Commit Graph

996217 Commits

Author SHA1 Message Date
Thomas Gleixner
765822e156 Merge tag 'irqchip-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Pull irqchip and irqdomain updates from Marc Zyngier:

 New HW support:

  - New driver for the Nuvoton WPCM450 interrupt controller
  - New driver for the IDT 79rc3243x interrupt controller
  - Add support for interrupt trigger configuration to the MStar irqchip
  - Add more external interrupt support to the STM32 irqchip
  - Add new compatible strings for QCOM SC7280 to the qcom-pdc binding

 Fixes and cleanups:

  - Drop irq_create_strict_mappings() and irq_create_identity_mapping()
    from the irqdomain API, with cleanups in a couple of drivers
  - Fix nested NMI issue with spurious interrupts on GICv3
  - Don't allow GICv4.1 vSGIs when the CPU doesn't support them
  - Various cleanups and minor fixes

Link: https://lore.kernel.org/r/20210424094640.1731920-1-maz@kernel.org
2021-04-24 21:18:44 +02:00
Robert Hancock
debf69cfd4 irqchip/xilinx: Expose Kconfig option for Zynq/ZynqMP
Previously the XILINX_INTC config option was hidden and only
auto-selected on the MicroBlaze platform. However, this IP can also be
used on the Zynq and ZynqMP platforms as a secondary cascaded
controller. Allow this option to be user-enabled on those platforms.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210423185853.2556087-1-robert.hancock@calian.com
2021-04-24 09:50:03 +01:00
He Ying
a97709f563 irqchip/gic-v3: Do not enable irqs when handling spurious interrups
We triggered the following error while running our 4.19 kernel
with the pseudo-NMI patches backported to it:

[   14.816231] ------------[ cut here ]------------
[   14.816231] kernel BUG at irq.c:99!
[   14.816232] Internal error: Oops - BUG: 0 [#1] SMP
[   14.816232] Process swapper/0 (pid: 0, stack limit = 0x(____ptrval____))
[   14.816233] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G           O      4.19.95.aarch64 #14
[   14.816233] Hardware name: evb (DT)
[   14.816234] pstate: 80400085 (Nzcv daIf +PAN -UAO)
[   14.816234] pc : asm_nmi_enter+0x94/0x98
[   14.816235] lr : asm_nmi_enter+0x18/0x98
[   14.816235] sp : ffff000008003c50
[   14.816235] pmr_save: 00000070
[   14.816237] x29: ffff000008003c50 x28: ffff0000095f56c0
[   14.816238] x27: 0000000000000000 x26: ffff000008004000
[   14.816239] x25: 00000000015e0000 x24: ffff8008fb916000
[   14.816240] x23: 0000000020400005 x22: ffff0000080817cc
[   14.816241] x21: ffff000008003da0 x20: 0000000000000060
[   14.816242] x19: 00000000000003ff x18: ffffffffffffffff
[   14.816243] x17: 0000000000000008 x16: 003d090000000000
[   14.816244] x15: ffff0000095ea6c8 x14: ffff8008fff5ab40
[   14.816244] x13: ffff8008fff58b9d x12: 0000000000000000
[   14.816245] x11: ffff000008c8a200 x10: 000000008e31fca5
[   14.816246] x9 : ffff000008c8a208 x8 : 000000000000000f
[   14.816247] x7 : 0000000000000004 x6 : ffff8008fff58b9e
[   14.816248] x5 : 0000000000000000 x4 : 0000000080000000
[   14.816249] x3 : 0000000000000000 x2 : 0000000080000000
[   14.816250] x1 : 0000000000120000 x0 : ffff0000095f56c0
[   14.816251] Call trace:
[   14.816251]  asm_nmi_enter+0x94/0x98
[   14.816251]  el1_irq+0x8c/0x180                    (IRQ C)
[   14.816252]  gic_handle_irq+0xbc/0x2e4
[   14.816252]  el1_irq+0xcc/0x180                    (IRQ B)
[   14.816253]  arch_timer_handler_virt+0x38/0x58
[   14.816253]  handle_percpu_devid_irq+0x90/0x240
[   14.816253]  generic_handle_irq+0x34/0x50
[   14.816254]  __handle_domain_irq+0x68/0xc0
[   14.816254]  gic_handle_irq+0xf8/0x2e4
[   14.816255]  el1_irq+0xcc/0x180                    (IRQ A)
[   14.816255]  arch_cpu_idle+0x34/0x1c8
[   14.816255]  default_idle_call+0x24/0x44
[   14.816256]  do_idle+0x1d0/0x2c8
[   14.816256]  cpu_startup_entry+0x28/0x30
[   14.816256]  rest_init+0xb8/0xc8
[   14.816257]  start_kernel+0x4c8/0x4f4
[   14.816257] Code: 940587f1 d5384100 b9401001 36a7fd01 (d4210000)
[   14.816258] Modules linked in: start_dp(O) smeth(O)
[   15.103092] ---[ end trace 701753956cb14aa8 ]---
[   15.103093] Kernel panic - not syncing: Fatal exception in interrupt
[   15.103099] SMP: stopping secondary CPUs
[   15.103100] Kernel Offset: disabled
[   15.103100] CPU features: 0x36,a2400218
[   15.103100] Memory Limit: none

