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-rw-r--r--arch/powerpc/lib/copyuser_64.S564
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diff --git a/arch/powerpc/lib/copyuser_64.S b/arch/powerpc/lib/copyuser_64.S
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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2002 Paul Mackerras, IBM Corp.
+ */
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/export.h>
+#include <asm/asm-compat.h>
+#include <asm/feature-fixups.h>
+
+#ifndef SELFTEST_CASE
+/* 0 == most CPUs, 1 == POWER6, 2 == Cell */
+#define SELFTEST_CASE 0
+#endif
+
+#ifdef __BIG_ENDIAN__
+#define sLd sld /* Shift towards low-numbered address. */
+#define sHd srd /* Shift towards high-numbered address. */
+#else
+#define sLd srd /* Shift towards low-numbered address. */
+#define sHd sld /* Shift towards high-numbered address. */
+#endif
+
+/*
+ * These macros are used to generate exception table entries.
+ * The exception handlers below use the original arguments
+ * (stored on the stack) and the point where we're up to in
+ * the destination buffer, i.e. the address of the first
+ * unmodified byte. Generally r3 points into the destination
+ * buffer, but the first unmodified byte is at a variable
+ * offset from r3. In the code below, the symbol r3_offset
+ * is set to indicate the current offset at each point in
+ * the code. This offset is then used as a negative offset
+ * from the exception handler code, and those instructions
+ * before the exception handlers are addi instructions that
+ * adjust r3 to point to the correct place.
+ */
+ .macro lex /* exception handler for load */
+100: EX_TABLE(100b, .Lld_exc - r3_offset)
+ .endm
+
+ .macro stex /* exception handler for store */
+100: EX_TABLE(100b, .Lst_exc - r3_offset)
+ .endm
+
+ .align 7
+_GLOBAL_TOC(__copy_tofrom_user)
+#ifdef CONFIG_PPC_BOOK3S_64
+BEGIN_FTR_SECTION
+ nop
+FTR_SECTION_ELSE
+ b __copy_tofrom_user_power7
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_VMX_COPY)
+#endif
+_GLOBAL(__copy_tofrom_user_base)
+ /* first check for a 4kB copy on a 4kB boundary */
+ cmpldi cr1,r5,16
+ cmpdi cr6,r5,4096
+ or r0,r3,r4
+ neg r6,r3 /* LS 3 bits = # bytes to 8-byte dest bdry */
+ andi. r0,r0,4095
+ std r3,-24(r1)
+ crand cr0*4+2,cr0*4+2,cr6*4+2
+ std r4,-16(r1)
+ std r5,-8(r1)
+ dcbt 0,r4
+ beq .Lcopy_page_4K
+ andi. r6,r6,7
+ PPC_MTOCRF(0x01,r5)
+ blt cr1,.Lshort_copy
+/* Below we want to nop out the bne if we're on a CPU that has the
+ * CPU_FTR_UNALIGNED_LD_STD bit set and the CPU_FTR_CP_USE_DCBTZ bit
+ * cleared.
+ * At the time of writing the only CPU that has this combination of bits
+ * set is Power6.
+ */
+test_feature = (SELFTEST_CASE == 1)
+BEGIN_FTR_SECTION
+ nop
+FTR_SECTION_ELSE
+ bne .Ldst_unaligned
+ALT_FTR_SECTION_END(CPU_FTR_UNALIGNED_LD_STD | CPU_FTR_CP_USE_DCBTZ, \
+ CPU_FTR_UNALIGNED_LD_STD)
+.Ldst_aligned:
+ addi r3,r3,-16
+r3_offset = 16
+test_feature = (SELFTEST_CASE == 0)
+BEGIN_FTR_SECTION
+ andi. r0,r4,7
+ bne .Lsrc_unaligned
