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-rw-r--r--arch/arm/lib/uaccess.S564
1 files changed, 564 insertions, 0 deletions
diff --git a/arch/arm/lib/uaccess.S b/arch/arm/lib/uaccess.S
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@@ -0,0 +1,564 @@
+/*
+ * linux/arch/arm/lib/uaccess.S
+ *
+ * Copyright (C) 1995, 1996,1997,1998 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Routines to block copy data to/from user memory
+ * These are highly optimised both for the 4k page size
+ * and for various alignments.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+#include <asm/domain.h>
+
+ .text
+
+#define PAGE_SHIFT 12
+
+/* Prototype: int __copy_to_user(void *to, const char *from, size_t n)
+ * Purpose : copy a block to user memory from kernel memory
+ * Params : to - user memory
+ * : from - kernel memory
+ * : n - number of bytes to copy
+ * Returns : Number of bytes NOT copied.
+ */
+
+.Lc2u_dest_not_aligned:
+ rsb ip, ip, #4
+ cmp ip, #2
+ ldrb r3, [r1], #1
+USER( TUSER( strb) r3, [r0], #1) @ May fault
+ ldrgeb r3, [r1], #1
+USER( TUSER( strgeb) r3, [r0], #1) @ May fault
+ ldrgtb r3, [r1], #1
+USER( TUSER( strgtb) r3, [r0], #1) @ May fault
+ sub r2, r2, ip
+ b .Lc2u_dest_aligned
+
+ENTRY(__copy_to_user)
+ stmfd sp!, {r2, r4 - r7, lr}
+ cmp r2, #4
+ blt .Lc2u_not_enough
+ ands ip, r0, #3
+ bne .Lc2u_dest_not_aligned
+.Lc2u_dest_aligned:
+
+ ands ip, r1, #3
+ bne .Lc2u_src_not_aligned
+/*
+ * Seeing as there has to be at least 8 bytes to copy, we can
+ * copy one word, and force a user-mode page fault...
+ */
+
+.Lc2u_0fupi: subs r2, r2, #4
+ addmi ip, r2, #4
+ bmi .Lc2u_0nowords
+ ldr r3, [r1], #4
+USER( TUSER( str) r3, [r0], #4) @ May fault
+ mov ip, r0, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
+ rsb ip, ip, #0
+ movs ip, ip, lsr #32 - PAGE_SHIFT
+ beq .Lc2u_0fupi
+/*
+ * ip = max no. of bytes to copy before needing another "strt" insn
+ */
+ cmp r2, ip
+ movlt ip, r2
+ sub r2, r2, ip
+ subs ip, ip, #32
+ blt .Lc2u_0rem8lp
+
+.Lc2u_0cpy8lp: ldmia r1!, {r3 - r6}
+ stmia r0!, {r3 - r6} @ Shouldnt fault
+ ldmia r1!, {r3 - r6}
+ subs ip, ip, #32
+ stmia r0!, {r3 - r6} @ Shouldnt fault
+ bpl .Lc2u_0cpy8lp
+
+.Lc2u_0rem8lp: cmn ip, #16
+ ldmgeia r1!, {r3 - r6}
+ stmgeia r0!, {r3 - r6} @ Shouldnt fault
+ tst ip, #8
+ ldmneia r1!, {r3 - r4}
+ stmneia r0!, {r3 - r4} @ Shouldnt fault
+ tst ip, #4
+ ldrne r3, [r1], #4
+ TUSER( strne) r3, [r0], #4 @ Shouldnt fault
+ ands ip, ip, #3
+ beq .Lc2u_0fupi
+.Lc2u_0nowords: teq ip, #0