which is cause by a 'BUG_ON(in_nmi())' in nmi_enter().

From the call trace, we can find three interrupts (noted A, B, C above):
interrupt (A) is preempted by (B), which is further interrupted by (C).

Subsequent investigations show that (B) results in nmi_enter() being
called, but that it actually is a spurious interrupt. Furthermore,
interrupts are reenabled in the context of (B), and (C) fires with
NMI priority. We end-up with a nested NMI situation, something
we definitely do not want to (and cannot) handle.

The bug here is that spurious interrupts should never result in any
state change, and we should just return to the interrupted context.
Moving the handling of spurious interrupts as early as possible in
the GICv3 handler fixes this issue.

Fixes: 3f1f3234bc ("irqchip/gic-v3: Switch to PMR masking before calling IRQ handler")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: He Ying <heying24@huawei.com>
[maz: rewrote commit message, corrected Fixes: tag]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210423083516.170111-1-heying24@huawei.com
Cc: stable@vger.kernel.org
2021-04-23 13:19:08 +01:00
Thomas Bogendoerfer
05d7bf8170 dt-bindings: interrupt-controller: Add IDT 79RC3243x Interrupt Controller
Document DT bindings for IDT 79RC3243x Interrupt Controller.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210422145330.73452-2-tsbogend@alpha.franken.de
2021-04-22 16:03:18 +01:00
Thomas Bogendoerfer
529ea36818 irqchip: Add support for IDT 79rc3243x interrupt controller
IDT 79rc3243x SoCs have rather simple interrupt controllers connected
to the MIPS CPU interrupt lines. Each of them has room for up to
32 interrupts.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210422145330.73452-1-tsbogend@alpha.franken.de
2021-04-22 16:03:18 +01:00
Marc Zyngier
817aad5d08 irqdomain: Drop references to recusive irqdomain setup
It was never completely implemented, and was removed a long time
ago. Adjust the documentation to reflect this.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210406093557.1073423-8-maz@kernel.org
2021-04-22 15:55:22 +01:00
Marc Zyngier
1a0b05e435 irqdomain: Get rid of irq_create_strict_mappings()
No user of this helper is left, remove it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-04-22 15:55:22 +01:00
Marc Zyngier
5f8b938bd7 irqchip/jcore-aic: Kill use of irq_create_strict_mappings()
irq_create_strict_mappings() is a poor way to allow the use of
a linear IRQ domain as a legacy one. Let's be upfront about it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210406093557.1073423-4-maz@kernel.org
2021-04-22 15:55:22 +01:00
Marc Zyngier
b68761da01 ARM: PXA: Kill use of irq_create_strict_mappings()
irq_create_strict_mappings() is a poor way to allow the use of
a linear IRQ domain as a legacy one. Let's be upfront about
it and use a legacy domain when appropriate.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210406093557.1073423-3-maz@kernel.org
2021-04-22 15:55:21 +01:00
Lorenzo Pieralisi
46135d6f87 irqchip/gic-v4.1: Disable vSGI upon (GIC CPUIF < v4.1) detection
GIC CPU interfaces versions predating GIC v4.1 were not built to
accommodate vINTID within the vSGI range; as reported in the GIC
specifications (8.2 "Changes to the CPU interface"), it is
CONSTRAINED UNPREDICTABLE to deliver a vSGI to a PE with
ID_AA64PFR0_EL1.GIC < b0011.

