[PATCH] s390/pkey: fix paes selftest failure with paes and pkey static build

[Harald Freudenberger <freude@xxxxxxxxxxxxx>]

When both the paes and the pkey kernel module are statically build
into the kernel, the paes cipher selftests run before the pkey
kernel module is initialized. So a static variable set in the pkey
init function and used in the pkey_clr2protkey function is not
initialized when the paes cipher's selftests request to call pckmo for
transforming a clear key value into a protected key.

This patch moves the initial setup of the static variable into
the function pck_clr2protkey. So it's possible, to use the function
for transforming a clear to a protected key even before the pkey
init function has been called and the paes selftests may run
successful.

Signed-off-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>
Reported-by: Alexander Egorenkov <Alexander.Egorenkov@xxxxxxx>
Cc: Stable <stable@xxxxxxxxxxxxxxx>
---
 drivers/s390/crypto/pkey_api.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/s390/crypto/pkey_api.c b/drivers/s390/crypto/pkey_api.c
index 490917cd44d0..5f75c9dfe071 100644
--- a/drivers/s390/crypto/pkey_api.c
+++ b/drivers/s390/crypto/pkey_api.c
@@ -34,9 +34,6 @@ MODULE_DESCRIPTION("s390 protected key interface");
 #define KEYBLOBBUFSIZE 8192  /* key buffer size used for internal processing */
 #define MAXAPQNSINLIST 64    /* max 64 apqns within a apqn list */
 
-/* mask of available pckmo subfunctions, fetched once at module init */
-static cpacf_mask_t pckmo_functions;
-
 /*
  * debug feature data and functions
  */
@@ -90,6 +87,9 @@ static int pkey_clr2protkey(u32 keytype,
 			    const struct pkey_clrkey *clrkey,
 			    struct pkey_protkey *protkey)
 {
+	/* mask of available pckmo subfunctions */
+	static cpacf_mask_t pckmo_functions;
+
 	long fc;
 	int keysize;
 	u8 paramblock[64];
@@ -113,11 +113,13 @@ static int pkey_clr2protkey(u32 keytype,
 		return -EINVAL;
 	}
 
-	/*
-	 * Check if the needed pckmo subfunction is available.
-	 * These subfunctions can be enabled/disabled by customers
-	 * in the LPAR profile or may even change on the fly.
-	 */
+	/* did we already check for PCKMO ? */
+	if (!pckmo_functions.bytes[0]) {
+		/* no, so check now */
+		if (!cpacf_query(CPACF_PCKMO, &pckmo_functions))
+			return -ENODEV;
+	}
+	/* check for the pckmo subfunction we need now */
 	if (!cpacf_test_func(&pckmo_functions, fc)) {
 		DEBUG_ERR("%s pckmo functions not available\n", __func__);
 		return -ENODEV;
@@ -1853,7 +1855,7 @@ static struct miscdevice pkey_dev = {
  */
 static int __init pkey_init(void)
 {
-	cpacf_mask_t kmc_functions;
+	cpacf_mask_t func_mask;
 
 	/*
 	 * The pckmo instruction should be available - even if we don't
@@ -1861,15 +1863,15 @@ static int __init pkey_init(void)
 	 * is also the minimum level for the kmc instructions which
 	 * are able to work with protected keys.
 	 */
-	if (!cpacf_query(CPACF_PCKMO, &pckmo_functions))
+	if (!cpacf_query(CPACF_PCKMO, &func_mask))
 		return -ENODEV;
 
 	/* check for kmc instructions available */
-	if (!cpacf_query(CPACF_KMC, &kmc_functions))
+	if (!cpacf_query(CPACF_KMC, &func_mask))
 		return -ENODEV;
-	if (!cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_128) ||
-	    !cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_192) ||
-	    !cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_256))
+	if (!cpacf_test_func(&func_mask, CPACF_KMC_PAES_128) ||
+	    !cpacf_test_func(&func_mask, CPACF_KMC_PAES_192) ||
+	    !cpacf_test_func(&func_mask, CPACF_KMC_PAES_256))
 		return -ENODEV;
 
 	pkey_debug_init();
-- 
2.17.1