+ beq .Lc2u_finished
+.Lc2u_nowords: cmp ip, #2
+ ldrb r3, [r1], #1
+USER( TUSER( strb) r3, [r0], #1) @ May fault
+ ldrgeb r3, [r1], #1
+USER( TUSER( strgeb) r3, [r0], #1) @ May fault
+ ldrgtb r3, [r1], #1
+USER( TUSER( strgtb) r3, [r0], #1) @ May fault
+ b .Lc2u_finished
+
+.Lc2u_not_enough:
+ movs ip, r2
+ bne .Lc2u_nowords
+.Lc2u_finished: mov r0, #0
+ ldmfd sp!, {r2, r4 - r7, pc}
+
+.Lc2u_src_not_aligned:
+ bic r1, r1, #3
+ ldr r7, [r1], #4
+ cmp ip, #2
+ bgt .Lc2u_3fupi
+ beq .Lc2u_2fupi
+.Lc2u_1fupi: subs r2, r2, #4
+ addmi ip, r2, #4
+ bmi .Lc2u_1nowords
+ mov r3, r7, pull #8
+ ldr r7, [r1], #4
+ orr r3, r3, r7, push #24
+USER( TUSER( str) r3, [r0], #4) @ May fault
+ mov ip, r0, lsl #32 - PAGE_SHIFT
+ rsb ip, ip, #0
+ movs ip, ip, lsr #32 - PAGE_SHIFT
+ beq .Lc2u_1fupi
+ cmp r2, ip
+ movlt ip, r2
+ sub r2, r2, ip
+ subs ip, ip, #16
+ blt .Lc2u_1rem8lp
+
+.Lc2u_1cpy8lp: mov r3, r7, pull #8
+ ldmia r1!, {r4 - r7}
+ subs ip, ip, #16
+ orr r3, r3, r4, push #24
+ mov r4, r4, pull #8
+ orr r4, r4, r5, push #24
+ mov r5, r5, pull #8
+ orr r5, r5, r6, push #24
+ mov r6, r6, pull #8
+ orr r6, r6, r7, push #24
+ stmia r0!, {r3 - r6} @ Shouldnt fault
+ bpl .Lc2u_1cpy8lp
+
+.Lc2u_1rem8lp: tst ip, #8
+ movne r3, r7, pull #8
+ ldmneia r1!, {r4, r7}
+ orrne r3, r3, r4, push #24
+ movne r4, r4, pull #8
+ orrne r4, r4, r7, push #24
+ stmneia r0!, {r3 - r4} @ Shouldnt fault
+ tst ip, #4
+ movne r3, r7, pull #8
+ ldrne r7, [r1], #4
+ orrne r3, r3, r7, push #24
+ TUSER( strne) r3, [r0], #4 @ Shouldnt fault
+ ands ip, ip, #3
+ beq .Lc2u_1fupi
+.Lc2u_1nowords: mov r3, r7, get_byte_1
+ teq ip, #0
+ beq .Lc2u_finished
+ cmp ip, #2
+USER( TUSER( strb) r3, [r0], #1) @ May fault
+ movge r3, r7, get_byte_2
+USER( TUSER( strgeb) r3, [r0], #1) @ May fault
+ movgt r3, r7, get_byte_3
+USER( TUSER( strgtb) r3, [r0], #1) @ May fault
+ b .Lc2u_finished
+
+.Lc2u_2fupi: subs r2, r2, #4
+ addmi ip, r2, #4
+ bmi .Lc2u_2nowords
+ mov r3, r7, pull #16
+ ldr r7, [r1], #4
+ orr r3, r3, r7, push #16
+USER( TUSER( str) r3, [r0], #4) @ May fault
+ mov ip, r0, lsl #32 - PAGE_SHIFT
+ rsb ip, ip, #0
+ movs ip, ip, lsr #32 - PAGE_SHIFT
+ beq .Lc2u_2fupi
+ cmp r2, ip
+ movlt ip, r2
+ sub r2, r2, ip
+ subs ip, ip, #16
+ blt .Lc2u_2rem8lp
+
+.Lc2u_2cpy8lp: mov r3, r7, pull #16
+ ldmia r1!, {r4 - r7}
+ subs ip, ip, #16
+ orr r3, r3, r4, push #16
+ mov r4, r4, pull #16
+ orr r4, r4, r5, push #16
+ mov r5, r5, pull #16
+ orr r5, r5, r6, push #16
+ mov r6, r6, pull #16
+ orr r6, r6, r7, push #16
