97f78759ea
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>