File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/blackfin/mach-common/interrupt.S b/arch/blackfin/mach-common/interrupt.S
new file mode 100644
index 0000000..469ce72
--- /dev/null
+++ b/arch/blackfin/mach-common/interrupt.S
@@ -0,0 +1,326 @@
+/*
+ * Interrupt Entries
+ *
+ * Copyright 2005-2009 Analog Devices Inc.
+ * D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>
+ * Kenneth Albanowski <kjahds@kjahds.com>
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#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
+#ifdef CONFIG_TRACE_IRQFLAGS
+ [--sp] = r0;
+ sp += -12;
+ call _trace_hardirqs_off;
+ sp += 12;
+ r0 = [sp++];
+#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
+
+ ANOMALY_283_315_WORKAROUND(p5, r7)
+
+ 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 */
+
+#ifdef CONFIG_PREEMPT
+ r7 = sp;
+ r4.l = lo(ALIGN_PAGE_MASK);
+ r4.h = hi(ALIGN_PAGE_MASK);
+ r7 = r7 & r4;
+ p5 = r7;
+ r7 = [p5 + TI_PREEMPT]; /* get preempt count */
+ r7 += 1; /* increment it */
+ [p5 + TI_PREEMPT] = r7;
+#endif
+ pseudo_long_call _do_irq, p2;
+
+#ifdef CONFIG_PREEMPT
+ r7 += -1;
+ [p5 + TI_PREEMPT] = r7; /* restore preempt count */
+#endif
+
+ SP += 12;
+#endif /* CONFIG_IPIPE */
+ pseudo_long_call _return_from_int, p2;
+.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
+
+ ANOMALY_283_315_WORKAROUND(p5, r7)
+
+ /* 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;
+ pseudo_long_call _trap_c, p5;
+ 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
+
+ pseudo_long_call _ret_from_exception, p2;
+
+.Lcommon_restore_all_sys:
+ RESTORE_ALL_SYS
+ rti;
+ENDPROC(_evt_ivhw)
+
+/* Interrupt routine for evt2 (NMI).
+ * For inner circle type details, please see:
+ * http://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:nmi
+ */
+ENTRY(_evt_nmi)
+#ifndef CONFIG_NMI_WATCHDOG
+.weak _evt_nmi
+#else
+ /* Not take account of CPLBs, this handler will not return */
+ SAVE_ALL_SYS
+ r0 = sp;
+ r1 = retn;
+ [sp + PT_PC] = r1;
+ trace_buffer_save(p4,r5);
+
+ ANOMALY_283_315_WORKAROUND(p4, r5)
+
+ SP += -12;
+ call _do_nmi;
+ SP += 12;
+1:
+ jump 1b;
+#endif
+ 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
+ pseudo_long_call _system_call, p2;
+ 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 feature in two occasions:
+ *
+ * - before branching 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.
+ *
+ * - before branching to __ipipe_sync_root(), 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 */