diff options
| -rw-r--r-- | arch/hexagon/include/asm/uaccess.h | 116 | ||||
| -rw-r--r-- | arch/hexagon/mm/copy_from_user.S | 114 | ||||
| -rw-r--r-- | arch/hexagon/mm/copy_to_user.S | 92 | ||||
| -rw-r--r-- | arch/hexagon/mm/copy_user_template.S | 185 | ||||
| -rw-r--r-- | arch/hexagon/mm/strnlen_user.S | 139 | ||||
| -rw-r--r-- | arch/hexagon/mm/uaccess.c | 59 |
6 files changed, 705 insertions, 0 deletions
diff --git a/arch/hexagon/include/asm/uaccess.h b/arch/hexagon/include/asm/uaccess.h new file mode 100644 index 0000000..7e706ea --- /dev/null +++ b/arch/hexagon/include/asm/uaccess.h @@ -0,0 +1,116 @@ +/* + * User memory access support for Hexagon + * + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#ifndef _ASM_UACCESS_H +#define _ASM_UACCESS_H +/* + * User space memory access functions + */ +#include <linux/sched.h> +#include <linux/mm.h> +#include <asm/segment.h> +#include <asm/sections.h> + +/* + * access_ok: - Checks if a user space pointer is valid + * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that + * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe + * to write to a block, it is always safe to read from it. + * @addr: User space pointer to start of block to check + * @size: Size of block to check + * + * Context: User context only. This function may sleep. + * + * Checks if a pointer to a block of memory in user space is valid. + * + * Returns true (nonzero) if the memory block *may* be valid, false (zero) + * if it is definitely invalid. + * + * User address space in Hexagon, like x86, goes to 0xbfffffff, so the + * simple MSB-based tests used by MIPS won't work. Some further + * optimization is probably possible here, but for now, keep it + * reasonably simple and not *too* slow. After all, we've got the + * MMU for backup. + */ +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +#define __access_ok(addr, size) \ + ((get_fs().seg == KERNEL_DS.seg) || \ + (((unsigned long)addr < get_fs().seg) && \ + (unsigned long)size < (get_fs().seg - (unsigned long)addr))) + +/* + * When a kernel-mode page fault is taken, the faulting instruction + * address is checked against a table of exception_table_entries. + * Each entry is a tuple of the address of an instruction that may + * be authorized to fault, and the address at which execution should + * be resumed instead of the faulting instruction, so as to effect + * a workaround. + */ + +/* Assembly somewhat optimized copy routines */ +unsigned long __copy_from_user_hexagon(void *to, const void __user *from, + unsigned long n); +unsigned long __copy_to_user_hexagon(void __user *to, const void *from, + unsigned long n); + +#define __copy_from_user(to, from, n) __copy_from_user_hexagon(to, from, n) +#define __copy_to_user(to, from, n) __copy_to_user_hexagon(to, from, n) + +/* + * XXX todo: some additonal performance gain is possible by + * implementing __copy_to/from_user_inatomic, which is much + * like __copy_to/from_user, but performs slightly less checking. + */ + +__kernel_size_t __clear_user_hexagon(void __user *dest, unsigned long count); +#define __clear_user(a, s) __clear_user_hexagon((a), (s)) + +#define __strncpy_from_user(dst, src, n) hexagon_strncpy_from_user(dst, src, n) + +/* get around the ifndef in asm-generic/uaccess.h */ +#define __strnlen_user __strnlen_user + +extern long __strnlen_user(const char __user *src, long n); + +static inline long hexagon_strncpy_from_user(char *dst, const char __user *src, + long n); + +#include <asm-generic/uaccess.h> + +/* Todo: an actual accelerated version of this. */ +static inline long hexagon_strncpy_from_user(char *dst, const char __user *src, + long n) +{ + long res = __strnlen_user(src, n); + + /* return from strnlen can't be zero -- that would be rubbish. */ + + if (res > n) { + copy_from_user(dst, src, n); + return n; + } else { + copy_from_user(dst, src, res); + return res-1; + } +} + +#endif diff --git a/arch/hexagon/mm/copy_from_user.S b/arch/hexagon/mm/copy_from_user.S new file mode 100644 index 0000000..8eb1d4d --- /dev/null +++ b/arch/hexagon/mm/copy_from_user.S @@ -0,0 +1,114 @@ +/* + * User memory copy functions for kernel + * + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +/* + * The right way to do this involves valignb + * The easy way to do this is only speed up src/dest similar alignment. + */ + +/* + * Copy to/from user are the same, except that for packets with a load and + * a store, I don't know how to tell which kind of exception we got. + * Therefore, we duplicate the function, and handle faulting addresses + * differently for each function + */ + +/* + * copy from user: loads can fault + */ +#define src_sav r13 +#define dst_sav r12 +#define src_dst_sav r13:12 +#define d_dbuf r15:14 +#define w_dbuf r15 + +#define dst r0 +#define src r1 +#define bytes r2 +#define loopcount r5 + +#define FUNCNAME __copy_from_user_hexagon +#include "copy_user_template.S" + + /* LOAD FAULTS from COPY_FROM_USER */ + + /* Alignment loop. r2 has been updated. Return it. */ + .falign +1009: +2009: +4009: + { + r0 = r2 + jumpr r31 + } + /* Normal copy loops. Do epilog. Use src-src_sav to compute distance */ + /* X - (A - B) == X + B - A */ + .falign +8089: + { + memd(dst) = d_dbuf + r2 += sub(src_sav,src) + } + { + r0 = r2 + jumpr r31 + } + .falign +4089: + { + memw(dst) = w_dbuf + r2 += sub(src_sav,src) + } + { + r0 = r2 + jumpr r31 + } + .falign +2089: + { + memh(dst) = w_dbuf + r2 += sub(src_sav,src) + } + { + r0 = r2 + jumpr r31 + } + .falign +1089: + { + memb(dst) = w_dbuf + r2 += sub(src_sav,src) + } + { + r0 = r2 + jumpr r31 + } + + /* COPY FROM USER: only loads can fail */ + + .section __ex_table,"a" + .long 1000b,1009b + .long 2000b,2009b + .long 4000b,4009b + .long 8080b,8089b + .long 4080b,4089b + .long 2080b,2089b + .long 1080b,1089b + .previous diff --git a/arch/hexagon/mm/copy_to_user.S b/arch/hexagon/mm/copy_to_user.S new file mode 100644 index 0000000..cb9740e --- /dev/null +++ b/arch/hexagon/mm/copy_to_user.S @@ -0,0 +1,92 @@ +/* + * User memory copying routines for the Hexagon Kernel + * + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +/* The right way to do this involves valignb + * The easy way to do this is only speed up src/dest similar alignment. + */ + +/* + * Copy to/from user are the same, except that for packets with a load and + * a store, I don't know how to tell which kind of exception we got. + * Therefore, we duplicate the function, and handle faulting addresses + * differently for each function + */ + +/* + * copy to user: stores can fault + */ +#define src_sav r13 +#define dst_sav r12 +#define src_dst_sav r13:12 +#define d_dbuf r15:14 +#define w_dbuf r15 + +#define dst r0 +#define src r1 +#define bytes r2 +#define loopcount r5 + +#define FUNCNAME __copy_to_user_hexagon +#include "copy_user_template.S" + + /* STORE FAULTS from COPY_TO_USER */ + .falign +1109: +2109: +4109: + /* Alignment loop. r2 has been updated. Return it. */ + { + r0 = r2 + jumpr r31 + } + /* Normal copy loops. Use