+ stmia r0!, {r3 - r6} @ Shouldnt fault
+ bpl .Lc2u_2cpy8lp
+
+.Lc2u_2rem8lp: tst ip, #8
+ movne r3, r7, pull #16
+ ldmneia r1!, {r4, r7}
+ orrne r3, r3, r4, push #16
+ movne r4, r4, pull #16
+ orrne r4, r4, r7, push #16
+ stmneia r0!, {r3 - r4} @ Shouldnt fault
+ tst ip, #4
+ movne r3, r7, pull #16
+ ldrne r7, [r1], #4
+ orrne r3, r3, r7, push #16
+ TUSER( strne) r3, [r0], #4 @ Shouldnt fault
+ ands ip, ip, #3
+ beq .Lc2u_2fupi
+.Lc2u_2nowords: mov r3, r7, get_byte_2
+ teq ip, #0
+ beq .Lc2u_finished
+ cmp ip, #2
+USER( TUSER( strb) r3, [r0], #1) @ May fault
+ movge r3, r7, get_byte_3
+USER( TUSER( strgeb) r3, [r0], #1) @ May fault
+ ldrgtb r3, [r1], #0
+USER( TUSER( strgtb) r3, [r0], #1) @ May fault
+ b .Lc2u_finished
+
+.Lc2u_3fupi: subs r2, r2, #4
+ addmi ip, r2, #4
+ bmi .Lc2u_3nowords
+ mov r3, r7, pull #24
+ ldr r7, [r1], #4
+ orr r3, r3, r7, push #8
+USER( TUSER( str) r3, [r0], #4) @ May fault
+ mov ip, r0, lsl #32 - PAGE_SHIFT
+ rsb ip, ip, #0
+ movs ip, ip, lsr #32 - PAGE_SHIFT
+ beq .Lc2u_3fupi
+ cmp r2, ip
+ movlt ip, r2
+ sub r2, r2, ip
+ subs ip, ip, #16
+ blt .Lc2u_3rem8lp
+
+.Lc2u_3cpy8lp: mov r3, r7, pull #24
+ ldmia r1!, {r4 - r7}
+ subs ip, ip, #16
+ orr r3, r3, r4, push #8
+ mov r4, r4, pull #24
+ orr r4, r4, r5, push #8
+ mov r5, r5, pull #24
+ orr r5, r5, r6, push #8
+ mov r6, r6, pull #24
+ orr r6, r6, r7, push #8
+ stmia r0!, {r3 - r6} @ Shouldnt fault
+ bpl .Lc2u_3cpy8lp
+
+.Lc2u_3rem8lp: tst ip, #8
+ movne r3, r7, pull #24
+ ldmneia r1!, {r4, r7}
+ orrne r3, r3, r4, push #8
+ movne r4, r4, pull #24
+ orrne r4, r4, r7, push #8
+ stmneia r0!, {r3 - r4} @ Shouldnt fault
+ tst ip, #4
+ movne r3, r7, pull #24
+ ldrne r7, [r1], #4
+ orrne r3, r3, r7, push #8
+ TUSER( strne) r3, [r0], #4 @ Shouldnt fault
+ ands ip, ip, #3
+ beq .Lc2u_3fupi
+.Lc2u_3nowords: mov r3, r7, get_byte_3
+ teq ip, #0
+ beq .Lc2u_finished
+ cmp ip, #2
+USER( TUSER( strb) r3, [r0], #1) @ May fault
+ ldrgeb r3, [r1], #1
+USER( TUSER( strgeb) r3, [r0], #1) @ May fault
+ ldrgtb r3, [r1], #0
+USER( TUSER( strgtb) r3, [r0], #1) @ May fault
+ b .Lc2u_finished
+ENDPROC(__copy_to_user)
+
+ .pushsection .fixup,"ax"
+ .align 0
+9001: ldmfd sp!, {r0, r4 - r7, pc}
+ .popsection
+
+/* Prototype: unsigned long __copy_from_user(void *to,const void *from,unsigned long n);
+ * Purpose : copy a block from user memory to kernel memory
+ * Params : to - kernel memory
+ * : from - user memory
+ * : n - number of bytes to copy
+ * Returns : Number of bytes NOT copied.
