hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
linux-sg2042/Documentation
History
Mark Rutland 4155fc07fa Doc: dt: arch_timer: discourage clock-frequency use 
The ARM Generic Timer (AKA the architected timer, arm_arch_timer)
features a CPU register (CNTFRQ) which firmware is intended to
initialize, and non-secure software can read to determine the frequency
of the timer. On CPUs with secure state, this register cannot be written
from non-secure states.

The firmware of early SoCs featuring the timer did not correctly
initialize CNTFRQ correctly on all CPUs, requiring the frequency to be
described in DT as a workaround. This workaround is not complete however
as it is exposed to all software in a privileged non-secure mode
(including guests running under a hypervisor). The firmware and DTs for
recent SoCs have followed the example set by these early SoCs.

This patch updates the arch timer binding documentation to make it
clearer that the use of the clock-frequency property is a poor
work-around. The MMIO generic timer binding is similarly updated, though
this is less of a concern as there is generally no need to expose the
MMIO timers to guest OSs.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
 		2015-04-16 09:08:45 -05:00
..
ABI platform-drivers-x86 for 3.20 2015-02-19 10:56:51 -08:00
DocBook KGDB/KDB New: 2015-02-20 15:13:29 -08:00
EDID
…
PCI
…
RCU
…
accounting
…
acpi
…
aoe
…
arm ARM: SoC platform changes 2015-02-17 09:27:54 -08:00
arm64
…
auxdisplay
…
backlight
…
blackfin Documentation: fix blackfin gptimers-example build errors 2015-01-28 12:07:58 -07:00
block
…
blockdev
…
bus-devices
…
cdrom
…
cgroups mm: memcontrol: use "max" instead of "infinity" in control knobs 2015-02-28 09:57:51 -08:00
connector
…
console
…
cpu-freq intel_pstate: Add num_pstates to sysfs 2015-01-30 01:52:17 +01:00
cpuidle
…
cris
…
crypto
…
development-process
…
device-mapper dm crypt: add 'submit_from_crypt_cpus' option 2015-02-16 11:11:15 -05:00
devicetree Doc: dt: arch_timer: discourage clock-frequency use 2015-04-16 09:08:45 -05:00
dmaengine Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-02-18 08:49:20 -08:00
driver-model Staging drivers patches for 3.20-rc1 2015-02-15 11:30:39 -08:00
dvb
…
early-userspace
…
extcon
…
fault-injection
…
fb
…
filesystems ocfs2: update web page + git tree in documentation 2015-02-28 09:57:50 -08:00
firmware_class
…
fmc
…
frv
…
gpio gpio: board.txt: Fix the gpio name example 2015-01-28 11:14:00 -07:00
hid
…
hwmon
…
i2c i2c: fix reference to functionality constants definition 2015-02-19 16:57:48 +01:00
i2o
…
ia64 virtual: Documentation: simplify and generalize paravirt_ops.txt 2015-02-13 17:15:44 +10:30
ide
…
infiniband
…
input Input: ALPS - move v7 packet info to Documentation and v6 packet info 2015-02-15 16:04:23 -08:00
ioctl
…
isdn
…
ja_JP
…
kbuild Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2015-02-19 10:31:37 -08:00
kdump
…
ko_KR
…
laptops
…
leds
…
locking Documentation changes for 3.20 2015-02-11 13:03:11 -08:00
m68k
…
memory-devices
…
metag
…
mic
…
mips
…
misc-devices Documentation/misc-devices/mei: Fix indentation of embedded code. 2015-01-29 12:56:20 -07:00
mmc
…
mn10300
…
mtd
…
namespaces
…
netlabel
…
networking Documentation changes for 3.20 2015-02-11 13:03:11 -08:00
nfc
…
nios2
…
parisc
…
pcmcia
…
phy
…
platform
…
power genirq / PM: describe IRQF_COND_SUSPEND 2015-03-06 01:28:14 +01:00
powerpc
…
pps
…
prctl
…
pti
…
ptp
…
rapidio
…
s390
…
