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      1  1.1  joerg /*	$NetBSD: elf_support.h,v 1.1 2018/03/29 13:23:40 joerg Exp $	*/
      2  1.1  joerg 
      3  1.1  joerg /*-
      4  1.1  joerg  * Copyright (c) 2000 Eduardo Horvath.
      5  1.1  joerg  * Copyright (c) 2018 The NetBSD Foundation, Inc.
      6  1.1  joerg  * All rights reserved.
      7  1.1  joerg  *
      8  1.1  joerg  * Redistribution and use in source and binary forms, with or without
      9  1.1  joerg  * modification, are permitted provided that the following conditions
     10  1.1  joerg  * are met:
     11  1.1  joerg  * 1. Redistributions of source code must retain the above copyright
     12  1.1  joerg  *    notice, this list of conditions and the following disclaimer.
     13  1.1  joerg  * 2. Redistributions in binary form must reproduce the above copyright
     14  1.1  joerg  *    notice, this list of conditions and the following disclaimer in the
     15  1.1  joerg  *    documentation and/or other materials provided with the distribution.
     16  1.1  joerg  *
     17  1.1  joerg  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     18  1.1  joerg  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     19  1.1  joerg  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     20  1.1  joerg  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     21  1.1  joerg  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     22  1.1  joerg  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     23  1.1  joerg  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     24  1.1  joerg  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     25  1.1  joerg  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26  1.1  joerg  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     27  1.1  joerg  * POSSIBILITY OF SUCH DAMAGE.
     28  1.1  joerg  */
     29  1.1  joerg #ifndef _SPARC64_ELF_SUPPORT_H
     30  1.1  joerg #define _SPARC64_ELF_SUPPORT_H
     31  1.1  joerg 
     32  1.1  joerg #ifdef __arch64__
     33  1.1  joerg /*
     34  1.1  joerg  * Create a jump to the location `target` starting at `where`.
     35  1.1  joerg  * This requires up to 6 instructions.
     36  1.1  joerg  * The first instruction is written last as it replaces a branch
     37  1.1  joerg  * in the PLT during lazy binding.
     38  1.1  joerg  * The resulting code can trash %g1 and %g5.
     39  1.1  joerg  */
     40  1.1  joerg static inline void
     41  1.1  joerg sparc_write_branch(void *where_, void *target)
     42  1.1  joerg {
     43  1.1  joerg 	const unsigned int BAA     = 0x30800000U; /* ba,a  (offset / 4) */
     44  1.1  joerg 	const unsigned int SETHI   = 0x03000000U; /* sethi %hi(0), %g1 */
     45  1.1  joerg 	const unsigned int JMP     = 0x81c06000U; /* jmpl  %g1+%lo(0), %g0 */
     46  1.1  joerg 	const unsigned int OR      = 0x82106000U; /* or    %g1, 0, %g1 */
     47  1.1  joerg 	const unsigned int XOR     = 0x82186000U; /* xor   %g1, 0, %g1 */
     48  1.1  joerg 	const unsigned int MOV71   = 0x8213e000U; /* or    %o7, 0, %g1 */
     49  1.1  joerg 	const unsigned int MOV17   = 0x9e106000U; /* or    %g1, 0, %o7 */
     50  1.1  joerg 	const unsigned int CALL    = 0x40000000U; /* call  0 */
     51  1.1  joerg 	const unsigned int SLLX    = 0x83287000U; /* sllx  %g1, 0, %g1 */
     52  1.1  joerg 	const unsigned int NEG     = 0x82200001U; /* neg   %g1 */
     53  1.1  joerg 	const unsigned int SETHIG5 = 0x0b000000U; /* sethi %hi(0), %g5 */
     54  1.1  joerg 	const unsigned int ORG5    = 0x82104005U; /* or    %g1, %g5, %g1 */
     55  1.1  joerg 
     56  1.1  joerg 	unsigned int *where = (unsigned int *)where_;
     57  1.1  joerg 	unsigned long value = (unsigned long)target;
     58  1.1  joerg 	unsigned long offset = value - (unsigned long)where;
     59  1.1  joerg 
     60  1.1  joerg #define	HIVAL(v, s)	(((v) >> (s)) & 0x003fffffU)
     61  1.1  joerg #define	LOVAL(v, s)	(((v) >> (s)) & 0x000003ffU)
     62  1.1  joerg 	if (offset + 0x800000 <= 0x7ffffc) {
     63  1.1  joerg 		/* Displacement is within 8MB, use a direct branch. */
     64  1.1  joerg 		where[0] = BAA | ((offset >> 2) & 0x3fffff);
     65  1.1  joerg 		__asm volatile("iflush %0+0" : : "r" (where));
     66  1.1  joerg 		return;
     67  1.1  joerg 	}
     68  1.1  joerg 
     69  1.1  joerg 	if (value <= 0xffffffffUL) {
     70  1.1  joerg 		/*
     71  1.1  joerg 		 * The absolute address is a 32bit value.
