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| #include <linux/linkage.h>
| #include <asm-generic/export.h>
| #include <asm/asm.h>
| #include <asm/csr.h>
|
| .macro fixup op reg addr lbl
| 100:
| \op \reg, \addr
| .section __ex_table,"a"
| .balign RISCV_SZPTR
| RISCV_PTR 100b, \lbl
| .previous
| .endm
|
| ENTRY(__asm_copy_to_user)
| ENTRY(__asm_copy_from_user)
|
| /* Enable access to user memory */
| li t6, SR_SUM
| csrs CSR_STATUS, t6
|
| add a3, a1, a2
| /* Use word-oriented copy only if low-order bits match */
| andi t0, a0, SZREG-1
| andi t1, a1, SZREG-1
| bne t0, t1, 2f
|
| addi t0, a1, SZREG-1
| andi t1, a3, ~(SZREG-1)
| andi t0, t0, ~(SZREG-1)
| /*
| * a3: terminal address of source region
| * t0: lowest XLEN-aligned address in source
| * t1: highest XLEN-aligned address in source
| */
| bgeu t0, t1, 2f
| bltu a1, t0, 4f
| 1:
| fixup REG_L, t2, (a1), 10f
| fixup REG_S, t2, (a0), 10f
| addi a1, a1, SZREG
| addi a0, a0, SZREG
| bltu a1, t1, 1b
| 2:
| bltu a1, a3, 5f
|
| 3:
| /* Disable access to user memory */
| csrc CSR_STATUS, t6
| li a0, 0
| ret
| 4: /* Edge case: unalignment */
| fixup lbu, t2, (a1), 10f
| fixup sb, t2, (a0), 10f
| addi a1, a1, 1
| addi a0, a0, 1
| bltu a1, t0, 4b
| j 1b
| 5: /* Edge case: remainder */
| fixup lbu, t2, (a1), 10f
| fixup sb, t2, (a0), 10f
| addi a1, a1, 1
| addi a0, a0, 1
| bltu a1, a3, 5b
| j 3b
| ENDPROC(__asm_copy_to_user)
| ENDPROC(__asm_copy_from_user)
| EXPORT_SYMBOL(__asm_copy_to_user)
| EXPORT_SYMBOL(__asm_copy_from_user)
|
|
| ENTRY(__clear_user)
|
| /* Enable access to user memory */
| li t6, SR_SUM
| csrs CSR_STATUS, t6
|
| add a3, a0, a1
| addi t0, a0, SZREG-1
| andi t1, a3, ~(SZREG-1)
| andi t0, t0, ~(SZREG-1)
| /*
| * a3: terminal address of target region
| * t0: lowest doubleword-aligned address in target region
| * t1: highest doubleword-aligned address in target region
| */
| bgeu t0, t1, 2f
| bltu a0, t0, 4f
| 1:
| fixup REG_S, zero, (a0), 11f
| addi a0, a0, SZREG
| bltu a0, t1, 1b
| 2:
| bltu a0, a3, 5f
|
| 3:
| /* Disable access to user memory */
| csrc CSR_STATUS, t6
| li a0, 0
| ret
| 4: /* Edge case: unalignment */
| fixup sb, zero, (a0), 11f
| addi a0, a0, 1
| bltu a0, t0, 4b
| j 1b
| 5: /* Edge case: remainder */
| fixup sb, zero, (a0), 11f
| addi a0, a0, 1
| bltu a0, a3, 5b
| j 3b
| ENDPROC(__clear_user)
| EXPORT_SYMBOL(__clear_user)
|
| .section .fixup,"ax"
| .balign 4
| /* Fixup code for __copy_user(10) and __clear_user(11) */
| 10:
| /* Disable access to user memory */
| csrs CSR_STATUS, t6
| mv a0, a2
| ret
| 11:
| csrs CSR_STATUS, t6
| mv a0, a1
| ret
| .previous
|
|
