LoongArch: Use ABI names of registers where appropriate

Some of the assembly in the LoongArch port seem to come from a
prehistoric time, when the assembler didn't even have support for the
ABI names we all come to know and love, thus used raw register numbers
which hampered readability.

The usages are found with a regex match inside arch/loongarch, then
manually adjusted for those non-definitions.
Signed-off-by: NWANG Xuerui <git@xen0n.name>
Signed-off-by: NHuacai Chen <chenhuacai@loongson.cn>

arch/loongarch/include/asm/barrier.h

@@ -48,9 +48,9 @@ static inline unsigned long array_index_mask_nospec(unsigned long index,
 	__asm__ __volatile__(
 		"sltu	%0, %1, %2\n\t"
 #if (__SIZEOF_LONG__ == 4)
-		"sub.w	%0, $r0, %0\n\t"
+		"sub.w	%0, $zero, %0\n\t"
 #elif (__SIZEOF_LONG__ == 8)
-		"sub.d	%0, $r0, %0\n\t"
+		"sub.d	%0, $zero, %0\n\t"
 #endif
 		: "=r" (mask)
 		: "r" (index), "r" (size)

arch/loongarch/include/asm/loongson.h

@@ -58,7 +58,7 @@ static inline void xconf_writel(u32 val, volatile void __iomem *addr)
 {
 	asm volatile (
 	"	st.w	%[v], %[hw], 0	\n"
-	"	ld.b	$r0, %[hw], 0	\n"
+	"	ld.b	$zero, %[hw], 0	\n"
 	:
 	: [hw] "r" (addr), [v] "r" (val)
 	);
@@ -68,7 +68,7 @@ static inline void xconf_writeq(u64 val64, volatile void __iomem *addr)
 {
 	asm volatile (
 	"	st.d	%[v], %[hw], 0	\n"
-	"	ld.b	$r0, %[hw], 0	\n"
+	"	ld.b	$zero, %[hw], 0	\n"
 	:
 	: [hw] "r" (addr),  [v] "r" (val64)
 	);

arch/loongarch/include/asm/stacktrace.h

@@ -23,13 +23,13 @@
 static __always_inline void prepare_frametrace(struct pt_regs *regs)
 {
 	__asm__ __volatile__(
-		/* Save $r1 */
+		/* Save $ra */
 		STORE_ONE_REG(1)
-		/* Use $r1 to save PC */
-		"pcaddi	$r1, 0\n\t"
-		STR_LONG_S " $r1, %0\n\t"
-		/* Restore $r1 */
-		STR_LONG_L " $r1, %1, "STR_LONGSIZE"\n\t"
+		/* Use $ra to save PC */
+		"pcaddi	$ra, 0\n\t"
+		STR_LONG_S " $ra, %0\n\t"
+		/* Restore $ra */
+		STR_LONG_L " $ra, %1, "STR_LONGSIZE"\n\t"
 		STORE_ONE_REG(2)
 		STORE_ONE_REG(3)
 		STORE_ONE_REG(4)

arch/loongarch/include/asm/thread_info.h

@@ -44,14 +44,14 @@ struct thread_info {
 }
 
 /* How to get the thread information struct from C. */
-register struct thread_info *__current_thread_info __asm__("$r2");
+register struct thread_info *__current_thread_info __asm__("$tp");
 
 static inline struct thread_info *current_thread_info(void)
 {
 	return __current_thread_info;
 }
 
-register unsigned long current_stack_pointer __asm__("$r3");
+register unsigned long current_stack_pointer __asm__("$sp");
 
 #endif /* !__ASSEMBLY__ */
 

arch/loongarch/include/asm/uaccess.h

@@ -162,7 +162,7 @@ do {									\
 	"2:							\n"	\
 	"	.section .fixup,\"ax\"				\n"	\
 	"3:	li.w	%0, %3					\n"	\
-	"	or	%1, $r0, $r0				\n"	\
+	"	or	%1, $zero, $zero			\n"	\
 	"	b	2b					\n"	\
 	"	.previous					\n"	\
 	"	.section __ex_table,\"a\"			\n"	\

arch/loongarch/mm/page.S

@@ -32,7 +32,7 @@ SYM_FUNC_START(clear_page)
 	st.d     zero, a0, -8
 	bne      t0,   a0, 1b
 
-	jirl     $r0, ra, 0
+	jirl     zero, ra, 0
 SYM_FUNC_END(clear_page)
 EXPORT_SYMBOL(clear_page)
 