scheduler doc: brief user documentation for completion 2015-01-30 11:19:25 -07:00
scsi
…
security
…
serial
…
sh
…
sound
…
spi
…
sysctl Merge branch 'akpm' (patches from Andrew) 2015-02-11 18:23:28 -08:00
target
…
thermal
…
timers
…
tpm
…
trace Char / Misc patches for 3.20-rc1 2015-02-15 10:48:44 -08:00
usb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2015-02-10 18:57:15 -08:00
vDSO
…
video4linux MODULE_DEVICE_TABLE: fix some callsites 2015-02-13 21:21:40 -08:00
virtual OK, this has the big virtio 1.0 implementation, as specified by OASIS. 2015-02-18 09:24:01 -08:00
vm mm:add KPF_ZERO_PAGE flag for /proc/kpageflags 2015-02-11 17:06:00 -08:00
w1
…
watchdog
…
wimax
…
x86 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-02-21 10:41:29 -08:00
xtensa
…
zh_CN
…
00-INDEX
…
BUG-HUNTING
…
Changes
…
CodeOfConflict Code of Conflict 2015-02-27 11:44:24 -08:00
CodingStyle CodingStyle: enable emacs display of trailing whitespace 2015-01-28 12:05:46 -07:00
DMA-API-HOWTO.txt
…
DMA-API.txt
…
DMA-ISA-LPC.txt
…
DMA-attributes.txt
…
HOWTO
…
IPMI.txt
…
IRQ-affinity.txt
…
IRQ-domain.txt
…
IRQ.txt
…
Intel-IOMMU.txt
…
Makefile
…
ManagementStyle
…
SAK.txt
…
SM501.txt
…
SecurityBugs
…
SubmitChecklist
…
SubmittingDrivers
…
SubmittingPatches Merge branch 'doc/sp-update' into docs-next 2015-01-29 13:11:58 -07:00
VGA-softcursor.txt
…
applying-patches.txt
…
assoc_array.txt
…
atomic_ops.txt
…
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: Add rate constraints to clocks 2015-02-02 14:23:42 -08:00
coccinelle.txt
…
cpu-hotplug.txt
…
cpu-load.txt
…
cputopology.txt
…
crc32.txt
…
dcdbas.txt
…
debugging-modules.txt
…
debugging-via-ohci1394.txt
…
dell_rbu.txt
…
devices.txt
…
digsig.txt
…
dma-buf-sharing.txt
…
dontdiff
…
dynamic-debug-howto.txt
…
edac.txt
…
efi-stub.txt
…
eisa.txt
…
email-clients.txt
…
flexible-arrays.txt
…
futex-requeue-pi.txt
…
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
…
hwspinlock.txt
…
init.txt
…
initrd.txt
…
intel_txt.txt
…
io-mapping.txt
…
io_ordering.txt
…
iostats.txt
…
irqflags-tracing.txt
…
isapnp.txt
…
java.txt
…
kasan.txt kasan: enable instrumentation of global variables 2015-02-13 21:21:42 -08:00
kernel-doc-nano-HOWTO.txt
…
kernel-docs.txt
…
kernel-parameters.txt TTY/Serial driver patches for 3.20-rc1 2015-02-15 11:37:02 -08:00
kernel-per-CPU-kthreads.txt
…
kmemcheck.txt
…
kmemleak.txt
…
kobject.txt
…
kprobes.txt Documentation: add description for FTRACE probe status 2015-02-04 16:05:44 -05:00
kref.txt
…
kselftest.txt
…
ldm.txt
…
local_ops.txt
…
lockup-watchdogs.txt
…
logo.gif
…
logo.txt
…
lzo.txt
…
magic-number.txt
…
mailbox.txt
…
md.txt
…
media-framework.txt
…
memory-barriers.txt
…
memory-hotplug.txt
…
module-signing.txt
…
mono.txt
…
nommu-mmap.txt
…
numastat.txt
…
oops-tracing.txt
…
padata.txt
…
parport-lowlevel.txt
…
parport.txt
…
percpu-rw-semaphore.txt
…
phy.txt
…
pi-futex.txt
…
pinctrl.txt
…
pnp.txt
…
preempt-locking.txt
…
printk-formats.txt
…
pwm.txt
…
ramoops.txt
…
rbtree.txt
…
remoteproc.txt
…
rfkill.txt
…
robust-futex-ABI.txt
…
robust-futexes.txt
…
rpmsg.txt
…
rtc.txt
…
serial-console.txt
…
sgi-ioc4.txt
…
smsc_ece1099.txt
…
sparse.txt
…
stable_api_nonsense.txt
…
stable_kernel_rules.txt
…
static-keys.txt
…
svga.txt
…
sysfs-rules.txt
…
sysrq.txt
…
this_cpu_ops.txt
…
unaligned-memory-access.txt
…
unicode.txt
…
unshare.txt
…
vfio.txt
…
vgaarbiter.txt
…
video-output.txt
…
vme_api.txt
…
volatile-considered-harmful.txt
…
workqueue.txt
…
xillybus.txt
…
xz.txt
…
zorro.txt
…