+ */
+.Lcfu_dest_not_aligned:
+ rsb ip, ip, #4
+ cmp ip, #2
+USER( TUSER( ldrb) r3, [r1], #1) @ May fault
+ strb r3, [r0], #1
+USER( TUSER( ldrgeb) r3, [r1], #1) @ May fault
+ strgeb r3, [r0], #1
+USER( TUSER( ldrgtb) r3, [r1], #1) @ May fault
+ strgtb r3, [r0], #1
+ sub r2, r2, ip
+ b .Lcfu_dest_aligned
+
+ENTRY(__copy_from_user)
+ stmfd sp!, {r0, r2, r4 - r7, lr}
+ cmp r2, #4
+ blt .Lcfu_not_enough
+ ands ip, r0, #3
+ bne .Lcfu_dest_not_aligned
+.Lcfu_dest_aligned:
+ ands ip, r1, #3
+ bne .Lcfu_src_not_aligned
+
+/*
+ * Seeing as there has to be at least 8 bytes to copy, we can
+ * copy one word, and force a user-mode page fault...
+ */
+
+.Lcfu_0fupi: subs r2, r2, #4
+ addmi ip, r2, #4
+ bmi .Lcfu_0nowords
+USER( TUSER( ldr) r3, [r1], #4)
+ str r3, [r0], #4
+ mov ip, r1, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
+ rsb ip, ip, #0
+ movs ip, ip, lsr #32 - PAGE_SHIFT
+ beq .Lcfu_0fupi
+/*
+ * ip = max no. of bytes to copy before needing another "strt" insn
+ */
+ cmp r2, ip
+ movlt ip, r2
+ sub r2, r2, ip
+ subs ip, ip, #32
+ blt .Lcfu_0rem8lp
+
+.Lcfu_0cpy8lp: ldmia r1!, {r3 - r6} @ Shouldnt fault
+ stmia r0!, {r3 - r6}
+ ldmia r1!, {r3 - r6} @ Shouldnt fault
+ subs ip, ip, #32
+ stmia r0!, {r3 - r6}
+ bpl .Lcfu_0cpy8lp
+
+.Lcfu_0rem8lp: cmn ip, #16
+ ldmgeia r1!, {r3 - r6} @ Shouldnt fault
+ stmgeia r0!, {r3 - r6}
+ tst ip, #8
+ ldmneia r1!, {r3 - r4} @ Shouldnt fault
+ stmneia r0!, {r3 - r4}
+ tst ip, #4
+ TUSER( ldrne) r3, [r1], #4 @ Shouldnt fault
+ strne r3, [r0], #4
+ ands ip, ip, #3
+ beq .Lcfu_0fupi
+.Lcfu_0nowords: teq ip, #0
+ beq .Lcfu_finished
+.Lcfu_nowords: cmp ip, #2
+USER( TUSER( ldrb) r3, [r1], #1) @ May fault
+ strb r3, [r0], #1
+USER( TUSER( ldrgeb) r3, [r1], #1) @ May fault
+ strgeb r3, [r0], #1
+USER( TUSER( ldrgtb) r3, [r1], #1) @ May fault
+ strgtb r3, [r0], #1
+ b .Lcfu_finished
+
+.Lcfu_not_enough:
+ movs ip, r2
+ bne .Lcfu_nowords
+.Lcfu_finished: mov r0, #0
+ add sp, sp, #8
+ ldmfd sp!, {r4 - r7, pc}
+
+.Lcfu_src_not_aligned:
+ bic r1, r1, #3
+USER( TUSER( ldr) r7, [r1], #4) @ May fault
+ cmp ip, #2
+ bgt .Lcfu_3fupi
+ beq .Lcfu_2fupi
+.Lcfu_1fupi: subs r2, r2, #4
+ addmi ip, r2, #4
