Use unified device properties API in meaningful way.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Since we got rid of platform data, the driver may use GPIO descriptor
directly.
Looking deeply to the use of the GPIO pin it looks like it should be
a GPIO based reset control rather than custom GPIO handling. But this
is out of scope of the change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
I2C and SPI frameworks followed by IRQ framework do set
interrupt polarity correctly if it's properly specified in firmware
(ACPI or DT).
Get rid of the redundant trick when requesting interrupt.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Legacy platform data must go away. We are on the safe side here since
there are no users of it in the kernel.
If anyone by any odd reason needs it the GPIO lookup tables and
built-in device properties at your service.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In order to make GPIO ACPI library stricter prepare users of
gpiod_get_index() to correctly behave when there no mapping is
provided by firmware.
Here we add explicit mapping between _CRS GpioIo() resources and
their names used in the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
It looks like there are two leftovers, at least one of which can leak
the resource (IRQ).
Convert both places to use managed variants of the functions.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
There is no platform code that uses i2c module table.
Remove it altogether and adjust ->probe() to be ->probe_new().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Since OF and ACPI case almost the same get rid of code duplication
by moving gpiod_get() calls directly to ->probe().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In order to make GPIO ACPI library stricter prepare users of
gpiod_get_index() to correctly behave when there no mapping is
provided by firmware.
Here we add explicit mapping between _CRS GpioIo() resources and
their names used in the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Switch to use managed variant of acpi_dev_add_driver_gpios() to simplify
error path and fix potentially wrong assignment if ->probe() fails.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Allow gpio 0 to be used for reset signalling, and instead use negative
errnos to disable the reset functionality.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Use the USB-interface rather than parent USB-device device, which is
what this driver binds to, when registering the nci device.
Note that using the right device is important when dealing with device-
managed resources as the interface can be unbound independently of the
parent device.
Also note that private device pointer had already been set by
nfcmrvl_nci_register_dev() so the redundant assignment can therefore be
removed.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Make sure to release the device-node reference when done parsing the
node.
Fixes: e097dc624f ("NFC: nfcmrvl: add UART driver")
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The nci-device was never deregistered in the event that
fw-initialisation failed.
Fix this by moving the firmware initialisation before device
registration since the firmware work queue should be available before
registering.
Note that this depends on a recent fix that moved device-name
initialisation back to to nci_allocate_device() as the
firmware-workqueue name is now derived from the nfc-device name.
Fixes: 3194c68701 ("NFC: nfcmrvl: add firmware download support")
Cc: stable <stable@vger.kernel.org> # 4.4
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Use the nfc- rather than phy-device in firmware-management code that
needs a valid struct device.
This specifically fixes a NULL-pointer dereference in
nfcmrvl_fw_dnld_init() during registration when the underlying tty is
one end of a Unix98 pty.
Note that the driver still uses the phy device for any debugging, which
is fine for now.
Fixes: 3194c68701 ("NFC: nfcmrvl: add firmware download support")
Cc: stable <stable@vger.kernel.org> # 4.4
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This specifically fixes resource leaks in the registration error paths.
Device-managed resources is a bad fit for this driver as devices can be
registered from the n_nci line discipline. Firstly, a tty may not even
have a corresponding device (should it be part of a Unix98 pty)
something which would lead to a NULL-pointer dereference when
registering resources.
Secondly, if the tty has a class device, its lifetime exceeds that of
the line discipline, which means that resources would leak every time
the line discipline is closed (or if registration fails).
Currently, the devres interface was only being used to request a reset
gpio despite the fact that it was already explicitly freed in
nfcmrvl_nci_unregister_dev() (along with the private data), something
which also prevented the resource leak at close.
Note that the driver treats gpio number 0 as invalid despite it being
perfectly valid. This will be addressed in a follow-up patch.
Fixes: b2fe288eac ("NFC: nfcmrvl: free reset gpio")
Fixes: 4a2b947f56 ("NFC: nfcmrvl: add chip reset management")
Cc: stable <stable@vger.kernel.org> # 4.2: b2fe288eac
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Make sure to check the tty-device pointer before trying to access the
parent device to avoid dereferencing a NULL-pointer when the tty is one
end of a Unix98 pty.