+END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
+ blt cr1,.Ldo_tail /* if < 16 bytes to copy */
+ srdi r0,r5,5
+ cmpdi cr1,r0,0
+lex; ld r7,0(r4)
+lex; ld r6,8(r4)
+ addi r4,r4,16
+ mtctr r0
+ andi. r0,r5,0x10
+ beq 22f
+ addi r3,r3,16
+r3_offset = 0
+ addi r4,r4,-16
+ mr r9,r7
+ mr r8,r6
+ beq cr1,72f
+21:
+lex; ld r7,16(r4)
+lex; ld r6,24(r4)
+ addi r4,r4,32
+stex; std r9,0(r3)
+r3_offset = 8
+stex; std r8,8(r3)
+r3_offset = 16
+22:
+lex; ld r9,0(r4)
+lex; ld r8,8(r4)
+stex; std r7,16(r3)
+r3_offset = 24
+stex; std r6,24(r3)
+ addi r3,r3,32
+r3_offset = 0
+ bdnz 21b
+72:
+stex; std r9,0(r3)
+r3_offset = 8
+stex; std r8,8(r3)
+r3_offset = 16
+ andi. r5,r5,0xf
+ beq+ 3f
+ addi r4,r4,16
+.Ldo_tail:
+ addi r3,r3,16
+r3_offset = 0
+ bf cr7*4+0,246f
+lex; ld r9,0(r4)
+ addi r4,r4,8
+stex; std r9,0(r3)
+ addi r3,r3,8
+246: bf cr7*4+1,1f
+lex; lwz r9,0(r4)
+ addi r4,r4,4
+stex; stw r9,0(r3)
+ addi r3,r3,4
+1: bf cr7*4+2,2f
+lex; lhz r9,0(r4)
+ addi r4,r4,2
+stex; sth r9,0(r3)
+ addi r3,r3,2
+2: bf cr7*4+3,3f
+lex; lbz r9,0(r4)
+stex; stb r9,0(r3)
+3: li r3,0
+ blr
+
+.Lsrc_unaligned:
+r3_offset = 16
+ srdi r6,r5,3
+ addi r5,r5,-16
+ subf r4,r0,r4
+ srdi r7,r5,4
+ sldi r10,r0,3
+ cmpldi cr6,r6,3
+ andi. r5,r5,7
+ mtctr r7
+ subfic r11,r10,64
+ add r5,r5,r0
+ bt cr7*4+0,28f
+
+lex; ld r9,0(r4) /* 3+2n loads, 2+2n stores */
+lex; ld r0,8(r4)
+ sLd r6,r9,r10
+lex; ldu r9,16(r4)
+ sHd r7,r0,r11
+ sLd r8,r0,r10
+ or r7,r7,r6
+ blt cr6,79f
+lex; ld r0,8(r4)
+ b 2f
+
+28:
+lex; ld r0,0(r4) /* 4+2n loads, 3+2n stores */
+lex; ldu r9,8(r4)
+ sLd r8,r0,r10
+ addi r3,r3,-8
+r3_offset = 24
+ blt cr6,5f
+lex; ld r0,8(r4)
+ sHd r12,r9,r11
+ sLd r6,r9,r10
+lex; ldu r9,16(r4)
+ or r12,r8,r12
+ sHd r7,r0,r11
+ sLd r8,r0,r10
+ addi r3,r3,16
+r3_offset = 8
+ beq cr6,78f
+
+1: or r7,r7,r6
+lex; ld r0,8(r4)
+stex; std r12,8(r3)
+r3_offset = 16
+2: sHd r12,r9,r11
+ sLd r6,r9,r10
+lex; ldu r9,16(r4)
+ or r12,r8,r12
+stex; stdu r7,16(r3)
+r3_offset = 8
+ sHd r7,r0,r11
+ sLd r8,r0,r10
+ bdnz 1b
+
+78:
+stex; std r12,8(r3)
+r3_offset = 16
+ or r7,r7,r6
+79:
+stex; std r7,16(r3)
+r3_offset = 24
+5: sHd r12,r9,r11
+ or r12,r8,r12
+stex; std r12,24(r3)
+r3_offset = 32
+ bne 6f
+ li r3,0
+ blr
+6: cmpwi cr1,r5,8
+ addi r3,r3,32
+r3_offset = 0
+ sLd r9,r9,r10
+ ble cr1,7f
+lex; ld r0,8(r4)
+ sHd r7,r0,r11
+ or r9,r7,r9
+7:
+ bf cr7*4+1,1f
+#ifdef __BIG_ENDIAN__
+ rotldi r9,r9,32
+#endif
+stex; stw r9,0(r3)
+#ifdef __LITTLE_ENDIAN__
+ rotrdi r9,r9,32
+#endif
+ addi r3,r3,4
+1: bf cr7*4+2,2f
+#ifdef __BIG_ENDIAN__
+ rotldi r9,r9,16
+#endif
+stex; sth r9,0(r3)
+#ifdef __LITTLE_ENDIAN__
+ rotrdi r9,r9,16
+#endif
+ addi r3,r3,2
+2: bf cr7*4+3,3f
+#ifdef __BIG_ENDIAN__
+ rotldi r9,r9,8
+#endif
+stex; stb r9,0(r3)
+#ifdef __LITTLE_ENDIAN__
+ rotrdi r9,r9,8
+#endif
+3: li r3,0
+ blr
+
+.Ldst_unaligned:
+r3_offset = 0
+ PPC_MTOCRF(0x01,r6) /* put #bytes to 8B bdry into cr7 */
+ subf r5,r6,r5
+ li r7,0
+ cmpldi cr1,r5,16
+ bf cr7*4+3,1f
+100: EX_TABLE(100b, .Lld_exc_r7)
+ lbz r0,0(r4)
+100: EX_TABLE(100b, .Lst_exc_r7)
+ stb r0,0(r3)
