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authorRussell King <rmk+kernel@armlinux.org.uk>2020-11-09 10:19:25 +0000
committerRussell King <rmk+kernel@armlinux.org.uk>2020-11-09 10:19:25 +0000
commitae73ad0527075a39122e5374504e1137c2e2d14f (patch)
tree9f2e11d7eabc4edb61c76f5d1ed1453c864b43a0 /arch/arm/kernel/head.S
parent3650b228f83adda7e5ee532e2b90429c03f7b9ec (diff)
parent9443076e4330a14ae2c6114307668b98a8293b77 (diff)
Merge tag 'arm-p2v-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux into devel-stable
Implement the necessary changes in the ARM assembler boot code to permit the relative alignment of the physical and the virtual addresses of the kernel to be as little as 2 MiB, as opposed to the minimum of 16 MiB we support today. Series was posted here, and reviewed by Nicolas Pitre and Linus Walleij: https://lore.kernel.org/linux-arm-kernel/20200921154117.757-1-ardb@kernel.org/
Diffstat (limited to 'arch/arm/kernel/head.S')
-rw-r--r--arch/arm/kernel/head.S142
1 files changed, 0 insertions, 142 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index f8904227e7fd..7e3f36809011 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -586,146 +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
-#ifdef CONFIG_CPU_ENDIAN_BE8
- moveq r0, #0x00004000 @ set bit 22, mov to mvn instruction
-#else
- moveq r0, #0x400000 @ set bit 22, mov to mvn instruction
-#endif
- 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 @ 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"