Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 568 insertions, 0 deletions

diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S
new file mode 100644
index 000000000..99f0a65e6
--- /dev/null
+++ b/arch/nios2/kernel/entry.S
@@ -0,0 +1,568 @@
+/*
+ * linux/arch/nios2/kernel/entry.S
+ *
+ * Copyright (C) 2013-2014  Altera Corporation
+ * Copyright (C) 2009, Wind River Systems Inc
+ *
+ * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
+ *
+ *  Copyright (C) 1999-2002, Greg Ungerer (gerg@snapgear.com)
+ *  Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>,
+ *                      Kenneth Albanowski <kjahds@kjahds.com>,
+ *  Copyright (C) 2000  Lineo Inc. (www.lineo.com)
+ *  Copyright (C) 2004  Microtronix Datacom Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Linux/m68k support by Hamish Macdonald
+ *
+ * 68060 fixes by Jesper Skov
+ * ColdFire support by Greg Ungerer (gerg@snapgear.com)
+ * 5307 fixes by David W. Miller
+ * linux 2.4 support David McCullough <davidm@snapgear.com>
+ */
+
+#include <linux/sys.h>
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/asm-macros.h>
+#include <asm/thread_info.h>
+#include <asm/errno.h>
+#include <asm/setup.h>
+#include <asm/entry.h>
+#include <asm/unistd.h>
+#include <asm/processor.h>
+
+.macro GET_THREAD_INFO reg
+.if THREAD_SIZE & 0xffff0000
+	andhi	\reg, sp, %hi(~(THREAD_SIZE-1))
+.else
+	addi	\reg, r0, %lo(~(THREAD_SIZE-1))
+	and	\reg, \reg, sp
+.endif
+.endm
+
+.macro	kuser_cmpxchg_check
+	/*
+	 * Make sure our user space atomic helper is restarted if it was
+	 * interrupted in a critical region.
+	 * ea-4 = address of interrupted insn (ea must be preserved).
+	 * sp = saved regs.
+	 * cmpxchg_ldw = first critical insn, cmpxchg_stw = last critical insn.
+	 * If ea <= cmpxchg_stw and ea > cmpxchg_ldw then saved EA is set to
+	 * cmpxchg_ldw + 4.
+	*/
+	/* et = cmpxchg_stw + 4 */
+	movui   et, (KUSER_BASE + 4 + (cmpxchg_stw - __kuser_helper_start))
+	bgtu	ea, et, 1f
+
+	subi	et, et, (cmpxchg_stw - cmpxchg_ldw) /* et = cmpxchg_ldw + 4 */
+	bltu	ea, et, 1f
+	stw	et, PT_EA(sp)	/* fix up EA */
+	mov	ea, et
+1:
+.endm
+
+.section .rodata
+.align 4
+exception_table:
+	.word unhandled_exception	/* 0 - Reset */
+	.word unhandled_exception	/* 1 - Processor-only Reset */
+	.word external_interrupt	/* 2 - Interrupt */
+	.word handle_trap		/* 3 - Trap Instruction */
+
+	.word instruction_trap		/* 4 - Unimplemented instruction */
+	.word handle_illegal		/* 5 - Illegal instruction */
+	.word handle_unaligned		/* 6 - Misaligned data access */
+	.word handle_unaligned		/* 7 - Misaligned destination address */
+
+	.word handle_diverror		/* 8 - Division error */
+	.word protection_exception_ba	/* 9 - Supervisor-only instr. address */
+	.word protection_exception_instr /* 10 - Supervisor only instruction */
+	.word protection_exception_ba	/* 11 - Supervisor only data address */
+
+	.word unhandled_exception	/* 12 - Double TLB miss (data) */
+	.word protection_exception_pte	/* 13 - TLB permission violation (x) */
+	.word protection_exception_pte	/* 14 - TLB permission violation (r) */
+	.word protection_exception_pte	/* 15 - TLB permission violation (w) */
+
+	.word unhandled_exception	/* 16 - MPU region violation */
+
+trap_table:
+	.word	handle_system_call	/* 0  */
