crypto: nx - prevent nx 842 load if no hw driver
Change the nx-842 common driver to wait for loading of both platform
drivers, and fail loading if the platform driver pointer is not set.
Add an independent platform driver pointer, that the platform drivers
set if they find they are able to load (i.e. if they find their platform
devicetree node(s)).
The problem is currently, the main nx-842 driver will stay loaded even
if there is no platform driver and thus no possible way it can do any
compression or decompression. This allows the crypto 842-nx driver
to load even if it won't actually work. For crypto compression users
(e.g. zswap) that expect an available crypto compression driver to
actually work, this is bad. This patch fixes that, so the 842-nx crypto
compression driver won't load if it doesn't have the driver and hardware
available to perform the compression.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/nx/nx-842-pseries.c b/drivers/crypto/nx/nx-842-pseries.c
index 85837e9..17f1917 100644
--- a/drivers/crypto/nx/nx-842-pseries.c
+++ b/drivers/crypto/nx/nx-842-pseries.c
@@ -26,7 +26,6 @@
#include "nx-842.h"
#include "nx_csbcpb.h" /* struct nx_csbcpb */
-#define MODULE_NAME NX842_PSERIES_MODULE_NAME
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Robert Jennings <rcj@linux.vnet.ibm.com>");
MODULE_DESCRIPTION("842 H/W Compression driver for IBM Power processors");
@@ -965,6 +964,7 @@
};
static struct nx842_driver nx842_pseries_driver = {
+ .name = KBUILD_MODNAME,
.owner = THIS_MODULE,
.constraints = &nx842_pseries_constraints,
.compress = nx842_pseries_compress,
@@ -1033,8 +1033,6 @@
goto error;
}
- nx842_register_driver(&nx842_pseries_driver);
-
return 0;
error_unlock:
@@ -1066,18 +1064,16 @@
kfree(old_devdata->counters);
kfree(old_devdata);
- nx842_unregister_driver(&nx842_pseries_driver);
-
return 0;
}
static struct vio_device_id nx842_vio_driver_ids[] = {
- {NX842_PSERIES_COMPAT_NAME "-v1", NX842_PSERIES_COMPAT_NAME},
+ {"ibm,compression-v1", "ibm,compression"},
{"", ""},
};
static struct vio_driver nx842_vio_driver = {
- .name = MODULE_NAME,
+ .name = KBUILD_MODNAME,
.probe = nx842_probe,
.remove = __exit_p(nx842_remove),
.get_desired_dma = nx842_get_desired_dma,
@@ -1087,10 +1083,15 @@
static int __init nx842_init(void)
{
struct nx842_devdata *new_devdata;
+ int ret;
+
pr_info("Registering IBM Power 842 compression driver\n");
BUILD_BUG_ON(sizeof(struct nx842_workmem) > NX842_MEM_COMPRESS);
+ if (!of_find_compatible_node(NULL, NULL, "ibm,compression"))
+ return -ENODEV;
+
RCU_INIT_POINTER(devdata, NULL);
new_devdata = kzalloc(sizeof(*new_devdata), GFP_KERNEL);
if (!new_devdata) {
@@ -1100,7 +1101,21 @@
new_devdata->status = UNAVAILABLE;
RCU_INIT_POINTER(devdata, new_devdata);
- return vio_register_driver(&nx842_vio_driver);
+ ret = vio_register_driver(&nx842_vio_driver);
+ if (ret) {
+ pr_err("Could not register VIO driver %d\n", ret);
+
+ kfree(new_devdata);
+ return ret;
+ }
+
+ if (!nx842_platform_driver_set(&nx842_pseries_driver)) {
+ vio_unregister_driver(&nx842_vio_driver);
+ kfree(new_devdata);
+ return -EEXIST;
+ }
+
+ return 0;
}
module_init(nx842_init);
@@ -1111,6 +1126,7 @@
unsigned long flags;
pr_info("Exiting IBM Power 842 compression driver\n");
+ nx842_platform_driver_unset(&nx842_pseries_driver);
spin_lock_irqsave(&devdata_mutex, flags);
old_devdata = rcu_dereference_check(devdata,
lockdep_is_held(&devdata_mutex));
@@ -1120,7 +1136,6 @@
if (old_devdata && old_devdata->dev)
dev_set_drvdata(old_devdata->dev, NULL);
kfree(old_devdata);
- nx842_unregister_driver(&nx842_pseries_driver);
vio_unregister_driver(&nx842_vio_driver);
}