linux/Documentation
Michael S. Tsirkin 6a65d26385 asm-generic: implement virt_xxx memory barriers
Guests running within virtual machines might be affected by SMP effects even if
the guest itself is compiled without SMP support.  This is an artifact of
interfacing with an SMP host while running an UP kernel.  Using mandatory
barriers for this use-case would be possible but is often suboptimal.

In particular, virtio uses a bunch of confusing ifdefs to work around
this, while xen just uses the mandatory barriers.

To better handle this case, low-level virt_mb() etc macros are made available.
These are implemented trivially using the low-level __smp_xxx macros,
the purpose of these wrappers is to annotate those specific cases.

These have the same effect as smp_mb() etc when SMP is enabled, but generate
identical code for SMP and non-SMP systems. For example, virtual machine guests
should use virt_mb() rather than smp_mb() when synchronizing against a
(possibly SMP) host.

Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:59 +02:00
..
ABI SCSI misc on 20151113 2015-11-13 20:35:54 -08:00
DocBook Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-11-10 09:33:06 -08:00
EDID
PCI The documentation tree update for 4.1. Numerous fixes, the overdue removal 2015-04-18 11:10:49 -04:00
RCU Merge branches 'doc.2015.10.06a', 'percpu-rwsem.2015.10.06a' and 'torture.2015.10.06a' into HEAD 2015-10-07 16:06:25 -07:00
accounting
acpi mfd: core: redo ACPI matching of the children devices 2015-10-26 15:25:53 +01:00
aoe
arm ARM: dts: keystone: k2l: fix kernel crash when clk_ignore_unused is not in bootargs 2015-11-23 10:36:27 -08:00
arm64 arm64 updates for 4.4: 2015-11-04 14:47:13 -08:00
auxdisplay
backlight
blackfin Docs: blackfin: Use new switch macro SAMPLE_IRQ_TIMER instead of IRQ_TIMER5 2015-05-07 09:35:14 -06:00
block null_blk: register as a LightNVM device 2015-11-16 15:22:28 -07:00
blockdev zram: update documentation 2015-09-24 15:39:42 -06:00
bus-devices
cdrom
cgroups There is a nice new document from Neil on how pathname lookups work and 2015-11-05 15:59:24 -08:00
cma cma: debug: document new debugfs interface 2015-04-14 16:49:00 -07:00
connector
console
cpu-freq cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event 2015-09-01 15:50:38 +02:00
cpuidle
cris
crypto KEYS: Merge the type-specific data with the payload data 2015-10-21 15:18:36 +01:00
development-process
device-mapper - Revert a dm-multipath change that caused a regression for unprivledged 2015-11-04 21:19:53 -08:00
devicetree Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-12-31 14:40:43 -08:00
dmaengine Documentation: dmaengine: Add DMA_CTRL_REUSE documentation 2015-08-17 13:46:22 +05:30
driver-model driver-core: platform: Provide helpers for multi-driver modules 2015-10-05 05:02:40 +01:00
dvb
early-userspace
extcon
fault-injection futex: Fault/error injection capabilities 2015-07-20 11:45:45 +02:00
fb Documentation/fb: add documentation for sm712fb 2015-08-07 15:05:01 -07:00
features arm64 updates for 4.4: 2015-11-04 14:47:13 -08:00
filesystems Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-11-13 20:04:17 -08:00
firmware_class
fmc
fpga usage documentation for FPGA manager core 2015-10-07 18:07:20 +01:00
frv
gpio There is a nice new document from Neil on how pathname lookups work and 2015-11-05 15:59:24 -08:00
hid HID: sensor: Update document for custom sensor 2015-04-10 22:22:56 +02:00
hwmon ARM: SoC driver updates for v4.4 2015-11-10 15:00:03 -08:00
i2c i2c: i801: add Intel Lewisburg device IDs 2015-11-20 16:22:21 +01:00