+	.word	handle_trap_1		/* 1  */
+	.word	handle_trap_2		/* 2  */
+	.word	handle_trap_3		/* 3  */
+	.word	handle_trap_reserved	/* 4  */
+	.word	handle_trap_reserved	/* 5  */
+	.word	handle_trap_reserved	/* 6  */
+	.word	handle_trap_reserved	/* 7  */
+	.word	handle_trap_reserved	/* 8  */
+	.word	handle_trap_reserved	/* 9  */
+	.word	handle_trap_reserved	/* 10 */
+	.word	handle_trap_reserved	/* 11 */
+	.word	handle_trap_reserved	/* 12 */
+	.word	handle_trap_reserved	/* 13 */
+	.word	handle_trap_reserved	/* 14 */
+	.word	handle_trap_reserved	/* 15 */
+	.word	handle_trap_reserved	/* 16 */
+	.word	handle_trap_reserved	/* 17 */
+	.word	handle_trap_reserved	/* 18 */
+	.word	handle_trap_reserved	/* 19 */
+	.word	handle_trap_reserved	/* 20 */
+	.word	handle_trap_reserved	/* 21 */
+	.word	handle_trap_reserved	/* 22 */
+	.word	handle_trap_reserved	/* 23 */
+	.word	handle_trap_reserved	/* 24 */
+	.word	handle_trap_reserved	/* 25 */
+	.word	handle_trap_reserved	/* 26 */
+	.word	handle_trap_reserved	/* 27 */
+	.word	handle_trap_reserved	/* 28 */
+	.word	handle_trap_reserved	/* 29 */
+#ifdef CONFIG_KGDB
+	.word	handle_kgdb_breakpoint	/* 30 KGDB breakpoint */
+#else
+	.word	instruction_trap		/* 30 */
+#endif
+	.word	handle_breakpoint	/* 31 */
+
+.text
+.set noat
+.set nobreak
+
+ENTRY(inthandler)
+	SAVE_ALL
+
+	kuser_cmpxchg_check
+
+	/* Clear EH bit before we get a new excpetion in the kernel
+	 * and after we have saved it to the exception frame. This is done
+	 * whether it's trap, tlb-miss or interrupt. If we don't do this
+	 * estatus is not updated the next exception.
+	 */
+	rdctl	r24, status
+	movi	r9, %lo(~STATUS_EH)
+	and	r24, r24, r9
+	wrctl	status, r24
+
+	/* Read cause and vector and branch to the associated handler */
+	mov	r4, sp
+	rdctl	r5, exception
+	movia	r9, exception_table
+	add	r24, r9, r5
+	ldw	r24, 0(r24)
+	jmp	r24
+
+
+/***********************************************************************
+ * Handle traps
+ ***********************************************************************
+ */
+ENTRY(handle_trap)
+	ldwio	r24, -4(ea)	/* instruction that caused the exception */
+	srli	r24, r24, 4
+	andi	r24, r24, 0x7c
+	movia	r9,trap_table
+	add	r24, r24, r9
+	ldw	r24, 0(r24)
+	jmp	r24
+
+
+/***********************************************************************
+ * Handle system calls
+ ***********************************************************************
+ */
+ENTRY(handle_system_call)
+	/* Enable interrupts */
+	rdctl	r10, status
+	ori	r10, r10, STATUS_PIE
+	wrctl	status, r10
+
+	/* Reload registers destroyed by common code. */
+	ldw	r4, PT_R4(sp)
+	ldw	r5, PT_R5(sp)
+
+local_restart:
+	stw	r2, PT_ORIG_R2(sp)
+	/* Check that the requested system call is within limits */
+	movui	r1, __NR_syscalls
+	bgeu	r2, r1, ret_invsyscall
+	slli	r1, r2, 2
+	movhi	r11, %hiadj(sys_call_table)
+	add	r1, r1, r11
+	ldw	r1, %lo(sys_call_table)(r1)
+
+	/* Check if we are being traced */
+	GET_THREAD_INFO r11
+	ldw	r11,TI_FLAGS(r11)
+	BTBNZ   r11,r11,TIF_SYSCALL_TRACE,traced_system_call
+
+	/* Execute the system call */
+	callr	r1
+
+	/* If the syscall returns a negative result:
+	 *   Set r7 to 1 to indicate error,
+	 *   Negate r2 to get a positive error code
+	 * If the syscall returns zero or a positive value:
+	 *   Set r7 to 0.
