[PATCH v2 03/10] ARM: p2v: move patching code to separate assembler source file
Ard Biesheuvel
ardb at kernel.org
Mon Sep 21 11:41:10 EDT 2020
Move the phys2virt patching code into a separate .S file before doing
some work on it.
Suggested-by: Nicolas Pitre <nico at fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
---
arch/arm/kernel/Makefile | 1 +
arch/arm/kernel/head.S | 138 ------------------
arch/arm/kernel/phys2virt.S | 151 ++++++++++++++++++++
3 files changed, 152 insertions(+), 138 deletions(-)
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 89e5d864e923..9e465efcc8b6 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -92,6 +92,7 @@ obj-$(CONFIG_PARAVIRT) += paravirt.o
head-y := head$(MMUEXT).o
obj-$(CONFIG_DEBUG_LL) += debug.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
+obj-$(CONFIG_ARM_PATCH_PHYS_VIRT) += phys2virt.o
# This is executed very early using a temporary stack when no memory allocator
# nor global data is available. Everything has to be allocated on the stack.
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 98c1e68bdfcb..7e3f36809011 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -586,142 +586,4 @@ ENTRY(fixup_smp)
ldmfd sp!, {r4 - r6, pc}
ENDPROC(fixup_smp)
-#ifdef __ARMEB__
-#define LOW_OFFSET 0x4
-#define HIGH_OFFSET 0x0
-#else
-#define LOW_OFFSET 0x0
-#define HIGH_OFFSET 0x4
-#endif
-
-#ifdef CONFIG_ARM_PATCH_PHYS_VIRT
-
-/* __fixup_pv_table - patch the stub instructions with the delta between
- * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be 16MiB aligned and
- * can be expressed by an immediate shifter operand. The stub instruction
- * has a form of '(add|sub) rd, rn, #imm'.
- */
- __HEAD
-__fixup_pv_table:
- adr r0, 1f
- ldmia r0, {r3-r7}
- mvn ip, #0
- subs r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET
- add r4, r4, r3 @ adjust table start address
- add r5, r5, r3 @ adjust table end address
- add r6, r6, r3 @ adjust __pv_phys_pfn_offset address
- add r7, r7, r3 @ adjust __pv_offset address
- mov r0, r8, lsr #PAGE_SHIFT @ convert to PFN
- str r0, [r6] @ save computed PHYS_OFFSET to __pv_phys_pfn_offset
- strcc ip, [r7, #HIGH_OFFSET] @ save to __pv_offset high bits
- mov r6, r3, lsr #24 @ constant for add/sub instructions
- teq r3, r6, lsl #24 @ must be 16MiB aligned
-THUMB( it ne @ cross section branch )
- bne __error
- str r3, [r7, #LOW_OFFSET] @ save to __pv_offset low bits
- b __fixup_a_pv_table
-ENDPROC(__fixup_pv_table)
-
- .align
-1: .long .
- .long __pv_table_begin
- .long __pv_table_end
-2: .long __pv_phys_pfn_offset
- .long __pv_offset
-
- .text
-__fixup_a_pv_table:
- adr r0, 3f
- ldr r6, [r0]
- add r6, r6, r3
- ldr r0, [r6, #HIGH_OFFSET] @ pv_offset high word
- ldr r6, [r6, #LOW_OFFSET] @ pv_offset low word
- mov r6, r6, lsr #24
- cmn r0, #1
-#ifdef CONFIG_THUMB2_KERNEL
- moveq r0, #0x200000 @ set bit 21, mov to mvn instruction
- lsls r6, #24
- beq 2f
- clz r7, r6
- lsr r6, #24
- lsl r6, r7
- bic r6, #0x0080
- lsrs r7, #1
- orrcs r6, #0x0080
- orr r6, r6, r7, lsl #12
- orr r6, #0x4000
- b 2f
-1: add r7, r3
- ldrh ip, [r7, #2]
-ARM_BE8(rev16 ip, ip)
- tst ip, #0x4000
- and ip, #0x8f00
- orrne ip, r6 @ mask in offset bits 31-24
- orreq ip, r0 @ mask in offset bits 7-0