dst-dst_sav to compute distance */ + /* dst holds best write, no need to unwind any loops */ + /* X - (A - B) == X + B - A */ + .falign +8189: +8199: +4189: +4199: +2189: +2199: +1189: +1199: + { + r2 += sub(dst_sav,dst) + } + { + r0 = r2 + jumpr r31 + } + + /* COPY TO USER: only stores can fail */ + .section __ex_table,"a" + .long 1100b,1109b + .long 2100b,2109b + .long 4100b,4109b + .long 8180b,8189b + .long 8190b,8199b + .long 4180b,4189b + .long 4190b,4199b + .long 2180b,2189b + .long 2190b,2199b + .long 1180b,1189b + .long 1190b,1199b + .previous diff --git a/arch/hexagon/mm/copy_user_template.S b/arch/hexagon/mm/copy_user_template.S new file mode 100644 index 0000000..08d7d7b --- /dev/null +++ b/arch/hexagon/mm/copy_user_template.S @@ -0,0 +1,185 @@ +/* + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +/* Numerology: + * WXYZ + * W: width in bytes + * X: Load=0, Store=1 + * Y: Location 0=preamble,8=loop,9=epilog + * Z: Location=0,handler=9 + */ + .text + .global FUNCNAME + .type FUNCNAME, @function + .p2align 5 +FUNCNAME: + { + p0 = cmp.gtu(bytes,#0) + if (!p0.new) jump:nt .Ldone + r3 = or(dst,src) + r4 = xor(dst,src) + } + { + p1 = cmp.gtu(bytes,#15) + p0 = bitsclr(r3,#7) + if (!p0.new) jump:nt .Loop_not_aligned_8 + src_dst_sav = combine(src,dst) + } + + { + loopcount = lsr(bytes,#3) + if (!p1) jump .Lsmall + } + p3=sp1loop0(.Loop8,loopcount) +.Loop8: +8080: +8180: + { + if (p3) memd(dst++#8) = d_dbuf + d_dbuf = memd(src++#8) + }:endloop0 +8190: + { + memd(dst++#8) = d_dbuf + bytes -= asl(loopcount,#3) + jump .Lsmall + } + +.Loop_not_aligned_8: + { + p0 = bitsclr(r4,#7) + if (p0.new) jump:nt .Lalign + } + { + p0 = bitsclr(r3,#3) + if (!p0.new) jump:nt .Loop_not_aligned_4 + p1 = cmp.gtu(bytes,#7) + } + + { + if (!p1) jump .Lsmall + loopcount = lsr(bytes,#2) + } + p3=sp1loop0(.Loop4,loopcount) +.Loop4: +4080: +4180: + { + if (p3) memw(dst++#4) = w_dbuf + w_dbuf = memw(src++#4) + }:endloop0 +4190: + { + memw(dst++#4) = w_dbuf + bytes -= asl(loopcount,#2) + jump .Lsmall + } + +.Loop_not_aligned_4: + { + p0 = bitsclr(r3,#1) + if (!p0.new) jump:nt .Loop_not_aligned + p1 = cmp.gtu(bytes,#3) + } + + { + if (!p1) jump .Lsmall + loopcount = lsr(bytes,#1) + } + p3=sp1loop0(.Loop2,loopcount) +.Loop2: +2080: +2180: + { + if (p3) memh(dst++#2) = w_dbuf + w_dbuf = memuh(src++#2) + }:endloop0 +2190: + { + memh(dst++#2) = w_dbuf + bytes -= asl(loopcount,#1) + jump .Lsmall + } + +.Loop_not_aligned: /* Works for as small as one byte */ + p3=sp1loop0(.Loop1,bytes) +.Loop1: +1080: +1180: + { + if (p3) memb(dst++#1) = w_dbuf + w_dbuf = memub(src++#1) + }:endloop0 + /* Done */ +1190: + { + memb(dst) = w_dbuf + jumpr r31 + r0 = #0 + } + +.Lsmall: + { + p0 = cmp.gtu(bytes,#0) + if (p0.new) jump:nt .Loop_not_aligned + } +.Ldone: + { + r0 = #0 + jumpr r31 + } + .falign +.Lalign: +1000: + { + if (p0.new) w_dbuf = memub(src) + p0 = tstbit(src,#0) + if (!p1) jump .Lsmall + } +1100: + { + if (p0) memb(dst++#1) = w_dbuf + if (p0) bytes = add(bytes,#-1) + if (p0) src = add(src,#1) + } +2000: + { + if (p0.new) w_dbuf = memuh(src) + p0 = tstbit(src,#1) + if (!p1) jump .Lsmall + } +2100: + { + if (p0) memh(dst++#2) = w_dbuf + if (p0) bytes = add(bytes,#-2) + if (p0) src = add(src,#2) + } +4000: + { + if (p0.new) w_dbuf = memw(src) + p0 = tstbit(src,#2) + if (!p1) jump .Lsmall + } +4100: + { + if (p0) memw(dst++#4) = w_dbuf + if (p0) bytes = add(bytes,#-4) + if (p0) src = add(src,#4) + jump FUNCNAME + } + .size FUNCNAME,.