ia64 virtual: Documentation: simplify and generalize paravirt_ops.txt 2015-02-13 17:15:44 +10:30
ide
infiniband IB/hfi1: add driver files 2015-08-28 22:59:36 -04:00
input Input: add userio module 2015-10-27 18:55:31 -07:00
ioctl char/misc drivers for 4.4-rc1 2015-11-04 22:15:15 -08:00
isdn
ja_JP Doc: ja_JP: Fix typo in HOWTO 2015-06-08 16:43:09 -06:00
kbuild kbuild: document recursive dependency limitation / resolution 2015-10-08 15:36:16 +02:00
kdump
ko_KR
laptops Move freefall program from Documentation/ to tools/ 2015-06-08 16:42:07 -06:00
leds Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds 2015-07-01 19:09:11 -07:00
locking Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 16:10:43 -08:00
m68k
memory-devices
metag
mic misc: mic: Update MIC host daemon with COSM changes 2015-10-04 12:54:54 +01:00
mips
misc-devices Doc:misc-devices: Fix typo in Documentation/misc-devices 2015-09-18 10:04:24 -06:00
mmc mmc: core: Remove MMC_CLKGATE 2015-10-26 16:00:09 +01:00
mn10300
mtd
namespaces
netlabel
networking e100.txt: Cleanup license info in kernel doc 2015-12-03 12:58:10 -08:00
nfc NFC: Fix typo in nfc-hci.txt 2015-06-08 23:15:45 +02:00
nios2
nvdimm libnvdimm: documentation clarifications 2015-11-12 09:55:23 -08:00
nvmem Documentation: nvmem: add nvmem api level and how-to doc 2015-08-05 13:43:45 -07:00
parisc
pcmcia pcmcia: Fix typo in locking documentation 2015-08-07 14:34:58 +02:00
phy
platform
power PCI / PM: Update runtime PM documentation for PCI devices 2015-09-25 02:48:44 +02:00
powerpc SCSI misc on 20150901 2015-09-02 12:22:54 -07:00
pps Doc: pps: Fix file name in pps.txt 2015-07-14 12:35:42 -06:00
prctl Documentation/prctl: don't build tsc tests when cross compiling 2015-06-22 16:05:04 -06:00
pti
ptp testptp: Silence compiler warnings on ppc64 2015-09-29 21:16:56 -07:00
rapidio
s390 KVM: s390: remove outdated documentation 2015-07-29 11:02:35 +02:00
scheduler sched/dl/Documentation: Split Section 3 2015-05-19 08:39:21 +02:00
scsi st: allow debug output to be enabled or disabled via sysfs 2015-11-09 17:17:27 -08:00
security KEYS: Merge the type-specific data with the payload data 2015-10-21 15:18:36 +01:00
serial Documentation: improve line discipline method descriptions 2015-10-05 04:53:26 +01:00
sh
sound ALSA: hda - Remove obsoleted documentation 2015-10-17 18:34:24 +02:00
spi ARM: pxa: Remove unused clock_enable field from struct pxa2xx_spi_master 2015-09-20 19:37:20 +02:00
sysctl Documentation/sysctl/vm.txt: fix misleading code reference of overcommit_memory 2015-11-09 15:11:24 -08:00
target target: use per-attribute show and store methods 2015-10-13 22:17:49 -07:00
thermal thermal: power_allocator: relax the requirement of two passive trip points 2015-09-14 07:41:45 -07:00
timers documentation: Update NO_HZ_FULL interaction with POSIX timers 2015-02-26 11:57:29 -08:00
tpm
trace Most of the changes are clean ups and small fixes. Some of them have 2015-11-06 13:30:20 -08:00
usb usb: interface authorization: Documentation part 2015-09-22 12:08:40 -07:00
vDSO Documentation/vDSO: don't build tests when cross compiling 2015-06-22 16:04:57 -06:00
video4linux [media] media: videobuf2: Change queue_setup argument 2015-10-20 14:48:39 -02:00
virtual s390: A bunch of fixes and optimizations for interrupt and time 2015-11-05 16:26:26 -08:00
vm mm: make compound_head() robust 2015-11-06 17:50:42 -08:00
w1 w1: masters: omap_hdq: add support for 1-wire mode 2015-10-05 04:47:09 +01:00
watchdog Documentation/watchdog: add timeout and ping rate control to watchdog-test.c 2015-09-09 21:33:36 +02:00
