David Howells 8cefc107ca pipe: Use head and tail pointers for the ring, not cursor and length ... Convert pipes to use head and tail pointers for the buffer ring rather than pointer and length as the latter requires two atomic ops to update (or a combined op) whereas the former only requires one. (1) The head pointer is the point at which production occurs and points to the slot in which the next buffer will be placed. This is equivalent to pipe->curbuf + pipe->nrbufs. The head pointer belongs to the write-side. (2) The tail pointer is the point at which consumption occurs. It points to the next slot to be consumed. This is equivalent to pipe->curbuf. The tail pointer belongs to the read-side. (3) head and tail are allowed to run to UINT_MAX and wrap naturally. They are only masked off when the array is being accessed, e.g.: pipe->bufs[head & mask] This means that it is not necessary to have a dead slot in the ring as head == tail isn't ambiguous. (4) The ring is empty if "head == tail". A helper, pipe_empty(), is provided for this. (5) The occupancy of the ring is "head - tail". A helper, pipe_occupancy(), is provided for this. (6) The number of free slots in the ring is "pipe->ring_size - occupancy". A helper, pipe_space_for_user() is provided to indicate how many slots userspace may use. (7) The ring is full if "head - tail >= pipe->ring_size". A helper, pipe_full(), is provided for this. Signed-off-by: David Howells <dhowells@redhat.com>		2019-10-31 15:12:34 +00:00
..
accessibility	…
acpi	Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-09-28 08:14:15 -07:00
amba	ARM updates for 5.4-rc1:	2019-09-22 09:39:09 -07:00
android	…
ata	ata: libahci_platform: Add of_node_put() before loop exit	2019-09-19 12:21:44 -06:00
atm	atm: he: clean up an indentation issue	2019-09-25 13:54:45 +02:00
auxdisplay	It's a somewhat calmer cycle for docs this time, as the churn of the mass	2019-09-17 16:22:26 -07:00
base	mm,thp: stats for file backed THP	2019-09-24 15:54:11 -07:00
bcma	bcma: make arrays pwr_info_offset and sprom_sizes static const, shrinks object size	2019-09-13 16:44:49 +03:00
block	for-linus-2019-10-03	2019-10-04 09:56:51 -07:00
bluetooth	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2019-09-15 14:17:27 +02:00
bus	ARM: SoC fixes	2019-09-30 10:04:28 -07:00
cdrom	…
char	pipe: Use head and tail pointers for the ring, not cursor and length	2019-10-31 15:12:34 +00:00
clk	Fixes for omaps for v5.4-rc cycle	2019-10-03 09:15:19 -07:00
clocksource	timer-of: don't use conditional expression with mixed 'void' types	2019-10-02 16:16:07 -07:00
connector	…
counter	…
cpufreq	Power management updates for 5.4-rc1	2019-09-17 19:15:14 -07:00
cpuidle	Power management updates for 5.4-rc1	2019-09-17 19:15:14 -07:00
crypto	Merge branch 'akpm' (patches from Andrew)	2019-09-24 16:10:23 -07:00
dax	…
dca	…
devfreq	…
dio	…
dma	Main MIPS changes for v5.4:	2019-09-22 09:30:30 -07:00
dma-buf	…
edac	ARM updates for 5.4-rc1:	2019-09-22 09:39:09 -07:00
eisa	…
extcon	chrome platform changes for v5.4	2019-09-19 14:14:28 -07:00
firewire	…
firmware	ARM: SoC fixes	2019-09-30 10:04:28 -07:00
fpga	Char/Misc driver patches for 5.4-rc1	2019-09-18 11:14:31 -07:00
fsi	…
gnss	…
gpio	pwm: Changes for v5.4-rc1	2019-09-27 12:19:47 -07:00
gpu	- Fix DP-MST crtc_mask	2019-10-04 16:31:06 +10:00
greybus	…
hid	- First round of vmbus hibernation support from Dexuan Cui.	2019-09-24 12:36:31 -07:00
hsi	HSI changes for the 5.4 series	2019-09-22 12:02:21 -07:00
hv	- First round of vmbus hibernation support from Dexuan Cui.	2019-09-24 12:36:31 -07:00
hwmon	ARM SCMI fixes for v5.4	2019-09-29 11:20:41 -07:00
hwspinlock	…
hwtracing	Char/Misc driver patches for 5.4-rc1	2019-09-18 11:14:31 -07:00
i2c	i2c: slave-eeprom: Add read only mode	2019-09-28 20:44:12 +02:00
i3c	…
ide	…
idle	…
iio	chrome platform changes for v5.4	2019-09-19 14:14:28 -07:00
infiniband	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2019-09-28 17:47:33 -07:00
input	chrome platform changes for v5.4	2019-09-19 14:14:28 -07:00
interconnect	…
iommu	IOMMU Fixes for Linux v5.4-rc1	2019-09-29 10:00:14 -07:00
ipack	…
irqchip	Main MIPS changes for v5.4:	2019-09-22 09:30:30 -07:00
isdn	mISDN: enforce CAP_NET_RAW for raw sockets	2019-09-24 16:37:18 +02:00
leds	leds: lm3532: Fix optional led-max-microamp prop error handling	2019-09-12 20:45:52 +02:00
lightnvm	lightnvm: print error when target is not found	2019-09-05 13:17:01 -06:00
macintosh	…
mailbox	mailbox: qcom-apcs: fix max_register value	2019-09-17 00:54:29 -05:00
mcb	…
md	for-5.4/post-2019-09-24	2019-09-24 16:31:50 -07:00
media	media/v4l2-core: untag user pointers in videobuf_dma_contig_user_get	2019-09-25 17:51:41 -07:00
memory	…
memstick	ms_block: fix spelling mistake "randomally" -> "randomly"	2019-09-11 16:11:01 +02:00
message	…
mfd	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal	2019-09-29 10:24:23 -07:00
misc	Merge branch 'i2c/for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux	2019-09-24 16:48:02 -07:00
mmc	mmc: host: sdhci-pci: Add Genesys Logic GL975x support	2019-09-27 20:48:20 +02:00
mtd	Main MIPS changes for v5.4:	2019-09-22 09:30:30 -07:00
mux	…
net	net: qlogic: Fix memory leak in ql_alloc_large_buffers	2019-10-04 18:33:13 -07:00
nfc	NFC: st95hf: clean up indentation issue	2019-09-27 20:31:18 +02:00
ntb	NTB: fix IDT Kconfig typos/spellos	2019-09-23 17:20:40 -04:00
nubus	…
nvdimm	libnvdimm fixes v5.4-rc1	2019-09-29 10:33:41 -07:00
nvme	Merge branch 'nvme-5.4' of git://git.infradead.org/nvme into for-linus	2019-09-27 13:17:37 -06:00
nvmem	Char/Misc driver patches for 5.4-rc1	2019-09-18 11:14:31 -07:00
of	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2019-09-28 17:47:33 -07:00
opp	…
oprofile	…
parisc	dma-mapping updates for 5.4:	2019-09-19 13:27:23 -07:00
parport	Char/Misc driver patches for 5.4-rc1	2019-09-18 11:14:31 -07:00
pci	Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-09-28 08:14:15 -07:00
pcmcia	Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-09-28 08:14:15 -07:00
perf	…
phy	pci-v5.4-changes	2019-09-23 19:16:01 -07:00
pinctrl	This is the bulk of pin control changes for the v5.4 kernel	2019-09-19 14:19:33 -07:00
platform	platform-drivers-x86 for v5.4-2	2019-09-24 12:39:40 -07:00
pnp	…
power	power supply and reset changes for the v5.4 series	2019-09-22 12:04:59 -07:00
powercap	Power management updates for 5.4-rc1	2019-09-17 19:15:14 -07:00
pps	…
ps3	…
ptp	ptp_qoriq: Initialize the registers' spinlock before calling ptp_qoriq_settime	2019-10-02 12:20:38 -04:00
pwm	pwm: Changes for v5.4-rc1	2019-09-27 12:19:47 -07:00
rapidio	…
ras	…
regulator	LED updates for 5.4-rc1	2019-09-17 18:40:42 -07:00
remoteproc	remoteproc updates for v5.4	2019-09-22 10:55:08 -07:00
reset	ARM: SoC fixes	2019-09-30 10:04:28 -07:00
rpmsg	rpmsg: glink-smem: Name the edge based on parent remoteproc	2019-09-17 15:33:31 -07:00
rtc	RTC for 5.4	2019-09-22 11:05:43 -07:00
s390	s390 updates for 5.4-rc2	2019-10-05 08:44:02 -07:00
sbus	…
scsi	SCSI fixes on 20191004	2019-10-05 12:53:27 -07:00
sfi	…
sh	…
siox	…
slimbus	…
soc	ARM: SoC driver updates for v5.4	2019-09-16 15:52:38 -07:00
soundwire	soundwire updates for v5.4-rc1	2019-09-22 10:52:23 -07:00
spi	LED updates for 5.4-rc1	2019-09-17 18:40:42 -07:00
spmi	…
ssb	ssb: make array pwr_info_offset static const, makes object smaller	2019-09-13 17:23:18 +03:00
staging	netfilter: drop bridge nf reset from nf_reset	2019-10-01 18:42:15 +02:00
target	mm: introduce page_size()	2019-09-24 15:54:08 -07:00
tc	…
tee	tee/shm: untag user pointers in tee_shm_register	2019-09-25 17:51:41 -07:00
thermal	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal	2019-09-29 10:24:23 -07:00
thunderbolt	…
tty	Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-09-28 08:14:15 -07:00
uio	Char/Misc driver patches for 5.4-rc1	2019-09-18 11:14:31 -07:00
usb	Merge branch 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-09-24 12:33:34 -07:00
vfio	vfio/type1: untag user pointers in vaddr_get_pfn	2019-09-25 17:51:41 -07:00
vhost	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2019-09-15 14:17:27 +02:00
video	video/logo: do not generate unneeded logo C files	2019-10-05 15:29:49 +09:00
virt	…
virtio	virtio_ring: fix unmap of indirect descriptors	2019-09-09 10:43:15 -04:00
visorbus	…
vlynq	…
vme	…
w1	…
watchdog	linux-watchdog 5.4-rc1 tag	2019-09-27 11:17:38 -07:00
xen	xen: fixes and cleanups for 5.4-rc2	2019-10-04 11:13:09 -07:00
zorro	…
Kconfig	Staging/IIO driver patches for 5.4-rc1	2019-09-18 11:05:34 -07:00
Makefile	Staging/IIO driver patches for 5.4-rc1	2019-09-18 11:05:34 -07:00