[kvm-unit-tests PATCH v7 1/3] s390x: Give name to return value of tprot()

[Janis Schoetterl-Glausch <scgl@linux.ibm.com>]

Improve readability by making the return value of tprot() an enum.

No functional change intended.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/asm/arch_def.h | 11 +++++++++--
 lib/s390x/sclp.c         |  6 +++---
 s390x/tprot.c            | 24 ++++++++++++------------
 3 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index bab3c374..46c370e6 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -228,7 +228,14 @@ static inline uint64_t stidp(void)
 	return cpuid;
 }
 
-static inline int tprot(unsigned long addr, char access_key)
+enum tprot_permission {
+	TPROT_READ_WRITE = 0,
+	TPROT_READ = 1,
+	TPROT_RW_PROTECTED = 2,
+	TPROT_TRANSL_UNAVAIL = 3,
+};
+
+static inline enum tprot_permission tprot(unsigned long addr, char access_key)
 {
 	int cc;
 
@@ -237,7 +244,7 @@ static inline int tprot(unsigned long addr, char access_key)
 		"	ipm	%0\n"
 		"	srl	%0,28\n"
 		: "=d" (cc) : "a" (addr), "a" (access_key << 4) : "cc");
-	return cc;
+	return (enum tprot_permission)cc;
 }
 
 static inline void lctlg(int cr, uint64_t value)
diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
index 33985eb4..b8204c5f 100644
--- a/lib/s390x/sclp.c
+++ b/lib/s390x/sclp.c
@@ -198,7 +198,7 @@ int sclp_service_call(unsigned int command, void *sccb)
 void sclp_memory_setup(void)
 {
 	uint64_t rnmax, rnsize;
-	int cc;
+	enum tprot_permission permission;
 
 	assert(read_info);
 
@@ -222,9 +222,9 @@ void sclp_memory_setup(void)
 	/* probe for r/w memory up to max memory size */
 	while (ram_size < max_ram_size) {
 		expect_pgm_int();
-		cc = tprot(ram_size + storage_increment_size - 1, 0);
+		permission = tprot(ram_size + storage_increment_size - 1, 0);
 		/* stop once we receive an exception or have protected memory */
-		if (clear_pgm_int() || cc != 0)
+		if (clear_pgm_int() || permission != TPROT_READ_WRITE)
 			break;
 		ram_size += storage_increment_size;
 	}
diff --git a/s390x/tprot.c b/s390x/tprot.c
index 460a0db7..8eb91c18 100644
--- a/s390x/tprot.c
+++ b/s390x/tprot.c
@@ -20,26 +20,26 @@ static uint8_t pagebuf[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
 
 static void test_tprot_rw(void)
 {
-	int cc;
+	enum tprot_permission permission;
 
 	report_prefix_push("Page read/writeable");
 
-	cc = tprot((unsigned long)pagebuf, 0);
-	report(cc == 0, "CC = 0");
+	permission = tprot((unsigned long)pagebuf, 0);
+	report(permission == TPROT_READ_WRITE, "CC = 0");
 
 	report_prefix_pop();
 }
 
 static void test_tprot_ro(void)
 {
-	int cc;
+	enum tprot_permission permission;
 
 	report_prefix_push("Page readonly");
 
 	protect_dat_entry(pagebuf, PAGE_ENTRY_P, 5);
 
-	cc = tprot((unsigned long)pagebuf, 0);
-	report(cc == 1, "CC = 1");
+	permission = tprot((unsigned long)pagebuf, 0);
+	report(permission == TPROT_READ, "CC = 1");
 
 	unprotect_dat_entry(pagebuf, PAGE_ENTRY_P, 5);
 
@@ -48,28 +48,28 @@ static void test_tprot_ro(void)
 
 static void test_tprot_low_addr_prot(void)
 {
-	int cc;
+	enum tprot_permission permission;
 
 	report_prefix_push("low-address protection");
 
 	low_prot_enable();
-	cc = tprot(0, 0);
+	permission = tprot(0, 0);
 	low_prot_disable();
-	report(cc == 1, "CC = 1");
+	report(permission == TPROT_READ, "CC = 1");
 
 	report_prefix_pop();
 }
 
 static void test_tprot_transl_unavail(void)
 {
-	int cc;
+	enum tprot_permission permission;
 
 	report_prefix_push("Page translation unavailable");
 
 	protect_dat_entry(pagebuf, PAGE_ENTRY_I, 5);
 
-	cc = tprot((unsigned long)pagebuf, 0);
-	report(cc == 3, "CC = 3");
+	permission = tprot((unsigned long)pagebuf, 0);
+	report(permission == TPROT_TRANSL_UNAVAIL, "CC = 3");
 
 	unprotect_dat_entry(pagebuf, PAGE_ENTRY_I, 5);
 
-- 
2.33.1