freebsd-dev/sys/dev/iicbus
Gleb Smirnoff b8a6e03fac Widen NET_EPOCH coverage.
When epoch(9) was introduced to network stack, it was basically
dropped in place of existing locking, which was mutexes and
rwlocks. For the sake of performance mutex covered areas were
as small as possible, so became epoch covered areas.

However, epoch doesn't introduce any contention, it just delays
memory reclaim. So, there is no point to minimise epoch covered
areas in sense of performance. Meanwhile entering/exiting epoch
also has non-zero CPU usage, so doing this less often is a win.

Not the least is also code maintainability. In the new paradigm
we can assume that at any stage of processing a packet, we are
inside network epoch. This makes coding both input and output
path way easier.

On output path we already enter epoch quite early - in the
ip_output(), in the ip6_output().

This patch does the same for the input path. All ISR processing,
network related callouts, other ways of packet injection to the
network stack shall be performed in net_epoch. Any leaf function
that walks network configuration now asserts epoch.

Tricky part is configuration code paths - ioctls, sysctls. They
also call into leaf functions, so some need to be changed.

This patch would introduce more epoch recursions (see EPOCH_TRACE)
than we had before. They will be cleaned up separately, as several
of them aren't trivial. Note, that unlike a lock recursion the
epoch recursion is safe and just wastes a bit of resources.

Reviewed by:	gallatin, hselasky, cy, adrian, kristof
Differential Revision:	https://reviews.freebsd.org/D19111
2019-10-07 22:40:05 +00:00
..
twsi twsi: Fix build when DEBUG is used on 32bits arch. 2019-08-15 18:59:52 +00:00
ad7417.c
ad7418.c Remove some unused header files from the ad7418 driver. 2019-06-23 17:20:39 +00:00
adm1030.c
ads111x.c Use a single write of 3 bytes instead of iicdev_writeto() in ads111x. 2019-09-05 19:17:53 +00:00
adt746x.c
ds13rtc.c Add pnpinfo to all i2c drivers that have FDT compat data. 2019-05-23 18:24:27 +00:00
ds1307.c Add pnpinfo to all i2c drivers that have FDT compat data. 2019-05-23 18:24:27 +00:00
ds1307reg.h
ds1631.c
ds1672.c
ds1775.c
ds3231.c
ds3231reg.h
icee.c Rename IICBUS_FDT_PNPINFO -> IICBUS_FDT_PNP_INFO because all the other 2019-05-23 16:03:30 +00:00
if_ic.c Widen NET_EPOCH coverage. 2019-10-07 22:40:05 +00:00
iic_recover_bus.c
iic_recover_bus.h
iic.c
iic.h
iicbb_if.m
iicbb.c
iicbus_if.m
iicbus.c revert r273728 and parts of r306589, iicbus no-stop by default feature 2019-05-29 09:08:20 +00:00
iicbus.h Restore the ability for i2c slave devices to do IO from their probe method. 2019-07-08 20:26:56 +00:00
iicoc.c
iicoc.h
iiconf.c Create a mechanism for encoding a system errno into the IIC_Exxxxx space. 2019-09-14 19:33:36 +00:00
iiconf.h Create a mechanism for encoding a system errno into the IIC_Exxxxx space. 2019-09-14 19:33:36 +00:00
iicsmb.c
isl12xx.c Add pnpinfo to all i2c drivers that have FDT compat data. 2019-05-23 18:24:27 +00:00
lm75.c
max6690.c
nxprtc.c Add support for setting the aging/frequency-offset register via sysctl. 2019-07-21 17:14:39 +00:00
ofw_iicbus.c
rtc8583.c Add pnpinfo to all i2c drivers that have FDT compat data. 2019-05-23 18:24:27 +00:00
s35390a.c
sy8106a.c Add pnpinfo to all i2c drivers that have FDT compat data. 2019-05-23 18:24:27 +00:00
syr827.c syr827: Switch to iicdev_{readfrom,writeto} 2019-10-01 18:32:27 +00:00