diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2021-12-02 09:36:59 +0100 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2021-12-06 12:49:17 +0100 |
| commit | cafc0eab168917ec9c0cd47d530a40cd40eb2928 (patch) | |
| tree | 92146e58caa9f383a8a6894aeeaa54bb1c563f7f | |
| parent | 9c46929e7989efacc1dd0a1dd662a839897ea2b6 (diff) | |
ARM: v7m: enable support for IRQ stacks
Enable support for IRQ stacks on !MMU, and add the code to the IRQ entry
path to switch to the IRQ stack if not running from it already.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-v7m.S | 17 |
2 files changed, 15 insertions, 3 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 50ae5286f59b..359a3b85c8b3 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1158,7 +1158,6 @@ config CURRENT_POINTER_IN_TPIDRURO config IRQSTACKS def_bool y - depends on MMU select HAVE_IRQ_EXIT_ON_IRQ_STACK select HAVE_SOFTIRQ_ON_OWN_STACK diff --git a/arch/arm/kernel/entry-v7m.S b/arch/arm/kernel/entry-v7m.S index 4e0d318b67c6..de8a60363c85 100644 --- a/arch/arm/kernel/entry-v7m.S +++ b/arch/arm/kernel/entry-v7m.S @@ -40,11 +40,24 @@ __irq_entry: @ Invoke the IRQ handler @ mov r0, sp - stmdb sp!, {lr} + ldr_this_cpu sp, irq_stack_ptr, r1, r2 + + @ + @ If we took the interrupt while running in the kernel, we may already + @ be using the IRQ stack, so revert to the original value in that case. + @ + subs r2, sp, r0 @ SP above bottom of IRQ stack? + rsbscs r2, r2, #THREAD_SIZE @ ... and below the top? + movcs sp, r0 + + push {r0, lr} @ preserve LR and original SP + @ routine called with r0 = struct pt_regs * bl generic_handle_arch_irq - pop {lr} + pop {r0, lr} + mov sp, r0 + @ @ Check for any pending work if returning to user @ |