Fixes: e097dc624f ("NFC: nfcmrvl: add UART driver")
Cc: stable <stable@vger.kernel.org> # 4.2
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Commit 7eda8b8e96 ("NFC: Use IDR library to assing NFC devices IDs")
moved device-id allocation and struct-device initialisation from
nfc_allocate_device() to nfc_register_device().
This broke just about every nfc-device-registration error path, which
continue to call nfc_free_device() that tries to put the device
reference of the now uninitialised (but zeroed) struct device:
kobject: '(null)' (ce316420): is not initialized, yet kobject_put() is being called.
The late struct-device initialisation also meant that various work
queues whose names are derived from the nfc device name were also
misnamed:
421 root 0 SW< [(null)_nci_cmd_]
422 root 0 SW< [(null)_nci_rx_w]
423 root 0 SW< [(null)_nci_tx_w]
Move the id-allocation and struct-device initialisation back to
nfc_allocate_device() and fix up the single call site which did not use
nfc_free_device() in its error path.
Fixes: 7eda8b8e96 ("NFC: Use IDR library to assing NFC devices IDs")
Cc: stable <stable@vger.kernel.org> # 3.8
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Clean up coding style issues according to scripts/Lindent.
Some scripts/Lindent changes were reverted when it appeared
to make the code less readable or when it made the line run
over 80 characters.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The trf7970a driver uses the deprecated integer-based GPIO consumer
interface so convert it to use the new descriptor-based GPIO
consumer interface.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The example DTS code for the trf7970a sets the GPIOs for the EN
and EN2 pins to active low when they are really active high so
correct the error.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The 'vin-voltage-override' DT property is used by the trf7970a
driver to override the voltage presented to the driver by the
regulator subsystem. This is unnecessary as properly specifying
the regulator chain via DT properties will accomplish the same
thing. Therefore, remove support for 'vin-voltage-override'.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The last entry in the trf7970a_of_match[] table must be an empty
entry to demarcate the end of the table. Currently, there is a
comment indicating this but it is obvious so remove the comment.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The quirk indicated by the 'en2-rf-quirk' device tree property
is only relevant when there is a GPIO connected to the EN2 pin
of the trf7970a. This means we should only check for 'en2-rf-quirk'
when EN2 is specified in the 'ti,enable-gpios' property of the
device tree.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
As of commit ce69b95ca4 ("NFC: Make EN2 pin optional in the
TRF7970A driver"), only the GPIO for the 'EN' enable pin needs
to be specified in the device tree so update the comments that
says both 'EN' and 'EN2' must be specified.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When the trf7970a part has the bug related to 'en2-rf-quirk',
the GPIO connected to the EN2 pin will not be asserted by the
driver when powering up so it shouldn't be de-asserted when
powering down.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Add Mark Greer as the maintainer of the trf7970a NFC driver.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
After commit 6d3c8c0dd8 ("net: dsa: Remove master_netdev and
use dst->cpu_dp->netdev") and a29342e739 ("net: dsa: Associate
slave network device with CPU port") we would be seeing NULL pointer
dereferences when accessing dst->cpu_dp->netdev too early. In the legacy
code, we actually know early in advance the master network device, so
pass it down to the relevant functions.
Fixes: 6d3c8c0dd8 ("net: dsa: Remove master_netdev and use dst->cpu_dp->netdev")
Fixes: a29342e739 ("net: dsa: Associate slave network device with CPU port")
Reported-by: Jason Cobham <jcobham@questertangent.com>
Tested-by: Jason Cobham <jcobham@questertangent.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Missing crypto deps for some platforms.
Default to n for new module.
config: m68k-amcore_defconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 4.9.0
make.cross ARCH=m68k
All errors (new ones prefixed by >>):
net/built-in.o: In function `tls_set_sw_offload':
>> (.text+0x732f8): undefined reference to `crypto_alloc_aead'
net/built-in.o: In function `tls_set_sw_offload':
>> (.text+0x7333c): undefined reference to `crypto_aead_setkey'
net/built-in.o: In function `tls_set_sw_offload':
>> (.text+0x73354): undefined reference to `crypto_aead_setauthsize'
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Wei Wang says:
====================
remove dst garbage collector logic
The current mechanism of dst release is a bit complicated. It is because
the users of dst get divided into 2 situations:
1. Most users take the reference count when using a dst and release the
reference count when done.
