[S390] zcrypt: Introduce check for 4096 bit support.
Implemented an asm in the ap bus and made it accessible for the card
specific parts of the zcrypt driver. Thus when a cex3a is recognized
a check can be performed to dermine whether the card supports 4096 bit
RSA keys.
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 4f37c45..67302b9 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -222,6 +222,69 @@
}
#endif
+static inline struct ap_queue_status __ap_4096_commands_available(ap_qid_t qid,
+ int *support)
+{
+ register unsigned long reg0 asm ("0") = 0UL | qid | (1UL << 23);
+ register struct ap_queue_status reg1 asm ("1");
+ register unsigned long reg2 asm ("2") = 0UL;
+
+ asm volatile(
+ ".long 0xb2af0000\n"
+ "0: la %1,0\n"
+ "1:\n"
+ EX_TABLE(0b, 1b)
+ : "+d" (reg0), "=d" (reg1), "=d" (reg2)
+ :
+ : "cc");
+
+ if (reg2 & 0x6000000000000000ULL)
+ *support = 1;
+ else
+ *support = 0;
+
+ return reg1;
+}
+
+/**
+ * ap_4096_commands_availablen(): Check for availability of 4096 bit RSA
+ * support.
+ * @qid: The AP queue number
+ *
+ * Returns 1 if 4096 bit RSA keys are support fo the AP, returns 0 if not.
+ */
+int ap_4096_commands_available(ap_qid_t qid)
+{
+ struct ap_queue_status status;
+ int i, support = 0;
+ status = __ap_4096_commands_available(qid, &support);
+
+ for (i = 0; i < AP_MAX_RESET; i++) {
+ switch (status.response_code) {
+ case AP_RESPONSE_NORMAL:
+ return support;
+ case AP_RESPONSE_RESET_IN_PROGRESS:
+ case AP_RESPONSE_BUSY:
+ break;
+ case AP_RESPONSE_Q_NOT_AVAIL:
+ case AP_RESPONSE_DECONFIGURED:
+ case AP_RESPONSE_CHECKSTOPPED:
+ case AP_RESPONSE_INVALID_ADDRESS:
+ return 0;
+ case AP_RESPONSE_OTHERWISE_CHANGED:
+ break;
+ default:
+ break;
+ }
+ if (i < AP_MAX_RESET - 1) {
+ udelay(5);
+ status = __ap_4096_commands_available(qid, &support);
+ }
+ }
+ return support;
+}
+EXPORT_SYMBOL(ap_4096_commands_available);
+
/**
* ap_queue_enable_interruption(): Enable interruption on an AP.
* @qid: The AP queue number
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index 4785d07..08b9738 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -196,4 +196,6 @@
int ap_module_init(void);
void ap_module_exit(void);
+int ap_4096_commands_available(ap_qid_t qid);
+
#endif /* _AP_BUS_H_ */