -2096,11 +2142,11 @@ int spu_save(struct spu_state *prev, struct spu *spu)
acquire_spu_lock(spu); /* Step 1. */
rc = __do_spu_save(prev, spu); /* Steps 2-53. */
release_spu_lock(spu);
if (rc) {
if (rc != 0 && rc != 2 && rc != 6) {
panic("%s failed on SPU[%d], rc=%d.\n",
__func__, spu->number, rc);
}
return rc;
return 0;
}
EXPORT_SYMBOL_GPL(spu_save);

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5 changes: 4 additions & 1 deletion include/asm-powerpc/spu.h
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Original file line number Diff line number Diff line change
Expand Up @@ -181,8 +181,10 @@ extern struct spufs_calls {
*/
#define SPU_CREATE_EVENTS_ENABLED 0x0001
#define SPU_CREATE_GANG 0x0002
#define SPU_CREATE_NOSCHED 0x0004
#define SPU_CREATE_ISOLATE 0x0008

#define SPU_CREATE_FLAG_ALL 0x0003 /* mask of all valid flags */
#define SPU_CREATE_FLAG_ALL 0x000f /* mask of all valid flags */


#ifdef CONFIG_SPU_FS_MODULE
Expand Down Expand Up @@ -276,6 +278,7 @@ struct spu_problem {
u32 spu_runcntl_RW; /* 0x401c */
#define SPU_RUNCNTL_STOP 0L
#define SPU_RUNCNTL_RUNNABLE 1L
#define SPU_RUNCNTL_ISOLATE 2L
u8 pad_0x4020_0x4024[0x4]; /* 0x4020 */
u32 spu_status_R; /* 0x4024 */
#define SPU_STOP_STATUS_SHIFT 16
Expand Down

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