kernel-ark/include/asm-arm/arch-realview/entry-macro.S
Dan Williams f80dff9da0 [ARM] 4185/2: entry: introduce get_irqnr_preamble and arch_ret_to_user
get_irqnr_preamble allows machines to take some action before entering the
get_irqnr_and_base loop.  On iop we enable cp6 access.

arch_ret_to_user is added to the userspace return path to allow individual
architectures to take actions, like disabling coprocessor access, before
the final return to userspace.

Per Nicolas Pitre's note, there is no need to cp_wait on the return to user
as the latency to return is sufficient.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-02-17 15:04:29 +00:00

81 lines
2.2 KiB
ArmAsm

/*
* include/asm-arm/arch-realview/entry-macro.S
*
* Low-level IRQ helper macros for RealView platforms
*
* 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.h>
#include <asm/hardware/gic.h>
.macro disable_fiq
.endm
.macro get_irqnr_preamble, base, tmp
.endm
.macro arch_ret_to_user, tmp1, tmp2
.endm
/*
* 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 \base, =IO_ADDRESS(REALVIEW_GIC_CPU_BASE)
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