-ARM_BE8(rev16 ip, ip)
- strh ip, [r7, #2]
- bne 2f
- ldrh ip, [r7]
-ARM_BE8(rev16 ip, ip)
- bic ip, #0x20
- orr ip, ip, r0, lsr #16
-ARM_BE8(rev16 ip, ip)
- strh ip, [r7]
-2: cmp r4, r5
- ldrcc r7, [r4], #4 @ use branch for delay slot
- bcc 1b
- bx lr
-#else
- moveq r0, #0x400000 @ set bit 22, mov to mvn instruction
- b 2f
-1: ldr ip, [r7, r3]
-#ifdef CONFIG_CPU_ENDIAN_BE8
- @ in BE8, we load data in BE, but instructions still in LE
- bic ip, ip, #0xff000000
- tst ip, #0x000f0000 @ check the rotation field
- orrne ip, ip, r6, lsl #24 @ mask in offset bits 31-24
- biceq ip, ip, #0x00004000 @ clear bit 22
- orreq ip, ip, r0, ror #8 @ mask in offset bits 7-0
-#else
- bic ip, ip, #0x000000ff
- tst ip, #0xf00 @ check the rotation field
- orrne ip, ip, r6 @ mask in offset bits 31-24
- biceq ip, ip, #0x400000 @ clear bit 22
- orreq ip, ip, r0 @ mask in offset bits 7-0
-#endif
- str ip, [r7, r3]
-2: cmp r4, r5
- ldrcc r7, [r4], #4 @ use branch for delay slot
- bcc 1b
- ret lr
-#endif
-ENDPROC(__fixup_a_pv_table)
-
- .align
-3: .long __pv_offset
-
-ENTRY(fixup_pv_table)
- stmfd sp!, {r4 - r7, lr}
- mov r3, #0 @ no offset
- mov r4, r0 @ r0 = table start
- add r5, r0, r1 @ r1 = table size
- bl __fixup_a_pv_table
- ldmfd sp!, {r4 - r7, pc}
-ENDPROC(fixup_pv_table)
-
- .data
- .align 2
- .globl __pv_phys_pfn_offset
- .type __pv_phys_pfn_offset, %object
-__pv_phys_pfn_offset:
- .word 0
- .size __pv_phys_pfn_offset, . -__pv_phys_pfn_offset
-
- .globl __pv_offset
- .type __pv_offset, %object
-__pv_offset:
- .quad 0
- .size __pv_offset, . -__pv_offset
-#endif
-
#include "head-common.S"
diff --git a/arch/arm/kernel/phys2virt.S b/arch/arm/kernel/phys2virt.S
new file mode 100644
index 000000000000..7c17fbfeeedd
--- /dev/null
+++ b/arch/arm/kernel/phys2virt.S
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 1994-2002 Russell King
+ * Copyright (c) 2003 ARM Limited
+ * All Rights Reserved
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/page.h>
+
+#ifdef __ARMEB__
+#define LOW_OFFSET 0x4
+#define HIGH_OFFSET 0x0
+#else
+#define LOW_OFFSET 0x0
+#define HIGH_OFFSET 0x4
+#endif
+
+/*
+ * __fixup_pv_table - patch the stub instructions with the delta between
+ * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be
+ * 16MiB aligned.
+ *
+ * Called from head.S, which expects the following registers to be preserved:
+ * r1 = machine no, r2 = atags or dtb,
+ * r8 = phys_offset, r9 = cpuid, r10 = procinfo
+ */
+ __HEAD
+ENTRY(__fixup_pv_table)
+ adr r0, 1f
+ ldmia r0, {r3-r7}
+ mvn ip, #0
+ subs r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET
+ add r4, r4, r3 @ adjust table start address
+ add r5, r5, r3 @ adjust table end address
+ add r6, r6, r3 @ adjust __pv_phys_pfn_offset address
+ add r7, r7, r3 @ adjust __pv_offset address
+ mov r0, r8, lsr #PAGE_SHIFT @ convert to PFN
+ str r0, [r6] @ save computed PHYS_OFFSET to __pv_phys_pfn_offset
+ strcc ip, [r7, #HIGH_OFFSET] @ save to __pv_offset high bits
+ mov r6, r3, lsr #24 @ constant for add/sub instructions
+ teq r3, r6, lsl #24 @ must be 16MiB aligned
+ bne 0f
+ str r3, [r7, #LOW_OFFSET] @ save to __pv_offset low bits
+ b __fixup_a_pv_table
+0: mov r0, r0 @ deadloop on error
+ b 0b
+ENDPROC(__fixup_pv_table)
+
+ .align
+1: .long .
