[kvm-unit-tests PATCH v2 1/5] s390x: css: Store CSS Characteristics

Pierre Morel
2021-02-10T13:21:46Z

CSS characteristics exposes the features of the Channel SubSystem.
Let's use Store Channel Subsystem Characteristics to retrieve
the features of the CSS.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
lib/s390x/css.h | 69 +++++++++++++++++++++++++++
lib/s390x/css_lib.c | 112 +++++++++++++++++++++++++++++++++++++++++++-
s390x/css.c | 12 +++++
3 files changed, 192 insertions(+), 1 deletion(-)

diff --git a/lib/s390x/css.h b/lib/s390x/css.h
index 3e57445..1e317d1 100644
--- a/lib/s390x/css.h
+++ b/lib/s390x/css.h
@@ -288,4 +288,73 @@ int css_residual_count(unsigned int schid);
void enable_io_isc(uint8_t isc);
int wait_and_check_io_completion(int schid);

+/*
+ * CHSC definitions
+ */
+struct chsc_header {
+ u16 len;
+ u16 code;
+};
+
+/* Store Channel Subsystem Characteristics */
+struct chsc_scsc {
+ struct chsc_header req;
+ u16 req_fmt;
+ u8 cssid;
+ u8 res_03;
+ u32 res_04[2];
+ struct chsc_header res;
+ u32 res_fmt;
+ u64 general_char[255];
+ u64 chsc_char[254];
+};
+extern struct chsc_scsc *chsc_scsc;
+#define CHSC_SCSC 0x0010
+#define CHSC_SCSC_LEN 0x0010
+
+int get_chsc_scsc(void);
+
+
+#define CSS_GENERAL_FEAT_BITLEN (255 * 64)
+#define CSS_CHSC_FEAT_BITLEN (254 * 64)
+
+#define CHSC_SCSC 0x0010
+#define CHSC_SCSC_LEN 0x0010
+
+#define CHSC_ERROR 0x0000
+#define CHSC_RSP_OK 0x0001
+#define CHSC_RSP_INVAL 0x0002
+#define CHSC_RSP_REQERR 0x0003
+#define CHSC_RSP_ENOCMD 0x0004
+#define CHSC_RSP_NODATA 0x0005
+#define CHSC_RSP_SUP31B 0x0006
+#define CHSC_RSP_EFRMT 0x0007
+#define CHSC_RSP_ECSSID 0x0008
+#define CHSC_RSP_ERFRMT 0x0009
+#define CHSC_RSP_ESSID 0x000A
+#define CHSC_RSP_EBUSY 0x000B
+#define CHSC_RSP_MAX 0x000B
+
+static inline int _chsc(void *p)
+{
+ int cc;
+
+ asm volatile(
+ " .insn rre,0xb25f0000,%2,0\n"
+ " ipm %0\n"
+ " srl %0,28\n"
+ : "=d" (cc), "=m" (p)
+ : "d" (p), "m" (p)
+ : "cc");
+
+ return cc;
+}
+
+int chsc(void *p, uint16_t code, uint16_t len);
+
+
+#include <bitops.h>
+#define css_general_feature(bit) test_bit_inv(bit, chsc_scsc->general_char)
+#define css_chsc_feature(bit) test_bit_inv(bit, chsc_scsc->chsc_char)
+
#endif
diff --git a/lib/s390x/css_lib.c b/lib/s390x/css_lib.c
index 3c24480..88aa7a1 100644
--- a/lib/s390x/css_lib.c
+++ b/lib/s390x/css_lib.c
@@ -15,11 +15,121 @@
#include <asm/arch_def.h>
#include <asm/time.h>
#include <asm/arch_def.h>
-
+#include <alloc_page.h>
#include <malloc_io.h>
#include <css.h>

