[POWERPC] spufs: implement error event delivery to user space

This tries to fix spufs so we have an interface closer to what is
specified in the man page for events returned in the third argument of
spu_run.

Fortunately, libspe has never been using the returned contents of that
register, as they were the same as the return code of spu_run (duh!).

Unlike the specification that we never implemented correctly, we now
require a SPU_CREATE_EVENTS_ENABLED flag passed to spu_create, in
order to get the new behavior. When this flag is not passed, spu_run
will simply ignore the third argument now.

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

6 files changed, 54 insertions, 24 deletions

diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c
index 5931973..bfbd045 100644
--- a/arch/powerpc/platforms/cell/spu_base.c
+++ b/arch/powerpc/platforms/cell/spu_base.c
@@ -46,21 +46,21 @@ EXPORT_SYMBOL_GPL(spu_priv1_ops);
 static int __spu_trap_invalid_dma(struct spu *spu)
 {
 	pr_debug("%s\n", __FUNCTION__);
-	force_sig(SIGBUS, /* info, */ current);
+	spu->dma_callback(spu, SPE_EVENT_INVALID_DMA);
 	return 0;
 }
 
 static int __spu_trap_dma_align(struct spu *spu)
 {
 	pr_debug("%s\n", __FUNCTION__);
-	force_sig(SIGBUS, /* info, */ current);
+	spu->dma_callback(spu, SPE_EVENT_DMA_ALIGNMENT);
 	return 0;
 }
 
 static int __spu_trap_error(struct spu *spu)
 {
 	pr_debug("%s\n", __FUNCTION__);
-	force_sig(SIGILL, /* info, */ current);
+	spu->dma_callback(spu, SPE_EVENT_SPE_ERROR);
 	return 0;
 }
 
diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 3950ddc..8cc615f 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -224,7 +224,8 @@ struct file_operations spufs_context_fops = {
 };
 
 static int
-spufs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+spufs_mkdir(struct inode *dir, struct dentry *dentry, unsigned int flags,
+		int mode)
 {
 	int ret;
 	struct inode *inode;
@@ -244,6 +245,8 @@ spufs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	if (!ctx)
 		goto out_iput;
 
+	ctx->flags = flags;
+
 	inode->i_op = &spufs_dir_inode_operations;
 	inode->i_fop = &simple_dir_operations;
 	ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
@@ -304,7 +307,7 @@ long spufs_create_thread(struct nameidata *nd,
 		goto out;
 
 	/* all flags are reserved */
-	if (flags)
+	if (flags & (~SPU_CREATE_FLAG_ALL))
 		goto out;
 
 	dentry = lookup_create(nd, 1);
@@ -317,7 +320,7 @@ long spufs_create_thread(struct nameidata *nd,
 		goto out_dput;
 
 	mode &= ~current->fs->umask;
-	ret = spufs_mkdir(nd->dentry->d_inode, dentry, mode & S_IRWXUGO);
+	ret = spufs_mkdir(nd->dentry->d_inode, dentry, flags, mode & S_IRWXUGO);
 	if (ret)
 		goto out_dput;
 
diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index 483c8b7..63df8cf 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -14,6 +14,26 @@ void spufs_stop_callback(struct spu *spu)
 	wake_up_all(&ctx->stop_wq);
 }
 
+void spufs_dma_callback(struct spu *spu, int type)
+{
+	struct spu_context *ctx = spu->ctx;
+
+	if (ctx->flags & SPU_CREATE_EVENTS_ENABLED) {
+		ctx->event_return |= type;
+		wake_up_all(&ctx->stop_wq);
+	} else {
+		switch (type) {
+		case SPE_EVENT_DMA_ALIGNMENT:
+		case SPE_EVENT_INVALID_DMA:
+			force_sig(SIGBUS, /* info, */ current);
+			break;
+		case SPE_EVENT_SPE_ERROR:
+			force_sig(SIGILL, /* info */ current);
+			break;
+		}
+	}
+}
+
 static inline int spu_stopped(struct spu_context *ctx, u32 * stat)
 {
 	struct spu *spu;
@@ -28,8 +48,7 @@ static inline int spu_stopped(struct spu_context *ctx, u32 * stat)
 	return (!(*stat & 0x1) || pte_fault || spu->class_0_pending) ? 1 : 0;
 }
 
-static inline int spu_run_init(struct spu_context *ctx, u32 * npc,
-			       u32 * status)
+static inline int spu_run_init(struct spu_context *ctx, u32 * npc)
 {
 	int ret;
 
@@ -72,7 +91,7 @@ static inline int spu_reacquire_runnable(struct spu_context *ctx, u32 *npc,
 		       SPU_STATUS_STOPPED_BY_HALT)) {
 		return *status;
 	}
-	if ((ret = spu_run_init(ctx, npc, status)) != 0)
+	if ((ret = spu_run_init(ctx, npc)) != 0)
 		return ret;
 	return 0;
 }
@@ -177,46 +196,49 @@ static inline int spu_process_events(struct spu_context *ctx)
 }
 
 long spufs_run_spu(struct file *file, struct spu_context *ctx,
-		   u32 * npc, u32 * status)
+		   u32 *npc, u32 *event)
 {
 	int ret;
+	u32 status;
 
 	if (down_interruptible(&ctx->run_sema))
 		return -ERESTARTSYS;
 