@@ -79,6 +79,6 @@ SYM_FUNC_START(copy_page)
 	st.d     t7, a0,  -8
 
 	bne      t8, a0, 1b
-	jirl     $r0, ra, 0
+	jirl     zero, ra, 0
 SYM_FUNC_END(copy_page)
 EXPORT_SYMBOL(copy_page)

arch/loongarch/mm/tlbex.S

@@ -47,7 +47,7 @@ SYM_FUNC_START(handle_tlb_load)
 	 * The vmalloc handling is not in the hotpath.
 	 */
 	csrrd	t0, LOONGARCH_CSR_BADV
-	blt	t0, $r0, vmalloc_load
+	blt	t0, zero, vmalloc_load
 	csrrd	t1, LOONGARCH_CSR_PGDL
 
 vmalloc_done_load:
@@ -80,7 +80,7 @@ vmalloc_done_load:
 	 * see if we need to jump to huge tlb processing.
 	 */
 	andi	t0, ra, _PAGE_HUGE
-	bne	t0, $r0, tlb_huge_update_load
+	bne	t0, zero, tlb_huge_update_load
 
 	csrrd	t0, LOONGARCH_CSR_BADV
 	srli.d	t0, t0, (PAGE_SHIFT + PTE_ORDER)
@@ -100,12 +100,12 @@ smp_pgtable_change_load:
 
 	srli.d	ra, t0, _PAGE_PRESENT_SHIFT
 	andi	ra, ra, 1
-	beq	ra, $r0, nopage_tlb_load
+	beq	ra, zero, nopage_tlb_load
 
 	ori	t0, t0, _PAGE_VALID
 #ifdef CONFIG_SMP
 	sc.d	t0, t1, 0
-	beq	t0, $r0, smp_pgtable_change_load
+	beq	t0, zero, smp_pgtable_change_load
 #else
 	st.d	t0, t1, 0
 #endif
@@ -139,23 +139,23 @@ tlb_huge_update_load:
 #endif
 	srli.d	ra, t0, _PAGE_PRESENT_SHIFT
 	andi	ra, ra, 1
-	beq	ra, $r0, nopage_tlb_load
+	beq	ra, zero, nopage_tlb_load
 	tlbsrch
 
 	ori	t0, t0, _PAGE_VALID
 #ifdef CONFIG_SMP
 	sc.d	t0, t1, 0
-	beq	t0, $r0, tlb_huge_update_load
+	beq	t0, zero, tlb_huge_update_load
 	ld.d	t0, t1, 0
 #else
 	st.d	t0, t1, 0
 #endif
-	addu16i.d	t1, $r0, -(CSR_TLBIDX_EHINV >> 16)
+	addu16i.d	t1, zero, -(CSR_TLBIDX_EHINV >> 16)
 	addi.d	ra, t1, 0
 	csrxchg	ra, t1, LOONGARCH_CSR_TLBIDX
 	tlbwr
 
-	csrxchg	$r0, t1, LOONGARCH_CSR_TLBIDX
+	csrxchg	zero, t1, LOONGARCH_CSR_TLBIDX
 
 	/*
 	 * A huge PTE describes an area the size of the
@@ -178,27 +178,27 @@ tlb_huge_update_load:
 	addi.d	t0, ra, 0
 
 	/* Convert to entrylo1 */
-	addi.d	t1, $r0, 1
+	addi.d	t1, zero, 1
 	slli.d	t1, t1, (HPAGE_SHIFT - 1)
 	add.d	t0, t0, t1
 	csrwr	t0, LOONGARCH_CSR_TLBELO1
 
 	/* Set huge page tlb entry size */
-	addu16i.d	t0, $r0, (CSR_TLBIDX_PS >> 16)
-	addu16i.d	t1, $r0, (PS_HUGE_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
+	addu16i.d	t0, zero, (CSR_TLBIDX_PS >> 16)
+	addu16i.d	t1, zero, (PS_HUGE_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
 	csrxchg		t1, t0, LOONGARCH_CSR_TLBIDX
 
 	tlbfill
 
-	addu16i.d	t0, $r0, (CSR_TLBIDX_PS >> 16)
-	addu16i.d	t1, $r0, (PS_DEFAULT_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
+	addu16i.d	t0, zero, (CSR_TLBIDX_PS >> 16)
+	addu16i.d	t1, zero, (PS_DEFAULT_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
 	csrxchg		t1, t0, LOONGARCH_CSR_TLBIDX
 
 nopage_tlb_load:
 	dbar	0
 	csrrd	ra, EXCEPTION_KS2
 	la.abs	t0, tlb_do_page_fault_0
-	jirl	$r0, t0, 0
+	jirl	zero, t0, 0
 SYM_FUNC_END(handle_tlb_load)
 