+ .long __pv_table_begin
+ .long __pv_table_end
+2: .long __pv_phys_pfn_offset
+ .long __pv_offset
+
+ .text
+__fixup_a_pv_table:
+ adr r0, 3f
+ ldr r6, [r0]
+ add r6, r6, r3
+ ldr r0, [r6, #HIGH_OFFSET] @ pv_offset high word
+ ldr r6, [r6, #LOW_OFFSET] @ pv_offset low word
+ mov r6, r6, lsr #24
+ cmn r0, #1
+#ifdef CONFIG_THUMB2_KERNEL
+ moveq r0, #0x200000 @ set bit 21, mov to mvn instruction
+ lsls r6, #24
+ beq 2f
+ clz r7, r6
+ lsr r6, #24
+ lsl r6, r7
+ bic r6, #0x0080
+ lsrs r7, #1
+ orrcs r6, #0x0080
+ orr r6, r6, r7, lsl #12
+ orr r6, #0x4000
+ b 2f
+1: add r7, r3
+ ldrh ip, [r7, #2]
+ARM_BE8(rev16 ip, ip)
+ tst ip, #0x4000
+ and ip, #0x8f00
+ orrne ip, r6 @ mask in offset bits 31-24
+ orreq ip, r0 @ mask in offset bits 7-0
+ARM_BE8(rev16 ip, ip)
+ strh ip, [r7, #2]
+ bne 2f
+ ldrh ip, [r7]
+ARM_BE8(rev16 ip, ip)
+ bic ip, #0x20
+ orr ip, ip, r0, lsr #16
+ARM_BE8(rev16 ip, ip)
+ strh ip, [r7]
+2: cmp r4, r5
+ ldrcc r7, [r4], #4 @ use branch for delay slot
+ bcc 1b
+ bx lr
+#else
+ moveq r0, #0x400000 @ set bit 22, mov to mvn instruction
+ b 2f
+1: ldr ip, [r7, r3]
+#ifdef CONFIG_CPU_ENDIAN_BE8
+ @ in BE8, we load data in BE, but instructions still in LE
+ bic ip, ip, #0xff000000
+ tst ip, #0x000f0000 @ check the rotation field
+ orrne ip, ip, r6, lsl #24 @ mask in offset bits 31-24
+ biceq ip, ip, #0x00004000 @ clear bit 22
+ orreq ip, ip, r0, ror #8 @ mask in offset bits 7-0
+#else
+ bic ip, ip, #0x000000ff
+ tst ip, #0xf00 @ check the rotation field
+ orrne ip, ip, r6 @ mask in offset bits 31-24
+ biceq ip, ip, #0x400000 @ clear bit 22
+ orreq ip, ip, r0 @ mask in offset bits 7-0
+#endif
+ str ip, [r7, r3]
+2: cmp r4, r5
+ ldrcc r7, [r4], #4 @ use branch for delay slot
+ bcc 1b
+ ret lr
+#endif
+ENDPROC(__fixup_a_pv_table)
+
+ .align
+3: .long __pv_offset
+
+ENTRY(fixup_pv_table)
+ stmfd sp!, {r4 - r7, lr}
+ mov r3, #0 @ no offset
+ mov r4, r0 @ r0 = table start
+ add r5, r0, r1 @ r1 = table size
+ bl __fixup_a_pv_table
+ ldmfd sp!, {r4 - r7, pc}
+ENDPROC(fixup_pv_table)
+
+ .data
+ .align 2
+ .globl __pv_phys_pfn_offset
+ .type __pv_phys_pfn_offset, %object
+__pv_phys_pfn_offset:
+ .word 0
+ .size __pv_phys_pfn_offset, . -__pv_phys_pfn_offset
+
+ .globl __pv_offset
+ .type __pv_offset, %object
+__pv_offset:
+ .quad 0
+ .size __pv_offset, . -__pv_offset
--
2.17.1
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