2. Exceptional users like IPv4/IPv6/decnet/xfrm routing code do not take
reference count when referencing to a dst due to some histotic reasons.
Due to those exceptional use cases in 2, reference count being 0 is not an
adequate evidence to indicate that no user is using this dst. So users in 1
can't free the dst simply based on reference count being 0 because users in
2 might still hold reference to it.
Instead, a dst garbage list is needed to hold the dst entries that already
get removed by the users in 2 but are still held by users in 1. And a periodic
garbage collector task is run to check all the dst entries in the list to see
if the users in 1 have released the reference to those dst entries.
If so, the dst is now ready to be freed.
This logic introduces unnecessary complications in the dst code which makes it
hard to understand and to debug.
In order to get rid of the whole dst garbage collector (gc) and make the dst
code more unified and simplified, we can make the users in 2 also take reference
count on the dst and release it properly when done.
This way, dst can be safely freed once the refcount drops to 0 and no gc
thread is needed anymore.
This patch series' target is to completely get rid of dst gc logic and free
dst based on reference count only.
Patch 1-3 are preparation patches to do some cleanup/improvement on the existing
code to make later work easier.
Patch 4-21 are real implementations.
In these patches, a temporary flag DST_NOGC is used to help transition
those exceptional users one by one. Once every component is transitioned,
this temporary flag is removed.
By the end of this patch series, all dst are refcounted when being used
and released when done. And dst will be freed when its refcount drops to 0.
No dst gc task is running anymore.
Note: This patch series depends on the decnet fix that was sent right before:
"decnet: always not take dst->__refcnt when inserting dst into hash table"
v2:
add curly braces in udp_v4/6_early_demux() in patch 02
add EXPORT_SYMBOL() for dst_dev_put() in patch 05
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is meant to add a debug warning on the situation where dst is
being held during its destroy phase. This could potentially cause double
free issue on the dst.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As some dst flags are removed, reorder the dst flags to fill in the
blanks.
Note: these flags are not exposed into user space. So it is safe to
reorder.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
DST_NOCACHE flag check has been removed from dst_release() and
dst_hold_safe() in a previous patch because all the dst are now ref
counted properly and can be released based on refcnt only.
Looking at the rest of the DST_NOCACHE use, all of them can now be
removed or replaced with other checks.
So this patch gets rid of all the DST_NOCACHE usage and remove this flag
completely.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that all the components have been changed to release dst based on
refcnt only and not depend on dst gc anymore, we can remove the
temporary flag DST_NOGC.
Note that we also need to remove the DST_NOCACHE check in dst_release()
and dst_hold_safe() because now all the dst are released based on refcnt
and behaves as DST_NOCACHE.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes all dst gc related code and all the dst free
functions
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct dn_route is inserted into dn_rt_hash_table but no dst->__refcnt
is taken.
This patch makes sure the dn_rt_hash_table's reference to the dst is ref
counted.
As the dst is always ref counted properly, we can safely mark
DST_NOGC flag so dst_release() will release dst based on refcnt only.
And dst gc is no longer needed and all dst_free() or its related
function calls should be replaced with dst_release() or
dst_release_immediate(). And dst_dev_put() is called when removing dst
from the hash table to release the reference on dst->dev before we lose
pointer to it.
Also, correct the logic in dn_dst_check_expire() and dn_dst_gc() to
check dst->__refcnt to be > 1 to indicate it is referenced by other
users.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
During the creation of xfrm_dst bundle, always take ref count when
allocating the dst. This way, xfrm_bundle_create() will form a linked
list of dst with dst->child pointing to a ref counted dst child. And
the returned dst pointer is also ref counted. This makes the link from
the flow cache to this dst now ref counted properly.
