| #include <linux/linkage.h> |
| #include <asm/asm.h> |
| #include <asm/csr.h> |
| |
| .altmacro |
| .macro fixup op reg addr lbl |
| LOCAL _epc |
| _epc: |
| \op \reg, \addr |
| .section __ex_table,"a" |
| .balign RISCV_SZPTR |
| RISCV_PTR _epc, \lbl |
| .previous |
| .endm |
| |
| ENTRY(__asm_copy_to_user) |
| ENTRY(__asm_copy_from_user) |
| |
| /* Enable access to user memory */ |
| li t6, SR_SUM |
| csrs sstatus, 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 sstatus, 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) |
| |
| |
| ENTRY(__clear_user) |
| |
| /* Enable access to user memory */ |
| li t6, SR_SUM |
| csrs sstatus, 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 sstatus, 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) |
| |
| .section .fixup,"ax" |
| .balign 4 |
| /* Fixup code for __copy_user(10) and __clear_user(11) */ |
| 10: |
| /* Disable access to user memory */ |
| csrs sstatus, t6 |
| mv a0, a2 |
| ret |
| 11: |
| csrs sstatus, t6 |
| mv a0, a1 |
| ret |
| .previous |