hwrng: geode - Revert managed API changes

After commit e9afc746299d ("hwrng: geode - Use linux/io.h instead of
asm/io.h") the geode-rng driver uses devres with pci_dev->dev to keep
track of resources, but does not actually register a PCI driver.  This
results in the following issues:

1.  The driver leaks memory because the driver does not attach to a
device.  The driver only uses the PCI device as a reference.   devm_*()
functions will release resources on driver detach, which the geode-rng
driver will never do.  As a result,

2.  The driver cannot be reloaded because there is always a use of the
ioport and region after the first load of the driver.

Revert the changes made by  e9afc746299d ("hwrng: geode - Use linux/io.h
instead of asm/io.h").

Cc: <stable@vger.kernel.org>
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Fixes: 6e9b5e76882c ("hwrng: geode - Migrate to managed API")
Cc: Matt Mackall <mpm@selenic.com>
Cc: Corentin LABBE <clabbe.montjoie@gmail.com>
Cc: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-geode@lists.infradead.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 35 insertions, 15 deletions

diff --git a/drivers/char/hw_random/geode-rng.c b/drivers/char/hw_random/geode-rng.c
index e7a245942029..e1d421a36a13 100644
--- a/drivers/char/hw_random/geode-rng.c
+++ b/drivers/char/hw_random/geode-rng.c
@@ -31,6 +31,9 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 
+
+#define PFX     KBUILD_MODNAME ": "
+
 #define GEODE_RNG_DATA_REG   0x50
 #define GEODE_RNG_STATUS_REG 0x54
 
@@ -82,6 +85,7 @@ static struct hwrng geode_rng = {
 
 static int __init mod_init(void)
 {
+        int err = -ENODEV;
         struct pci_dev *pdev = NULL;
         const struct pci_device_id *ent;
         void __iomem *mem;
@@ -89,27 +93,43 @@ static int __init mod_init(void)
 
         for_each_pci_dev(pdev) {
                 ent = pci_match_id(pci_tbl, pdev);
-                if (ent) {
-                        rng_base = pci_resource_start(pdev, 0);
-                        if (rng_base == 0)
-                                return -ENODEV;
-
-                        mem = devm_ioremap(&pdev->dev, rng_base, 0x58);
-                        if (!mem)
-                                return -ENOMEM;
-                        geode_rng.priv = (unsigned long)mem;
-
-                        pr_info("AMD Geode RNG detected\n");
-                        return devm_hwrng_register(&pdev->dev, &geode_rng);
-                }
+                if (ent)
+                        goto found;
         }
-
         /* Device not found. */
-        return -ENODEV;
+        goto out;
+
+found:
+        rng_base = pci_resource_start(pdev, 0);
+        if (rng_base == 0)
+                goto out;
+        err = -ENOMEM;
+        mem = ioremap(rng_base, 0x58);
+        if (!mem)
+                goto out;
+        geode_rng.priv = (unsigned long)mem;
+
+        pr_info("AMD Geode RNG detected\n");
+        err = hwrng_register(&geode_rng);
+        if (err) {
+                pr_err(PFX "RNG registering failed (%d)\n",
+                       err);
+                goto err_unmap;
+        }
+out:
+        return err;
+
+err_unmap:
+        iounmap(mem);
+        goto out;
 }
 
 static void __exit mod_exit(void)
 {
+        void __iomem *mem = (void __iomem *)geode_rng.priv;
+
+        hwrng_unregister(&geode_rng);
+        iounmap(mem);
 }
 
 module_init(mod_init);