As the dst is always ref counted properly, we can safely mark
DST_NOGC flag so dst_release() will release dst based on refcnt only.
And dst gc is no longer needed and all dst_free() and its related
function calls should be replaced with dst_release() or
dst_release_immediate().
The special handling logic for dst->child in dst_destroy() can be
replaced with a simple dst_release_immediate() call on the child to
release the whole list linked by dst->child pointer.
Previously used DST_NOHASH flag is not needed anymore as well. The
reason that DST_NOHASH is used in the existing code is mainly to prevent
the dst inserted in the fib tree to be wrongly destroyed during the
deletion of the xfrm_dst bundle. So in the existing code, DST_NOHASH
flag is marked in all the dst children except the one which is in the
fib tree.
However, with this patch series to remove dst gc logic and release dst
only based on ref count, it is safe to release all the children from a
xfrm_dst bundle as long as the dst children are all ref counted
properly which is already the case in the existing code.
So, this patch removes the use of DST_NOHASH flag.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
icmp6 dst route is currently ref counted during creation and will be
freed by user during its call of dst_release(). So no need of a garbage
collector for it.
Remove all icmp6 dst garbage collector related code.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the previous preparation patches, we are ready to get rid of the
dst gc operation in ipv6 code and release dst based on refcnt only.
So this patch adds DST_NOGC flag for all IPv6 dst and remove the calls
to dst_free() and its related functions.
At this point, all dst created in ipv6 code do not use the dst gc
anymore and will be destroyed at the point when refcnt drops to 0.
Also, as icmp6 dst route is refcounted during creation and will be freed
by user during its call of dst_release(), there is no need to add this
dst to the icmp6 gc list as well.
Instead, we need to add it into uncached list so that when a
NETDEV_DOWN/NETDEV_UNREGISRER event comes, we can properly go through
these icmp6 dst as well and release the net device properly.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar as ipv4, ipv6 path also needs to call dst_hold_safe() when
necessary to avoid double free issue on the dst.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the intend of this patch series is to completely remove dst gc,
we need to call dst_dev_put() to release the reference to dst->dev
when removing routes from fib because we won't keep the gc list anymore
and will lose the dst pointer right after removing the routes.
Without the gc list, there is no way to find all the dst's that have
dst->dev pointing to the going-down dev.
Hence, we are doing dst_dev_put() immediately before we lose the last
reference of the dst from the routing code. The next dst_check() will
trigger a route re-lookup to find another route (if there is any).
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In IPv6 routing code, struct rt6_info is created for each static route
and RTF_CACHE route and inserted into fib6 tree. In both cases, dst
ref count is not taken.
As explained in the previous patch, this leads to the need of the dst
garbage collector.
This patch holds ref count of dst before inserting the route into fib6
tree and properly releases the dst when deleting it from the fib6 tree
as a preparation in order to fully get rid of dst gc later.
Also, correct fib6_age() logic to check dst->__refcnt to be 1 to indicate
no user is referencing the dst.
And remove dst_hold() in vrf_rt6_create() as ip6_dst_alloc() already puts
dst->__refcnt to 1.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the previous preparation patches, we are ready to get rid of the
dst gc operation in ipv4 code and release dst based on refcnt only.
So this patch adds DST_NOGC flag for all IPv4 dst and remove the calls
to dst_free().
At this point, all dst created in ipv4 code do not use the dst gc
anymore and will be destroyed at the point when refcnt drops to 0.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch checks all the calls to
dst_hold()/skb_dst_force()/dst_clone()/dst_use() to see if
dst_hold_safe() is needed to avoid double free issue if dst
gc is removed and dst_release() directly destroys dst when
dst->__refcnt drops to 0.
In tx path, TCP hold sk->sk_rx_dst ref count and also hold sock_lock().
UDP and other similar protocols always hold refcount for
skb->_skb_refdst. So both paths seem to be safe.
In rx path, as it is lockless and skb_dst_set_noref() is likely to be
used, dst_hold_safe() should always be used when trying to hold dst.
