[Cbe-oss-dev] [RFC] implement error event delivery to user space
Arnd Bergmann
arnd.bergmann at de.ibm.com
Sat Jun 24 05:12:58 EST 2006
From: Christoph Hellwig <hch at infradead.org>
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!).
This returns what we need from libspe, but only
when a flag was set on spu_create. Now that flag
was previously not documented, so we're actually
extending the semantics here.
One big question that keeps nagging me is whether
we want to actually allow a thread to run on after
it has hit a critical error like invalid DMA addresses
or illegal opcodes. I can't really think of an example
where we would want to do that, so I tend to go down
the easy route of not supporting that, but there may
be scenarios that I haven't thought of.
Signed-off-by: Arnd Bergmann <arnd.bergmann at de.ibm.com>
Index: linus-2.6/arch/powerpc/platforms/cell/spu_base.c
===================================================================
--- linus-2.6.orig/arch/powerpc/platforms/cell/spu_base.c
+++ linus-2.6/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;
}
Index: linus-2.6/arch/powerpc/platforms/cell/spufs/inode.c
===================================================================
--- linus-2.6.orig/arch/powerpc/platforms/cell/spufs/inode.c
+++ linus-2.6/arch/powerpc/platforms/cell/spufs/inode.c
@@ -225,7 +225,8 @@ struct file_operations spufs_context_fop
};
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;
@@ -245,6 +246,8 @@ spufs_mkdir(struct inode *dir, struct de
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);
@@ -305,7 +308,7 @@ long spufs_create_thread(struct nameidat
goto out;
/* all flags are reserved */
- if (flags)
+ if (flags & (~SPU_CREATE_FLAG_ALL))
goto out;
dentry = lookup_create(nd, 1);
@@ -318,7 +321,7 @@ long spufs_create_thread(struct nameidat
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;
Index: linus-2.6/arch/powerpc/platforms/cell/spufs/run.c
===================================================================
--- linus-2.6.orig/arch/powerpc/platforms/cell/spufs/run.c
+++ linus-2.6/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
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
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(str
}
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;
}
Index: linus-2.6/arch/powerpc/platforms/cell/spufs/sched.c
===================================================================
--- linus-2.6.orig/arch/powerpc/platforms/cell/spufs/sched.c
+++ linus-2.6/arch/powerpc/platforms/cell/spufs/sched.c
@@ -102,7 +102,6 @@ static inline void bind_context(struct s
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;
@@ -113,6 +112,7 @@ static inline void bind_context(struct s
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);
@@ -134,12 +134,12 @@ static inline void unbind_context(struct
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;
}
Index: linus-2.6/arch/powerpc/platforms/cell/spufs/spufs.h
===================================================================
--- linus-2.6.orig/arch/powerpc/platforms/cell/spufs/spufs.h
+++ linus-2.6/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -67,7 +67,8 @@ 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 {
@@ -184,5 +185,6 @@ 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
Index: linus-2.6/include/asm-powerpc/spu.h
===================================================================
--- linus-2.6.orig/include/asm-powerpc/spu.h
+++ linus-2.6/include/asm-powerpc/spu.h
@@ -138,6 +138,7 @@ struct spu {
void (* ibox_callback)(struct spu *spu);
void (* stop_callback)(struct spu *spu);
void (* mfc_callback)(struct spu *spu);
+ void (* dma_callback)(struct spu *spu, int type);
char irq_c0[8];
char irq_c1[8];
@@ -169,6 +170,19 @@ extern struct spufs_calls {
struct module *owner;
} spufs_calls;
+/* return status from spu_run, same as in libspe */
+#define SPE_EVENT_DMA_ALIGNMENT 0x0008 /*A DMA alignment error */
+#define SPE_EVENT_SPE_ERROR 0x0010 /*An illegal instruction error*/
+#define SPE_EVENT_SPE_DATA_SEGMENT 0x0020 /*A DMA segmentation error */
+#define SPE_EVENT_SPE_DATA_STORAGE 0x0040 /*A DMA storage error */
+#define SPE_EVENT_INVALID_DMA 0x0800 /* Invalid MFC DMA */
+
+/*
+ * Flags for sys_spu_create.
+ */
+#define SPU_CREATE_EVENTS_ENABLED 0x0001
+#define SPU_CREATE_FLAG_ALL 0x0001 /* mask of all valid flags */
+
#ifdef CONFIG_SPU_FS_MODULE
int register_spu_syscalls(struct spufs_calls *calls);
void unregister_spu_syscalls(struct spufs_calls *calls);
Index: linus-2.6/arch/powerpc/platforms/cell/spufs/syscalls.c
===================================================================
--- linus-2.6.orig/arch/powerpc/platforms/cell/spufs/syscalls.c
+++ linus-2.6/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;
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