1/* 2 * Copyright 2010 Tilera Corporation. All Rights Reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 11 * NON INFRINGEMENT. See the GNU General Public License for 12 * more details. 13 */ 14 15#include <linux/linkage.h> 16#include <asm/errno.h> 17#include <asm/cache.h> 18#include <arch/chip.h> 19 20/* Access user memory, but use MMU to avoid propagating kernel exceptions. */ 21 22/* 23 * clear_user_asm takes the user target address in r0 and the 24 * number of bytes to zero in r1. 25 * It returns the number of uncopiable bytes (hopefully zero) in r0. 26 * Note that we don't use a separate .fixup section here since we fall 27 * through into the "fixup" code as the last straight-line bundle anyway. 28 */ 29STD_ENTRY(clear_user_asm) 30 { bz r1, 2f; or r2, r0, r1 } 31 andi r2, r2, 3 32 bzt r2, .Lclear_aligned_user_asm 331: { sb r0, zero; addi r0, r0, 1; addi r1, r1, -1 } 34 bnzt r1, 1b 352: { move r0, r1; jrp lr } 36 .pushsection __ex_table,"a" 37 .align 4 38 .word 1b, 2b 39 .popsection 40 41.Lclear_aligned_user_asm: 421: { sw r0, zero; addi r0, r0, 4; addi r1, r1, -4 } 43 bnzt r1, 1b 442: { move r0, r1; jrp lr } 45 STD_ENDPROC(clear_user_asm) 46 .pushsection __ex_table,"a" 47 .align 4 48 .word 1b, 2b 49 .popsection 50 51/* 52 * flush_user_asm takes the user target address in r0 and the 53 * number of bytes to flush in r1. 54 * It returns the number of unflushable bytes (hopefully zero) in r0. 55 */ 56STD_ENTRY(flush_user_asm) 57 bz r1, 2f 58 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } 59 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } 60 { and r0, r0, r2; and r1, r1, r2 } 61 { sub r1, r1, r0 } 621: { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() } 63 { addi r0, r0, CHIP_FLUSH_STRIDE(); bnzt r1, 1b } 642: { move r0, r1; jrp lr } 65 STD_ENDPROC(flush_user_asm) 66 .pushsection __ex_table,"a" 67 .align 4 68 .word 1b, 2b 69 .popsection 70 71/* 72 * finv_user_asm takes the user target address in r0 and the 73 * number of bytes to flush-invalidate in r1. 74 * It returns the number of not finv'able bytes (hopefully zero) in r0. 75 */ 76STD_ENTRY(finv_user_asm) 77 bz r1, 2f 78 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } 79 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } 80 { and r0, r0, r2; and r1, r1, r2 } 81 { sub r1, r1, r0 } 821: { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() } 83 { addi r0, r0, CHIP_FINV_STRIDE(); bnzt r1, 1b } 842: { move r0, r1; jrp lr } 85 STD_ENDPROC(finv_user_asm) 86 .pushsection __ex_table,"a" 87 .align 4 88 .word 1b, 2b 89 .popsection 90