When the membase and pci_dev pointer were moved to a new struct in priv,
the actual membase users were left untouched, and they started reading
out arbitrary memory behind the struct instead of registers. This
unfortunately turned the RNG into a constant number generator, depending
on the content of what was at that offset.

To fix this, update geode_rng_data_{read,present}() to also get the
membase via amd_geode_priv, and properly read from the right addresses
again.

Fixes: 9f6ec8dc574e ("hwrng: geode - Fix PCI device refcount leak")
Reported-by: Timur I. Davletshin <timur.davletshin@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217882
Tested-by: Timur I. Davletshin <timur.davletshin@gmail.com>
Suggested-by: Jo-Philipp Wich <jo@mein.io>
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.

If we break for_each_pci_dev() loop with pdev not NULL, we need to call
pci_dev_put() to decrease the reference count. We add a new struct
'amd_geode_priv' to record pointer of the pci_dev and membase, and then
add missing pci_dev_put() for the normal and error path.

Fixes: ef5d862734b8 ("[PATCH] Add Geode HW RNG driver")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Rename module_init & module_exit functions that are named
"mod_init" and "mod_exit" so that they are unique in both the
System.map file and in initcall_debug output instead of showing
up as almost anonymous "mod_init".

This is helpful for debugging and in determining how long certain
module_init calls take to execute.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andres Salomon <dilinger@queued.net>
Cc: linux-geode@lists.infradead.org
Cc: Matt Mackall <mpm@selenic.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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>

In case of error, the function devm_ioremap() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should
be replaced with NULL test.

Fixes: 6e9b5e76882c ("hwrng: geode - Migrate to managed API")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Fix checkpatch.pl warning by changing from asm/io.h to linux/io.h. In
the mean time arrange the includes in alphabetical order.

Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Use devm_ioremap and devm_hwrng_register instead of ioremap and
hwrng_register. This removes error handling code. Also moved code around
by removing goto statements. This improves code readability.

Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

as pr_* macros are more preffered over printk, so printk replaced with corresponding pr_* macros

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>