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linux-next/include/asm-arm/arch-s3c2410/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

79 lines
1.8 KiB
ArmAsm

/*
* include/asm-arm/arch-s3c2410/entry-macro.S
*
* Low-level IRQ helper macros for S3C2410-based 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.
*/
/* We have a problem that the INTOFFSET register does not always
* show one interrupt. Occasionally we get two interrupts through
* the prioritiser, and this causes the INTOFFSET register to show
* what looks like the logical-or of the two interrupt numbers.
*
* Thanks to Klaus, Shannon, et al for helping to debug this problem
*/
#define INTPND (0x10)
#define INTOFFSET (0x14)
#include <asm/hardware.h>
#include <asm/irq.h>
.macro get_irqnr_preamble, base, tmp
.endm
.macro arch_ret_to_user, tmp1, tmp2
.endm
.macro get_irqnr_and_base, irqnr, irqstat, base, tmp
mov \base, #S3C24XX_VA_IRQ
@@ try the interrupt offset register, since it is there
ldr \irqstat, [ \base, #INTPND ]
teq \irqstat, #0
beq 1002f
ldr \irqnr, [ \base, #INTOFFSET ]
mov \tmp, #1
tst \irqstat, \tmp, lsl \irqnr
bne 1001f
@@ the number specified is not a valid irq, so try
@@ and work it out for ourselves
mov \irqnr, #0 @@ start here
@@ work out which irq (if any) we got
movs \tmp, \irqstat, lsl#16
addeq \irqnr, \irqnr, #16
moveq \irqstat, \irqstat, lsr#16
tst \irqstat, #0xff
addeq \irqnr, \irqnr, #8
moveq \irqstat, \irqstat, lsr#8
tst \irqstat, #0xf
addeq \irqnr, \irqnr, #4
moveq \irqstat, \irqstat, lsr#4
tst \irqstat, #0x3
addeq \irqnr, \irqnr, #2
moveq \irqstat, \irqstat, lsr#2
tst \irqstat, #0x1
addeq \irqnr, \irqnr, #1
@@ we have the value
1001:
adds \irqnr, \irqnr, #IRQ_EINT0
1002:
@@ exit here, Z flag unset if IRQ
.endm
/* currently don't need an disable_fiq macro */
.macro disable_fiq
.endm