This patches fixes two bugs in the scsi target infrastructure's
user/kernel interface.
- It wrongly assumes that the ring buffer size of the interface (64KB)
is larger than or equal to the system page size. This patch sets the
ring buffer size to PAGE_SIZE if the system page size is larger.
- It uses PAGE_SIZE in the header file exported to userspace. This
patch removes it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/scsi/scsi_tgt_if.c: In function 'tgt_uspace_send_event':
drivers/scsi/scsi_tgt_if.c:88: warning: implicit declaration of function 'flush_dcache_page'
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The user-space daemon and tgt kernel module need bi-directional
kernel/user high-performance interface, however, mainline provides no
standard interface like that.
This patch adds shared memory interface between kernel and user spaces
like some other drivers do by using own character device. The
user-space daemon and tgt kernel module creates shared memory via mmap
and use it like ring buffer. poll (kernel to user) and write (user to
kernel) system calls are used for notification.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
