Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 184 insertions, 0 deletions

diff --git a/arch/nds32/kernel/ex-exit.S b/arch/nds32/kernel/ex-exit.S
new file mode 100644
index 000000000..f00af92f7
--- /dev/null
+++ b/arch/nds32/kernel/ex-exit.S
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/linkage.h>
+#include <asm/unistd.h>
+#include <asm/assembler.h>
+#include <asm/nds32.h>
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
+#include <asm/current.h>
+
+
+
+#ifdef CONFIG_HWZOL
+	.macro pop_zol
+	mtusr	$r14, $LB
+	mtusr	$r15, $LE
+	mtusr	$r16, $LC
+	.endm
+#endif
+
+	.macro	restore_user_regs_first
+	setgie.d
+	isb
+
+	addi	$sp, $sp, FUCOP_CTL_OFFSET
+
+	lmw.adm $r12, [$sp], $r24, #0x0
+	mtsr	$r12, $SP_USR
+	mtsr	$r13, $IPC
+#ifdef CONFIG_HWZOL
+	pop_zol
+#endif
+	mtsr	$r19, $PSW
+	mtsr	$r20, $IPSW
+	mtsr    $r21, $P_IPSW
+	mtsr	$r22, $P_IPC
+	mtsr	$r23, $P_P0
+	mtsr	$r24, $P_P1
+	lmw.adm $sp, [$sp], $sp, #0xe
+	.endm
+
+	.macro	restore_user_regs_last
+	pop	$p0
+	cmovn	$sp, $p0, $p0
+
+	iret
+	nop
+
+	.endm
+
+	.macro	restore_user_regs
+	restore_user_regs_first
+	lmw.adm $r0, [$sp], $r25, #0x0
+	addi	$sp, $sp, OSP_OFFSET
+	restore_user_regs_last
+	.endm
+
+	.macro	fast_restore_user_regs
+	restore_user_regs_first
+	lmw.adm $r1, [$sp], $r25, #0x0
+	addi	$sp, $sp, OSP_OFFSET-4
+	restore_user_regs_last
+	.endm
+
+#ifdef CONFIG_PREEMPT
+	.macro	preempt_stop
+	.endm
+#else
+	.macro	preempt_stop
+	setgie.d
+	isb
+	.endm
+#define	resume_kernel	no_work_pending
+#endif
+
+ENTRY(ret_from_exception)
+	preempt_stop
+ENTRY(ret_from_intr)
+
+/*
+ * judge Kernel or user mode
+ *
+ */
+	lwi	$p0, [$sp+(#IPSW_OFFSET)]	! Check if in nested interrupt
+	andi	$p0, $p0, #PSW_mskINTL
+	bnez	$p0, resume_kernel		! done with iret
+	j	resume_userspace
+
+
+/*
+ * This is the fast syscall return path.  We do as little as
+ * possible here, and this includes saving $r0 back into the SVC
+ * stack.
+ * fixed: tsk - $r25, syscall # - $r7, syscall table pointer - $r8
+ */
+ENTRY(ret_fast_syscall)
+	gie_disable
+	lwi	$r1, [tsk+#TSK_TI_FLAGS]
+	andi	$p1, $r1, #_TIF_WORK_MASK
+	bnez	$p1, fast_work_pending
+	fast_restore_user_regs			! iret
+
+/*
+ * Ok, we need to do extra processing,
+ * enter the slow path returning from syscall, while pending work.
+ */
+fast_work_pending:
+	swi	$r0, [$sp+(#R0_OFFSET)]		! what is different from ret_from_exception
+work_pending:
+	andi	$p1, $r1, #_TIF_NEED_RESCHED
+	bnez	$p1, work_resched
+
+	andi	$p1, $r1, #_TIF_SIGPENDING|#_TIF_NOTIFY_RESUME
+	beqz	$p1, no_work_pending
+
+	move	$r0, $sp			! 'regs'
+	gie_enable
+	bal	do_notify_resume
+	b       ret_slow_syscall
+work_resched:
+	bal	schedule			! path, return to user mode
+
+/*
+ * "slow" syscall return path.
+ */
+ENTRY(resume_userspace)
+ENTRY(ret_slow_syscall)
+	gie_disable
+	lwi	$p0, [$sp+(#IPSW_OFFSET)]	! Check if in nested interrupt
+	andi	$p0, $p0, #PSW_mskINTL
+	bnez	$p0, no_work_pending		! done with iret
+	lwi	$r1, [tsk+#TSK_TI_FLAGS]
+	andi	$p1, $r1, #_TIF_WORK_MASK
+	bnez	$p1, work_pending		! handle work_resched, sig_pend
+
+no_work_pending:
+#ifdef CONFIG_TRACE_IRQFLAGS
+	lwi	$p0, [$sp+(#IPSW_OFFSET)]
+	andi	$p0, $p0, #0x1
+	la	$r10, __trace_hardirqs_off
+	la	$r9, __trace_hardirqs_on
+	cmovz	$r9, $p0, $r10
+	jral	$r9
+#endif
+	restore_user_regs			! return from iret
+
+
+/*
+ * preemptive kernel
+ */
+#ifdef CONFIG_PREEMPT
+resume_kernel:
+	gie_disable
+	lwi	$t0, [tsk+#TSK_TI_PREEMPT]
+	bnez	$t0, no_work_pending
+need_resched:
+	lwi	$t0, [tsk+#TSK_TI_FLAGS]
+	andi	$p1, $t0, #_TIF_NEED_RESCHED
+	beqz	$p1, no_work_pending
+
+	lwi	$t0, [$sp+(#IPSW_OFFSET)]	! Interrupts off?
+	andi	$t0, $t0, #1
+	beqz	$t0, no_work_pending
+
+	jal	preempt_schedule_irq
+	b	need_resched
+#endif
+
+/*
+ * This is how we return from a fork.
+ */
+ENTRY(ret_from_fork)
+	bal	schedule_tail
+	beqz	$r6, 1f				! r6 stores fn for kernel thread
+	move	$r0, $r7			! prepare kernel thread arg
+	jral	$r6
+1:
+	lwi	$r1, [tsk+#TSK_TI_FLAGS]		! check for syscall tracing
+	andi	$p1, $r1, #_TIF_WORK_SYSCALL_LEAVE	! are we tracing syscalls?
+	beqz	$p1, ret_slow_syscall
+	move    $r0, $sp
+	bal	syscall_trace_leave
+	b	ret_slow_syscall