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											2006-12-01 03:00:50 +09:00
										 |  |  | #ifndef __LIBSRP_H__
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							|  |  |  | #define __LIBSRP_H__
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							|  |  |  | #include <linux/list.h>
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											2009-12-30 13:21:06 -06:00
										 |  |  | #include <linux/kfifo.h>
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											2006-12-01 03:00:50 +09:00
										 |  |  | #include <scsi/scsi_cmnd.h>
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							|  |  |  | #include <scsi/scsi_host.h>
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							|  |  |  | #include <scsi/srp.h>
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							|  |  |  | enum iue_flags { | 
					
						
							|  |  |  | 	V_DIOVER, | 
					
						
							|  |  |  | 	V_WRITE, | 
					
						
							|  |  |  | 	V_LINKED, | 
					
						
							|  |  |  | 	V_FLYING, | 
					
						
							|  |  |  | }; | 
					
						
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							|  |  |  | struct srp_buf { | 
					
						
							|  |  |  | 	dma_addr_t dma; | 
					
						
							|  |  |  | 	void *buf; | 
					
						
							|  |  |  | }; | 
					
						
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							|  |  |  | struct srp_queue { | 
					
						
							|  |  |  | 	void *pool; | 
					
						
							|  |  |  | 	void *items; | 
					
						
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												kfifo: move struct kfifo in place
This is a new generic kernel FIFO implementation.
The current kernel fifo API is not very widely used, because it has to
many constrains.  Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.
I think this are the reasons why kfifo is not in use:
 - The API is to simple, important functions are missing
 - A fifo can be only allocated dynamically
 - There is a requirement of a spinlock whether you need it or not
 - There is no support for data records inside a fifo
So I decided to extend the kfifo in a more generic way without blowing up
the API to much.  The new API has the following benefits:
 - Generic usage: For kernel internal use and/or device driver.
 - Provide an API for the most use case.
 - Slim API: The whole API provides 25 functions.
 - Linux style habit.
 - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
 - Direct copy_to_user from the fifo and copy_from_user into the fifo.
 - The kfifo itself is an in place member of the using data structure, this save an
   indirection access and does not waste the kernel allocator.
 - Lockless access: if only one reader and one writer is active on the fifo,
   which is the common use case, no additional locking is necessary.
 - Remove spinlock - give the user the freedom of choice what kind of locking to use if
   one is required.
 - Ability to handle records. Three type of records are supported:
   - Variable length records between 0-255 bytes, with a record size
     field of 1 bytes.
   - Variable length records between 0-65535 bytes, with a record size
     field of 2 bytes.
   - Fixed size records, which no record size field.
 - Preserve memory resource.
 - Performance!
 - Easy to use!
This patch:
Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure.  This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them.  This
patch changes the implementation and all existing users.
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
											
										 
											2009-12-21 14:37:26 -08:00
										 |  |  | 	struct kfifo queue; | 
					
						
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										 |  |  | 	spinlock_t lock; | 
					
						
							|  |  |  | }; | 
					
						
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							|  |  |  | struct srp_target { | 
					
						
							|  |  |  | 	struct Scsi_Host *shost; | 
					
						
							|  |  |  | 	struct device *dev; | 
					
						
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							|  |  |  | 	spinlock_t lock; | 
					
						
							|  |  |  | 	struct list_head cmd_queue; | 
					
						
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							|  |  |  | 	size_t srp_iu_size; | 
					
						
							|  |  |  | 	struct srp_queue iu_queue; | 
					
						
							|  |  |  | 	size_t rx_ring_size; | 
					
						
							|  |  |  | 	struct srp_buf **rx_ring; | 
					
						
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							|  |  |  | 	void *ldata; | 
					
						
							|  |  |  | }; | 
					
						
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							|  |  |  | struct iu_entry { | 
					
						
							|  |  |  | 	struct srp_target *target; | 
					
						
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							|  |  |  | 	struct list_head ilist; | 
					
						
							|  |  |  | 	dma_addr_t remote_token; | 
					
						
							|  |  |  | 	unsigned long flags; | 
					
						
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							|  |  |  | 	struct srp_buf *sbuf; | 
					
						
							|  |  |  | }; | 
					
						
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							|  |  |  | typedef int (srp_rdma_t)(struct scsi_cmnd *, struct scatterlist *, int, | 
					
						
							|  |  |  | 			 struct srp_direct_buf *, int, | 
					
						
							|  |  |  | 			 enum dma_data_direction, unsigned int); | 
					
						
							|  |  |  | extern int srp_target_alloc(struct srp_target *, struct device *, size_t, size_t); | 
					
						
							|  |  |  | extern void srp_target_free(struct srp_target *); | 
					
						
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							|  |  |  | extern struct iu_entry *srp_iu_get(struct srp_target *); | 
					
						
							|  |  |  | extern void srp_iu_put(struct iu_entry *); | 
					
						
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											2007-07-11 15:08:21 +09:00
										 |  |  | extern int srp_cmd_queue(struct Scsi_Host *, struct srp_cmd *, void *, u64, u64); | 
					
						
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										 |  |  | extern int srp_transfer_data(struct scsi_cmnd *, struct srp_cmd *, | 
					
						
							|  |  |  | 			     srp_rdma_t, int, int); | 
					
						
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							|  |  |  | static inline struct srp_target *host_to_srp_target(struct Scsi_Host *host) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	return (struct srp_target *) host->hostdata; | 
					
						
							|  |  |  | } | 
					
						
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							|  |  |  | static inline int srp_cmd_direction(struct srp_cmd *cmd) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	return (cmd->buf_fmt >> 4) ? DMA_TO_DEVICE : DMA_FROM_DEVICE; | 
					
						
							|  |  |  | } | 
					
						
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							|  |  |  | #endif
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