-	ret = spu_run_init(ctx, npc, status);
+	ctx->event_return = 0;
+	ret = spu_run_init(ctx, npc);
 	if (ret)
 		goto out;
 
 	do {
-		ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, status));
+		ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, &status));
 		if (unlikely(ret))
 			break;
-		if ((*status & SPU_STATUS_STOPPED_BY_STOP) &&
-		    (*status >> SPU_STOP_STATUS_SHIFT == 0x2104)) {
+		if ((status & SPU_STATUS_STOPPED_BY_STOP) &&
+		    (status >> SPU_STOP_STATUS_SHIFT == 0x2104)) {
 			ret = spu_process_callback(ctx);
 			if (ret)
 				break;
-			*status &= ~SPU_STATUS_STOPPED_BY_STOP;
+			status &= ~SPU_STATUS_STOPPED_BY_STOP;
 		}
 		if (unlikely(ctx->state != SPU_STATE_RUNNABLE)) {
-			ret = spu_reacquire_runnable(ctx, npc, status);
+			ret = spu_reacquire_runnable(ctx, npc, &status);
 			if (ret)
 				goto out;
 			continue;
 		}
 		ret = spu_process_events(ctx);
 
-	} while (!ret && !(*status & (SPU_STATUS_STOPPED_BY_STOP |
+	} while (!ret && !(status & (SPU_STATUS_STOPPED_BY_STOP |
 				      SPU_STATUS_STOPPED_BY_HALT)));
 
 	ctx->ops->runcntl_stop(ctx);
-	ret = spu_run_fini(ctx, npc, status);
+	ret = spu_run_fini(ctx, npc, &status);
 	if (!ret)
-		ret = *status;
+		ret = status;
 	spu_yield(ctx);
 
 out:
+	*event = ctx->event_return;
 	up(&ctx->run_sema);
 	return ret;
 }
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index bd4e2c3..a824b60 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -81,7 +81,6 @@ static inline void bind_context(struct spu *spu, struct spu_context *ctx)
 		 spu->number, spu->node);
 	spu->ctx = ctx;
 	spu->flags = 0;
-	ctx->flags = 0;
 	ctx->spu = spu;
 	ctx->ops = &spu_hw_ops;
 	spu->pid = current->pid;
@@ -92,6 +91,7 @@ static inline void bind_context(struct spu *spu, struct spu_context *ctx)
 	spu->wbox_callback = spufs_wbox_callback;
 	spu->stop_callback = spufs_stop_callback;
 	spu->mfc_callback = spufs_mfc_callback;
+	spu->dma_callback = spufs_dma_callback;
 	mb();
 	spu_unmap_mappings(ctx);
 	spu_restore(&ctx->csa, spu);
@@ -111,12 +111,12 @@ static inline void unbind_context(struct spu *spu, struct spu_context *ctx)
 	spu->wbox_callback = NULL;
 	spu->stop_callback = NULL;
 	spu->mfc_callback = NULL;
+	spu->dma_callback = NULL;
 	spu->mm = NULL;
 	spu->pid = 0;
 	spu->prio = MAX_PRIO;
 	ctx->ops = &spu_backing_ops;
 	ctx->spu = NULL;
-	ctx->flags = 0;
 	spu->flags = 0;
 	spu->ctx = NULL;
 }
diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index 4485738..2fb6a00 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -66,7 +66,8 @@ struct spu_context {
 	u32 tagwait;
 	struct spu_context_ops *ops;
 	struct work_struct reap_work;
-	u64 flags;
+	unsigned long flags;
+	unsigned long event_return;
 };
 
 struct mfc_dma_command {
@@ -183,5 +184,6 @@ void spufs_ibox_callback(struct spu *spu);
 void spufs_wbox_callback(struct spu *spu);
 void spufs_stop_callback(struct spu *spu);
 void spufs_mfc_callback(struct spu *spu);
+void spufs_dma_callback(struct spu *spu, int type);
 
 #endif
diff --git a/arch/powerpc/platforms/cell/spufs/syscalls.c b/arch/powerpc/platforms/cell/spufs/syscalls.c
index e6565a9..ef33a0c 100644
--- a/arch/powerpc/platforms/cell/spufs/syscalls.c
+++ b/arch/powerpc/platforms/cell/spufs/syscalls.c
@@ -38,7 +38,7 @@ static long do_spu_run(struct file *filp,
 	u32 npc, status;
 
 	ret = -EFAULT;
-	if (get_user(npc, unpc) || get_user(status, ustatus))
+	if (get_user(npc, unpc))
 		goto out;
 
 	/* check if this file was created by spu_create */
@@ -49,7 +49,10 @@ static long do_spu_run(struct file *filp,
 	i = SPUFS_I(filp->f_dentry->d_inode);
 	ret = spufs_run_spu(filp, i->i_ctx, &npc, &status);
 
-	if (put_user(npc, unpc) || put_user(status, ustatus))
+	if (put_user(npc, unpc))
+		ret = -EFAULT;
+
+	if (ustatus && put_user(status, ustatus))
 		ret = -EFAULT;
 out:
 	return ret;