 SYM_FUNC_START(handle_tlb_store)
@@ -210,7 +210,7 @@ SYM_FUNC_START(handle_tlb_store)
 	 * The vmalloc handling is not in the hotpath.
 	 */
 	csrrd	t0, LOONGARCH_CSR_BADV
-	blt	t0, $r0, vmalloc_store
+	blt	t0, zero, vmalloc_store
 	csrrd	t1, LOONGARCH_CSR_PGDL
 
 vmalloc_done_store:
@@ -244,7 +244,7 @@ vmalloc_done_store:
 	 * see if we need to jump to huge tlb processing.
 	 */
 	andi	t0, ra, _PAGE_HUGE
-	bne	t0, $r0, tlb_huge_update_store
+	bne	t0, zero, tlb_huge_update_store
 
 	csrrd	t0, LOONGARCH_CSR_BADV
 	srli.d	t0, t0, (PAGE_SHIFT + PTE_ORDER)
@@ -265,12 +265,12 @@ smp_pgtable_change_store:
 	srli.d	ra, t0, _PAGE_PRESENT_SHIFT
 	andi	ra, ra, ((_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT)
 	xori	ra, ra, ((_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT)
-	bne	ra, $r0, nopage_tlb_store
+	bne	ra, zero, nopage_tlb_store
 
 	ori	t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
 #ifdef CONFIG_SMP
 	sc.d	t0, t1, 0
-	beq	t0, $r0, smp_pgtable_change_store
+	beq	t0, zero, smp_pgtable_change_store
 #else
 	st.d	t0, t1, 0
 #endif
@@ -306,24 +306,24 @@ tlb_huge_update_store:
 	srli.d	ra, t0, _PAGE_PRESENT_SHIFT
 	andi	ra, ra, ((_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT)
 	xori	ra, ra, ((_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT)
-	bne	ra, $r0, nopage_tlb_store
+	bne	ra, zero, nopage_tlb_store
 
 	tlbsrch
 	ori	t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
 
 #ifdef CONFIG_SMP
 	sc.d	t0, t1, 0
-	beq	t0, $r0, tlb_huge_update_store
+	beq	t0, zero, tlb_huge_update_store
 	ld.d	t0, t1, 0
 #else
 	st.d	t0, t1, 0
 #endif
-	addu16i.d	t1, $r0, -(CSR_TLBIDX_EHINV >> 16)
+	addu16i.d	t1, zero, -(CSR_TLBIDX_EHINV >> 16)
 	addi.d	ra, t1, 0
 	csrxchg	ra, t1, LOONGARCH_CSR_TLBIDX
 	tlbwr
 
-	csrxchg	$r0, t1, LOONGARCH_CSR_TLBIDX
+	csrxchg	zero, t1, LOONGARCH_CSR_TLBIDX
 	/*
 	 * A huge PTE describes an area the size of the
 	 * configured huge page size. This is twice the
@@ -345,28 +345,28 @@ tlb_huge_update_store:
 	addi.d	t0, ra, 0
 
 	/* Convert to entrylo1 */
-	addi.d	t1, $r0, 1
+	addi.d	t1, zero, 1
 	slli.d	t1, t1, (HPAGE_SHIFT - 1)
 	add.d	t0, t0, t1
 	csrwr	t0, LOONGARCH_CSR_TLBELO1
 
 	/* Set huge page tlb entry size */
-	addu16i.d	t0, $r0, (CSR_TLBIDX_PS >> 16)
-	addu16i.d	t1, $r0, (PS_HUGE_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
+	addu16i.d	t0, zero, (CSR_TLBIDX_PS >> 16)
+	addu16i.d	t1, zero, (PS_HUGE_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
 	csrxchg		t1, t0, LOONGARCH_CSR_TLBIDX
 
 	tlbfill
 
 	/* Reset default page size */
-	addu16i.d	t0, $r0, (CSR_TLBIDX_PS >> 16)
-	addu16i.d	t1, $r0, (PS_DEFAULT_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
+	addu16i.d	t0, zero, (CSR_TLBIDX_PS >> 16)
+	addu16i.d	t1, zero, (PS_DEFAULT_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
 	csrxchg		t1, t0, LOONGARCH_CSR_TLBIDX
 
 nopage_tlb_store:
 	dbar	0
 	csrrd	ra, EXCEPTION_KS2
 	la.abs	t0, tlb_do_page_fault_1
-	jirl	$r0, t0, 0
+	jirl	zero, t0, 0
 SYM_FUNC_END(handle_tlb_store)
 