Check the GIC CPUIF version by reading the SYS_ID_AA64_PFR0_EL1.

Disable vSGIs if a CPUIF version < 4.1 is detected to prevent using
vSGIs on systems where they may misbehave.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210317100719.3331-2-lorenzo.pieralisi@arm.com
2021-04-22 15:55:21 +01:00
Randy Dunlap
a6992bbe97 irqchip/tb10x: Use 'fallthrough' to eliminate a warning
Use the 'fallthrough' macro to document that this switch case
does indeed fall through to the next case.

../drivers/irqchip/irq-tb10x.c: In function 'tb10x_irq_set_type':
../drivers/irqchip/irq-tb10x.c:62:13: warning: this statement may fall through [-Wimplicit-fallthrough=]
   62 |   flow_type = IRQ_TYPE_LEVEL_LOW;
../drivers/irqchip/irq-tb10x.c:63:2: note: here
   63 |  case IRQ_TYPE_LEVEL_LOW:
      |  ^~~~

Fixes: b06eb0173e ("irqchip: Add TB10x interrupt controller driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210422051620.23021-1-rdunlap@infradead.org
2021-04-22 13:53:33 +01:00
Nicholas Piggin
7c07012eb1 genirq: Reduce irqdebug cacheline bouncing
note_interrupt() increments desc->irq_count for each interrupt even for
percpu interrupt handlers, even when they are handled successfully. This
causes cacheline bouncing and limits scalability.

Instead of incrementing irq_count every time, only start incrementing it
after seeing an unhandled irq, which should avoid the cache line
bouncing in the common path.

This actually should give better consistency in handling misbehaving
irqs too, because instead of the first unhandled irq arriving at an
arbitrary point in the irq_count cycle, its arrival will begin the
irq_count cycle.

Cédric reports the result of his IPI throughput test:

               Millions of IPIs/s
 -----------   --------------------------------------
               upstream   upstream   patched
 chips  cpus   default    noirqdebug default (irqdebug)
 -----------   -----------------------------------------
 1      0-15     4.061      4.153      4.084
        0-31     7.937      8.186      8.158
        0-47    11.018     11.392     11.233
        0-63    11.460     13.907     14.022
 2      0-79     8.376     18.105     18.084
        0-95     7.338     22.101     22.266
        0-111    6.716     25.306     25.473
        0-127    6.223     27.814     28.029

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210402132037.574661-1-npiggin@gmail.com
2021-04-10 13:35:54 +02:00
Tetsuo Handa
c5e3a41187 kernel: Initialize cpumask before parsing
KMSAN complains that new_value at cpumask_parse_user() from
write_irq_affinity() from irq_affinity_proc_write() is uninitialized.

  [  148.133411][ T5509] =====================================================
  [  148.135383][ T5509] BUG: KMSAN: uninit-value in find_next_bit+0x325/0x340
  [  148.137819][ T5509]
  [  148.138448][ T5509] Local variable ----new_value.i@irq_affinity_proc_write created at:
  [  148.140768][ T5509]  irq_affinity_proc_write+0xc3/0x3d0
  [  148.142298][ T5509]  irq_affinity_proc_write+0xc3/0x3d0
  [  148.143823][ T5509] =====================================================

Since bitmap_parse() from cpumask_parse_user() calls find_next_bit(),
any alloc_cpumask_var() + cpumask_parse_user() sequence has possibility
that find_next_bit() accesses uninitialized cpu mask variable. Fix this
problem by replacing alloc_cpumask_var() with zalloc_cpumask_var().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20210401055823.3929-1-penguin-kernel@I-love.SAKURA.ne.jp
2021-04-10 13:35:54 +02:00
Marc Zyngier
94bc94209a irqchip/wpcm450: Drop COMPILE_TEST
This driver is (for now) ARM specific, and currently doesn't
build with a variety of architectures (ia64, RISC-V, x86_64
at the very least).

Drop COMPILE_TEST from Kconfig until it gets sorted out.

Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-04-08 11:37:14 +01:00
Mark-PK Tsai
ea4aeaa5c8 irqchip/irq-mst: Support polarity configuration
Support irq polarity configuration and save and restore the config
when system suspend and resume.

Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
[maz: fixed irq_set_type callback]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210315131848.31840-1-mark-pk.tsai@mediatek.com
2021-04-07 13:26:00 +01:00
Jonathan Neuschäfer
fead4dd496 irqchip: Add driver for WPCM450 interrupt controller
The WPCM450 AIC ("Advanced Interrupt Controller") is the interrupt
controller found in the Nuvoton WPCM450 SoC and other Winbond/Nuvoton
SoCs.

The list of registers if based on the AMI vendor kernel and the
Nuvoton W90N745 datasheet.

Although the hardware supports other interrupt modes, the driver only
supports high-level interrupts at the moment, because other modes could
not be tested so far.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210406120921.2484986-7-j.neuschaefer@gmx.net
2021-04-07 13:26:00 +01:00
Jonathan Neuschäfer
7c18715546 dt-bindings: interrupt-controller: Add nuvoton, wpcm450-aic
The WPCM450 AIC ("Advanced Interrupt Controller") is the interrupt
controller found in the Nuvoton WPCM450 SoC and other Winbond/Nuvoton
SoCs.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210406120921.2484986-4-j.neuschaefer@gmx.net
2021-04-07 13:26:00 +01:00
Rajendra Nayak
5deaa1d7c4 dt-bindings: qcom,pdc: Add compatible for sc7280
Add the compatible string for sc7280 SoC from Qualcomm

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1615787946-26474-1-git-send-email-rnayak@codeaurora.org
2021-04-07 13:26:00 +01:00
Erwan Le Ray
e12c455055 irqchip/stm32: Add usart instances exti direct event support
Add following usart instances exti direct event support (used for UART wake
up).
- exti 26 (USART1) is mapped to GIC 37
- exti 27 (USART2) is mapped to GIC 38
- exti 28 (USART3) is mapped to GIC 39
- exti 29 (USART6) is mapped to GIC 71
- exti 31 (UART5) is mapped to GIC 53
- exti 32 (UART7) is mapped to GIC 82
- exti 33 (UART8) is mapped to GIC 83

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319184253.5841-4-erwan.leray@foss.st.com
2021-04-07 13:25:52 +01:00
Arnd Bergmann
8e13d96670 irqchip/gic-v3: Fix OF_BAD_ADDR error handling
When building with extra warnings enabled, clang points out a
mistake in the error handling:

drivers/irqchip/irq-gic-v3-mbi.c:306:21: error: result of comparison of constant 18446744073709551615 with expression of type 'phys_addr_t' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
                if (mbi_phys_base == OF_BAD_ADDR) {

Truncate the constant to the same type as the variable it gets compared
to, to shut make the check work and void the warning.

Fixes: 505287525c ("irqchip/gic-v3: Add support for Message Based Interrupts as an MSI controller")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210323131842.2773094-1-arnd@kernel.org
2021-04-07 13:25:52 +01:00
Jisheng Zhang
e03b7c1bcb irqchip/sifive-plic: Mark two global variables __ro_after_init
All of these two are never modified after init, so they can be
 __ro_after_init.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210330020911.26423e9e@xhacker
2021-04-07 13:25:52 +01:00
Hao Fang
64ec2ad3b8 irqchip/hisi: Use the correct HiSilicon copyright
s/Hisilicon/HiSilicon/
It should use capital S, according to
https://www.hisilicon.com/en/terms-of-use.

Signed-off-by: Hao Fang <fanghao11@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1617086780-8521-1-git-send-email-fanghao11@huawei.com
2021-04-07 13:25:52 +01:00
Marc Zyngier
bd781ae53f mips: netlogic: Use irq_domain_simple_ops for XLP PIC
Use the generic irq_domain_simple_ops structure instead of
a home-grown one.

Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-04-07 13:25:52 +01:00
Marc Zyngier
4a35d6a037 irqdomain: Get rid of irq_create_identity_mapping()
The sole user of irq_create_identity_mapping() having been converted,
get rid of the unused helper.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-04-07 13:25:52 +01:00
Marc Zyngier
eef56c3a04 sh: intc: Drop the use of irq_create_identity_mapping()
Instead of playing games with using irq_create_identity_mapping()
and irq_domain_associate(), drop the use of the former and only
use the latter, together with the allocation of the irq_desc
as needed.

It doesn't make the code less awful, but at least the intent
is clearer.

Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-04-07 12:12:52 +01:00
Bartosz Golaszewski
883ccef355 genirq/irq_sim: Shrink devm_irq_domain_create_sim()
The custom devres structure manages only a single pointer which can
can be achieved by using devm_add_action_or_reset() as well which
makes the code simpler.

[ tglx: Fixed return value handling - found by smatch ]

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210301142659.8971-1-brgl@bgdev.pl
2021-03-30 13:21:27 +02:00
Sebastian Andrzej Siewior
6e45791493 drm/i915: Use tasklet_unlock_spin_wait() in __tasklet_disable_sync_once()
The i915 driver has its own tasklet interface which was overseen in the
tasklet rework. __tasklet_disable_sync_once() is a wrapper around
tasklet_unlock_wait(). tasklet_unlock_wait() might sleep, but the i915
wrappers invokes it from non-preemtible contexts with bottom halves disabled.

Use tasklet_unlock_spin_wait() instead which can be invoked from
non-preemptible contexts.

Fixes: da04474740 ("tasklets: Replace spin wait in tasklet_unlock_wait()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210323092221.awq7g5b2muzypjw3@flow
2021-03-25 18:21:03 +01:00
Ingo Molnar
a359f75796 irq: Fix typos in comments
Fix ~36 single-word typos in the IRQ, irqchip and irqdomain code comments.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-03-22 04:23:14 +01:00
Vitaly Kuznetsov
c93a5e20c3 genirq/matrix: Prevent allocation counter corruption
When irq_matrix_free() is called for an unallocated vector the
managed_allocated and total_allocated counters get out of sync with the
real state of the matrix. Later, when the last interrupt is freed, these
counters will underflow resulting in UINTMAX because the counters are
unsigned.

While this is certainly a problem of the calling code, this can be catched
in the allocator by checking the allocation bit for the to be freed vector
which simplifies debugging.

An example of the problem described above:
https://lore.kernel.org/lkml/20210318192819.636943062@linutronix.de/

Add the missing sanity check and emit a warning when it triggers.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210319111823.1105248-1-vkuznets@redhat.com
2021-03-19 22:52:11 +01:00
Juergen Gross
2c6b02185c irq: Simplify condition in irq_matrix_reserve()
The if condition in irq_matrix_reserve() can be much simpler.

While at it fix a typo in the comment.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210211070953.5914-1-jgross@suse.com
2021-03-17 21:44:01 +01:00
Thomas Gleixner
ba9e6cab49 rcu: Prevent false positive softirq warning on RT
Soft interrupt disabled sections can legitimately be preempted or schedule
out when blocking on a lock on RT enabled kernels so the RCU preempt check
warning has to be disabled for RT kernels.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309085727.626304079@linutronix.de
2021-03-17 16:34:12 +01:00
Thomas Gleixner
47c218dcae tick/sched: Prevent false positive softirq pending warnings on RT
On RT a task which has soft interrupts disabled can block on a lock and
schedule out to idle while soft interrupts are pending. This triggers the
warning in the NOHZ idle code which complains about going idle with pending
soft interrupts. But as the task is blocked soft interrupt processing is
temporarily blocked as well which means that such a warning is a false
positive.

To prevent that check the per CPU state which indicates that a scheduled
out task has soft interrupts disabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309085727.527563866@linutronix.de
2021-03-17 16:34:11 +01:00
Thomas Gleixner
8b1c04acad softirq: Make softirq control and processing RT aware
Provide a local lock based serialization for soft interrupts on RT which
allows the local_bh_disabled() sections and servicing soft interrupts to be
preemptible.

Provide the necessary inline helpers which allow to reuse the bulk of the
softirq processing code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309085727.426370483@linutronix.de
2021-03-17 16:34:10 +01:00
Thomas Gleixner
f02fc963e9 softirq: Move various protections into inline helpers
To allow reuse of the bulk of softirq processing code for RT and to avoid
#ifdeffery all over the place, split protections for various code sections
out into inline helpers so the RT variant can just replace them in one go.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309085727.310118772@linutronix.de
2021-03-17 16:34:10 +01:00
Thomas Gleixner
6516b386d8 irqtime: Make accounting correct on RT
vtime_account_irq and irqtime_account_irq() base checks on preempt_count()
which fails on RT because preempt_count() does not contain the softirq
accounting which is seperate on RT.

These checks do not need the full preempt count as they only operate on the
hard and softirq sections.

