This series implements Sstc extension support which was ratified
recently. Before the Sstc extension, an SBI call is necessary to
generate timer interrupts as only M-mode have access to the timecompare
registers. Thus, there is significant latency to generate timer
interrupts at kernel. For virtualized enviornments, its even worse as
the KVM handles the SBI call and uses a software timer to emulate the
timecomapre register.
Sstc extension solves both these problems by defining a
stimecmp/vstimecmp at supervisor (host/guest) level. It allows kernel to
program a timer and recieve interrupt without supervisor execution
enviornment (M-mode/HS mode) intervention.
* palmer/riscv-sstc:
RISC-V: Prefer sstc extension if available
RISC-V: Enable sstc extension parsing from DT
RISC-V: Add SSTC extension CSR details
Pull RISC-V updates from Palmer Dabbelt:
- Enabling the FPU is now a static_key
- Improvements to the Svpbmt support
- CPU topology bindings for a handful of systems
- Support for systems with 64-bit hart IDs
- Many settings have been enabled in the defconfig, including both
support for the StarFive systems and many of the Docker requirements
There are also a handful of cleanups and improvements, as usual.
* tag 'riscv-for-linus-5.20-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (28 commits)
riscv: enable Docker requirements in defconfig
riscv: convert the t-head pbmt errata to use the __nops macro
riscv: introduce nops and __nops macros for NOP sequences
RISC-V: Add fast call path of crash_kexec()
riscv: mmap with PROT_WRITE but no PROT_READ is invalid
riscv/efi_stub: Add 64bit boot-hartid support on RV64
riscv: cpu: Add 64bit hartid support on RV64
riscv: smp: Add 64bit hartid support on RV64
riscv: spinwait: Fix hartid variable type
riscv: cpu_ops_sbi: Add 64bit hartid support on RV64
riscv: dts: sifive: "fix" pmic watchdog node name
riscv: dts: canaan: Add k210 topology information
riscv: dts: sifive: Add fu740 topology information
riscv: dts: sifive: Add fu540 topology information
riscv: dts: starfive: Add JH7100 CPU topology
RISC-V: Add CONFIG_{NON,}PORTABLE
riscv: config: enable SOC_STARFIVE in defconfig
riscv: dts: microchip: Add mpfs' topology information
riscv: Kconfig.socs: Add comments
riscv: Kconfig.erratas: Add comments
...
Pull clockevent/source updates from Daniel Lezcano:
- Add the missing DT bindings for the MTU nomadik timer (Linus
Walleij)
- Fix grammar typo in the ARM global timer Kconfig option (Randy
Dunlap)
- Add the tegra186 timer and use it on the tegra234 board (Thierry
Reding)
- Add the 'CPUXGPT' CPU timer for Mediatek MT6795 and implement a
workaround to overcome an ATF bug where the timer is not correctly
initialized (AngeloGioacchino Del Regno)
- Rework the suspend/resume approach to enable the feature on the
timer even it is not an active clock and fix a compilation warning
(Claudiu Beznea)
- Add the Add R-Car Gen4 timer support along with the DT bindings
(Wolfram Sang)
- Add compatible for ti,am654-timer to support AM6 SoC (Tony Lindgren)
- Fix Kconfig option to put it back to 'bool' instead of 'tristate'
for the tegra186 (Daniel Lezcano)
- Sort 'family,type' DT bindings for the Renesas timers (Geert
Uytterhoeven)
- Add compatible 'allwinner,sun20i-d1-timer' for Allwinner D1 (Samuel
Holland)
- Remove unnecessary (void*) conversions for sun4i (XU pengfei)
- Remove unnecessary (void*) conversions for sun5i (Li zeming)
Link: https://lore.kernel.org/all/7472984e-f502-5f27-82bf-070127dd85a5@linaro.org
The __omap_dm_timer_* inline functions in the header are no longer needed
outside the driver, and the header ifdefs prevent the driver working for
ARCH_K3.
Let's move the inline functions to the driver and drop the ifdefs and
drop the unused functions __omap_dm_timer_override_errata() and
__omap_dm_timer_load_start().
Cc: Keerthy <j-keerthy@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20220408101715.43697-2-tony@atomide.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Fix the following compilation warnings:
timer-microchip-pit64b.c:68: warning: cannot understand function prototype: 'struct mchp_pit64b_clkevt '
timer-microchip-pit64b.c:82: warning: cannot understand function prototype: 'struct mchp_pit64b_clksrc '
timer-microchip-pit64b.c:283: warning: Function parameter or member 'timer' not described in 'mchp_pit64b_init_mode'
timer-microchip-pit64b.c:283: warning: Function parameter or member 'max_rate' not described in 'mchp_pit64b_init_mode'
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220609094041.1796372-4-claudiu.beznea@microchip.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Some MediaTek platforms with a buggy TrustZone ATF firmware will not
initialize the AArch64 System Timer correctly: in these cases, the
System Timer address is correctly programmed, as well as the CNTFRQ_EL0
register (reading 13MHz, as it should be), but the assigned hardware
timers are never started before (or after) booting Linux.