wimax
x86 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 10:07:40 -07:00
xtensa
zh_CN sysfs.txt: fix pre-kernfs sysfs_dirent reference 2015-09-13 14:38:50 -06:00
00-INDEX Update of Documentation/dmaengine/00-INDEX 2014-12-29 15:28:24 -07:00
BUG-HUNTING
Changes There is a nice new document from Neil on how pathname lookups work and 2015-11-05 15:59:24 -08:00
CodeOfConflict Code of Conflict 2015-02-27 11:44:24 -08:00
CodingStyle Documentation: CodingStyle: remove broken links in the References section 2015-07-10 13:54:34 -06:00
DMA-API-HOWTO.txt Documentation: DMA API: Be more explicit that nents is always the same 2015-09-24 15:50:06 -06:00
DMA-API.txt dma: remove external references to dma_supported 2015-11-09 15:11:24 -08:00
DMA-ISA-LPC.txt
DMA-attributes.txt
HOWTO docs: update HOWTO for 3.x -> 4.x versioning 2015-08-24 11:28:17 -06:00
IPMI.txt ipmi watchdog : add panic_wdt_timeout parameter 2015-11-16 06:28:43 -06:00
IRQ-affinity.txt
IRQ-domain.txt irqdomain: Documentation updates 2015-10-13 19:01:25 +02:00
IRQ.txt
Intel-IOMMU.txt x86/vt-d: Fix documentation of DRHD 2015-08-25 10:44:49 +02:00
Makefile Documentation: Remove ZBOOT MMC/SDHI utility and docs 2015-02-24 06:45:25 +09:00
ManagementStyle
SAK.txt
SM501.txt
SecurityBugs
SubmitChecklist
SubmittingDrivers
SubmittingPatches A few more documentation patches that wandered in and have no reason to 2015-11-13 09:19:05 -08:00
VGA-softcursor.txt
adding-syscalls.txt Documentation: describe how to add a system call 2015-08-13 17:54:06 -06:00
applying-patches.txt
assoc_array.txt
atomic_ops.txt locking/atomics, cmpxchg: Privatize the inclusion of asm/cmpxchg.h 2015-09-13 10:35:46 +02:00
bad_memory.txt
basic_profiling.txt
bcache.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
cachetlb.txt rmap: drop support of non-linear mappings 2015-02-10 14:30:31 -08:00
circular-buffers.txt
clk.txt clk: change clk_ops' ->determine_rate() prototype 2015-07-27 18:12:01 -07:00
coccinelle.txt
cpu-hotplug.txt cpumask: fix cpu-hotplug documentation 2015-03-05 13:37:01 +10:30
cpu-load.txt
cputopology.txt Documentation: Update cputopology.txt 2015-05-27 15:22:15 +02:00
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt Doc: Change wikipedia's URL from http to https 2015-06-22 10:14:05 -06:00
dell_rbu.txt
devices.txt
digsig.txt
dma-buf-sharing.txt dma-buf: cleanup dma_buf_export() to make it easily extensible 2015-04-21 14:47:16 +05:30
dontdiff Documentation: dontdiff: remove media from dontdiff 2015-11-11 10:08:07 -07:00
dynamic-debug-howto.txt
edac.txt Documentation/EDAC: Add reference documents section for amd64_edac 2015-09-29 13:42:41 +02:00
efi-stub.txt
eisa.txt
email-clients.txt A few more documentation patches that wandered in and have no reason to 2015-11-13 09:19:05 -08:00
flexible-arrays.txt
futex-requeue-pi.txt doc: Fix misnamed FUTEX_CMP_REQUEUE_PI op constants 2015-01-19 12:05:32 +01:00
gcov.txt
gdb-kernel-debugging.txt scripts/gdb: add basic documentation 2015-02-17 14:34:54 -08:00
highuid.txt
hsi.txt
hw_random.txt hwrng: doc - Fix device node name reference /dev/hw_random => /dev/hwrng 2015-09-21 22:00:41 +08:00
hwspinlock.txt hwspinlock/core: add device tree support 2015-05-02 09:54:30 +03:00
init.txt
initrd.txt
intel_txt.txt
io-mapping.txt
io_ordering.txt
iostats.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kasan.txt mm, slub, kasan: enable user tracking by default with KASAN=y 2015-11-05 19:34:48 -08:00
kernel-doc-nano-HOWTO.txt Documenation: Update location of docproc.c 2015-07-14 12:36:39 -06:00
