Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / tile / lib / usercopy_64.S

diff --git a/kernel/arch/tile/lib/usercopy_64.S b/kernel/arch/tile/lib/usercopy_64.S
new file mode 100644 (file)
index 0000000..b3b31a3
--- /dev/null
+++ b/kernel/arch/tile/lib/usercopy_64.S
@@ -0,0 +1,135 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/linkage.h>
+#include <asm/errno.h>
+#include <asm/cache.h>
+#include <arch/chip.h>
+
+/* Access user memory, but use MMU to avoid propagating kernel exceptions. */
+
+/*
+ * strnlen_user_asm takes the pointer in r0, and the length bound in r1.
+ * It returns the length, including the terminating NUL, or zero on exception.
+ * If length is greater than the bound, returns one plus the bound.
+ */
+STD_ENTRY(strnlen_user_asm)
+       { beqz r1, 2f; addi r3, r0, -1 }  /* bias down to include NUL */
+1:      { ld1u r4, r0; addi r1, r1, -1 }
+       beqz r4, 2f
+       { bnezt r1, 1b; addi r0, r0, 1 }
+2:      { sub r0, r0, r3; jrp lr }
+       STD_ENDPROC(strnlen_user_asm)
+       .pushsection .fixup,"ax"
+strnlen_user_fault:
+       { move r0, zero; jrp lr }
+       ENDPROC(strnlen_user_fault)
+       .section __ex_table,"a"
+       .align 8
+       .quad 1b, strnlen_user_fault
+       .popsection
+
+/*
+ * strncpy_from_user_asm takes the kernel target pointer in r0,
+ * the userspace source pointer in r1, and the length bound (including
+ * the trailing NUL) in r2.  On success, it returns the string length
+ * (not including the trailing NUL), or -EFAULT on failure.
+ */
+STD_ENTRY(strncpy_from_user_asm)
+       { beqz r2, 2f; move r3, r0 }
+1:     { ld1u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
+       { st1 r0, r4; addi r0, r0, 1 }
+       beqz r4, 2f
+       bnezt r2, 1b
+       { sub r0, r0, r3; jrp lr }
+2:     addi r0, r0, -1   /* don't count the trailing NUL */
+       { sub r0, r0, r3; jrp lr }
+       STD_ENDPROC(strncpy_from_user_asm)
+       .pushsection .fixup,"ax"
+strncpy_from_user_fault:
+       { movei r0, -EFAULT; jrp lr }
+       ENDPROC(strncpy_from_user_fault)
+       .section __ex_table,"a"
+       .align 8
+       .quad 1b, strncpy_from_user_fault
+       .popsection
+
+/*
+ * clear_user_asm takes the user target address in r0 and the
+ * number of bytes to zero in r1.
+ * It returns the number of uncopiable bytes (hopefully zero) in r0.
+ * Note that we don't use a separate .fixup section here since we fall
+ * through into the "fixup" code as the last straight-line bundle anyway.
+ */
+STD_ENTRY(clear_user_asm)
+       { beqz r1, 2f; or r2, r0, r1 }
+       andi r2, r2, 7
+       beqzt r2, .Lclear_aligned_user_asm
+1:      { st1 r0, zero; addi r0, r0, 1; addi r1, r1, -1 }
+       bnezt r1, 1b
+2:      { move r0, r1; jrp lr }
+       .pushsection __ex_table,"a"
+       .align 8
+       .quad 1b, 2b
+       .popsection
+
+.Lclear_aligned_user_asm:
+1:      { st r0, zero; addi r0, r0, 8; addi r1, r1, -8 }
+       bnezt r1, 1b
+2:      { move r0, r1; jrp lr }
+       STD_ENDPROC(clear_user_asm)
+       .pushsection __ex_table,"a"
+       .align 8
+       .quad 1b, 2b
+       .popsection
+
+/*
+ * flush_user_asm takes the user target address in r0 and the
+ * number of bytes to flush in r1.
+ * It returns the number of unflushable bytes (hopefully zero) in r0.
+ */
+STD_ENTRY(flush_user_asm)
+       beqz r1, 2f
+       { movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
+       { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
+       { and r0, r0, r2; and r1, r1, r2 }
+       { sub r1, r1, r0 }
+1:      { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() }
+       { addi r0, r0, CHIP_FLUSH_STRIDE(); bnezt r1, 1b }
+2:      { move r0, r1; jrp lr }
+       STD_ENDPROC(flush_user_asm)
+       .pushsection __ex_table,"a"
+       .align 8
+       .quad 1b, 2b
+       .popsection
+
+/*
+ * finv_user_asm takes the user target address in r0 and the
+ * number of bytes to flush-invalidate in r1.
+ * It returns the number of not finv'able bytes (hopefully zero) in r0.
+ */
+STD_ENTRY(finv_user_asm)
+       beqz r1, 2f
+       { movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
+       { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
+       { and r0, r0, r2; and r1, r1, r2 }
+       { sub r1, r1, r0 }
+1:      { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() }
+       { addi r0, r0, CHIP_FINV_STRIDE(); bnezt r1, 1b }
+2:      { move r0, r1; jrp lr }
+       STD_ENDPROC(finv_user_asm)
+       .pushsection __ex_table,"a"
+       .align 8
+       .quad 1b, 2b
+       .popsection