[S390] dasd: add High Performance FICON support
To support High Performance FICON, the DASD device driver has to
translate I/O requests into the new transport mode control words (TCW)
instead of the traditional (command mode) CCW requests.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index 3433990..da231a7 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -67,6 +67,8 @@
int dasd_autodetect = 0; /* is true, when autodetection is active */
int dasd_nopav = 0; /* is true, when PAV is disabled */
EXPORT_SYMBOL_GPL(dasd_nopav);
+int dasd_nofcx; /* disable High Performance Ficon */
+EXPORT_SYMBOL_GPL(dasd_nofcx);
/*
* char *dasd[] is intended to hold the ranges supplied by the dasd= statement
@@ -272,6 +274,11 @@
}
return residual_str;
}
+ if (strncmp("nofcx", parsestring, length) == 0) {
+ dasd_nofcx = 1;
+ MESSAGE(KERN_INFO, "%s", "disable High Performance Ficon");
+ return residual_str;
+ }
if (strncmp("fixedbuffers", parsestring, length) == 0) {
if (dasd_page_cache)
return residual_str;