If we spin for a long time in memory reads that (for some reason in
hardware) take a long time, then we'll eventually get messages such
as
watchdog: BUG: soft lockup - CPU#2 stuck for 24s! [kworker/2:2:272]
This is because the reading really does take a very long time, and
we don't schedule, so we're hogging the CPU with this task, at least
if CONFIG_PREEMPT is not set, e.g. with CONFIG_PREEMPT_VOLUNTARY=y.
Previously I misinterpreted the situation and thought that this was
only going to happen if we had interrupts disabled, and then fixed
this (which is good anyway, however), but that didn't always help;
looking at it again now I realized that the spin unlock will only
reschedule if CONFIG_PREEMPT is used.
In order to avoid this issue, change the code to cond_resched() if
we've been spinning for too long here.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Fixes: 04516706bb ("iwlwifi: pcie: limit memory read spin time")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20210115130253.217a9d6a6a12.If964cb582ab0aaa94e81c4ff3b279eaafda0fd3f@changeid
We no longer need code that was introduced to differentiate
between two early versions of 8260.
We can remove this convoluted way to get the hardware version
that was needed because of a bug in the register's
configuration.
Moreover, since we no longer need to access the PRPH
registers, we no longer need to wake up the device,
request ownership, etc...
Remove all that.
This allows us to get the rid of the obsolete comment
about the AUX bus MISC address space which should have
been moved when this code was moved away from here.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201209231352.4a5665ccd8a6.Iff3879405c15758ba661c430e77dc2160ddada1c@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
When we read device memory, we lock a spinlock, write the address we
want to read from the device and then spin in a loop reading the data
in 32-bit quantities from another register.
As the description makes clear, this is rather inefficient, incurring
a PCIe bus transaction for every read. In a typical device today, we
want to read 786k SMEM if it crashes, leading to 192k register reads.
Occasionally, we've seen the whole loop take over 20 seconds and then
triggering the soft lockup detector.
Clearly, it is unreasonable to spin here for such extended periods of
time.
To fix this, break the loop down into an outer and an inner loop, and
break out of the inner loop if more than half a second elapsed. To
avoid too much overhead, check for that only every 128 reads, though
there's no particular reason for that number. Then, unlock and relock
to obtain NIC access again, reprogram the start address and continue.
This will keep (interrupt) latencies on the CPU down to a reasonable
time.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20201022165103.45878a7e49aa.I3b9b9c5a10002915072312ce75b68ed5b3dc6e14@changeid
To avoid duplicating code we need to call iwl_pcie_txq_update_byte_cnt_tbl
function from non bus independent code so make it bus independent.
Used spatch rule
@r1@
struct iwl_trans_pcie *trans_pcie;
@@
(
-trans_pcie->scd_bc_tbls
+trans->txqs.scd_bc_tbls
|
-iwl_pcie_txq_update_byte_cnt_tbl
+iwl_txq_gen1_update_byte_cnt_tbl
|
-iwl_pcie_txq_inval_byte_cnt_tbl
+iwl_txq_gen1_inval_byte_cnt_tbl
|
-iwl_pcie_tfd_unmap
+iwl_txq_gen1_tfd_unmap
|
-iwl_pcie_tfd_tb_get_addr
+iwl_txq_gen1_tfd_tb_get_addr
|
-iwl_pcie_tfd_tb_get_len
+iwl_txq_gen1_tfd_tb_get_len
|
-iwl_pcie_tfd_get_num_tbs
+iwl_txq_gen1_tfd_get_num_tbs
)
/* clean all new unused variables */
@ depends on r1@
type T;
identifier i;
expression E;
@@
- T i = E;
... when != i
Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200930191738.8d33e791ec8c.Ica35125ed640aa3aa1ecc38fb5e8f1600caa8df6@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
As said by Linus:
A symmetric naming is only helpful if it implies symmetries in use.
Otherwise it's actively misleading.
In "kzalloc()", the z is meaningful and an important part of what the
caller wants.
In "kzfree()", the z is actively detrimental, because maybe in the
future we really _might_ want to use that "memfill(0xdeadbeef)" or
something. The "zero" part of the interface isn't even _relevant_.
The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.
Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.
The renaming is done by using the command sequence:
git grep -w --name-only kzfree |\
xargs sed -i 's/kzfree/kfree_sensitive/'
followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.
[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We don't want to have txq code in the PCIe transport code, so move all
the relevant elements to a new iwl_txq structure and store it in
iwl_trans.
spatch
@ replace_pcie @
struct iwl_trans_pcie *trans_pcie;
@@
(
-trans_pcie->queue_stopped
+trans->txqs.queue_stopped
|
-trans_pcie->queue_used
+trans->txqs.queue_used
|
-trans_pcie->txq
+trans->txqs.txq
|
-trans_pcie->txq
+trans->txqs.txq
|
-trans_pcie->cmd_queue
+trans->txqs.cmd.q_id
|
-trans_pcie->cmd_fifo
+trans->txqs.cmd.fifo
|
-trans_pcie->cmd_q_wdg_timeout
+trans->txqs.cmd.wdg_timeout
)
// clean all new unused variables
@ depends on replace_pcie @
type T;
identifier i;
expression E;
@@
- T i = E;
... when != i
Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200529092401.a428d3c9d66f.Ie04ae55f33954636a39c98e7ae1e739c0507435b@changeid
Kalle Valo says:
====================
wireless-drivers-next patches for v5.8
Second set of patches for v5.8. Lots of new features and new supported
hardware for mt76. Also rtw88 got new hardware support.
Major changes:
rtw88
* add support for Realtek 8723DE PCI adapter
* rename rtw88.ko/rtwpci.ko to rtw88_core.ko/rtw88_pci.ko
iwlwifi
* stop supporting swcrypto and bt_coex_active module parameters on
mvm devices
* enable A-AMSDU in low latency
mt76
* new devices for mt76x0/mt76x2
* support for non-offload firmware on mt7663
* hw/sched scan support for mt7663
* mt7615/mt7663 MSI support
* TDLS support
* mt7603/mt7615 rate control fixes
* new driver for mt7915
* wowlan support for mt7663
* suspend/resume support for mt7663
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