+	 * The sigreturn system calls will skip the code below by
+	 * adding to register ra. To avoid destroying registers
+	 */
+translate_rc_and_ret:
+	movi	r1, 0
+	bge	r2, zero, 3f
+	ldw	r1, PT_ORIG_R2(sp)
+	addi	r1, r1, 1
+	beq	r1, zero, 3f
+	sub	r2, zero, r2
+	movi	r1, 1
+3:
+	stw	r2, PT_R2(sp)
+	stw	r1, PT_R7(sp)
+end_translate_rc_and_ret:
+
+ret_from_exception:
+	ldw	r1, PT_ESTATUS(sp)
+	/* if so, skip resched, signals */
+	TSTBNZ	r1, r1, ESTATUS_EU, Luser_return
+
+restore_all:
+	rdctl	r10, status			/* disable intrs */
+	andi	r10, r10, %lo(~STATUS_PIE)
+	wrctl	status, r10
+	RESTORE_ALL
+	eret
+
+	/* If the syscall number was invalid return ENOSYS */
+ret_invsyscall:
+	movi	r2, -ENOSYS
+	br	translate_rc_and_ret
+
+	/* This implements the same as above, except it calls
+	 * do_syscall_trace_enter and do_syscall_trace_exit before and after the
+	 * syscall in order for utilities like strace and gdb to work.
+	 */
+traced_system_call:
+	SAVE_SWITCH_STACK
+	call	do_syscall_trace_enter
+	RESTORE_SWITCH_STACK
+
+	/* Create system call register arguments. The 5th and 6th
+	   arguments on stack are already in place at the beginning
+	   of pt_regs. */
+	ldw	r2, PT_R2(sp)
+	ldw	r4, PT_R4(sp)
+	ldw	r5, PT_R5(sp)
+	ldw	r6, PT_R6(sp)
+	ldw	r7, PT_R7(sp)
+
+	/* Fetch the syscall function. */
+	movui	r1, __NR_syscalls
+	bgeu	r2, r1, traced_invsyscall
+	slli	r1, r2, 2
+	movhi	r11,%hiadj(sys_call_table)
+	add	r1, r1, r11
+	ldw	r1, %lo(sys_call_table)(r1)
+
+	callr	r1
+
+	/* If the syscall returns a negative result:
+	 *   Set r7 to 1 to indicate error,
+	 *   Negate r2 to get a positive error code
+	 * If the syscall returns zero or a positive value:
+	 *   Set r7 to 0.
+	 * The sigreturn system calls will skip the code below by
+	 * adding to register ra. To avoid destroying registers
+	 */
+translate_rc_and_ret2:
+	movi	r1, 0
+	bge	r2, zero, 4f
+	ldw	r1, PT_ORIG_R2(sp)
+	addi	r1, r1, 1
+	beq	r1, zero, 4f
+	sub	r2, zero, r2
+	movi	r1, 1
+4:
+	stw	r2, PT_R2(sp)
+	stw	r1, PT_R7(sp)
+end_translate_rc_and_ret2:
+	SAVE_SWITCH_STACK
+	call	do_syscall_trace_exit
+	RESTORE_SWITCH_STACK
+	br	ret_from_exception
+
+	/* If the syscall number was invalid return ENOSYS */
+traced_invsyscall:
+	movi	r2, -ENOSYS
+	br	translate_rc_and_ret2
+
+Luser_return:
+	GET_THREAD_INFO	r11			/* get thread_info pointer */
+	ldw	r10, TI_FLAGS(r11)		/* get thread_info->flags */
+	ANDI32	r11, r10, _TIF_WORK_MASK
+	beq	r11, r0, restore_all		/* Nothing to do */
+	BTBZ	r1, r10, TIF_NEED_RESCHED, Lsignal_return
+
+	/* Reschedule work */
+	call	schedule
+	br	ret_from_exception
+
+Lsignal_return:
+	ANDI32	r1, r10, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
+	beq	r1, r0, restore_all
+	mov	r4, sp			/* pt_regs */
+	SAVE_SWITCH_STACK
+	call	do_notify_resume
+	beq	r2, r0, no_work_pending
+	RESTORE_SWITCH_STACK
+	/* prepare restart syscall here without leaving kernel */
+	ldw	r2, PT_R2(sp)	/* reload syscall number in r2 */
+	ldw 	r4, PT_R4(sp)	/* reload syscall arguments r4-r9 */
+	ldw 	r5, PT_R5(sp)
+	ldw 	r6, PT_R6(sp)
+	ldw 	r7, PT_R7(sp)
+	ldw 	r8, PT_R8(sp)
+	ldw 	r9, PT_R9(sp)
+	br	local_restart	/* restart syscall */
+
+no_work_pending:
+	RESTORE_SWITCH_STACK
+	br	ret_from_exception
+
+/***********************************************************************
+ * Handle external interrupts.
