20 Commits

Author SHA1 Message Date
Guo Ren
ebc9cb03b2
riscv: stack: Fixup independent softirq stack for CONFIG_FRAME_POINTER=n
The independent softirq stack uses s0 to save & restore sp, but s0 would
be corrupted when CONFIG_FRAME_POINTER=n. So add s0 in the clobber list
to fix the problem.

Fixes: dd69d07a5a6c ("riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK")
Cc: stable@vger.kernel.org
Reported-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Tested-by: Drew Fustini <dfustini@baylibre.com>
Link: https://lore.kernel.org/r/20230716001506.3506041-3-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-16 07:26:29 -07:00
Guo Ren
dd69d07a5a
riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK
Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config, and
the irq and softirq use the same irq_stack of percpu.

Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230614013018.2168426-3-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-22 10:38:36 -07:00
Guo Ren
163e76cc6e
riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK
Add independent irq stacks for percpu to prevent kernel stack overflows.
It is also compatible with VMAP_STACK by arch_alloc_vmap_stack.

Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Clément Léger <cleger@rivosinc.com>
Link: https://lore.kernel.org/r/20230614013018.2168426-2-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-22 10:38:35 -07:00
Anup Patel
832f15f426 RISC-V: Treat IPIs as normal Linux IRQs
Currently, the RISC-V kernel provides arch specific hooks (i.e.
struct riscv_ipi_ops) to register IPI handling methods. The stats
gathering of IPIs is also arch specific in the RISC-V kernel.

Other architectures (such as ARM, ARM64, and MIPS) have moved away
from custom arch specific IPI handling methods. Currently, these
architectures have Linux irqchip drivers providing a range of Linux
IRQ numbers to be used as IPIs and IPI triggering is done using
generic IPI APIs. This approach allows architectures to treat IPIs
as normal Linux IRQs and IPI stats gathering is done by the generic
Linux IRQ subsystem.

We extend the RISC-V IPI handling as-per above approach so that arch
specific IPI handling methods (struct riscv_ipi_ops) can be removed
and the IPI handling is done through the Linux IRQ subsystem.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230328035223.1480939-4-apatel@ventanamicro.com
2023-04-08 11:26:24 +01:00
Anup Patel
0c60a31ce6 irqchip/riscv-intc: Allow drivers to directly discover INTC hwnode
Various RISC-V drivers (such as SBI IPI, SBI Timer, SBI PMU, and
KVM RISC-V) don't have associated DT node but these drivers need
standard per-CPU (local) interrupts defined by the RISC-V privileged
specification.

We add riscv_get_intc_hwnode() in arch/riscv which allows RISC-V
drivers not having DT node to discover INTC hwnode which in-turn
helps these drivers to map per-CPU (local) interrupts provided
by the INTC driver.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230328035223.1480939-3-apatel@ventanamicro.com
2023-04-08 11:26:24 +01:00
Anup Patel
24dc17005c
RISC-V: Remove do_IRQ() function
The only thing do_IRQ() does is call handle_arch_irq function
pointer. We can very well call handle_arch_irq function pointer
directly from assembly and remove do_IRQ() function hence this
patch.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-09 19:11:24 -07:00
Anup Patel
6b7ce8927b
irqchip: RISC-V per-HART local interrupt controller driver
The RISC-V per-HART local interrupt controller manages software
interrupts, timer interrupts, external interrupts (which are routed
via the platform level interrupt controller) and other per-HART
local interrupts.

We add a driver for the RISC-V local interrupt controller, which
eventually replaces the RISC-V architecture code, allowing for a
better split between arch code and drivers.

The driver is compliant with RISC-V Hart-Level Interrupt Controller
DT bindings located at:
Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt

Co-developed-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
[Palmer: Cleaned up warnings]
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2020-06-09 19:11:21 -07:00
Anup Patel
5cf998ba8c
RISC-V: self-contained IPI handling routine
Currently, the IPI handling routine riscv_software_interrupt() does
not take any argument and also does not perform irq_enter()/irq_exit().

