From 748e4f3d702def1a4bff191e0cf93b6a05340f01 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 07:41:34 +0000
Subject: [PATCH] add gpio led uart
---
kernel/arch/arm/kernel/entry-armv.S | 146 +++++++++++++++++++++++++++++-------------------
1 files changed, 88 insertions(+), 58 deletions(-)
diff --git a/kernel/arch/arm/kernel/entry-armv.S b/kernel/arch/arm/kernel/entry-armv.S
index 857c9cd..030351d 100644
--- a/kernel/arch/arm/kernel/entry-armv.S
+++ b/kernel/arch/arm/kernel/entry-armv.S
@@ -1,13 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/kernel/entry-armv.S
*
* Copyright (C) 1996,1997,1998 Russell King.
* ARM700 fix by Matthew Godbolt (linux-user@willothewisp.demon.co.uk)
* nommu support by Hyok S. Choi (hyok.choi@samsung.com)
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*
* Low-level vector interface routines
*
@@ -207,20 +204,13 @@
svc_entry
irq_handler
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
- teq r8, #0 @ if preempt count != 0
- bne 1f @ return from exeption
ldr r0, [tsk, #TI_FLAGS] @ get flags
- tst r0, #_TIF_NEED_RESCHED @ if NEED_RESCHED is set
- blne svc_preempt @ preempt!
-
- ldr r8, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count
- teq r8, #0 @ if preempt lazy count != 0
+ teq r8, #0 @ if preempt count != 0
movne r0, #0 @ force flags to 0
- tst r0, #_TIF_NEED_RESCHED_LAZY
+ tst r0, #_TIF_NEED_RESCHED
blne svc_preempt
-1:
#endif
svc_exit r5, irq = 1 @ return from exception
@@ -229,20 +219,14 @@
.ltorg
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
svc_preempt:
mov r8, lr
1: bl preempt_schedule_irq @ irq en/disable is done inside
ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
tst r0, #_TIF_NEED_RESCHED
- bne 1b
- tst r0, #_TIF_NEED_RESCHED_LAZY
reteq r8 @ go again
- ldr r0, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count
- teq r0, #0 @ if preempt lazy count != 0
- beq 1b
- ret r8 @ go again
-
+ b 1b
#endif
__und_fault:
@@ -268,31 +252,10 @@
#else
svc_entry
#endif
- @
- @ call emulation code, which returns using r9 if it has emulated
- @ the instruction, or the more conventional lr if we are to treat
- @ this as a real undefined instruction
- @
- @ r0 - instruction
- @
-#ifndef CONFIG_THUMB2_KERNEL
- ldr r0, [r4, #-4]
-#else
- mov r1, #2
- ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2
- cmp r0, #0xe800 @ 32-bit instruction if xx >= 0
- blo __und_svc_fault
- ldrh r9, [r4] @ bottom 16 bits
- add r4, r4, #2
- str r4, [sp, #S_PC]
- orr r0, r9, r0, lsl #16
-#endif
- badr r9, __und_svc_finish
- mov r2, r4
- bl call_fpe
mov r1, #4 @ PC correction to apply
-__und_svc_fault:
+ THUMB( tst r5, #PSR_T_BIT ) @ exception taken in Thumb mode?
+ THUMB( movne r1, #2 ) @ if so, fix up PC correction
mov r0, sp @ struct pt_regs *regs
bl __und_fault
@@ -640,7 +603,7 @@
@ Test if we need to give access to iWMMXt coprocessors
ldr r5, [r10, #TI_FLAGS]
rsbs r7, r8, #(1 << 8) @ CP 0 or 1 only
- movcss r7, r5, lsr #(TIF_USING_IWMMXT + 1)
+ movscs r7, r5, lsr #(TIF_USING_IWMMXT + 1)
bcs iwmmxt_task_enable
#endif
ARM( add pc, pc, r8, lsr #6 )
@@ -833,7 +796,7 @@
* existing ones. This mechanism should be used only for things that are
* really small and justified, and not be abused freely.
*
- * See Documentation/arm/kernel_user_helpers.txt for formal definitions.
+ * See Documentation/arm/kernel_user_helpers.rst for formal definitions.
*/
THUMB( .arm )
@@ -876,7 +839,7 @@
smp_dmb arm
1: ldrexd r0, r1, [r2] @ load current val
eors r3, r0, r4 @ compare with oldval (1)
- eoreqs r3, r1, r5 @ compare with oldval (2)
+ eorseq r3, r1, r5 @ compare with oldval (2)
strexdeq r3, r6, r7, [r2] @ store newval if eq
teqeq r3, #1 @ success?
