[PATCH net-next 3/4] s390/diag: add diag26c support

Julian Wiedmann
2017-06-19T11:22:24Z

Implement support for the hypervisor diagnose 0x26c
('Access Certain System Information').
It passes a request buffer and a subfunction code, and receives
a response buffer and a return code.

Also add the scaffolding for the 'MAC Services' subfunction.
It may be used by network devices to obtain a hypervisor-managed
MAC address.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
arch/s390/include/asm/diag.h | 26 ++++++++++++++++++++++++++
arch/s390/kernel/diag.c | 29 +++++++++++++++++++++++++++++
2 files changed, 55 insertions(+)

diff --git a/arch/s390/include/asm/diag.h b/arch/s390/include/asm/diag.h
index 8acf482162ed..96abd80528fc 100644
--- a/arch/s390/include/asm/diag.h
+++ b/arch/s390/include/asm/diag.h
@@ -8,6 +8,7 @@
#ifndef _ASM_S390_DIAG_H
#define _ASM_S390_DIAG_H

+#include <linux/if_ether.h>
#include <linux/percpu.h>

enum diag_stat_enum {
@@ -24,6 +25,7 @@ enum diag_stat_enum {
DIAG_STAT_X224,
DIAG_STAT_X250,
DIAG_STAT_X258,
+ DIAG_STAT_X26C,
DIAG_STAT_X288,
DIAG_STAT_X2C4,
DIAG_STAT_X2FC,
@@ -225,6 +227,30 @@ struct diag204_x_phys_block {
struct diag204_x_phys_cpu cpus[];
} __packed;

+enum diag26c_sc {
+ DIAG26C_MAC_SERVICES = 0x00000030
+};
+
+enum diag26c_version {
+ DIAG26C_VERSION2 = 0x00000002 /* z/VM 5.4.0 */
+};
+
+#define DIAG26C_GET_MAC 0x0000
+struct diag26c_mac_req {
+ u32 resp_buf_len;
+ u32 resp_version;
+ u16 op_code;
+ u16 devno;
+ u8 res[4];
+} __packed;
+
+struct diag26c_mac_resp {
+ u32 version;
+ u8 mac[ETH_ALEN];
+ u16 res;
+} __packed __aligned(8);
+
int diag204(unsigned long subcode, unsigned long size, void *addr);
int diag224(void *ptr);
+int diag26c(void *req, void *resp, enum diag26c_sc subcode);
#endif /* _ASM_S390_DIAG_H */
diff --git a/arch/s390/kernel/diag.c b/arch/s390/kernel/diag.c
index ac6abcd3fe6a..349914571772 100644
--- a/arch/s390/kernel/diag.c
+++ b/arch/s390/kernel/diag.c
@@ -38,6 +38,7 @@ static const struct diag_desc diag_map[NR_DIAG_STAT] = {
[DIAG_STAT_X224] = { .code = 0x224, .name = "EBCDIC-Name Table" },
[DIAG_STAT_X250] = { .code = 0x250, .name = "Block I/O" },
[DIAG_STAT_X258] = { .code = 0x258, .name = "Page-Reference Services" },
+ [DIAG_STAT_X26C] = { .code = 0x26c, .name = "Certain System Information" },
[DIAG_STAT_X288] = { .code = 0x288, .name = "Time Bomb" },
[DIAG_STAT_X2C4] = { .code = 0x2c4, .name = "FTP Services" },
[DIAG_STAT_X2FC] = { .code = 0x2fc, .name = "Guest Performance Data" },
@@ -236,3 +237,31 @@ int diag224(void *ptr)
return rc;
}
EXPORT_SYMBOL(diag224);
+
+/*
+ * Diagnose 26C: Access Certain System Information
+ */
+static inline int __diag26c(void *req, void *resp, enum diag26c_sc subcode)
+{
+ register unsigned long _req asm("2") = (addr_t) req;
+ register unsigned long _resp asm("3") = (addr_t) resp;
+ register unsigned long _subcode asm("4") = subcode;
+ register unsigned long _rc asm("5") = -EOPNOTSUPP;
+
+ asm volatile(
+ " sam31\n"
+ " diag %[rx],%[ry],0x26c\n"
+ "0: sam64\n"
+ EX_TABLE(0b,0b)
+ : "+d" (_rc)
+ : [rx] "d" (_req), "d" (_resp), [ry] "d" (_subcode)
+ : "cc", "memory");
+ return _rc;
+}
+
+int diag26c(void *req, void *resp, enum diag26c_sc subcode)
+{
+ diag_stat_inc(DIAG_STAT_X26C);
+ return __diag26c(req, resp, subcode);
+}
+EXPORT_SYMBOL(diag26c);
--
2.11.2