[PATCH] spufs: implement mfc access for PPE-side DMA
This patch adds a new file called 'mfc' to each spufs directory.
The file accepts DMA commands that are a subset of what would
be legal DMA commands for problem state register access. Upon
reading the file, a bitmask is returned with the completed
tag groups set.
The file is meant to be used from an abstraction in libspe
that is added by a different patch.
From the kernel perspective, this means a process can now
offload a memory copy from or into an SPE local store
without having to run code on the SPE itself.
The transfer will only be performed while the SPE is owned
by one thread that is waiting in the spu_run system call
and the data will be transferred into that thread's
address space, independent of which thread started the
transfer.
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/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index db2601f..57d687c 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -55,13 +55,27 @@
wait_queue_head_t ibox_wq;
wait_queue_head_t wbox_wq;
wait_queue_head_t stop_wq;
+ wait_queue_head_t mfc_wq;
struct fasync_struct *ibox_fasync;
struct fasync_struct *wbox_fasync;
+ struct fasync_struct *mfc_fasync;
+ u32 tagwait;
struct spu_context_ops *ops;
struct work_struct reap_work;
u64 flags;
};
+struct mfc_dma_command {
+ int32_t pad; /* reserved */
+ uint32_t lsa; /* local storage address */
+ uint64_t ea; /* effective address */
+ uint16_t size; /* transfer size */
+ uint16_t tag; /* command tag */
+ uint16_t class; /* class ID */
+ uint16_t cmd; /* command opcode */
+};
+
+
/* SPU context query/set operations. */
struct spu_context_ops {
int (*mbox_read) (struct spu_context * ctx, u32 * data);
@@ -84,6 +98,11 @@
char*(*get_ls) (struct spu_context * ctx);
void (*runcntl_write) (struct spu_context * ctx, u32 data);
void (*runcntl_stop) (struct spu_context * ctx);
+ int (*set_mfc_query)(struct spu_context * ctx, u32 mask, u32 mode);
+ u32 (*read_mfc_tagstatus)(struct spu_context * ctx);
+ u32 (*get_mfc_free_elements)(struct spu_context *ctx);
+ int (*send_mfc_command)(struct spu_context *ctx,
+ struct mfc_dma_command *cmd);
};
extern struct spu_context_ops spu_hw_ops;
@@ -159,5 +178,6 @@
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);
#endif