beq 1b @ if no then retry
@@ -900,8 +863,8 @@
ldmia r1, {r6, lr} @ load new val
1: ldmia r2, {r0, r1} @ load current val
eors r3, r0, r4 @ compare with oldval (1)
- eoreqs r3, r1, r5 @ compare with oldval (2)
-2: stmeqia r2, {r6, lr} @ store newval if eq
+ eorseq r3, r1, r5 @ compare with oldval (2)
+2: stmiaeq r2, {r6, lr} @ store newval if eq
rsbs r0, r3, #0 @ set return val and C flag
ldmfd sp!, {r4, r5, r6, pc}
@@ -915,7 +878,7 @@
mov r7, #0xffff0fff
sub r7, r7, #(0xffff0fff - (0xffff0f60 + (1b - __kuser_cmpxchg64)))
subs r8, r4, r7
- rsbcss r8, r8, #(2b - 1b)
+ rsbscs r8, r8, #(2b - 1b)
strcs r7, [sp, #S_PC]
#if __LINUX_ARM_ARCH__ < 6
bcc kuser_cmpxchg32_fixup
@@ -973,7 +936,7 @@
mov r7, #0xffff0fff
sub r7, r7, #(0xffff0fff - (0xffff0fc0 + (1b - __kuser_cmpxchg)))
subs r8, r4, r7
- rsbcss r8, r8, #(2b - 1b)
+ rsbscs r8, r8, #(2b - 1b)
strcs r7, [sp, #S_PC]
ret lr
.previous
@@ -1042,12 +1005,11 @@
sub lr, lr, #\correction
.endif
- @
- @ Save r0, lr_<exception> (parent PC) and spsr_<exception>
- @ (parent CPSR)
- @
+ @ Save r0, lr_<exception> (parent PC)
stmia sp, {r0, lr} @ save r0, lr
- mrs lr, spsr
+
+ @ Save spsr_<exception> (parent CPSR)
+2: mrs lr, spsr
str lr, [sp, #8] @ save spsr
@
@@ -1068,6 +1030,44 @@
movs pc, lr @ branch to handler in SVC mode
ENDPROC(vector_\name)
+#ifdef CONFIG_HARDEN_BRANCH_HISTORY
+ .subsection 1
+ .align 5
+vector_bhb_loop8_\name:
+ .if \correction
+ sub lr, lr, #\correction
+ .endif
+
+ @ Save r0, lr_<exception> (parent PC)
+ stmia sp, {r0, lr}
+
+ @ bhb workaround
+ mov r0, #8
+3: W(b) . + 4
+ subs r0, r0, #1
+ bne 3b
+ dsb
+ isb
+ b 2b
+ENDPROC(vector_bhb_loop8_\name)
+
+vector_bhb_bpiall_\name:
+ .if \correction
+ sub lr, lr, #\correction
+ .endif
+
+ @ Save r0, lr_<exception> (parent PC)
+ stmia sp, {r0, lr}
+
+ @ bhb workaround
+ mcr p15, 0, r0, c7, c5, 6 @ BPIALL
+ @ isb not needed due to "movs pc, lr" in the vector stub
+ @ which gives a "context synchronisation".
+ b 2b
+ENDPROC(vector_bhb_bpiall_\name)
+ .previous
+#endif
+
.align 2
@ handler addresses follow this label
1:
@@ -1076,6 +1076,10 @@
.section .stubs, "ax", %progbits
@ This must be the first word
.word vector_swi
+#ifdef CONFIG_HARDEN_BRANCH_HISTORY
+ .word vector_bhb_loop8_swi
+ .word vector_bhb_bpiall_swi
+#endif
vector_rst:
ARM( swi SYS_ERROR0 )
@@ -1190,8 +1194,10 @@
* FIQ "NMI" handler
*-----------------------------------------------------------------------------
* Handle a FIQ using the SVC stack allowing FIQ act like NMI on x86
- * systems.
+ * systems. This must be the last vector stub, so lets place it in its own
+ * subsection.
*/
+ .subsection 2
vector_stub fiq, FIQ_MODE, 4
.long __fiq_usr @ 0 (USR_26 / USR_32)
@@ -1224,6 +1230,30 @@
W(b) vector_irq
W(b) vector_fiq
+#ifdef CONFIG_HARDEN_BRANCH_HISTORY
+ .section .vectors.bhb.loop8, "ax", %progbits
+.L__vectors_bhb_loop8_start:
+ W(b) vector_rst
+ W(b) vector_bhb_loop8_und
+ W(ldr) pc, .L__vectors_bhb_loop8_start + 0x1004
+ W(b) vector_bhb_loop8_pabt
+ W(b) vector_bhb_loop8_dabt
+ W(b) vector_addrexcptn
+ W(b) vector_bhb_loop8_irq
+ W(b) vector_bhb_loop8_fiq
+
+ .section .vectors.bhb.bpiall, "ax", %progbits
+.L__vectors_bhb_bpiall_start:
+ W(b) vector_rst
+ W(b) vector_bhb_bpiall_und
+ W(ldr) pc, .L__vectors_bhb_bpiall_start + 0x1008
+ W(b) vector_bhb_bpiall_pabt
+ W(b) vector_bhb_bpiall_dabt
+ W(b) vector_addrexcptn
+ W(b) vector_bhb_bpiall_irq
+ W(b) vector_bhb_bpiall_fiq
+#endif
+
.data
.align 2
--
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