Use irq_count() instead which provides the correct value on both RT and non
RT kernels. The compiler is clever enough to fold the masking for !RT:

       99b:	65 8b 05 00 00 00 00 	mov    %gs:0x0(%rip),%eax
 -     9a2:	25 ff ff ff 7f       	and    $0x7fffffff,%eax
 +     9a2:	25 00 ff ff 00       	and    $0xffff00,%eax

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309085727.153926793@linutronix.de
2021-03-17 16:34:09 +01:00
Thomas Gleixner
728b478d2d softirq: Add RT specific softirq accounting
RT requires the softirq processing and local bottomhalf disabled regions to
be preemptible. Using the normal preempt count based serialization is
therefore not possible because this implicitely disables preemption.

RT kernels use a per CPU local lock to serialize bottomhalfs. As
local_bh_disable() can nest the lock can only be acquired on the outermost
invocation of local_bh_disable() and released when the nest count becomes
zero. Tasks which hold the local lock can be preempted so its required to
keep track of the nest count per task.

Add a RT only counter to task struct and adjust the relevant macros in
preempt.h.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309085726.983627589@linutronix.de
2021-03-17 16:34:08 +01:00
Thomas Gleixner
6fd4e86125 tasklets: Switch tasklet_disable() to the sleep wait variant
-- NOT FOR IMMEDIATE MERGING --

Now that all users of tasklet_disable() are invoked from sleepable context,
convert it to use tasklet_unlock_wait() which might sleep.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084242.726452321@linutronix.de
2021-03-17 16:34:07 +01:00
Sebastian Andrzej Siewior
f339fc16fb firewire: ohci: Use tasklet_disable_in_atomic() where required
tasklet_disable() is invoked in several places. Some of them are in atomic
context which prevents a conversion of tasklet_disable() to a sleepable
function.

The atomic callchains are:

 ar_context_tasklet()
   ohci_cancel_packet()
     tasklet_disable()

 ...
   ohci_flush_iso_completions()
     tasklet_disable()

The invocation of tasklet_disable() from at_context_flush() is always in
preemptible context.

Use tasklet_disable_in_atomic() for the two invocations in
ohci_cancel_packet() and ohci_flush_iso_completions().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084242.616379058@linutronix.de
2021-03-17 16:34:05 +01:00
Sebastian Andrzej Siewior
be4017cea0 PCI: hv: Use tasklet_disable_in_atomic()
The hv_compose_msi_msg() callback in irq_chip::irq_compose_msi_msg is
invoked via irq_chip_compose_msi_msg(), which itself is always invoked from
atomic contexts from the guts of the interrupt core code.

There is no way to change this w/o rewriting the whole driver, so use
tasklet_disable_in_atomic() which allows to make tasklet_disable()
sleepable once the remaining atomic users are addressed.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084242.516519290@linutronix.de
2021-03-17 16:34:03 +01:00
Sebastian Andrzej Siewior
405698ca35 atm: eni: Use tasklet_disable_in_atomic() in the send() callback
The atmdev_ops::send callback which calls tasklet_disable() is invoked with
bottom halfs disabled from net_device_ops::ndo_start_xmit(). All other
invocations of tasklet_disable() in this driver happen in preemptible
context.

Change the send() call to use tasklet_disable_in_atomic() which allows
tasklet_disable() to be made sleepable once the remaining atomic context
usage sites are cleaned up.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084242.415583839@linutronix.de
2021-03-17 16:34:02 +01:00
Sebastian Andrzej Siewior
3250aa8a29 ath9k: Use tasklet_disable_in_atomic()
All callers of ath9k_beacon_ensure_primary_slot() are preemptible /
acquire a mutex except for this callchain:

  spin_lock_bh(&sc->sc_pcu_lock);
  ath_complete_reset()
  -> ath9k_calculate_summary_state()
     -> ath9k_beacon_ensure_primary_slot()

It's unclear how that can be distangled, so use tasklet_disable_in_atomic()
for now. This allows tasklet_disable() to become sleepable once the
remaining atomic users are cleaned up.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084242.313899703@linutronix.de
2021-03-17 16:34:02 +01:00
Sebastian Andrzej Siewior
25cf87df1a net: sundance: Use tasklet_disable_in_atomic().
tasklet_disable() is used in the timer callback. This might be distangled,
but without access to the hardware that's a bit risky.

