diff options
Diffstat (limited to 'arch/arm/include')
| -rw-r--r-- | arch/arm/include/asm/hardware/entry-macro-gic.S | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/arm/include/asm/hardware/entry-macro-gic.S b/arch/arm/include/asm/hardware/entry-macro-gic.S new file mode 100644 index 0000000..05587f1 --- /dev/null +++ b/arch/arm/include/asm/hardware/entry-macro-gic.S @@ -0,0 +1,68 @@ +/* + * arch/arm/include/asm/hardware/entry-macro-gic.S + * + * Low-level IRQ helper macros for GIC + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <asm/hardware/gic.h> + +/* + * The interrupt numbering scheme is defined in the + * interrupt controller spec. To wit: + * + * Interrupts 0-15 are IPI + * 16-28 are reserved + * 29-31 are local. We allow 30 to be used for the watchdog. + * 32-1020 are global + * 1021-1022 are reserved + * 1023 is "spurious" (no interrupt) + * + * For now, we ignore all local interrupts so only return an interrupt if it's + * between 30 and 1020. The test_for_ipi routine below will pick up on IPIs. + * + * A simple read from the controller will tell us the number of the highest + * priority enabled interrupt. We then just need to check whether it is in the + * valid range for an IRQ (30-1020 inclusive). + */ + + .macro get_irqnr_and_base, irqnr, irqstat, base, tmp + + ldr \irqstat, [\base, #GIC_CPU_INTACK] + /* bits 12-10 = src CPU, 9-0 = int # */ + + ldr \tmp, =1021 + bic \irqnr, \irqstat, #0x1c00 + cmp \irqnr, #29 + cmpcc \irqnr, \irqnr + cmpne \irqnr, \tmp + cmpcs \irqnr, \irqnr + .endm + +/* We assume that irqstat (the raw value of the IRQ acknowledge + * register) is preserved from the macro above. + * If there is an IPI, we immediately signal end of interrupt on the + * controller, since this requires the original irqstat value which + * we won't easily be able to recreate later. + */ + + .macro test_for_ipi, irqnr, irqstat, base, tmp + bic \irqnr, \irqstat, #0x1c00 + cmp \irqnr, #16 + strcc \irqstat, [\base, #GIC_CPU_EOI] + cmpcs \irqnr, \irqnr + .endm + +/* As above, this assumes that irqstat and base are preserved.. */ + + .macro test_for_ltirq, irqnr, irqstat, base, tmp + bic \irqnr, \irqstat, #0x1c00 + mov \tmp, #0 + cmp \irqnr, #29 + moveq \tmp, #1 + streq \irqstat, [\base, #GIC_CPU_EOI] + cmp \tmp, #0 + .endm |