+ ***********************************************************************
+ */
+/*
+ * This is the generic interrupt handler (for all hardware interrupt
+ * sources). It figures out the vector number and calls the appropriate
+ * interrupt service routine directly.
+ */
+external_interrupt:
+	rdctl	r12, ipending
+	rdctl	r9, ienable
+	and	r12, r12, r9
+	/* skip if no interrupt is pending */
+	beq	r12, r0, ret_from_interrupt
+
+	/*
+	 * Process an external hardware interrupt.
+	 */
+
+	addi	ea, ea, -4	/* re-issue the interrupted instruction */
+	stw	ea, PT_EA(sp)
+2:	movi	r4, %lo(-1)	/* Start from bit position 0,
+					highest priority */
+				/* This is the IRQ # for handler call */
+1:	andi	r10, r12, 1	/* Isolate bit we are interested in */
+	srli	r12, r12, 1	/* shift count is costly without hardware
+					multiplier */
+	addi	r4, r4, 1
+	beq	r10, r0, 1b
+	mov	r5, sp		/* Setup pt_regs pointer for handler call */
+	call	do_IRQ
+	rdctl	r12, ipending	/* check again if irq still pending */
+	rdctl	r9, ienable	/* Isolate possible interrupts */
+	and	r12, r12, r9
+	bne	r12, r0, 2b
+	/* br	ret_from_interrupt */ /* fall through to ret_from_interrupt */
+
+ENTRY(ret_from_interrupt)
+	ldw	r1, PT_ESTATUS(sp)	/* check if returning to kernel */
+	TSTBNZ	r1, r1, ESTATUS_EU, Luser_return
+
+#ifdef CONFIG_PREEMPTION
+	GET_THREAD_INFO	r1
+	ldw	r4, TI_PREEMPT_COUNT(r1)
+	bne	r4, r0, restore_all
+	ldw	r4, TI_FLAGS(r1)		/* ? Need resched set */
+	BTBZ	r10, r4, TIF_NEED_RESCHED, restore_all
+	ldw	r4, PT_ESTATUS(sp)	/* ? Interrupts off */
+	andi	r10, r4, ESTATUS_EPIE
+	beq	r10, r0, restore_all
+	call	preempt_schedule_irq
+#endif
+	br	restore_all
+
+/***********************************************************************
+ * A few syscall wrappers
+ ***********************************************************************
+ */
+/*
+ * int clone(unsigned long clone_flags, unsigned long newsp,
+ *		int __user * parent_tidptr, int __user * child_tidptr,
+ *		int tls_val)
+ */
+ENTRY(sys_clone)
+	SAVE_SWITCH_STACK
+	subi    sp, sp, 4 /* make space for tls pointer */
+	stw     r8, 0(sp) /* pass tls pointer (r8) via stack (5th argument) */
+	call	nios2_clone
+	addi    sp, sp, 4
+	RESTORE_SWITCH_STACK
+	ret
+
+ENTRY(sys_rt_sigreturn)
+	SAVE_SWITCH_STACK
+	mov	r4, sp
+	call	do_rt_sigreturn
+	RESTORE_SWITCH_STACK
+	addi	ra, ra, (end_translate_rc_and_ret - translate_rc_and_ret)
+	ret
+
+/***********************************************************************
+ * A few other wrappers and stubs
+ ***********************************************************************
+ */
+protection_exception_pte:
+	rdctl	r6, pteaddr
+	slli	r6, r6, 10
+	call	do_page_fault
+	br	ret_from_exception
+
+protection_exception_ba:
+	rdctl	r6, badaddr
+	call	do_page_fault
+	br	ret_from_exception
+
+protection_exception_instr:
+	call	handle_supervisor_instr
+	br	ret_from_exception
+
+handle_breakpoint:
