[POWERPC] spufs: add support for nonschedulable contexts

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>

diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index 0de8e11..8ca3306 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/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, },
+       {},
+};

diff --git a/arch/powerpc/platforms/cell/spufs/hw_ops.c b/arch/powerpc/platforms/cell/spufs/hw_ops.c
index efc452e..2ad534a 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/hw_ops.c
+++ b/arch/powerpc/platforms/cell/spufs/hw_ops.c
@@ -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)

diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 427d00a..787ae71 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -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;
 
@@ -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;

diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index 63df8cf..0c03a04 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -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;
 }
 

diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index a0f55ca..b17b809 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/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,

diff --git a/arch/powerpc/platforms/cell/spufs/switch.c b/arch/powerpc/platforms/cell/spufs/switch.c
index b85347f..b47fb50 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/switch.c
+++ b/arch/powerpc/platforms/cell/spufs/switch.c
@@ -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)
 {
        /*
@@ -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.  */
@@ -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);
 

diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h
index cac4ad9..a1cf476 100644 (file)
--- a/include/asm-powerpc/spu.h
+++ b/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