+ addi r7,r7,1
+1: bf cr7*4+2,2f
+100: EX_TABLE(100b, .Lld_exc_r7)
+ lhzx r0,r7,r4
+100: EX_TABLE(100b, .Lst_exc_r7)
+ sthx r0,r7,r3
+ addi r7,r7,2
+2: bf cr7*4+1,3f
+100: EX_TABLE(100b, .Lld_exc_r7)
+ lwzx r0,r7,r4
+100: EX_TABLE(100b, .Lst_exc_r7)
+ stwx r0,r7,r3
+3: PPC_MTOCRF(0x01,r5)
+ add r4,r6,r4
+ add r3,r6,r3
+ b .Ldst_aligned
+
+.Lshort_copy:
+r3_offset = 0
+ bf cr7*4+0,1f
+lex; lwz r0,0(r4)
+lex; lwz r9,4(r4)
+ addi r4,r4,8
+stex; stw r0,0(r3)
+stex; stw r9,4(r3)
+ addi r3,r3,8
+1: bf cr7*4+1,2f
+lex; lwz r0,0(r4)
+ addi r4,r4,4
+stex; stw r0,0(r3)
+ addi r3,r3,4
+2: bf cr7*4+2,3f
+lex; lhz r0,0(r4)
+ addi r4,r4,2
+stex; sth r0,0(r3)
+ addi r3,r3,2
+3: bf cr7*4+3,4f
+lex; lbz r0,0(r4)
+stex; stb r0,0(r3)
+4: li r3,0
+ blr
+
+/*
+ * exception handlers follow
+ * we have to return the number of bytes not copied
+ * for an exception on a load, we set the rest of the destination to 0
+ * Note that the number of bytes of instructions for adjusting r3 needs
+ * to equal the amount of the adjustment, due to the trick of using
+ * .Lld_exc - r3_offset as the handler address.
+ */
+
+.Lld_exc_r7:
+ add r3,r3,r7
+ b .Lld_exc
+
+ /* adjust by 24 */
+ addi r3,r3,8
+ nop
+ /* adjust by 16 */
+ addi r3,r3,8
+ nop
+ /* adjust by 8 */
+ addi r3,r3,8
+ nop
+
+/*
+ * Here we have had a fault on a load and r3 points to the first
+ * unmodified byte of the destination. We use the original arguments
+ * and r3 to work out how much wasn't copied. Since we load some
+ * distance ahead of the stores, we continue copying byte-by-byte until
+ * we hit the load fault again in order to copy as much as possible.
+ */
+.Lld_exc:
+ ld r6,-24(r1)
+ ld r4,-16(r1)
+ ld r5,-8(r1)
+ subf r6,r6,r3
+ add r4,r4,r6
+ subf r5,r6,r5 /* #bytes left to go */
+
+/*
+ * first see if we can copy any more bytes before hitting another exception
+ */
+ mtctr r5
+r3_offset = 0
+100: EX_TABLE(100b, .Ldone)
+43: lbz r0,0(r4)
+ addi r4,r4,1
+stex; stb r0,0(r3)
+ addi r3,r3,1
+ bdnz 43b
+ li r3,0 /* huh? all copied successfully this time? */
+ blr
+
+/*
+ * here we have trapped again, amount remaining is in ctr.
+ */
+.Ldone:
+ mfctr r3
+ blr
+
+/*
+ * exception handlers for stores: we need to work out how many bytes
+ * weren't copied, and we may need to copy some more.
+ * Note that the number of bytes of instructions for adjusting r3 needs
+ * to equal the amount of the adjustment, due to the trick of using
+ * .Lst_exc - r3_offset as the handler address.
+ */
+.Lst_exc_r7:
+ add r3,r3,r7
+ b .Lst_exc
+
+ /* adjust by 24 */
+ addi r3,r3,8
+ nop
+ /* adjust by 16 */
+ addi r3,r3,8
+ nop
+ /* adjust by 8 */
+ addi r3,r3,4
+ /* adjust by 4 */
+ addi r3,r3,4
+.Lst_exc:
+ ld r6,-24(r1) /* original destination pointer */
+ ld r4,-16(r1) /* original source pointer */
+ ld r5,-8(r1) /* original number of bytes */
+ add r7,r6,r5
+ /*
+ * If the destination pointer isn't 8-byte aligned,
+ * we may have got the exception as a result of a
+ * store that overlapped a page boundary, so we may be
+ * able to copy a few more bytes.