+	call	breakpoint_c
+	br	ret_from_exception
+
+#ifdef CONFIG_NIOS2_ALIGNMENT_TRAP
+handle_unaligned:
+	SAVE_SWITCH_STACK
+	call	handle_unaligned_c
+	RESTORE_SWITCH_STACK
+	br	ret_from_exception
+#else
+handle_unaligned:
+	call	handle_unaligned_c
+	br	ret_from_exception
+#endif
+
+handle_illegal:
+	call	handle_illegal_c
+	br	ret_from_exception
+
+handle_diverror:
+	call	handle_diverror_c
+	br	ret_from_exception
+
+#ifdef CONFIG_KGDB
+handle_kgdb_breakpoint:
+	call	kgdb_breakpoint_c
+	br	ret_from_exception
+#endif
+
+handle_trap_1:
+	call	handle_trap_1_c
+	br	ret_from_exception
+
+handle_trap_2:
+	call	handle_trap_2_c
+	br	ret_from_exception
+
+handle_trap_3:
+handle_trap_reserved:
+	call	handle_trap_3_c
+	br	ret_from_exception
+
+/*
+ * Beware - when entering resume, prev (the current task) is
+ * in r4, next (the new task) is in r5, don't change these
+ * registers.
+ */
+ENTRY(resume)
+
+	rdctl	r7, status			/* save thread status reg */
+	stw	r7, TASK_THREAD + THREAD_KPSR(r4)
+
+	andi	r7, r7, %lo(~STATUS_PIE)	/* disable interrupts */
+	wrctl	status, r7
+
+	SAVE_SWITCH_STACK
+	stw	sp, TASK_THREAD + THREAD_KSP(r4)/* save kernel stack pointer */
+	ldw	sp, TASK_THREAD + THREAD_KSP(r5)/* restore new thread stack */
+	movia	r24, _current_thread		/* save thread */
+	GET_THREAD_INFO r1
+	stw	r1, 0(r24)
+	RESTORE_SWITCH_STACK
+
+	ldw	r7, TASK_THREAD + THREAD_KPSR(r5)/* restore thread status reg */
+	wrctl	status, r7
+	ret
+
+ENTRY(ret_from_fork)
+	call	schedule_tail
+	br	ret_from_exception
+
+ENTRY(ret_from_kernel_thread)
+	call	schedule_tail
+	mov	r4,r17	/* arg */
+	callr	r16	/* function */
+	br	ret_from_exception
+
+/*
+ * Kernel user helpers.
+ *
+ * Each segment is 64-byte aligned and will be mapped to the <User space>.
+ * New segments (if ever needed) must be added after the existing ones.
+ * This mechanism should be used only for things that are really small and
+ * justified, and not be abused freely.
+ *
+ */
+
+ /* Filling pads with undefined instructions. */
+.macro	kuser_pad sym size
+	.if	((. - \sym) & 3)
+	.rept	(4 - (. - \sym) & 3)
+	.byte	0
+	.endr
+	.endif
+	.rept	((\size - (. - \sym)) / 4)
+	.word	0xdeadbeef
+	.endr
+.endm
+
+	.align	6
+	.globl	__kuser_helper_start
+__kuser_helper_start:
+
+__kuser_helper_version:				/* @ 0x1000 */
+	.word	((__kuser_helper_end - __kuser_helper_start) >> 6)
+
+__kuser_cmpxchg:				/* @ 0x1004 */
+	/*
+	 * r4 pointer to exchange variable
+	 * r5 old value
+	 * r6 new value
+	 */
+cmpxchg_ldw:
+	ldw	r2, 0(r4)			/* load current value */
+	sub	r2, r2, r5			/* compare with old value */
+	bne	r2, zero, cmpxchg_ret
+
+	/* We had a match, store the new value */
+cmpxchg_stw:
+	stw	r6, 0(r4)
+cmpxchg_ret:
+	ret
+
+	kuser_pad __kuser_cmpxchg, 64
+
+	.globl	__kuser_sigtramp
+__kuser_sigtramp:
+	movi	r2, __NR_rt_sigreturn
+	trap
+
+	kuser_pad __kuser_sigtramp, 64
+
+	.globl	__kuser_helper_end
+__kuser_helper_end: