From 5d8544e2d0075a5f3c9a2cf27152354d54360da1 Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Mon, 10 Jul 2017 18:03:19 -0700 Subject: RISC-V: Generic library routines and assembly This patch contains code that is more specific to the RISC-V ISA than it is to Linux. It contains string and math operations, C wrappers for various assembly instructions, stack walking code, and uaccess. Signed-off-by: Palmer Dabbelt --- arch/riscv/lib/memcpy.S | 115 +++++++++++++++++++++++++++++++++++++++++++++ arch/riscv/lib/memset.S | 120 +++++++++++++++++++++++++++++++++++++++++++++++ arch/riscv/lib/uaccess.S | 117 +++++++++++++++++++++++++++++++++++++++++++++ arch/riscv/lib/udivdi3.S | 38 +++++++++++++++ 4 files changed, 390 insertions(+) create mode 100644 arch/riscv/lib/memcpy.S create mode 100644 arch/riscv/lib/memset.S create mode 100644 arch/riscv/lib/uaccess.S create mode 100644 arch/riscv/lib/udivdi3.S (limited to 'arch/riscv/lib') diff --git a/arch/riscv/lib/memcpy.S b/arch/riscv/lib/memcpy.S new file mode 100644 index 000000000000..80f9c1a5c598 --- /dev/null +++ b/arch/riscv/lib/memcpy.S @@ -0,0 +1,115 @@ +/* + * Copyright (C) 2013 Regents of the University of California + * + * 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. See the + * GNU General Public License for more details. + */ + +#include +#include + +/* void *memcpy(void *, const void *, size_t) */ +ENTRY(memcpy) + move t6, a0 /* Preserve return value */ + + /* Defer to byte-oriented copy for small sizes */ + sltiu a3, a2, 128 + bnez a3, 4f + /* Use word-oriented copy only if low-order bits match */ + andi a3, t6, SZREG-1 + andi a4, a1, SZREG-1 + bne a3, a4, 4f + + beqz a3, 2f /* Skip if already aligned */ + /* + * Round to nearest double word-aligned address + * greater than or equal to start address + */ + andi a3, a1, ~(SZREG-1) + addi a3, a3, SZREG + /* Handle initial misalignment */ + sub a4, a3, a1 +1: + lb a5, 0(a1) + addi a1, a1, 1 + sb a5, 0(t6) + addi t6, t6, 1 + bltu a1, a3, 1b + sub a2, a2, a4 /* Update count */ + +2: + andi a4, a2, ~((16*SZREG)-1) + beqz a4, 4f + add a3, a1, a4 +3: + REG_L a4, 0(a1) + REG_L a5, SZREG(a1) + REG_L a6, 2*SZREG(a1) + REG_L a7, 3*SZREG(a1) + REG_L t0, 4*SZREG(a1) + REG_L t1, 5*SZREG(a1) + REG_L t2, 6*SZREG(a1) + REG_L t3, 7*SZREG(a1) + REG_L t4, 8*SZREG(a1) + REG_L t5, 9*SZREG(a1) + REG_S a4, 0(t6) + REG_S a5, SZREG(t6) + REG_S a6, 2*SZREG(t6) + REG_S a7, 3*SZREG(t6) + REG_S t0, 4*SZREG(t6) + REG_S t1, 5*SZREG(t6) + REG_S t2, 6*SZREG(t6) + REG_S t3, 7*SZREG(t6) + REG_S t4, 8*SZREG(t6) + REG_S t5, 9*SZREG(t6) + REG_L a4, 10*SZREG(a1) + REG_L a5, 11*SZREG(a1) + REG_L a6, 12*SZREG(a1) + REG_L a7, 13*SZREG(a1) + REG_L t0, 14*SZREG(a1) + REG_L t1, 15*SZREG(a1) + addi a1, a1, 16*SZREG + REG_S a4, 10*SZREG(t6) + REG_S a5, 11*SZREG(t6) + REG_S a6, 12*SZREG(t6) + REG_S a7, 13*SZREG(t6) + REG_S t0, 14*SZREG(t6) + REG_S t1, 15*SZREG(t6) + addi t6, t6, 16*SZREG + bltu a1, a3, 3b + andi a2, a2, (16*SZREG)-1 /* Update count */ + +4: + /* Handle trailing misalignment */ + beqz a2, 6f + add a3, a1, a2 + + /* Use word-oriented copy if co-aligned to word boundary */ + or a5, a1, t6 + or a5, a5, a3 + andi a5, a5, 3 + bnez a5, 5f +7: + lw a4, 0(a1) + addi a1, a1, 4 + sw a4, 0(t6) + addi t6, t6, 4 + bltu a1, a3, 7b + + ret + +5: + lb a4, 0(a1) + addi a1, a1, 1 + sb a4, 0(t6) + addi t6, t6, 1 + bltu a1, a3, 5b +6: + ret +END(memcpy) diff --git a/arch/riscv/lib/memset.S b/arch/riscv/lib/memset.S new file mode 100644 index 000000000000..a790107cf4c9 --- /dev/null +++ b/arch/riscv/lib/memset.S @@ -0,0 +1,120 @@ +/* + * Copyright (C) 2013 Regents of the University of California + * + * 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. See the + * GNU General Public License for more details. + */ + + +#include +#include + +/* void *memset(void *, int, size_t) */ +ENTRY(memset) + move t0, a0 /* Preserve return value */ + + /* Defer to byte-oriented fill for small sizes */ + sltiu a3, a2, 16 + bnez a3, 4f + + /* + * Round to nearest XLEN-aligned address + * greater than or equal to start address + */ + addi a3, t0, SZREG-1 + andi a3, a3, ~(SZREG-1) + beq a3, t0, 2f /* Skip if already aligned */ + /* Handle initial misalignment */ + sub a4, a3, t0 +1: + sb a1, 0(t0) + addi t0, t0, 1 + bltu t0, a3, 1b + sub a2, a2, a4 /* Update count */ + +2: /* Duff's device with 32 XLEN stores per iteration */ + /* Broadcast value into all bytes */ + andi a1, a1, 0xff + slli a3, a1, 8 + or a1, a3, a1 + slli a3, a1, 16 + or a1, a3, a1 +#ifdef CONFIG_64BIT + slli a3, a1, 32 + or a1, a3, a1 +#endif + + /* Calculate end address */ + andi a4, a2, ~(SZREG-1) + add a3, t0, a4 + + andi a4, a4, 31*SZREG /* Calculate remainder */ + beqz a4, 3f /* Shortcut if no remainder */ + neg a4, a4 + addi a4, a4, 32*SZREG /* Calculate initial offset */ + + /* Adjust start address with offset */ + sub t0, t0, a4 + + /* Jump into loop body */ + /* Assumes 32-bit instruction lengths */ + la a5, 3f +#ifdef CONFIG_64BIT + srli a4, a4, 1 +#endif + add a5, a5, a4 + jr a5 +3: + REG_S a1, 0(t0) + REG_S a1, SZREG(t0) + REG_S a1, 2*SZREG(t0) + REG_S a1, 3*SZREG(t0) + REG_S a1, 4*SZREG(t0) + REG_S a1, 5*SZREG(t0) + REG_S a1, 6*SZREG(t0) + REG_S a1, 7*SZREG(t0) + REG_S a1, 8*SZREG(t0) + REG_S a1, 9*SZREG(t0) + REG_S a1, 10*SZREG(t0) + REG_S a1, 11*SZREG(t0) + REG_S a1, 12*SZREG(t0) + REG_S a1, 13*SZREG(t0) + REG_S a1, 14*SZREG(t0) + REG_S a1, 15*SZREG(t0) + REG_S a1, 16*SZREG(t0) + REG_S a1, 17*SZREG(t0) + REG_S a1, 18*SZREG(t0) + REG_S a1, 19*SZREG(t0) + REG_S a1, 20*SZREG(t0) + REG_S a1, 21*SZREG(t0) + REG_S a1, 22*SZREG(t0) + REG_S a1, 23*SZREG(t0) + REG_S a1, 24*SZREG(t0) + REG_S a1, 25*SZREG(t0) + REG_S a1, 26*SZREG(t0) + REG_S a1, 27*SZREG(t0) + REG_S a1, 28*SZREG(t0) + REG_S a1, 29*SZREG(t0) + REG_S a1, 30*SZREG(t0) + REG_S a1, 31*SZREG(t0) + addi t0, t0, 32*SZREG + bltu t0, a3, 3b + andi a2, a2, SZREG-1 /* Update count */ + +4: + /* Handle trailing misalignment */ + beqz a2, 6f + add a3, t0, a2 +5: + sb a1, 0(t0) + addi t0, t0, 1 + bltu t0, a3, 5b +6: + ret +END(memset) diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S new file mode 100644 index 000000000000..58fb2877c865 --- /dev/null +++ b/arch/riscv/lib/uaccess.S @@ -0,0 +1,117 @@ +#include +#include +#include + + .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(__copy_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(__copy_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), 10f + 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), 10f + addi a0, a0, 1 + bltu a0, t0, 4b + j 1b +5: /* Edge case: remainder */ + fixup sb, zero, (a0), 10f + addi a0, a0, 1 + bltu a0, a3, 5b + j 3b +ENDPROC(__clear_user) + + .section .fixup,"ax" + .balign 4 +10: + /* Disable access to user memory */ + csrs sstatus, t6 + sub a0, a3, a0 + ret + .previous diff --git a/arch/riscv/lib/udivdi3.S b/arch/riscv/lib/udivdi3.S new file mode 100644 index 000000000000..cb01ae5b181a --- /dev/null +++ b/arch/riscv/lib/udivdi3.S @@ -0,0 +1,38 @@ +/* + * Copyright (C) 2016-2017 Free Software Foundation, Inc. + * + * 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. See the + * GNU General Public License for more details. + */ + + .globl __udivdi3 +__udivdi3: + mv a2, a1 + mv a1, a0 + li a0, -1 + beqz a2, .L5 + li a3, 1 + bgeu a2, a1, .L2 +.L1: + blez a2, .L2 + slli a2, a2, 1 + slli a3, a3, 1 + bgtu a1, a2, .L1 +.L2: + li a0, 0 +.L3: + bltu a1, a2, .L4 + sub a1, a1, a2 + or a0, a0, a3 +.L4: + srli a3, a3, 1 + srli a2, a2, 1 + bnez a3, .L3 +.L5: + ret -- cgit v1.2.3