This patch makes IPI handling routine more self-contained by:
1. Passing "pt_regs *" argument
2. Explicitly doing irq_enter()/irq_exit()
3. Explicitly save/restore "pt_regs *" using set_irq_regs()

With above changes, IPI handling routine does not depend on caller
function to perform irq_enter()/irq_exit() and save/restore of
"pt_regs *" hence its more self-contained. This also enables us
to call IPI handling routine from IRQCHIP drivers.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-09 19:11:19 -07:00
Paul Walmsley
2f3035da40 riscv: prefix IRQ_ macro names with an RV_ namespace
"IRQ_TIMER", used in the arch/riscv CSR header file, is a sufficiently
generic macro name that it's used by several source files across the
Linux code base.  Some of these other files ultimately include the
arch/riscv CSR include file, causing collisions.  Fix by prefixing the
RISC-V csr.h IRQ_ macro names with an RV_ prefix.

Fixes: a4c3733d32a72 ("riscv: abstract out CSR names for supervisor vs machine mode")
Reported-by: Olof Johansson <olof@lixom.net>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2020-01-04 21:48:59 -08:00
Christoph Hellwig
a4c3733d32 riscv: abstract out CSR names for supervisor vs machine mode
Many of the privileged CSRs exist in a supervisor and machine version
that are used very similarly.  Provide versions of the CSR names and
fields that map to either the S-mode or M-mode variant depending on
a new CONFIG_RISCV_M_MODE kconfig symbol.

Contains contributions from Damien Le Moal <Damien.LeMoal@wdc.com>
and Paul Walmsley <paul.walmsley@sifive.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource, drivers/irqchip
[paul.walmsley@sifive.com: updated to apply]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-05 09:20:42 -08:00
Paul Walmsley
f307307992 riscv: for C functions called only from assembly, mark with __visible
Rather than adding prototypes for C functions called only by assembly
code, mark them as __visible.  This avoids adding prototypes that will
never be used by the callers.  Resolves the following sparse warnings:

arch/riscv/kernel/irq.c:27:29: warning: symbol 'do_IRQ' was not declared. Should it be static?
arch/riscv/kernel/ptrace.c:151:6: warning: symbol 'do_syscall_trace_enter' was not declared. Should it be static?
arch/riscv/kernel/ptrace.c:165:6: warning: symbol 'do_syscall_trace_exit' was not declared. Should it be static?
arch/riscv/kernel/signal.c:295:17: warning: symbol 'do_notify_resume' was not declared. Should it be static?
arch/riscv/kernel/traps.c:92:1: warning: symbol 'do_trap_unknown' was not declared. Should it be static?
arch/riscv/kernel/traps.c:94:1: warning: symbol 'do_trap_insn_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:96:1: warning: symbol 'do_trap_insn_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:98:1: warning: symbol 'do_trap_insn_illegal' was not declared. Should it be static?
arch/riscv/kernel/traps.c💯1: warning: symbol 'do_trap_load_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:102:1: warning: symbol 'do_trap_load_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:104:1: warning: symbol 'do_trap_store_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:106:1: warning: symbol 'do_trap_store_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:108:1: warning: symbol 'do_trap_ecall_u' was not declared. Should it be static?
arch/riscv/kernel/traps.c:110:1: warning: symbol 'do_trap_ecall_s' was not declared. Should it be static?
arch/riscv/kernel/traps.c:112:1: warning: symbol 'do_trap_ecall_m' was not declared. Should it be static?
arch/riscv/kernel/traps.c:124:17: warning: symbol 'do_trap_break' was not declared. Should it be static?
arch/riscv/kernel/smpboot.c:136:24: warning: symbol 'smp_callin' was not declared. Should it be static?

Based on a suggestion from Luc Van Oostenryck.

