Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 160 insertions, 0 deletions

diff --git a/arch/arm/kernel/entry-v7m.S b/arch/arm/kernel/entry-v7m.S
new file mode 100644
index 0000000000..52bacf07ba
--- /dev/null
+++ b/arch/arm/kernel/entry-v7m.S
@@ -0,0 +1,160 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/arch/arm/kernel/entry-v7m.S
+ *
+ * Copyright (C) 2008 ARM Ltd.
+ *
+ * Low-level vector interface routines for the ARMv7-M architecture
+ */
+#include <asm/page.h>
+#include <asm/glue.h>
+#include <asm/thread_notify.h>
+#include <asm/v7m.h>
+
+#include "entry-header.S"
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+#error "CONFIG_TRACE_IRQFLAGS not supported on the current ARMv7M implementation"
+#endif
+
+__invalid_entry:
+	v7m_exception_entry
+#ifdef CONFIG_PRINTK
+	adr	r0, strerr
+	mrs	r1, ipsr
+	mov	r2, lr
+	bl	_printk
+#endif
+	mov	r0, sp
+	bl	show_regs
+1:	b	1b
+ENDPROC(__invalid_entry)
+
+strerr:	.asciz	"\nUnhandled exception: IPSR = %08lx LR = %08lx\n"
+
+	.align	2
+__irq_entry:
+	v7m_exception_entry
+
+	@
+	@ Invoke the IRQ handler
+	@
+	mov	r0, sp
+	ldr_this_cpu sp, irq_stack_ptr, r1, r2
+
+	@
+	@ If we took the interrupt while running in the kernel, we may already
+	@ be using the IRQ stack, so revert to the original value in that case.
+	@
+	subs	r2, sp, r0		@ SP above bottom of IRQ stack?
+	rsbscs	r2, r2, #THREAD_SIZE	@ ... and below the top?
+	movcs	sp, r0
+
+	push	{r0, lr}		@ preserve LR and original SP
+
+	@ routine called with r0 = struct pt_regs *
+	bl	generic_handle_arch_irq
+
+	pop	{r0, lr}
+	mov	sp, r0
+
+	@
+	@ Check for any pending work if returning to user
+	@
+	ldr	r1, =BASEADDR_V7M_SCB
+	ldr	r0, [r1, V7M_SCB_ICSR]
+	tst	r0, V7M_SCB_ICSR_RETTOBASE
+	beq	2f
+
+	get_thread_info tsk
+	ldr	r2, [tsk, #TI_FLAGS]
+	movs	r2, r2, lsl #16
+	beq	2f			@ no work pending
+	mov	r0, #V7M_SCB_ICSR_PENDSVSET
+	str	r0, [r1, V7M_SCB_ICSR]	@ raise PendSV
+
+2:
+	@ registers r0-r3 and r12 are automatically restored on exception
+	@ return. r4-r7 were not clobbered in v7m_exception_entry so for
+	@ correctness they don't need to be restored. So only r8-r11 must be
+	@ restored here. The easiest way to do so is to restore r0-r7, too.
+	ldmia	sp!, {r0-r11}
+	add	sp, #PT_REGS_SIZE-S_IP
+	cpsie	i
+	bx	lr
+ENDPROC(__irq_entry)
+
+__pendsv_entry:
+	v7m_exception_entry
+
+	ldr	r1, =BASEADDR_V7M_SCB
+	mov	r0, #V7M_SCB_ICSR_PENDSVCLR
+	str	r0, [r1, V7M_SCB_ICSR]	@ clear PendSV
+
+	@ execute the pending work, including reschedule
+	get_thread_info tsk
+	mov	why, #0
+	b	ret_to_user_from_irq
+ENDPROC(__pendsv_entry)
+
+/*
+ * Register switch for ARMv7-M processors.
+ * r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
+ * previous and next are guaranteed not to be the same.
+ */
+ENTRY(__switch_to)
+	.fnstart
+	.cantunwind
+	add	ip, r1, #TI_CPU_SAVE
+	stmia	ip!, {r4 - r11}		@ Store most regs on stack
+	str	sp, [ip], #4
+	str	lr, [ip], #4
+	mov	r5, r0
+	mov	r6, r2			@ Preserve 'next'
+	add	r4, r2, #TI_CPU_SAVE
+	ldr	r0, =thread_notify_head
+	mov	r1, #THREAD_NOTIFY_SWITCH
+	bl	atomic_notifier_call_chain
+	mov	r0, r5
+	mov	r1, r6
+	ldmia	r4, {r4 - r12, lr}	@ Load all regs saved previously
+	set_current r1, r2
+	mov	sp, ip
+	bx	lr
+	.fnend
+ENDPROC(__switch_to)
+
+	.data
+#if CONFIG_CPU_V7M_NUM_IRQ <= 112
+	.align	9
+#else
+	.align	10
+#endif
+
+/*
+ * Vector table (Natural alignment need to be ensured)
+ */
+ENTRY(vector_table)
+	.long	0			@ 0 - Reset stack pointer
+	.long	__invalid_entry		@ 1 - Reset
+	.long	__invalid_entry		@ 2 - NMI
+	.long	__invalid_entry		@ 3 - HardFault
+	.long	__invalid_entry		@ 4 - MemManage
+	.long	__invalid_entry		@ 5 - BusFault
+	.long	__invalid_entry		@ 6 - UsageFault
+	.long	__invalid_entry		@ 7 - Reserved
+	.long	__invalid_entry		@ 8 - Reserved
+	.long	__invalid_entry		@ 9 - Reserved
+	.long	__invalid_entry		@ 10 - Reserved
+	.long	vector_swi		@ 11 - SVCall
+	.long	__invalid_entry		@ 12 - Debug Monitor
+	.long	__invalid_entry		@ 13 - Reserved
+	.long	__pendsv_entry		@ 14 - PendSV
+	.long	__invalid_entry		@ 15 - SysTick
+	.rept	CONFIG_CPU_V7M_NUM_IRQ
+	.long	__irq_entry		@ External Interrupts
+	.endr
+	.align	2
+	.globl	exc_ret
+exc_ret:
+	.space	4