kernel-docs.txt kernel-docs.txt: update kernelnewbies reference 2015-10-11 15:36:43 -06:00
kernel-parameters.txt Merge branches 'pm-cpufreq' and 'acpi-cppc' 2015-11-20 01:22:10 +01:00
kernel-per-CPU-kthreads.txt documentation: Update per-CPU kthreads documentation 2015-02-26 11:57:30 -08:00
kmemcheck.txt Documentation: update the CONFIG_DEBUG_PAGEALLOC description 2015-03-20 07:41:55 -06:00
kmemleak.txt Doc: Change wikipedia's URL from http to https 2015-06-22 10:14:05 -06:00
kobject.txt
kprobes.txt kprobes: Update Documentation/kprobes.txt 2015-03-20 07:41:55 -06:00
kref.txt
kselftest.txt Documentation: Update kselftest.txt 2015-09-24 15:51:53 -06:00
ldm.txt
local_ops.txt
lockup-watchdogs.txt kernel/watchdog.c: add sysctl knob hardlockup_panic 2015-11-05 19:34:48 -08:00
logo.gif
logo.txt
lzo.txt
magic-number.txt Documentation/magic-number: Remove SCC_MAGIC 2015-05-13 15:39:04 -04:00
mailbox.txt Documentation: minor typo fix in mailbox.txt 2015-08-13 18:03:18 -06:00
md-cluster.txt md-cluster: fix deadlock issue on message lock 2015-08-31 19:41:41 +02:00
md.txt doc:md: fix typo in md.txt. 2015-06-23 06:49:44 -06:00
media-framework.txt
memory-barriers.txt asm-generic: implement virt_xxx memory barriers 2016-01-12 20:46:59 +02:00
memory-hotplug.txt mem-hotplug: fix typo in Documentation/memory-hotplug.txt 2015-03-20 07:41:55 -06:00
men-chameleon-bus.txt Documentation: Minor changes to men-chameleon-bus.txt 2015-07-24 15:15:17 +02:00
module-signing.txt Move certificate handling to its own directory 2015-08-14 16:06:13 +01:00
mono.txt
nommu-mmap.txt fs: introduce f_op->mmap_capabilities for nommu mmap support 2015-01-20 14:02:58 -07:00
ntb.txt NTB: Rename Intel code names to platform names 2015-07-04 14:09:25 -04:00
numastat.txt
oops-tracing.txt livepatch: kernel: add TAINT_LIVEPATCH 2014-12-22 15:40:48 +01:00
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt phy: core: Add devm_of_phy_get_by_index to phy-core 2015-05-11 21:42:23 +05:30
pi-futex.txt
pinctrl.txt pinctrl: move strict option to pinmux_ops 2015-05-06 14:45:19 +02:00
pnp.txt
preempt-locking.txt x86/fpu: Rename math_state_restore() to fpu__restore() 2015-05-19 15:47:18 +02:00
printk-formats.txt lib/vsprintf.c: update documentation 2015-11-06 17:50:42 -08:00
pwm.txt
ramoops.txt
rbtree.txt documentation: fix small typo in rbtree.txt 2015-09-13 14:38:50 -06:00
remoteproc.txt remoteproc: introduce rproc_get_by_phandle API 2015-06-16 21:12:52 +03:00
rfkill.txt rfkill: document rfkill module parameters 2015-01-09 23:22:12 +01:00
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt Documentation, split up rtc.txt into documentation and test file 2015-03-24 22:01:58 -06:00
serial-console.txt
sgi-ioc4.txt
smsc_ece1099.txt
sparse.txt
stable_api_nonsense.txt
stable_kernel_rules.txt stable: Update documentation to clarify preferred procedure 2015-05-22 09:38:56 -06:00
static-keys.txt locking/static_keys: Fix up the static keys documentation 2015-09-15 07:12:06 +02:00
svga.txt
sysfs-rules.txt
sysrq.txt mm, oom: do not panic for oom kills triggered from sysrq 2015-09-08 15:35:28 -07:00
this_cpu_ops.txt
unaligned-memory-access.txt
unicode.txt
unshare.txt
vfio.txt vfio: powerpc/spapr: Support Dynamic DMA windows 2015-06-11 15:16:55 +10:00
vgaarbiter.txt
video-output.txt
vme_api.txt Documentation: mention vme_master_mmap() in VME API 2015-06-12 17:26:56 -07:00
volatile-considered-harmful.txt
workqueue.txt workqueue: fix trivial typo in Documentation/workqueue.txt 2015-05-05 09:50:38 -04:00
xillybus.txt
xz.txt
zorro.txt