[PATCH v2 07/10] ARM: p2v: use relative references in patch site arrays
From: Ard Biesheuvel <ardb@kernel.org>
Date: 2020-09-21 15:44:01
Also in:
linux-efi
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
Free up a register in the p2v patching code by switching to relative references, which don't require keeping the phys-to-virt displacement live in a register. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm/include/asm/memory.h | 6 +++--- arch/arm/kernel/phys2virt.S | 18 +++++++----------- 2 files changed, 10 insertions(+), 14 deletions(-)
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index eb3c8e6e960a..4121662dea5a 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h@@ -187,7 +187,7 @@ extern const void *__pv_table_begin, *__pv_table_end; __asm__("@ __pv_stub\n" \ "1: " instr " %0, %1, %2\n" \ " .pushsection .pv_table,\"a\"\n" \ - " .long 1b\n" \ + " .long 1b - .\n" \ " .popsection\n" \ : "=r" (to) \ : "r" (from), "I" (__PV_BITS_31_24))
@@ -196,7 +196,7 @@ extern const void *__pv_table_begin, *__pv_table_end; __asm__ volatile("@ __pv_stub_mov\n" \ "1: mov %R0, %1\n" \ " .pushsection .pv_table,\"a\"\n" \ - " .long 1b\n" \ + " .long 1b - .\n" \ " .popsection\n" \ : "=r" (t) \ : "I" (__PV_BITS_7_0))
@@ -206,7 +206,7 @@ extern const void *__pv_table_begin, *__pv_table_end; "1: adds %Q0, %1, %2\n" \ " adc %R0, %R0, #0\n" \ " .pushsection .pv_table,\"a\"\n" \ - " .long 1b\n" \ + " .long 1b - .\n" \ " .popsection\n" \ : "+r" (y) \ : "r" (x), "I" (__PV_BITS_31_24) \
diff --git a/arch/arm/kernel/phys2virt.S b/arch/arm/kernel/phys2virt.S
index 5031e5a2e78b..8e4be15e1559 100644
--- a/arch/arm/kernel/phys2virt.S
+++ b/arch/arm/kernel/phys2virt.S@@ -58,9 +58,7 @@ ENDPROC(__fixup_pv_table) .text __fixup_a_pv_table: - adr r0, 3f - ldr r6, [r0] - add r6, r6, r3 + adr_l r6, __pv_offset ldr r0, [r6, #HIGH_OFFSET] @ pv_offset high word ldr r6, [r6, #LOW_OFFSET] @ pv_offset low word mov r6, r6, lsr #24
@@ -78,7 +76,8 @@ __fixup_a_pv_table: orr r6, r6, r7, lsl #12 orr r6, #0x4000 b .Lnext -.Lloop: add r7, r3 +.Lloop: add r7, r4 + adds r4, #4 ldrh ip, [r7, #2] ARM_BE8(rev16 ip, ip) tst ip, #0x4000
@@ -108,28 +107,25 @@ ARM_BE8(rev16 ip, ip) moveq r0, #0x400000 @ set bit 22, mov to mvn instruction b .Lnext -.Lloop: ldr ip, [r7, r3] +.Lloop: ldr ip, [r7, r4] bic ip, ip, #PV_IMM8_MASK tst ip, #PV_ROT_MASK @ check the rotation field orrne ip, ip, r6 ARM_BE8(, lsl #24) @ mask in offset bits 31-24 biceq ip, ip, #PV_BIT22 @ clear bit 22 orreq ip, ip, r0 ARM_BE8(, ror #8) @ mask in offset bits 7-0 (or bit 22) - str ip, [r7, r3] + str ip, [r7, r4] + add r4, r4, #4 #endif .Lnext: cmp r4, r5 - ldrcc r7, [r4], #4 @ use branch for delay slot + ldrcc r7, [r4] @ use branch for delay slot bcc .Lloop ret lr 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
--
2.17.1
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