linux/arch/blackfin/mach-common/interrupt.S
Philippe Gerum 7a7967dc1b Blackfin: document __ipipe_call_irqtail
Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2009-09-16 21:28:38 -04:00

320 lines
7.4 KiB
ArmAsm

/*
* File: arch/blackfin/mach-common/interrupt.S
* Based on:
* Author: D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>
* Kenneth Albanowski <kjahds@kjahds.com>
*
* Created: ?
* Description: Interrupt Entries
*
* Modified:
* Copyright 2004-2006 Analog Devices Inc.
*
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <asm/blackfin.h>
#include <mach/irq.h>
#include <linux/linkage.h>
#include <asm/entry.h>
#include <asm/asm-offsets.h>
#include <asm/trace.h>
#include <asm/traps.h>
#include <asm/thread_info.h>
#include <asm/context.S>
.extern _ret_from_exception
#ifdef CONFIG_I_ENTRY_L1
.section .l1.text
#else
.text
#endif
.align 4 /* just in case */
/* Common interrupt entry code. First we do CLI, then push
* RETI, to keep interrupts disabled, but to allow this state to be changed
* by local_bh_enable.
* R0 contains the interrupt number, while R1 may contain the value of IPEND,
* or garbage if IPEND won't be needed by the ISR. */
__common_int_entry:
[--sp] = fp;
[--sp] = usp;
[--sp] = i0;
[--sp] = i1;
[--sp] = i2;
[--sp] = i3;
[--sp] = m0;
[--sp] = m1;
[--sp] = m2;
[--sp] = m3;
[--sp] = l0;
[--sp] = l1;
[--sp] = l2;
[--sp] = l3;
[--sp] = b0;
[--sp] = b1;
[--sp] = b2;
[--sp] = b3;
[--sp] = a0.x;
[--sp] = a0.w;
[--sp] = a1.x;
[--sp] = a1.w;
[--sp] = LC0;
[--sp] = LC1;
[--sp] = LT0;
[--sp] = LT1;
[--sp] = LB0;
[--sp] = LB1;
[--sp] = ASTAT;
[--sp] = r0; /* Skip reserved */
[--sp] = RETS;
r2 = RETI;
[--sp] = r2;
[--sp] = RETX;
[--sp] = RETN;
[--sp] = RETE;
[--sp] = SEQSTAT;
[--sp] = r1; /* IPEND - R1 may or may not be set up before jumping here. */
/* Switch to other method of keeping interrupts disabled. */
#ifdef CONFIG_DEBUG_HWERR
r1 = 0x3f;
sti r1;
#else
cli r1;
#endif
[--sp] = RETI; /* orig_pc */
/* Clear all L registers. */
r1 = 0 (x);
l0 = r1;
l1 = r1;
l2 = r1;
l3 = r1;
#ifdef CONFIG_FRAME_POINTER
fp = 0;
#endif
#if ANOMALY_05000283 || ANOMALY_05000315
cc = r7 == r7;
p5.h = HI(CHIPID);
p5.l = LO(CHIPID);
if cc jump 1f;
r7.l = W[p5];
1:
#endif
r1 = sp;
SP += -12;
#ifdef CONFIG_IPIPE
call ___ipipe_grab_irq
SP += 12;
cc = r0 == 0;
if cc jump .Lcommon_restore_context;
#else /* CONFIG_IPIPE */
call _do_irq;
SP += 12;
#endif /* CONFIG_IPIPE */
call _return_from_int;
.Lcommon_restore_context:
RESTORE_CONTEXT
rti;
/* interrupt routine for ivhw - 5 */
ENTRY(_evt_ivhw)
/* In case a single action kicks off multiple memory transactions, (like
* a cache line fetch, - this can cause multiple hardware errors, let's
* catch them all. First - make sure all the actions are complete, and
* the core sees the hardware errors.
