diff options
Diffstat (limited to 'include/linux/firewire-cdev.h')
| -rw-r--r-- | include/linux/firewire-cdev.h | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h index da0fec7e8dc0..14831119ff71 100644 --- a/include/linux/firewire-cdev.h +++ b/include/linux/firewire-cdev.h @@ -394,6 +394,7 @@ union fw_cdev_event { * 4 (2.6.36) - added %FW_CDEV_EVENT_REQUEST2, %FW_CDEV_EVENT_PHY_PACKET_* * - implemented &fw_cdev_event_bus_reset.bm_node_id * - added %FW_CDEV_IOC_SEND_PHY_PACKET, _RECEIVE_PHY_PACKETS + * - added &fw_cdev_allocate.region_end */ #define FW_CDEV_VERSION 3 /* Meaningless; don't use this macro. */ @@ -473,17 +474,21 @@ struct fw_cdev_send_response { }; /** - * struct fw_cdev_allocate - Allocate a CSR address range + * struct fw_cdev_allocate - Allocate a CSR in an address range * @offset: Start offset of the address range * @closure: To be passed back to userspace in request events - * @length: Length of the address range, in bytes + * @length: Length of the CSR, in bytes * @handle: Handle to the allocation, written by the kernel + * @region_end: First address above the address range (added in ABI v4, 2.6.36) * * Allocate an address range in the 48-bit address space on the local node * (the controller). This allows userspace to listen for requests with an - * offset within that address range. When the kernel receives a request - * within the range, an &fw_cdev_event_request event will be written back. - * The @closure field is passed back to userspace in the response event. + * offset within that address range. Every time when the kernel receives a + * request within the range, an &fw_cdev_event_request2 event will be emitted. + * (If the kernel or the client implements ABI version <= 3, an + * &fw_cdev_event_request will be generated instead.) + * + * The @closure field is passed back to userspace in these request events. * The @handle field is an out parameter, returning a handle to the allocated * range to be used for later deallocation of the range. * @@ -491,12 +496,26 @@ struct fw_cdev_send_response { * is exclusive except for the FCP command and response registers. If an * exclusive address region is already in use, the ioctl fails with errno set * to %EBUSY. + * + * If kernel and client implement ABI version >= 4, the kernel looks up a free + * spot of size @length inside [@offset..@region_end) and, if found, writes + * the start address of the new CSR back in @offset. I.e. @offset is an + * in and out parameter. If this automatic placement of a CSR in a bigger + * address range is not desired, the client simply needs to set @region_end + * = @offset + @length. + * + * If the kernel or the client implements ABI version <= 3, @region_end is + * ignored and effectively assumed to be @offset + @length. + * + * @region_end is only present in a kernel header >= 2.6.36. If necessary, + * this can for example be tested by #ifdef FW_CDEV_EVENT_REQUEST2. */ struct fw_cdev_allocate { __u64 offset; __u64 closure; __u32 length; __u32 handle; + __u64 region_end; /* available since kernel version 2.6.36 */ }; /** |