In the routing code, if dst is held during an rcu protected session, it
is necessary to call dst_hold_safe() as the current dst might be in its
rcu grace period.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the intend of this patch series is to completely remove dst gc,
we need to call dst_dev_put() to release the reference to dst->dev
when removing routes from fib because we won't keep the gc list anymore
and will lose the dst pointer right after removing the routes.
Without the gc list, there is no way to find all the dst's that have
dst->dev pointing to the going-down dev.
Hence, we are doing dst_dev_put() immediately before we lose the last
reference of the dst from the routing code. The next dst_check() will
trigger a route re-lookup to find another route (if there is any).
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In IPv4 routing code, fib_nh and fib_nh_exception can hold pointers
to struct rtable but they never increment dst->__refcnt.
This leads to the need of the dst garbage collector because when user
is done with this dst and calls dst_release(), it can only decrement
dst->__refcnt and can not free the dst even it sees dst->__refcnt
drops from 1 to 0 (unless DST_NOCACHE flag is set) because the routing
code might still hold reference to it.
And when the routing code tries to delete a route, it has to put the
dst to the gc_list if dst->__refcnt is not yet 0 and have a gc thread
running periodically to check on dst->__refcnt and finally to free dst
when refcnt becomes 0.
This patch increments dst->__refcnt when
fib_nh/fib_nh_exception holds reference to this dst and properly release
the dst when fib_nh/fib_nh_exception has been updated with a new dst.
This patch is a preparation in order to fully get rid of dst gc later.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This function should be called when removing routes from fib tree after
the dst gc is no longer in use.
We first mark DST_OBSOLETE_DEAD on this dst to make sure next
dst_ops->check() fails and returns NULL.
Secondly, as we no longer keep the gc_list, we need to properly
release dst->dev right at the moment when the dst is removed from
the fib/fib6 tree.
It does the following:
1. change dst->input and output pointers to dst_discard/dst_dscard_out to
discard all packets
2. replace dst->dev with loopback interface
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current mechanism of freeing dst is a bit complicated. dst has its
ref count and when user grabs the reference to the dst, the ref count is
properly taken in most cases except in IPv4/IPv6/decnet/xfrm routing
code due to some historic reasons.
If the reference to dst is always taken properly, we should be able to
simplify the logic in dst_release() to destroy dst when dst->__refcnt
drops from 1 to 0. And this should be the only condition to determine
if we can call dst_destroy().
And as dst is always ref counted, there is no need for a dst garbage
list to hold the dst entries that already get removed by the routing
code but are still held by other users. And the task to periodically
check the list to free dst if ref count become 0 is also not needed
anymore.
This patch introduces a temporary flag DST_NOGC(no garbage collector).
If it is set in the dst, dst_release() will call dst_destroy() when
dst->__refcnt drops to 0. dst_hold_safe() will also check for this flag
and do atomic_inc_not_zero() similar as DST_NOCACHE to avoid double free
issue.
This temporary flag is mainly used so that we can make the transition
component by component without breaking other parts.
This flag will be removed after all components are properly transitioned.
This patch also introduces a new function dst_release_immediate() which
destroys dst without waiting on the rcu when refcnt drops to 0. It will
be used in later patches.
Follow-up patches will correct all the places to properly take ref count
on dst and mark DST_NOGC. dst_release() or dst_release_immediate() will
be used to release the dst instead of dst_free() and its related
functions.
And final clean-up patch will remove the DST_NOGC flag.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Existing ipv4/6_blackhole_route() code generates a blackhole route
with dst->dev pointing to the passed in dst->dev.
It is not necessary to hold reference to the passed in dst->dev
because the packets going through this route are dropped anyway.
A loopback interface is good enough so that we don't need to worry about
releasing this dst->dev when this dev is going down.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In udp_v4/6_early_demux() code, we try to hold dst->__refcnt for
dst with DST_NOCACHE flag. This is because later in udp_sk_rx_dst_set()
function, we will try to cache this dst in sk for connected case.
However, a better way to achieve this is to not try to hold dst in
early_demux(), but in udp_sk_rx_dst_set(), call dst_hold_safe(). This
approach is also more consistant with how tcp is handling it. And it
will make later changes simpler.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Andy Shevchenko