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| author | James Morse <james.morse@arm.com> | 2015-12-04 14:02:27 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2015-12-08 14:42:51 +0300 |
| commit | 8e23dacd12a48e58125b84c817da50850b73280a (patch) | |
| tree | b920b408538982d88d9482fc2c28f1b361062648 /arch/arm64/kernel/entry.S | |
| parent | 132cd887b5c54758d04bf25c52fa48f45e843a30 (diff) | |
| download | linux-8e23dacd12a48e58125b84c817da50850b73280a.tar.xz | |
arm64: Add do_softirq_own_stack() and enable irq_stacks
entry.S is modified to switch to the per_cpu irq_stack during el{0,1}_irq.
irq_count is used to detect recursive interrupts on the irq_stack, it is
updated late by do_softirq_own_stack(), when called on the irq_stack, before
__do_softirq() re-enables interrupts to process softirqs.
do_softirq_own_stack() is added by this patch, but does not yet switch
stack.
This patch adds the dummy stack frame and data needed by the previous
stack tracing patches.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/entry.S')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 42 |
1 files changed, 40 insertions, 2 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 245fa6837880..8f7e737949fe 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -27,6 +27,7 @@ #include <asm/cpufeature.h> #include <asm/errno.h> #include <asm/esr.h> +#include <asm/irq.h> #include <asm/thread_info.h> #include <asm/unistd.h> @@ -175,6 +176,42 @@ alternative_endif mrs \rd, sp_el0 .endm + .macro irq_stack_entry, dummy_lr + mov x19, sp // preserve the original sp + + adr_l x25, irq_stack + mrs x26, tpidr_el1 + add x25, x25, x26 + + /* + * Check the lowest address on irq_stack for the irq_count value, + * incremented by do_softirq_own_stack if we have re-enabled irqs + * while on the irq_stack. + */ + ldr x26, [x25] + cbnz x26, 9998f // recursive use? + + /* switch to the irq stack */ + mov x26, #IRQ_STACK_START_SP + add x26, x25, x26 + mov sp, x26 + + /* Add a dummy stack frame */ + stp x29, \dummy_lr, [sp, #-16]! // dummy stack frame + mov x29, sp + stp xzr, x19, [sp, #-16]! + +9998: + .endm + + /* + * x19 should be preserved between irq_stack_entry and + * irq_stack_exit. + */ + .macro irq_stack_exit + mov sp, x19 + .endm + /* * These are the registers used in the syscall handler, and allow us to * have in theory up to 7 arguments to a function - x0 to x6. @@ -190,10 +227,11 @@ tsk .req x28 // current thread_info * Interrupt handling. */ .macro irq_handler - adrp x1, handle_arch_irq - ldr x1, [x1, #:lo12:handle_arch_irq] + ldr_l x1, handle_arch_irq mov x0, sp + irq_stack_entry x22 blr x1 + irq_stack_exit .endm .text |