10aea86a2SCatalin Marinas/* 20aea86a2SCatalin Marinas * Copyright (C) 2012 ARM Ltd. 30aea86a2SCatalin Marinas * 40aea86a2SCatalin Marinas * This program is free software; you can redistribute it and/or modify 50aea86a2SCatalin Marinas * it under the terms of the GNU General Public License version 2 as 60aea86a2SCatalin Marinas * published by the Free Software Foundation. 70aea86a2SCatalin Marinas * 80aea86a2SCatalin Marinas * This program is distributed in the hope that it will be useful, 90aea86a2SCatalin Marinas * but WITHOUT ANY WARRANTY; without even the implied warranty of 100aea86a2SCatalin Marinas * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 110aea86a2SCatalin Marinas * GNU General Public License for more details. 120aea86a2SCatalin Marinas * 130aea86a2SCatalin Marinas * You should have received a copy of the GNU General Public License 140aea86a2SCatalin Marinas * along with this program. If not, see <http://www.gnu.org/licenses/>. 150aea86a2SCatalin Marinas */ 160aea86a2SCatalin Marinas 170aea86a2SCatalin Marinas#include <linux/linkage.h> 180aea86a2SCatalin Marinas#include <asm/assembler.h> 190aea86a2SCatalin Marinas 200aea86a2SCatalin Marinas/* 210aea86a2SCatalin Marinas * Copy from user space to a kernel buffer (alignment handled by the hardware) 220aea86a2SCatalin Marinas * 230aea86a2SCatalin Marinas * Parameters: 240aea86a2SCatalin Marinas * x0 - to 250aea86a2SCatalin Marinas * x1 - from 260aea86a2SCatalin Marinas * x2 - n 270aea86a2SCatalin Marinas * Returns: 280aea86a2SCatalin Marinas * x0 - bytes not copied 290aea86a2SCatalin Marinas */ 300aea86a2SCatalin MarinasENTRY(__copy_from_user) 310aea86a2SCatalin Marinas add x4, x1, x2 // upper user buffer boundary 320aea86a2SCatalin Marinas subs x2, x2, #8 330aea86a2SCatalin Marinas b.mi 2f 340aea86a2SCatalin Marinas1: 350aea86a2SCatalin MarinasUSER(9f, ldr x3, [x1], #8 ) 360aea86a2SCatalin Marinas subs x2, x2, #8 370aea86a2SCatalin Marinas str x3, [x0], #8 380aea86a2SCatalin Marinas b.pl 1b 390aea86a2SCatalin Marinas2: adds x2, x2, #4 400aea86a2SCatalin Marinas b.mi 3f 410aea86a2SCatalin MarinasUSER(9f, ldr w3, [x1], #4 ) 420aea86a2SCatalin Marinas sub x2, x2, #4 430aea86a2SCatalin Marinas str w3, [x0], #4 440aea86a2SCatalin Marinas3: adds x2, x2, #2 450aea86a2SCatalin Marinas b.mi 4f 460aea86a2SCatalin MarinasUSER(9f, ldrh w3, [x1], #2 ) 470aea86a2SCatalin Marinas sub x2, x2, #2 480aea86a2SCatalin Marinas strh w3, [x0], #2 490aea86a2SCatalin Marinas4: adds x2, x2, #1 500aea86a2SCatalin Marinas b.mi 5f 510aea86a2SCatalin MarinasUSER(9f, ldrb w3, [x1] ) 520aea86a2SCatalin Marinas strb w3, [x0] 530aea86a2SCatalin Marinas5: mov x0, #0 540aea86a2SCatalin Marinas ret 550aea86a2SCatalin MarinasENDPROC(__copy_from_user) 560aea86a2SCatalin Marinas 570aea86a2SCatalin Marinas .section .fixup,"ax" 580aea86a2SCatalin Marinas .align 2 590aea86a2SCatalin Marinas9: sub x2, x4, x1 600aea86a2SCatalin Marinas mov x3, x2 610aea86a2SCatalin Marinas10: strb wzr, [x0], #1 // zero remaining buffer space 620aea86a2SCatalin Marinas subs x3, x3, #1 630aea86a2SCatalin Marinas b.ne 10b 640aea86a2SCatalin Marinas mov x0, x2 // bytes not copied 650aea86a2SCatalin Marinas ret 660aea86a2SCatalin Marinas .previous 67