[PATCH 03/16] spufs: add support for nonschedulable contexts

arnd
2006-10-24T16:41:11Z

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From: Mark Nutter <mnutter@us.ibm.com>

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>

---

Update: add psmap file.

arch/powerpc/platforms/cell/spufs/file.c | 22 ++++++++++++
arch/powerpc/platforms/cell/spufs/hw_ops.c | 5 ++
arch/powerpc/platforms/cell/spufs/inode.c | 17 +++++++++
arch/powerpc/platforms/cell/spufs/run.c | 10 ++++-
arch/powerpc/platforms/cell/spufs/spufs.h | 1
arch/powerpc/platforms/cell/spufs/switch.c | 50 +++++++++++++++++++++++++++--
include/asm-powerpc/spu.h | 5 ++
7 files changed, 103 insertions(+), 7 deletions(-)

Index: linux-2.6/arch/powerpc/platforms/cell/spufs/file.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/file.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/file.c
@@ -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, },
+ {},
+};
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/hw_ops.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/hw_ops.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/hw_ops.c
@@ -219,8 +219,11 @@ static char *spu_hw_get_ls(struct spu_co

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)
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/inode.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/inode.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/inode.c
@@ -258,7 +258,12 @@ spufs_mkdir(struct inode *dir, struct de

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;

@@ -307,6 +312,16 @@ static int spufs_create_context(struct i
{
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;
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/run.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/run.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/run.c
@@ -51,11 +51,17 @@ static inline int spu_stopped(struct spu
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;
}

Index: linux-2.6/arch/powerpc/platforms/cell/spufs/spufs.h
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/spufs.h
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -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,
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/switch.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/switch.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/switch.c
@@ -1916,6 +1916,51 @@ static void save_lscsa(struct spu_state
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)
{
/*
@@ -1928,6 +1973,7 @@ static void harvest(struct spu_state *pr
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. */
@@ -2096,11 +2142,11 @@ int spu_save(struct spu_state *prev, str
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);

Index: linux-2.6/include/asm-powerpc/spu.h
===================================================================
--- linux-2.6.orig/include/asm-powerpc/spu.h
+++ linux-2.6/include/asm-powerpc/spu.h
@@ -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
@@ -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

--