s390/sysinfo,stsi: change return code handling

Change return code handling of the stsi() function:

In case function code 0 was specified the return value is the
current configuration level (already shifted). That way all
the code that actually copied the stsi_0() function can go
away.

Otherwise the return value is 0 (success) or negative to
indicate an error (currently only -EOPNOTSUPP).

Also stsi() is no longer an inline function. The function is
not performance critical, but every caller would generate an
exception table entry for this function.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 32 insertions, 11 deletions

diff --git a/arch/s390/kernel/sysinfo.c b/arch/s390/kernel/sysinfo.c
index 2af4ee67fe5..62f89d98e88 100644
--- a/arch/s390/kernel/sysinfo.c
+++ b/arch/s390/kernel/sysinfo.c
@@ -24,18 +24,38 @@
 
 int topology_max_mnest;
 
-static inline int stsi_0(void)
+/*
+ * stsi - store system information
+ *
+ * Returns the current configuration level if function code 0 was specified.
+ * Otherwise returns 0 on success or a negative value on error.
+ */
+int stsi(void *sysinfo, int fc, int sel1, int sel2)
 {
-        int rc = stsi(NULL, 0, 0, 0);
-
-        return rc == -ENOSYS ? rc : (((unsigned int) rc) >> 28);
+        register int r0 asm("0") = (fc << 28) | sel1;
+        register int r1 asm("1") = sel2;
+        int rc = 0;
+
+        asm volatile(
+                "       stsi    0(%3)\n"
+                "0:     jz      2f\n"
+                "1:     lhi     %1,%4\n"
+                "2:\n"
+                EX_TABLE(0b, 1b)
+                : "+d" (r0), "+d" (rc)
+                : "d" (r1), "a" (sysinfo), "K" (-EOPNOTSUPP)
+                : "cc", "memory");
+        if (rc)
+                return rc;
+        return fc ? 0 : ((unsigned int) r0) >> 28;
 }
+EXPORT_SYMBOL(stsi);
 
 static void stsi_1_1_1(struct seq_file *m, struct sysinfo_1_1_1 *info)
 {
         int i;
 
-        if (stsi(info, 1, 1, 1) == -ENOSYS)
+        if (stsi(info, 1, 1, 1))
                 return;
         EBCASC(info->manufacturer, sizeof(info->manufacturer));
         EBCASC(info->type, sizeof(info->type));
@@ -97,7 +117,8 @@ static void stsi_15_1_x(struct seq_file *m, struct sysinfo_15_1_x *info)
         seq_putc(m, '\n');
         if (!MACHINE_HAS_TOPOLOGY)
                 return;
-        stsi(info, 15, 1, topology_max_mnest);
+        if (stsi(info, 15, 1, topology_max_mnest))
+                return;
         seq_printf(m, "CPU Topology HW:     ");
         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
                 seq_printf(m, " %d", info->mag[i]);
@@ -116,7 +137,7 @@ static void stsi_1_2_2(struct seq_file *m, struct sysinfo_1_2_2 *info)
         struct sysinfo_1_2_2_extension *ext;
         int i;
 
-        if (stsi(info, 1, 2, 2) == -ENOSYS)
+        if (stsi(info, 1, 2, 2))
                 return;
         ext = (struct sysinfo_1_2_2_extension *)
                 ((unsigned long) info + info->acc_offset);
@@ -152,7 +173,7 @@ static void stsi_1_2_2(struct seq_file *m, struct sysinfo_1_2_2 *info)
 
 static void stsi_2_2_2(struct seq_file *m, struct sysinfo_2_2_2 *info)
 {
-        if (stsi(info, 2, 2, 2) == -ENOSYS)
+        if (stsi(info, 2, 2, 2))
                 return;
         EBCASC(info->name, sizeof(info->name));
         seq_putc(m, '\n');
@@ -179,7 +200,7 @@ static void stsi_3_2_2(struct seq_file *m, struct sysinfo_3_2_2 *info)
 {
         int i;
 
-        if (stsi(info, 3, 2, 2) == -ENOSYS)
+        if (stsi(info, 3, 2, 2))
                 return;
         for (i = 0; i < info->count; i++) {
                 EBCASC(info->vm[i].name, sizeof(info->vm[i].name));
@@ -202,7 +223,7 @@ static int sysinfo_show(struct seq_file *m, void *v)
 
         if (!info)
                 return 0;
-        level = stsi_0();
+        level = stsi(NULL, 0, 0, 0);
         if (level >= 1)
                 stsi_1_1_1(m, info);
         if (level >= 1)
@@ -365,7 +386,7 @@ void s390_adjust_jiffies(void)
         if (!info)
                 return;
 
-        if (stsi(info, 1, 2, 2) != -ENOSYS) {
+        if (stsi(info, 1, 2, 2) == 0) {
                 /*
                  * Major sigh. The cpu capability encoding is "special".
                  * If the first 9 bits of info->capability are 0 then it