+ bmi .Lcfu_1nowords
+ mov r3, r7, pull #8
+USER( TUSER( ldr) r7, [r1], #4) @ May fault
+ orr r3, r3, r7, push #24
+ str r3, [r0], #4
+ mov ip, r1, lsl #32 - PAGE_SHIFT
+ rsb ip, ip, #0
+ movs ip, ip, lsr #32 - PAGE_SHIFT
+ beq .Lcfu_1fupi
+ cmp r2, ip
+ movlt ip, r2
+ sub r2, r2, ip
+ subs ip, ip, #16
+ blt .Lcfu_1rem8lp
+
+.Lcfu_1cpy8lp: mov r3, r7, pull #8
+ ldmia r1!, {r4 - r7} @ Shouldnt fault
+ subs ip, ip, #16
+ orr r3, r3, r4, push #24
+ mov r4, r4, pull #8
+ orr r4, r4, r5, push #24
+ mov r5, r5, pull #8
+ orr r5, r5, r6, push #24
+ mov r6, r6, pull #8
+ orr r6, r6, r7, push #24
+ stmia r0!, {r3 - r6}
+ bpl .Lcfu_1cpy8lp
+
+.Lcfu_1rem8lp: tst ip, #8
+ movne r3, r7, pull #8
+ ldmneia r1!, {r4, r7} @ Shouldnt fault
+ orrne r3, r3, r4, push #24
+ movne r4, r4, pull #8
+ orrne r4, r4, r7, push #24
+ stmneia r0!, {r3 - r4}
+ tst ip, #4
+ movne r3, r7, pull #8
+USER( TUSER( ldrne) r7, [r1], #4) @ May fault
+ orrne r3, r3, r7, push #24
+ strne r3, [r0], #4
+ ands ip, ip, #3
+ beq .Lcfu_1fupi
+.Lcfu_1nowords: mov r3, r7, get_byte_1
+ teq ip, #0
+ beq .Lcfu_finished
+ cmp ip, #2
+ strb r3, [r0], #1
+ movge r3, r7, get_byte_2
+ strgeb r3, [r0], #1
+ movgt r3, r7, get_byte_3
+ strgtb r3, [r0], #1
+ b .Lcfu_finished
+
+.Lcfu_2fupi: subs r2, r2, #4
+ addmi ip, r2, #4
+ bmi .Lcfu_2nowords
+ mov r3, r7, pull #16
+USER( TUSER( ldr) r7, [r1], #4) @ May fault
+ orr r3, r3, r7, push #16
+ str r3, [r0], #4
+ mov ip, r1, lsl #32 - PAGE_SHIFT
+ rsb ip, ip, #0
+ movs ip, ip, lsr #32 - PAGE_SHIFT
+ beq .Lcfu_2fupi
+ cmp r2, ip
+ movlt ip, r2
+ sub r2, r2, ip
+ subs ip, ip, #16
+ blt .Lcfu_2rem8lp
+
+
+.Lcfu_2cpy8lp: mov r3, r7, pull #16
+ ldmia r1!, {r4 - r7} @ Shouldnt fault
+ subs ip, ip, #16
+ orr r3, r3, r4, push #16
+ mov r4, r4, pull #16
+ orr r4, r4, r5, push #16
+ mov r5, r5, pull #16
+ orr r5, r5, r6, push #16
+ mov r6, r6, pull #16
+ orr r6, r6, r7, push #16
+ stmia r0!, {r3 - r6}
+ bpl .Lcfu_2cpy8lp
+
+.Lcfu_2rem8lp: tst ip, #8
+ movne r3, r7, pull #16
+ ldmneia r1!, {r4, r7} @ Shouldnt fault
+ orrne r3, r3, r4, push #16
+ movne r4, r4, pull #16
+ orrne r4, r4, r7, push #16
+ stmneia r0!, {r3 - r4}
+ tst ip, #4
