crypto/nx: Enable and setup GZIP compression type

Changes to probe GZIP device-tree nodes, open RX windows and setup
GZIP compression type. No plans to provide GZIP usage in kernel right
now, but this patch enables GZIP for user space usage.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587114624.2275.1129.camel@hbabu-laptop

drivers/crypto/nx/nx-common-powernv.c

@@ -65,6 +65,7 @@ static unsigned int nx842_ct;	/* used in icswx function */
  * Using same values as in skiboot or coprocessor type representing
  * in NX workbook.
  */
+#define NX_CT_GZIP	(2)	/* on P9 and later */
 #define NX_CT_842	(3)
 
 static int (*nx842_powernv_exec)(const unsigned char *in,
@@ -819,6 +820,9 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
 	if (type == NX_CT_842)
 		ret = nx_set_ct(coproc, priority, VAS_COP_TYPE_842_HIPRI,
 			VAS_COP_TYPE_842);
+	else if (type == NX_CT_GZIP)
+		ret = nx_set_ct(coproc, priority, VAS_COP_TYPE_GZIP_HIPRI,
+				VAS_COP_TYPE_GZIP);
 
 	if (ret)
 		goto err_out;
@@ -867,12 +871,16 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
 	return ret;
 }
 
-static int __init nx_coproc_init(int chip_id, int ct_842)
+static int __init nx_coproc_init(int chip_id, int ct_842, int ct_gzip)
 {
 	int ret = 0;
 
 	if (opal_check_token(OPAL_NX_COPROC_INIT)) {
 		ret = opal_nx_coproc_init(chip_id, ct_842);
+
+		if (!ret)
+			ret = opal_nx_coproc_init(chip_id, ct_gzip);
+
 		if (ret) {
 			ret = opal_error_code(ret);
 			pr_err("Failed to initialize NX for chip(%d): %d\n",
@@ -902,8 +910,8 @@ static int __init find_nx_device_tree(struct device_node *dn, int chip_id,
 static int __init nx_powernv_probe_vas(struct device_node *pn)
 {
 	int chip_id, vasid, ret = 0;
+	int ct_842 = 0, ct_gzip = 0;
 	struct device_node *dn;
-	int ct_842 = 0;
 
 	chip_id = of_get_ibm_chip_id(pn);
 	if (chip_id < 0) {
@@ -920,19 +928,24 @@ static int __init nx_powernv_probe_vas(struct device_node *pn)
 	for_each_child_of_node(pn, dn) {
 		ret = find_nx_device_tree(dn, chip_id, vasid, NX_CT_842,
 					"ibm,p9-nx-842", &ct_842);
+
+		if (!ret)
+			ret = find_nx_device_tree(dn, chip_id, vasid,
+				NX_CT_GZIP, "ibm,p9-nx-gzip", &ct_gzip);
+
 		if (ret)
 			return ret;
 	}
 
-	if (!ct_842) {
-		pr_err("NX842 FIFO nodes are missing\n");
+	if (!ct_842 || !ct_gzip) {
+		pr_err("NX FIFO nodes are missing\n");
 		return -EINVAL;
 	}
 
 	/*
 	 * Initialize NX instance for both high and normal priority FIFOs.
 	 */
-	ret = nx_coproc_init(chip_id, ct_842);
+	ret = nx_coproc_init(chip_id, ct_842, ct_gzip);
 
 	return ret;
 }
@@ -1071,11 +1084,23 @@ static __init int nx_compress_powernv_init(void)
 
 		nx842_powernv_exec = nx842_exec_icswx;
 	} else {
+		/*
+		 * Register VAS user space API for NX GZIP so
+		 * that user space can use GZIP engine.
+		 * Using high FIFO priority for kernel requests and
+		 * normal FIFO priority is assigned for userspace.
+		 * 842 compression is supported only in kernel.
+		 */
+		ret = vas_register_coproc_api(THIS_MODULE, VAS_COP_TYPE_GZIP,
+						"nx-gzip");
+
 		/*
 		 * GZIP is not supported in kernel right now.
 		 * So open tx windows only for 842.
 		 */
-		ret = nx_open_percpu_txwins();
+		if (!ret)
+			ret = nx_open_percpu_txwins();
+
 		if (ret) {
 			nx_delete_coprocs();
 			return ret;
@@ -1096,6 +1121,15 @@ module_init(nx_compress_powernv_init);
 
 static void __exit nx_compress_powernv_exit(void)
 {
+	/*
+	 * GZIP engine is supported only in power9 or later and nx842_ct
+	 * is used on power8 (icswx).
+	 * VAS API for NX GZIP is registered during init for user space
+	 * use. So delete this API use for GZIP engine.
+	 */
+	if (!nx842_ct)
+		vas_unregister_coproc_api();
+
 	crypto_unregister_alg(&nx842_powernv_alg);
 
 	nx_delete_coprocs();