[S390] zcrypt adjunct processor bus.

Add a bus for the adjunct processor interface. Up to 64 devices can
be connect to the ap bus interface, each device with 16 domains. That
makes 1024 message queues. The interface is asynchronous, the answer
to a message sent to a queue needs to be received at some later point
in time. Unfortunately the interface does not provide interrupts when
a message reply is pending. So the ap bus needs to implement some
fancy polling, each active queue is polled once per 1/HZ second or
continuously if an idle cpus exsists and the poll thread is activ
(see poll_thread parameter).

The ap bus uses the sysfs path /sys/bus/ap and has two bus attributes,
ap_domain and config_time. The ap_domain selects one of the 16 domains
to be used for this system. This limits the maximum number of ap devices
to 64. The config_time attribute contains the number of seconds between
two ap bus scans to find new devices.

The ap bus uses the modalias entries of the form "ap:tN" to autoload
the ap driver for hardware type N. Currently known types are:
3 - PCICC, 4 - PCICA, 5 - PCIXCC, 6 - CEX2A and 7 - CEX2C.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index f6977708585c..f7ca0b09075d 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -148,6 +148,17 @@ struct ccw_device_id {
 #define CCW_DEVICE_ID_MATCH_DEVICE_TYPE         0x04
 #define CCW_DEVICE_ID_MATCH_DEVICE_MODEL        0x08
 
+/* s390 AP bus devices */
+struct ap_device_id {
+        __u16 match_flags;      /* which fields to match against */
+        __u8 dev_type;          /* device type */
+        __u8 pad1;
+        __u32 pad2;
+        kernel_ulong_t driver_info;
+};
+
+#define AP_DEVICE_ID_MATCH_DEVICE_TYPE          0x01
+
 
 #define PNP_ID_LEN      8
 #define PNP_MAX_DEVICES 8