Provide the ability to constrain the total number of enabled devices in
the system. Once maxdev devices have been configured, additional
devices are ignored.
Signed-off-by: Gary R Hook <gary.hook@xxxxxxx>
---
drivers/crypto/ccp/sp-pci.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/crypto/ccp/sp-pci.c b/drivers/crypto/ccp/sp-pci.c
index c167c4671f45..b81493810689 100644
--- a/drivers/crypto/ccp/sp-pci.c
+++ b/drivers/crypto/ccp/sp-pci.c
@@ -36,6 +36,13 @@
/*
* Limit CCP use to a specifed number of queues per device.
*/
+
+static struct mutex devcount_mutex ____cacheline_aligned;
+static unsigned int devcount = 0;
+static unsigned int maxdev = 0;
+module_param(maxdev, uint, 0444);
+MODULE_PARM_DESC(maxdev, "Total number of devices to register");
+
static unsigned int nqueues = MAX_HW_QUEUES;
module_param(nqueues, uint, 0444);
MODULE_PARM_DESC(nqueues, "Number of queues per CCP (default: 5)");
@@ -193,6 +200,9 @@ static int sp_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
int bar_mask;
int ret;
+ if (maxdev && (devcount >= maxdev)) /* Too many devices? */
+ return 0;
+
ret = -ENOMEM;
sp = sp_alloc_struct(dev);
if (!sp)
@@ -261,6 +271,11 @@ static int sp_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
if (ret)
goto e_err;
+ /* Increase count of devices */
+ mutex_lock(&devcount_mutex);
+ devcount++;
+ mutex_unlock(&devcount_mutex);
+
return 0;
e_err:
@@ -374,6 +389,7 @@ static struct pci_driver sp_pci_driver = {
int sp_pci_init(void)
{
+ mutex_init(&devcount_mutex);
return pci_register_driver(&sp_pci_driver);
}