+ movne r3, r7, pull #16
+USER( TUSER( ldrne) r7, [r1], #4) @ May fault
+ orrne r3, r3, r7, push #16
+ strne r3, [r0], #4
+ ands ip, ip, #3
+ beq .Lcfu_2fupi
+.Lcfu_2nowords: mov r3, r7, get_byte_2
+ teq ip, #0
+ beq .Lcfu_finished
+ cmp ip, #2
+ strb r3, [r0], #1
+ movge r3, r7, get_byte_3
+ strgeb r3, [r0], #1
+USER( TUSER( ldrgtb) r3, [r1], #0) @ May fault
+ strgtb r3, [r0], #1
+ b .Lcfu_finished
+
+.Lcfu_3fupi: subs r2, r2, #4
+ addmi ip, r2, #4
+ bmi .Lcfu_3nowords
+ mov r3, r7, pull #24
+USER( TUSER( ldr) r7, [r1], #4) @ May fault
+ orr r3, r3, r7, push #8
+ str r3, [r0], #4
+ mov ip, r1, lsl #32 - PAGE_SHIFT
+ rsb ip, ip, #0
+ movs ip, ip, lsr #32 - PAGE_SHIFT
+ beq .Lcfu_3fupi
+ cmp r2, ip
+ movlt ip, r2
+ sub r2, r2, ip
+ subs ip, ip, #16
+ blt .Lcfu_3rem8lp
+
+.Lcfu_3cpy8lp: mov r3, r7, pull #24
+ ldmia r1!, {r4 - r7} @ Shouldnt fault
+ orr r3, r3, r4, push #8
+ mov r4, r4, pull #24
+ orr r4, r4, r5, push #8
+ mov r5, r5, pull #24
+ orr r5, r5, r6, push #8
+ mov r6, r6, pull #24
+ orr r6, r6, r7, push #8
+ stmia r0!, {r3 - r6}
+ subs ip, ip, #16
+ bpl .Lcfu_3cpy8lp
+
+.Lcfu_3rem8lp: tst ip, #8
+ movne r3, r7, pull #24
+ ldmneia r1!, {r4, r7} @ Shouldnt fault
+ orrne r3, r3, r4, push #8
+ movne r4, r4, pull #24
+ orrne r4, r4, r7, push #8
+ stmneia r0!, {r3 - r4}
+ tst ip, #4
+ movne r3, r7, pull #24
+USER( TUSER( ldrne) r7, [r1], #4) @ May fault
+ orrne r3, r3, r7, push #8
+ strne r3, [r0], #4
+ ands ip, ip, #3
+ beq .Lcfu_3fupi
+.Lcfu_3nowords: mov r3, r7, get_byte_3
+ teq ip, #0
+ beq .Lcfu_finished
+ cmp ip, #2
+ strb r3, [r0], #1
+USER( TUSER( ldrgeb) r3, [r1], #1) @ May fault
+ strgeb r3, [r0], #1
+USER( TUSER( ldrgtb) r3, [r1], #1) @ May fault
+ strgtb r3, [r0], #1
+ b .Lcfu_finished
+ENDPROC(__copy_from_user)
+
+ .pushsection .fixup,"ax"
+ .align 0
+ /*
+ * We took an exception. r0 contains a pointer to
+ * the byte not copied.
+ */
+9001: ldr r2, [sp], #4 @ void *to
+ sub r2, r0, r2 @ bytes copied
+ ldr r1, [sp], #4 @ unsigned long count
+ subs r4, r1, r2 @ bytes left to copy
+ movne r1, r4
+ blne __memzero
+ mov r0, r4
+ ldmfd sp!, {r4 - r7, pc}
+ .popsection
+
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