+ */
+17: andi. r0,r3,7
+ beq 19f
+ subf r8,r6,r3 /* #bytes copied */
+100: EX_TABLE(100b,19f)
+ lbzx r0,r8,r4
+100: EX_TABLE(100b,19f)
+ stb r0,0(r3)
+ addi r3,r3,1
+ cmpld r3,r7
+ blt 17b
+19: subf r3,r3,r7 /* #bytes not copied in r3 */
+ blr
+
+/*
+ * Routine to copy a whole page of data, optimized for POWER4.
+ * On POWER4 it is more than 50% faster than the simple loop
+ * above (following the .Ldst_aligned label).
+ */
+ .macro exc
+100: EX_TABLE(100b, .Labort)
+ .endm
+.Lcopy_page_4K:
+ std r31,-32(1)
+ std r30,-40(1)
+ std r29,-48(1)
+ std r28,-56(1)
+ std r27,-64(1)
+ std r26,-72(1)
+ std r25,-80(1)
+ std r24,-88(1)
+ std r23,-96(1)
+ std r22,-104(1)
+ std r21,-112(1)
+ std r20,-120(1)
+ li r5,4096/32 - 1
+ addi r3,r3,-8
+ li r0,5
+0: addi r5,r5,-24
+ mtctr r0
+exc; ld r22,640(4)
+exc; ld r21,512(4)
+exc; ld r20,384(4)
+exc; ld r11,256(4)
+exc; ld r9,128(4)
+exc; ld r7,0(4)
+exc; ld r25,648(4)
+exc; ld r24,520(4)
+exc; ld r23,392(4)
+exc; ld r10,264(4)
+exc; ld r8,136(4)
+exc; ldu r6,8(4)
+ cmpwi r5,24
+1:
+exc; std r22,648(3)
+exc; std r21,520(3)
+exc; std r20,392(3)
+exc; std r11,264(3)
+exc; std r9,136(3)
+exc; std r7,8(3)
+exc; ld r28,648(4)
+exc; ld r27,520(4)
+exc; ld r26,392(4)
+exc; ld r31,264(4)
+exc; ld r30,136(4)
+exc; ld r29,8(4)
+exc; std r25,656(3)
+exc; std r24,528(3)
+exc; std r23,400(3)
+exc; std r10,272(3)
+exc; std r8,144(3)
+exc; std r6,16(3)
+exc; ld r22,656(4)
+exc; ld r21,528(4)
+exc; ld r20,400(4)
+exc; ld r11,272(4)
+exc; ld r9,144(4)
+exc; ld r7,16(4)
+exc; std r28,664(3)
+exc; std r27,536(3)
+exc; std r26,408(3)
+exc; std r31,280(3)
+exc; std r30,152(3)
+exc; stdu r29,24(3)
+exc; ld r25,664(4)
+exc; ld r24,536(4)
+exc; ld r23,408(4)
+exc; ld r10,280(4)
+exc; ld r8,152(4)
+exc; ldu r6,24(4)
+ bdnz 1b
+exc; std r22,648(3)
+exc; std r21,520(3)
+exc; std r20,392(3)
+exc; std r11,264(3)
+exc; std r9,136(3)
+exc; std r7,8(3)
+ addi r4,r4,640
+ addi r3,r3,648
+ bge 0b
+ mtctr r5
+exc; ld r7,0(4)
+exc; ld r8,8(4)
+exc; ldu r9,16(4)
+3:
+exc; ld r10,8(4)
+exc; std r7,8(3)
+exc; ld r7,16(4)
+exc; std r8,16(3)
+exc; ld r8,24(4)
+exc; std r9,24(3)
+exc; ldu r9,32(4)
+exc; stdu r10,32(3)
+ bdnz 3b
+4:
+exc; ld r10,8(4)
+exc; std r7,8(3)
+exc; std r8,16(3)
+exc; std r9,24(3)
+exc; std r10,32(3)
+9: ld r20,-120(1)
+ ld r21,-112(1)
+ ld r22,-104(1)
+ ld r23,-96(1)
+ ld r24,-88(1)
+ ld r25,-80(1)
+ ld r26,-72(1)
+ ld r27,-64(1)
+ ld r28,-56(1)
+ ld r29,-48(1)
+ ld r30,-40(1)
+ ld r31,-32(1)
+ li r3,0
+ blr
+
+/*
+ * on an exception, reset to the beginning and jump back into the
+ * standard __copy_tofrom_user
+ */
+.Labort:
+ ld r20,-120(1)
+ ld r21,-112(1)
+ ld r22,-104(1)
+ ld r23,-96(1)
+ ld r24,-88(1)
+ ld r25,-80(1)
+ ld r26,-72(1)
+ ld r27,-64(1)
+ ld r28,-56(1)
+ ld r29,-48(1)
+ ld r30,-40(1)
+ ld r31,-32(1)
+ ld r3,-24(r1)
+ ld r4,-16(r1)
+ li r5,4096
+ b .Ldst_aligned
+EXPORT_SYMBOL(__copy_tofrom_user)