-FUNCNAME diff --git a/arch/hexagon/mm/strnlen_user.S b/arch/hexagon/mm/strnlen_user.S new file mode 100644 index 0000000..5c6a16c --- /dev/null +++ b/arch/hexagon/mm/strnlen_user.S @@ -0,0 +1,139 @@ +/* + * User string length functions for kernel + * + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#define isrc r0 +#define max r1 /* Do not change! */ + +#define end r2 +#define tmp1 r3 + +#define obo r6 /* off-by-one */ +#define start r7 +#define mod8 r8 +#define dbuf r15:14 +#define dcmp r13:12 + +/* + * The vector mask version of this turned out *really* badly. + * The hardware loop version also turned out *really* badly. + * Seems straight pointer arithmetic basically wins here. + */ + +#define fname __strnlen_user + + .text + .global fname + .type fname, @function + .p2align 5 /* why? */ +fname: + { + mod8 = and(isrc,#7); + end = add(isrc,max); + start = isrc; + } + { + P0 = cmp.eq(mod8,#0); + mod8 = and(end,#7); + dcmp = #0; + if (P0.new) jump:t dw_loop; /* fire up the oven */ + } + +alignment_loop: +fail_1: { + tmp1 = memb(start++#1); + } + { + P0 = cmp.eq(tmp1,#0); + if (P0.new) jump:nt exit_found; + P1 = cmp.gtu(end,start); + mod8 = and(start,#7); + } + { + if (!P1) jump exit_error; /* hit the end */ + P0 = cmp.eq(mod8,#0); + } + { + if (!P0) jump alignment_loop; + } + + + +dw_loop: +fail_2: { + dbuf = memd(start); + obo = add(start,#1); + } + { + P0 = vcmpb.eq(dbuf,dcmp); + } + { + tmp1 = P0; + P0 = cmp.gtu(end,start); + } + { + tmp1 = ct0(tmp1); + mod8 = and(end,#7); + if (!P0) jump end_check; + } + { + P0 = cmp.eq(tmp1,#32); + if (!P0.new) jump:nt exit_found; + if (!P0.new) start = add(obo,tmp1); + } + { + start = add(start,#8); + jump dw_loop; + } /* might be nice to combine these jumps... */ + + +end_check: + { + P0 = cmp.gt(tmp1,mod8); + if (P0.new) jump:nt exit_error; /* neverfound! */ + start = add(obo,tmp1); + } + +exit_found: + { + R0 = sub(start,isrc); + jumpr R31; + } + +exit_error: + { + R0 = add(max,#1); + jumpr R31; + } + + /* Uh, what does the "fixup" return here? */ + .falign +fix_1: + { + R0 = #0; + jumpr R31; + } + + .size fname,.-fname + + +.section __ex_table,"a" +.long fail_1,fix_1 +.long fail_2,fix_1 +.previous diff --git a/arch/hexagon/mm/uaccess.c b/arch/hexagon/mm/uaccess.c new file mode 100644 index 0000000..e748108 --- /dev/null +++ b/arch/hexagon/mm/uaccess.c @@ -0,0 +1,59 @@ +/* + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +/* + * Support for user memory access from kernel. This will + * probably be inlined for performance at some point, but + * for ease of debug, and to a lesser degree for code size, + * we implement here as subroutines. + */ +#include <linux/types.h> +#include <asm/uaccess.h> +#include <asm/pgtable.h> + +/* + * For clear_user(), exploit previously defined copy_to_user function + * and the fact that we've got a handy zero page defined in kernel/head.S + * + * dczero here would be even faster. + */ +__kernel_size_t __clear_user_hexagon(void __user *dest, unsigned long count) +{ + long uncleared; + + while (count > PAGE_SIZE) { + uncleared = __copy_to_user_hexagon(dest, &empty_zero_page, + PAGE_SIZE); + if (uncleared) + return count - (PAGE_SIZE - uncleared); + count -= PAGE_SIZE; + dest += PAGE_SIZE; + } + if (count) + count = __copy_to_user_hexagon(dest, &empty_zero_page, count); + + return count; +} + +unsigned long clear_user_hexagon(void __user *dest, unsigned long count) +{ + if (!access_ok(VERIFY_WRITE, dest, count)) + return count; + else + return __clear_user_hexagon(dest, count); +} |