*/
SSYNC;
SSYNC;
SAVE_ALL_SYS
#ifdef CONFIG_FRAME_POINTER
fp = 0;
#endif
#if ANOMALY_05000283 || ANOMALY_05000315
cc = r7 == r7;
p5.h = HI(CHIPID);
p5.l = LO(CHIPID);
if cc jump 1f;
r7.l = W[p5];
1:
#endif
/* Handle all stacked hardware errors
* To make sure we don't hang forever, only do it 10 times
*/
R0 = 0;
R2 = 10;
1:
P0.L = LO(ILAT);
P0.H = HI(ILAT);
R1 = [P0];
CC = BITTST(R1, EVT_IVHW_P);
IF ! CC JUMP 2f;
/* OK a hardware error is pending - clear it */
R1 = EVT_IVHW_P;
[P0] = R1;
R0 += 1;
CC = R1 == R2;
if CC JUMP 2f;
JUMP 1b;
2:
# We are going to dump something out, so make sure we print IPEND properly
p2.l = lo(IPEND);
p2.h = hi(IPEND);
r0 = [p2];
[sp + PT_IPEND] = r0;
/* set the EXCAUSE to HWERR for trap_c */
r0 = [sp + PT_SEQSTAT];
R1.L = LO(VEC_HWERR);
R1.H = HI(VEC_HWERR);
R0 = R0 | R1;
[sp + PT_SEQSTAT] = R0;
r0 = sp; /* stack frame pt_regs pointer argument ==> r0 */
SP += -12;
call _trap_c;
SP += 12;
#ifdef EBIU_ERRMST
/* make sure EBIU_ERRMST is clear */
p0.l = LO(EBIU_ERRMST);
p0.h = HI(EBIU_ERRMST);
r0.l = (CORE_ERROR | CORE_MERROR);
w[p0] = r0.l;
#endif
call _ret_from_exception;
.Lcommon_restore_all_sys:
RESTORE_ALL_SYS
rti;
ENDPROC(_evt_ivhw)
/* Interrupt routine for evt2 (NMI).
* We don't actually use this, so just return.
* For inner circle type details, please see:
* http://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:nmi
*/
ENTRY(_evt_nmi)
.weak _evt_nmi
rtn;
ENDPROC(_evt_nmi)
/* interrupt routine for core timer - 6 */
ENTRY(_evt_timer)
TIMER_INTERRUPT_ENTRY(EVT_IVTMR_P)
/* interrupt routine for evt7 - 7 */
ENTRY(_evt_evt7)
INTERRUPT_ENTRY(EVT_IVG7_P)
ENTRY(_evt_evt8)
INTERRUPT_ENTRY(EVT_IVG8_P)
ENTRY(_evt_evt9)
INTERRUPT_ENTRY(EVT_IVG9_P)
ENTRY(_evt_evt10)
INTERRUPT_ENTRY(EVT_IVG10_P)
ENTRY(_evt_evt11)
INTERRUPT_ENTRY(EVT_IVG11_P)
ENTRY(_evt_evt12)
INTERRUPT_ENTRY(EVT_IVG12_P)
ENTRY(_evt_evt13)
INTERRUPT_ENTRY(EVT_IVG13_P)
/* interrupt routine for system_call - 15 */
ENTRY(_evt_system_call)
SAVE_CONTEXT_SYSCALL
#ifdef CONFIG_FRAME_POINTER
fp = 0;
#endif
call _system_call;
jump .Lcommon_restore_context;
ENDPROC(_evt_system_call)
#ifdef CONFIG_IPIPE
/*
* __ipipe_call_irqtail: lowers the current priority level to EVT15
* before running a user-defined routine, then raises the priority
* level to EVT14 to prepare the caller for a normal interrupt
* return through RTI.
*
* We currently use this facility in two occasions:
*
* - to branch to __ipipe_irq_tail_hook as requested by a high
* priority domain after the pipeline delivered an interrupt,
* e.g. such as Xenomai, in order to start its rescheduling
* procedure, since we may not switch tasks when IRQ levels are
* nested on the Blackfin, so we have to fake an interrupt return
* so that we may reschedule immediately.
*
* - to branch to sync_root_irqs, in order to play any interrupt
* pending for the root domain (i.e. the Linux kernel). This lowers
* the core priority level enough so that Linux IRQ handlers may
* never delay interrupts handled by high priority domains; we defer
* those handlers until this point instead. This is a substitute
* to using a threaded interrupt model for the Linux kernel.
*
* r0: address of user-defined routine
* context: caller must have preempted EVT15, hw interrupts must be off.
*/
ENTRY(___ipipe_call_irqtail)
p0 = r0;
r0.l = 1f;
r0.h = 1f;
reti = r0;
rti;
1:
[--sp] = rets;
[--sp] = ( r7:4, p5:3 );
sp += -12;
call (p0);
sp += 12;
( r7:4, p5:3 ) = [sp++];
rets = [sp++];
#ifdef CONFIG_DEBUG_HWERR
/* enable irq14 & hwerr interrupt, until we transition to _evt_evt14 */
r0 = (EVT_IVG14 | EVT_IVHW | \
EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
#else
/* Only enable irq14 interrupt, until we transition to _evt_evt14 */
r0 = (EVT_IVG14 | \
EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
#endif
sti r0;
raise 14; /* Branches to _evt_evt14 */
2:
jump 2b; /* Likely paranoid. */
ENDPROC(___ipipe_call_irqtail)
#endif /* CONFIG_IPIPE */