crypto: ccp - Add a module parameter to specify a queue count

Add a module parameter to limit the number of queues per CCP. The default
value (nqueues=0) is to set up every available queue on each device.

The count of queues starts from the first one found on the device (which
varies based on the device ID).

Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccp/ccp-dev-v3.c

@@ -379,7 +379,7 @@ static int ccp_init(struct ccp_device *ccp)
 	/* Find available queues */
 	ccp->qim = 0;
 	qmr = ioread32(ccp->io_regs + Q_MASK_REG);
-	for (i = 0; i < MAX_HW_QUEUES; i++) {
+	for (i = 0; (i < MAX_HW_QUEUES) && (ccp->cmd_q_count < ccp->max_q_count); i++) {
 		if (!(qmr & (1 << i)))
 			continue;
 

drivers/crypto/ccp/ccp-dev-v5.c

@@ -2,16 +2,14 @@
 /*
  * AMD Cryptographic Coprocessor (CCP) driver
  *
- * Copyright (C) 2016,2017 Advanced Micro Devices, Inc.
+ * Copyright (C) 2016,2019 Advanced Micro Devices, Inc.
  *
  * Author: Gary R Hook <gary.hook@amd.com>
  */
 
-#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/kthread.h>
-#include <linux/debugfs.h>
 #include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include <linux/compiler.h>
@@ -792,8 +790,7 @@ static int ccp5_init(struct ccp_device *ccp)
 
 	/* Find available queues */
 	qmr = ioread32(ccp->io_regs + Q_MASK_REG);
-	for (i = 0; i < MAX_HW_QUEUES; i++) {
-
+	for (i = 0; (i < MAX_HW_QUEUES) && (ccp->cmd_q_count < ccp->max_q_count); i++) {
 		if (!(qmr & (1 << i)))
 			continue;
 

drivers/crypto/ccp/ccp-dev.c

@@ -8,6 +8,7 @@
  * Author: Gary R Hook <gary.hook@amd.com>
  */
 
+#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/kthread.h>
 #include <linux/sched.h>
@@ -26,6 +27,11 @@
 
 #include "ccp-dev.h"
 
+/* Limit CCP use to a specifed number of queues per device */
+static unsigned int nqueues = 0;
+module_param(nqueues, uint, 0444);
+MODULE_PARM_DESC(nqueues, "Number of queues per CCP (minimum 1; default: all available)");
+
 struct ccp_tasklet_data {
 	struct completion completion;
 	struct ccp_cmd *cmd;
@@ -592,6 +598,11 @@ int ccp_dev_init(struct sp_device *sp)
 		goto e_err;
 	sp->ccp_data = ccp;
 
+	if (!nqueues || (nqueues > MAX_HW_QUEUES))
+		ccp->max_q_count = MAX_HW_QUEUES;
+	else
+		ccp->max_q_count = nqueues;
+
 	ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata;
 	if (!ccp->vdata || !ccp->vdata->version) {
 		ret = -ENODEV;

drivers/crypto/ccp/ccp-dev.h

@@ -379,6 +379,7 @@ struct ccp_device {
 	 */
 	struct ccp_cmd_queue cmd_q[MAX_HW_QUEUES];
 	unsigned int cmd_q_count;
+	unsigned int max_q_count;
 
 	/* Support for the CCP True RNG
 	 */