This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / avr32 / lib / copy_user.S

diff --git a/arch/avr32/lib/copy_user.S b/arch/avr32/lib/copy_user.S
new file mode 100644 (file)
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+++ b/arch/avr32/lib/copy_user.S
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+/*
+ * Copy to/from userspace with optional address space checking.
+ *
+ * Copyright 2004-2006 Atmel Corporation
+ *
+ * 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.
+ */
+#include <asm/page.h>
+#include <asm/thread_info.h>
+#include <asm/asm.h>
+
+       /*
+        * __kernel_size_t
+        * __copy_user(void *to, const void *from, __kernel_size_t n)
+        *
+        * Returns the number of bytes not copied. Might be off by
+        * max 3 bytes if we get a fault in the main loop.
+        *
+        * The address-space checking functions simply fall through to
+        * the non-checking version.
+        */
+       .text
+       .align  1
+       .global copy_from_user
+       .type   copy_from_user, @function
+copy_from_user:
+       branch_if_kernel r8, __copy_user
+       ret_if_privileged r8, r11, r10, r10
+       rjmp    __copy_user
+       .size   copy_from_user, . - copy_from_user
+
+       .global copy_to_user
+       .type   copy_to_user, @function
+copy_to_user:
+       branch_if_kernel r8, __copy_user
+       ret_if_privileged r8, r12, r10, r10
+       .size   copy_to_user, . - copy_to_user
+
+       .global __copy_user
+       .type   __copy_user, @function
+__copy_user:
+       mov     r9, r11
+       andl    r9, 3, COH
+       brne    6f
+
+       /* At this point, from is word-aligned */
+1:     sub     r10, 4
+       brlt    3f
+
+2:
+10:    ld.w    r8, r11++
+11:    st.w    r12++, r8
+       sub     r10, 4
+       brge    2b
+
+3:     sub     r10, -4
+       reteq   0
+
+       /*
+        * Handle unaligned count. Need to be careful with r10 here so
+        * that we return the correct value even if we get a fault
+        */
+4:
+20:    ld.ub   r8, r11++
+21:    st.b    r12++, r8
+       sub     r10, 1
+       reteq   0
+22:    ld.ub   r8, r11++
+23:    st.b    r12++, r8
+       sub     r10, 1
+       reteq   0
+24:    ld.ub   r8, r11++
+25:    st.b    r12++, r8
+       retal   0
+
+       /* Handle unaligned from-pointer */
+6:     cp.w    r10, 4
+       brlt    4b
+       rsub    r9, r9, 4
+
+30:    ld.ub   r8, r11++
+31:    st.b    r12++, r8
+       sub     r10, 1
+       sub     r9, 1
+       breq    1b
+32:    ld.ub   r8, r11++
+33:    st.b    r12++, r8
+       sub     r10, 1
+       sub     r9, 1
+       breq    1b
+34:    ld.ub   r8, r11++
+35:    st.b    r12++, r8
+       sub     r10, 1
+       rjmp    1b
+       .size   __copy_user, . - __copy_user
+
+       .section .fixup,"ax"
+       .align  1
+19:    sub     r10, -4
+29:    retal   r10
+
+       .section __ex_table,"a"
+       .align  2
+       .long   10b, 19b
+       .long   11b, 19b
+       .long   20b, 29b
+       .long   21b, 29b
+       .long   22b, 29b
+       .long   23b, 29b
+       .long   24b, 29b
+       .long   25b, 29b
+       .long   30b, 29b
+       .long   31b, 29b
+       .long   32b, 29b
+       .long   33b, 29b
+       .long   34b, 29b
+       .long   35b, 29b