In this condition, any call to function get_cycles() will be returning
zero, as CNTVCT_EL0 will always read zero.
One common critical symptom of that is trying to use the udelay()
function (calling __delay()), which executes the following loop:
start = get_cycles();
while ((get_cycles() - start) < cycles)
cpu_relax();
which, when CNTVCT_EL0 always reads zero, translates to:
while((0 - 0) < 0) ==> while(0 < 0)
... generating an infinite loop, even though zero is never less
than zero, but always equal to it (this has to be researched,
but it's out of the scope of this commit).
To fix this issue on the affected MediaTek platforms, the solution
is to simply start the timers that are designed to be System Timer(s).
These timers, downstream, are called "CPUXGPT" and there is one
timer per CPU core; luckily, it is not necessary to set a start bit
on each CPUX General Purpose Timer, but it's conveniently enough to:
- Set the clock divider (input = 26MHz, divider = 2, output = 13MHz);
- Set the ENABLE bit on a global register (starts all CPUX timers).
The only small hurdle with this setup is that it's all done through
the MCUSYS wrapper, where it is needed, for each read or write, to
select a register address (by writing it to an index register) and
then to perform any R/W on a "CON" register.
For example, writing "0x1" to the CPUXGPT register offset 0x4:
- Write 0x4 to mcusys INDEX register
- Write 0x1 to mcusys CON register
Reading from CPUXGPT register offset 0x4:
- Write 0x4 to mcusys INDEX register
- Read mcusys CON register.
Finally, starting this timer makes platforms affected by this issue
to work correctly.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20220613133819.35318-3-angelogioacchino.delregno@collabora.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
EXPORT_SYMBOL and __init is a bad combination because the .init.text
section is freed up after the initialization. Hence, modules cannot
use symbols annotated __init. The access to a freed symbol may end up
with kernel panic.
modpost used to detect it, but it has been broken for a decade.
Recently, I fixed modpost so it started to warn it again, then this
showed up in linux-next builds.
There are two ways to fix it:
- Remove __init
- Remove EXPORT_SYMBOL
I chose the latter for this case because the only in-tree call-site,
arch/x86/kernel/cpu/mshyperv.c is never compiled as modular.
(CONFIG_HYPERVISOR_GUEST is boolean)
Fixes: dd2cb34861 ("clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220606050238.4162200-1-masahiroy@kernel.org
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Pull clockevent/clocksource updates from Thomas Gleixner:
- Device tree bindings for MT8186
- Tell the kernel that the RISC-V SBI timer stops in deeper power
states
- Make device tree parsing in sp804 more robust
- Dead code removal and tiny fixes here and there
- Add the missing SPDX identifiers
* tag 'timers-core-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/drivers/oxnas-rps: Fix irq_of_parse_and_map() return value
clocksource/drivers/timer-ti-dm: Remove unnecessary NULL check
clocksource/drivers/timer-sun5i: Convert to SPDX identifier
clocksource/drivers/timer-sun4i: Convert to SPDX identifier
clocksource/drivers/pistachio: Convert to SPDX identifier
clocksource/drivers/orion: Convert to SPDX identifier
clocksource/drivers/lpc32xx: Convert to SPDX identifier
clocksource/drivers/digicolor: Convert to SPDX identifier
clocksource/drivers/armada-370-xp: Convert to SPDX identifier
clocksource/drivers/mips-gic-timer: Convert to SPDX identifier
clocksource/drivers/jcore: Convert to SPDX identifier
clocksource/drivers/bcm_kona: Convert to SPDX identifier
clocksource/drivers/sp804: Avoid error on multiple instances
clocksource/drivers/riscv: Events are stopped during CPU suspend
clocksource/drivers/ixp4xx: Drop boardfile probe path
dt-bindings: timer: Add compatible for Mediatek MT8186
Patch series from Nick Hawkins:
"The GXP is the HPE BMC SoC that is used in the majority of HPE current
generation servers. Traditionally the asic will last multiple
generations of server before being replaced.
Info about SoC:
HPE GXP is the name of the HPE Soc. This SoC is used to implement many
BMC features at HPE. It supports ARMv7 architecture based on the Cortex
A9 core. It is capable of using an AXI bus to which a memory controller
is attached. It has multiple SPI interfaces to connect boot flash and
BIOS flash. It uses a 10/100/1000 MAC for network connectivity. It has
multiple i2c engines to drive connectivity with a host infrastructure.