static struct schib schib;
+struct chsc_scsc *chsc_scsc;
+
+static const char *chsc_rsp_description[] = {
+ "CHSC unknown error",
+ "Command executed",
+ "Invalid command",
+ "Request-block error",
+ "Command not installed",
+ "Data not available",
+ "Absolute address of channel-subsystem"
+ "communication block exceeds 2 - 1.",
+ "Invalid command format",
+ "Invalid channel-subsystem identification (CSSID)",
+ "The command-request block specified an invalid format"
+ "for the command response block.",
+ "Invalid subchannel-set identification (SSID)",
+ "A busy condition precludes execution.",
+};
+
+static int check_response(void *p)
+{
+ struct chsc_header *h = p;
+
+ if (h->code == CHSC_RSP_OK) {
+ report(1, "CHSC command completed.");
+ return 0;
+ }
+ if (h->code > CHSC_RSP_MAX)
+ h->code = 0;
+ report(0, "Response code %04x: %s", h->code, chsc_rsp_description[h->code]);
+ return -1;
+}
+
+int chsc(void *p, uint16_t code, uint16_t len)
+{
+ struct chsc_header *h = p;
+ int cc;
+
+ report_prefix_push("Channel Subsystem Call");
+ h->code = code;
+ h->len = len;
+ cc = _chsc(p);
+ switch (cc) {
+ case 3:
+ report(0, "Subchannel invalid or not enabled.");
+ break;
+ case 2:
+ report(0, "CHSC subchannel busy.");
+ break;
+ case 1:
+ report(0, "Subchannel invalid or not enabled.");
+ break;
+ case 0:
+ cc = check_response(p + len);
+ break;
+ }
+
+ report_prefix_pop();
+ return cc;
+}
+
+int get_chsc_scsc(void)
+{
+ int i, n;
+ int ret = 0;
+ char buffer[510];
+ char *p;
+
+ report_prefix_push("Channel Subsystem Call");
+
+ if (chsc_scsc) {
+ report_info("chsc_scsc already initialized");
+ goto end;
+ }
+
+ chsc_scsc = alloc_page();
+ report_info("scsc_scsc at: %016lx", (u64)chsc_scsc);
+ if (!chsc_scsc) {
+ ret = -1;
+ report(0, "could not allocate chsc_scsc page!");
+ goto end;
+ }
+
+ report_info("scsc format %x\n", chsc_scsc->req_fmt);
+ ret = chsc(chsc_scsc, CHSC_SCSC, CHSC_SCSC_LEN);
+ if (ret) {
+ report(0, "chsc: CC %d", ret);
+ goto end;
+ }
+
+ for (i = 0, p = buffer; i < CSS_GENERAL_FEAT_BITLEN; i++) {
+ if (css_general_feature(i)) {
+ n = snprintf(p, sizeof(buffer) - ret, "%d,", i);
+ p += n;
+ }
+ }
+ report_info("General features: %s", buffer);
+
+ for (i = 0, p = buffer, ret = 0; i < CSS_CHSC_FEAT_BITLEN; i++) {
+ if (css_chsc_feature(i)) {
+ n = snprintf(p, sizeof(buffer) - ret, "%d,", i);
+ p += n;
+ }
+ }
+ report_info("CHSC features: %s", buffer);
+
+end:
+ report_prefix_pop();
+ return ret;
+}

/*
* css_enumerate:
diff --git a/s390x/css.c b/s390x/css.c
index 1a61a5c..18dbf01 100644
--- a/s390x/css.c
+++ b/s390x/css.c
@@ -14,6 +14,7 @@
#include <string.h>
#include <interrupt.h>
#include <asm/arch_def.h>
+#include <alloc_page.h>

#include <malloc_io.h>
#include <css.h>
@@ -140,10 +141,21 @@ error_senseid:
unregister_io_int_func(css_irq_io);
}

+static void css_init(void)
+{
+ int ret;
+
+ ret = get_chsc_scsc();
+ if (!ret)
+ report(1, " ");
+}
+
static struct {
const char *name;
void (*func)(void);
} tests[] = {
+ /* The css_init test is needed to initialize the CSS Characteristics */
+ { "initialize CSS (chsc)", css_init },
{ "enumerate (stsch)", test_enumerate },
{ "enable (msch)", test_enable },
{ "sense (ssch/tsch)", test_sense },
--
2.17.1