This version includes changes based on feedback from Christoph Hellwig
<hch@lst.de>.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de> # for do_syscall_trace_*
2019-10-28 00:46:02 -07:00
Anup Patel
6dcaf00487
RISC-V: Add interrupt related SCAUSE defines in asm/csr.h
This patch adds SCAUSE interrupt flag and SCAUSE interrupt related
defines to asm/csr.h. We also use these defines in kernel/irq.c and
express SIE/SIP flags in-terms of SCAUSE interrupt causes.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-05-16 20:42:11 -07:00
Christoph Hellwig
bed1378706
riscv: print the unexpected interrupt cause
This has been helpful when debugging my pending nommu port.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-04-25 14:51:11 -07:00
Anup Patel
8b20d2db0a
RISC-V: Show IPI stats
This patch provides arch_show_interrupts() implementation to
show IPI stats via /proc/interrupts.

Now the contents of /proc/interrupts" will look like below:
           CPU0       CPU1       CPU2       CPU3
  8:         17          7          6         14  SiFive PLIC   8  virtio0
 10:         10         10          9         11  SiFive PLIC  10  ttyS0
IPI0:       170        673        251         79  Rescheduling interrupts
IPI1:         1         12         27          1  Function call interrupts

Signed-off-by: Anup Patel <anup@brainfault.org>
[Atish - Fixed checkpatch errors]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>

Changes since v2:
 - Remove use of IPI_CALL_WAKEUP because it's being removed

Changes since v1:
 - Add stub inline show_ipi_stats() function for !CONFIG_SMP
 - Make ipi_names[] dynamically sized at compile time
 - Minor beautification of ipi_names[] using tabs

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:37 -07:00
Anup Patel
1ed4237ab6
RISC-V: No need to pass scause as arg to do_IRQ()
The scause is already part of pt_regs so no need to pass
scause as separate arg to do_IRQ().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:35 -07:00
Palmer Dabbelt
62b0194368
clocksource: new RISC-V SBI timer driver
The RISC-V ISA defines a per-hart real-time clock and timer, which is
present on all systems.  The clock is accessed via the 'rdtime'
pseudo-instruction (which reads a CSR), and the timer is set via an SBI
call.

Contains various improvements from Atish Patra <atish.patra@wdc.com>.

Signed-off-by: Dmitriy Cherkasov <dmitriy@oss-tech.org>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
[hch: remove dead code, add SPDX tags, used riscv_of_processor_hart(),
 minor cleanups, merged  hotplug cpu support and other improvements
 from Atish]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:31 -07:00
Christoph Hellwig
6ea0f26a79
RISC-V: implement low-level interrupt handling
Add support for a routine that dispatches exceptions with the interrupt
flags set to either the IPI or irqdomain code (and the clock source in the
future).

Loosely based on the irq-riscv-int.c irqchip driver from the RISC-V tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:31 -07:00
Palmer Dabbelt
8606544890
RISC-V: Don't include irq-riscv-intc.h
This file has never existed in the upstream kernel, but it's guarded by
an #ifdef that's also never existed in the upstream kernel.  As a part
of our interrupt controller refactoring this header is no longer
necessary, but this reference managed to sneak in anyway.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-07-04 14:12:42 -07:00
Palmer Dabbelt
cc6c98485f RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handler
The existing mechanism for handling IRQs on RISC-V is pretty ugly: the irq
entry code selects the handler via Kconfig dependencies.

Use the new generic IRQ handling infastructure, which allows boot time
registration of the low level entry handler.

This does add an additional load to the interrupt latency, but there's a
lot of tuning left to be done there on RISC-V so it's OK for now.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: jonas@southpole.se
Cc: catalin.marinas@arm.com
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux@armlinux.org.uk
Cc: stefan.kristiansson@saunalahti.fi
Cc: openrisc@lists.librecores.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/20180307235731.22627-3-palmer@sifive.com
2018-03-14 21:46:29 +01:00
Palmer Dabbelt
76d2a0493a RISC-V: Init and Halt Code
This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system.  When a file was
init-related this patch contains the entire file.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:44 -07:00