Replace it with tasklet_disable_in_atomic() so tasklet_disable() can be
changed to a sleep wait once all remaining atomic users are converted.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084242.209110861@linutronix.de
2021-03-17 16:34:00 +01:00
Sebastian Andrzej Siewior
c62c38e349 net: jme: Replace link-change tasklet with work
The link change tasklet disables the tasklets for tx/rx processing while
upating hw parameters and then enables the tasklets again.

This update can also be pushed into a workqueue where it can be performed
in preemptible context. This allows tasklet_disable() to become sleeping.

Replace the linkch_task tasklet with a work.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084242.106288922@linutronix.de
2021-03-17 16:33:58 +01:00
Thomas Gleixner
eb2dafbba8 tasklets: Prevent tasklet_unlock_spin_wait() deadlock on RT
tasklet_unlock_spin_wait() spin waits for the TASKLET_STATE_SCHED bit in
the tasklet state to be cleared. This works on !RT nicely because the
corresponding execution can only happen on a different CPU.

On RT softirq processing is preemptible, therefore a task preempting the
softirq processing thread can spin forever.

Prevent this by invoking local_bh_disable()/enable() inside the loop. In
case that the softirq processing thread was preempted by the current task,
current will block on the local lock which yields the CPU to the preempted
softirq processing thread. If the tasklet is processed on a different CPU
then the local_bh_disable()/enable() pair is just a waste of processor
cycles.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.988908275@linutronix.de
2021-03-17 16:33:57 +01:00
Peter Zijlstra
697d8c63c4 tasklets: Replace spin wait in tasklet_kill()
tasklet_kill() spin waits for TASKLET_STATE_SCHED to be cleared invoking
yield() from inside the loop. yield() is an ill defined mechanism and the
result might still be wasting CPU cycles in a tight loop which is
especially painful in a guest when the CPU running the tasklet is scheduled
out.

tasklet_kill() is used in teardown paths and not performance critical at
all. Replace the spin wait with wait_var_event().

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.890532921@linutronix.de
2021-03-17 16:33:57 +01:00
Peter Zijlstra
da04474740 tasklets: Replace spin wait in tasklet_unlock_wait()
tasklet_unlock_wait() spin waits for TASKLET_STATE_RUN to be cleared. This
is wasting CPU cycles in a tight loop which is especially painful in a
guest when the CPU running the tasklet is scheduled out.

tasklet_unlock_wait() is invoked from tasklet_kill() which is used in
teardown paths and not performance critical at all. Replace the spin wait
with wait_var_event().

There are no users of tasklet_unlock_wait() which are invoked from atomic
contexts. The usage in tasklet_disable() has been replaced temporarily with
the spin waiting variant until the atomic users are fixed up and will be
converted to the sleep wait variant later.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.783936921@linutronix.de
2021-03-17 16:33:55 +01:00
Thomas Gleixner
b0cd02c2a9 tasklets: Use spin wait in tasklet_disable() temporarily
To ease the transition use spin waiting in tasklet_disable() until all
usage sites from atomic context have been cleaned up.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.685352806@linutronix.de
2021-03-17 16:33:54 +01:00
Thomas Gleixner
ca5f625118 tasklets: Provide tasklet_disable_in_atomic()
Replacing the spin wait loops in tasklet_unlock_wait() with
wait_var_event() is not possible as a handful of tasklet_disable()
invocations are happening in atomic context. All other invocations are in
teardown paths which can sleep.

Provide tasklet_disable_in_atomic() and tasklet_unlock_spin_wait() to
convert the few atomic use cases over, which allows to change
tasklet_disable() and tasklet_unlock_wait() in a later step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.563164193@linutronix.de
2021-03-17 16:33:52 +01:00
Thomas Gleixner
6951547a13 tasklets: Use static inlines for stub implementations
Inlines exist for a reason.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.407702697@linutronix.de
2021-03-17 16:33:51 +01:00
Thomas Gleixner
d2da74d127 tasklets: Replace barrier() with cpu_relax() in tasklet_unlock_wait()
A barrier() in a tight loop which waits for something to happen on a remote
CPU is a pointless exercise. Replace it with cpu_relax() which allows HT
siblings to make progress.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.249343366@linutronix.de
2021-03-17 16:33:51 +01:00