The initial patches enable the watchdog and timer enabling the host to
be able to boot."
* hpe/gxp-soc:
MAINTAINERS: Introduce HPE GXP Architecture
ARM: dts: Introduce HPE GXP Device tree
dt-bindings: arm: hpe: add GXP Support
dt-bindings: timer: hpe,gxp-timer: Add HPE GXP Timer and Watchdog
clocksource/drivers/timer-gxp: Add HPE GXP Timer
watchdog: hpe-wdt: Introduce HPE GXP Watchdog
ARM: configs: multi_v7_defconfig: Add HPE GXP ARCH
ARM: hpe: Introduce the HPE GXP architecture
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull asm-generic updates from Arnd Bergmann:
"The asm-generic tree contains three separate changes for linux-5.19:
- The h8300 architecture is retired after it has been effectively
unmaintained for a number of years. This is the last architecture
we supported that has no MMU implementation, but there are still a
few architectures (arm, m68k, riscv, sh and xtensa) that support
CPUs with and without an MMU.
- A series to add a generic ticket spinlock that can be shared by
most architectures with a working cmpxchg or ll/sc type atomic,
including the conversion of riscv, csky and openrisc. This series
is also a prerequisite for the loongarch64 architecture port that
will come as a separate pull request.
- A cleanup of some exported uapi header files to ensure they can be
included from user space without relying on other kernel headers"
* tag 'asm-generic-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
h8300: remove stale bindings and symlink
sparc: add asm/stat.h to UAPI compile-test coverage
powerpc: add asm/stat.h to UAPI compile-test coverage
mips: add asm/stat.h to UAPI compile-test coverage
riscv: add linux/bpf_perf_event.h to UAPI compile-test coverage
kbuild: prevent exported headers from including <stdlib.h>, <stdbool.h>
agpgart.h: do not include <stdlib.h> from exported header
csky: Move to generic ticket-spinlock
RISC-V: Move to queued RW locks
RISC-V: Move to generic spinlocks
openrisc: Move to ticket-spinlock
asm-generic: qrwlock: Document the spinlock fairness requirements
asm-generic: qspinlock: Indicate the use of mixed-size atomics
asm-generic: ticket-lock: New generic ticket-based spinlock
remove the h8300 architecture
Pull ARMv4T/v5 multiplatform support from Arnd Bergmann:
"This series has been 12 years in the making, it mostly finishes the
work that was started with the founding of Linaro to clean up platform
support in the kernel.
The largest change here is a cleanup of the omap1 platform, which is
the final ARM machine type to get converted to the common-clk
subsystem. All the omap1 specific drivers are now made independent of
the mach/*.h headers to allow the platform to be part of a generic
ARMv4/v5 multiplatform kernel.
The last bit that enables this support is still missing here while we
wait for some last dependencies to make it into the mainline kernel
through other subsystems.
The s3c24xx, ixp4xx, iop32x, ep93xx and dove platforms were all almost
at the point of allowing multiplatform kernels, this work gets
completed here along with a few additional cleanup. At the same time,
the s3c24xx and s3c64xx are now deprecated and expected to get removed
in the future.
The PXA and OMAP1 bits are in a separate branch because of
dependencies. Once both branches are merged, only the three Intel
StrongARM platforms (RiscPC, Footbridge/NetWinder and StrongARM1100)
need separate kernels, and there are no plans to include these"
* tag 'arm-multiplatform-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (61 commits)
ARM: ixp4xx: Consolidate Kconfig fixing issue
ARM: versatile: Add missing of_node_put in dcscb_init
ARM: config: Refresh IXP4xx config after multiplatform
ARM: omap1: add back omap_set_dma_priority() stub
ARM: omap: fix missing declaration warnings
ARM: omap: fix address space warnings from sparse
ARM: spear: remove include/mach/ subdirectory
ARM: davinci: remove include/mach/ subdirectory
ARM: omap2: remove include/mach/ subdirectory
integrator: remove empty ap_init_early()
ARM: s3c: fix include path
MAINTAINERS: omap1: Add Janusz as an additional maintainer
ARM: omap1: htc_herald: fix typos in comments
ARM: OMAP1: fix typos in comments
ARM: OMAP1: clock: Remove noop code
ARM: OMAP1: clock: Remove unused code
ARM: OMAP1: clock: Fix UART rate reporting algorithm
ARM: OMAP1: clock: Fix early UART rate issues
ARM: OMAP1: Prepare for conversion of OMAP1 clocks to CCF
ARM: omap1: fix build with no SoC selected
...