 SYM_FUNC_START(handle_tlb_modify)
@@ -378,7 +378,7 @@ SYM_FUNC_START(handle_tlb_modify)
 	 * The vmalloc handling is not in the hotpath.
 	 */
 	csrrd	t0, LOONGARCH_CSR_BADV
-	blt	t0, $r0, vmalloc_modify
+	blt	t0, zero, vmalloc_modify
 	csrrd	t1, LOONGARCH_CSR_PGDL
 
 vmalloc_done_modify:
@@ -411,7 +411,7 @@ vmalloc_done_modify:
 	 * see if we need to jump to huge tlb processing.
 	 */
 	andi	t0, ra, _PAGE_HUGE
-	bne	t0, $r0, tlb_huge_update_modify
+	bne	t0, zero, tlb_huge_update_modify
 
 	csrrd	t0, LOONGARCH_CSR_BADV
 	srli.d	t0, t0, (PAGE_SHIFT + PTE_ORDER)
@@ -431,12 +431,12 @@ smp_pgtable_change_modify:
 
 	srli.d	ra, t0, _PAGE_WRITE_SHIFT
 	andi	ra, ra, 1
-	beq	ra, $r0, nopage_tlb_modify
+	beq	ra, zero, nopage_tlb_modify
 
 	ori	t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
 #ifdef CONFIG_SMP
 	sc.d	t0, t1, 0
-	beq	t0, $r0, smp_pgtable_change_modify
+	beq	t0, zero, smp_pgtable_change_modify
 #else
 	st.d	t0, t1, 0
 #endif
@@ -471,14 +471,14 @@ tlb_huge_update_modify:
 
 	srli.d	ra, t0, _PAGE_WRITE_SHIFT
 	andi	ra, ra, 1
-	beq	ra, $r0, nopage_tlb_modify
+	beq	ra, zero, nopage_tlb_modify
 
 	tlbsrch
 	ori	t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
 
 #ifdef CONFIG_SMP
 	sc.d	t0, t1, 0
-	beq	t0, $r0, tlb_huge_update_modify
+	beq	t0, zero, tlb_huge_update_modify
 	ld.d	t0, t1, 0
 #else
 	st.d	t0, t1, 0
@@ -504,28 +504,28 @@ tlb_huge_update_modify:
 	addi.d	t0, ra, 0
 
 	/* Convert to entrylo1 */
-	addi.d	t1, $r0, 1
+	addi.d	t1, zero, 1
 	slli.d	t1, t1, (HPAGE_SHIFT - 1)
 	add.d	t0, t0, t1
 	csrwr	t0, LOONGARCH_CSR_TLBELO1
 
 	/* Set huge page tlb entry size */
-	addu16i.d	t0, $r0, (CSR_TLBIDX_PS >> 16)
-	addu16i.d	t1, $r0, (PS_HUGE_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
+	addu16i.d	t0, zero, (CSR_TLBIDX_PS >> 16)
+	addu16i.d	t1, zero, (PS_HUGE_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
 	csrxchg	t1, t0, LOONGARCH_CSR_TLBIDX
 
 	tlbwr
 
 	/* Reset default page size */
-	addu16i.d	t0, $r0, (CSR_TLBIDX_PS >> 16)
-	addu16i.d	t1, $r0, (PS_DEFAULT_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
+	addu16i.d	t0, zero, (CSR_TLBIDX_PS >> 16)
+	addu16i.d	t1, zero, (PS_DEFAULT_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
 	csrxchg	t1, t0, LOONGARCH_CSR_TLBIDX
 
 nopage_tlb_modify:
 	dbar	0
 	csrrd	ra, EXCEPTION_KS2
 	la.abs	t0, tlb_do_page_fault_1
-	jirl	$r0, t0, 0
+	jirl	zero, t0, 0
 SYM_FUNC_END(handle_tlb_modify)
 
 SYM_FUNC_START(handle_tlb_refill)