     72  1.1  joerg 		 * This can be encoded as:
     73  1.1  joerg 		 *	sethi	%hi(value), %g1
     74  1.1  joerg 		 *	jmp	%g1+%lo(value)
     75  1.1  joerg 		 */
     76  1.1  joerg 		where[1] = JMP   | LOVAL(value, 0);
     77  1.1  joerg 		__asm volatile("iflush %0+4" : : "r" (where));
     78  1.1  joerg 		where[0] = SETHI | HIVAL(value, 10);
     79  1.1  joerg 		__asm volatile("iflush %0+0" : : "r" (where));
     80  1.1  joerg 		return;
     81  1.1  joerg 	}
     82  1.1  joerg 
     83  1.1  joerg 	if (value >= 0xffffffff00000000UL) {
     84  1.1  joerg 		/*
     85  1.1  joerg 		 * The top 32bit address range can be encoded as:
     86  1.1  joerg 		 *	sethi	%hix(addr), %g1
     87  1.1  joerg 		 *	xor	%g1, %lox(addr), %g1
     88  1.1  joerg 		 *	jmp	%g1
     89  1.1  joerg 		 */
     90  1.1  joerg 		where[2] = JMP;
     91  1.1  joerg 		where[1] = XOR | (value & 0x00003ff) | 0x1c00;
     92  1.1  joerg 		__asm volatile("iflush %0+4" : : "r" (where));
     93  1.1  joerg 		__asm volatile("iflush %0+8" : : "r" (where));
     94  1.1  joerg 		where[0] = SETHI | HIVAL(~value, 10);
     95  1.1  joerg 		__asm volatile("iflush %0+0" : : "r" (where));
     96  1.1  joerg 		return;
     97  1.1  joerg 	}
     98  1.1  joerg 
     99  1.1  joerg 	if ((offset + 4) + 0x80000000UL <= 0x100000000UL) {
    100  1.1  joerg 		/*
    101  1.1  joerg 		 * Displacement of the second instruction is within
    102  1.1  joerg 		 * +-2GB. This can use a direct call instruction:
    103  1.1  joerg 		 *	mov	%o7, %g1
    104  1.1  joerg 		 *	call	(value - .)
    105  1.1  joerg 		 *	 mov	%g1, %o7
    106  1.1  joerg 		 */
    107  1.1  joerg 		where[1] = CALL | ((-(offset + 4)>> 2) & 0x3fffffffU);
    108  1.1  joerg 		where[2] = MOV17;
    109  1.1  joerg 		__asm volatile("iflush %0+4" : : "r" (where));
    110  1.1  joerg 		__asm volatile("iflush %0+8" : : "r" (where));
    111  1.1  joerg 		where[0] = MOV71;
    112  1.1  joerg 		__asm volatile("iflush %0+0" : : "r" (where));
    113  1.1  joerg 		return;
    114  1.1  joerg 	}
    115  1.1  joerg 
    116  1.1  joerg 	if (value < 0x100000000000UL) {
    117  1.1  joerg 		/*
    118  1.1  joerg 		 * The absolute address is a 44bit value.
    119  1.1  joerg 		 * This can be encoded as:
    120  1.1  joerg 		 *	sethi	%h44(addr), %g1
    121  1.1  joerg 		 *	or	%g1, %m44(addr), %g1
    122  1.1  joerg 		 *	sllx	%g1, 12, %g1
    123  1.1  joerg 		 *	jmp	%g1+%l44(addr)
    124  1.1  joerg 		 */
    125  1.1  joerg 		where[1] = OR    | (((value) >> 12) & 0x00001fff);
    126  1.1  joerg 		where[2] = SLLX  | 12;
    127  1.1  joerg 		where[3] = JMP   | LOVAL(value, 0);
    128  1.1  joerg 		__asm volatile("iflush %0+4" : : "r" (where));
    129  1.1  joerg 		__asm volatile("iflush %0+8" : : "r" (where));
    130  1.1  joerg 		__asm volatile("iflush %0+12" : : "r" (where));
    131  1.1  joerg 		where[0] = SETHI | HIVAL(value, 22);
    132  1.1  joerg 		__asm volatile("iflush %0+0" : : "r" (where));
    133  1.1  joerg 		return;
    134  1.1  joerg 	}
    135  1.1  joerg 
    136  1.1  joerg 	if (value > 0xfffff00000000000UL) {
    137  1.1  joerg 		/*
    138  1.1  joerg 		 * The top 44bit address range can be encoded as:
    139  1.1  joerg 		 *	sethi	%hi((-addr)>>12), %g1
    140  1.1  joerg 		 *	or	%g1, %lo((-addr)>>12), %g1
    141  1.1  joerg 		 *	neg	%g1
    142  1.1  joerg 		 *	sllx	%g1, 12, %g1
    143  1.1  joerg 		 *	jmp	%g1+(addr&0x0fff)
    144  1.1  joerg 		 */
    145  1.1  joerg 		unsigned long neg = (-value)>>12;
    146  1.1  joerg 		where[1] = OR    | (LOVAL(neg, 0)+1);
    147  1.1  joerg 		where[2] = NEG;
    148  1.1  joerg 		where[3] = SLLX  | 12;
    149  1.1  joerg 		where[4] = JMP   | (value & 0x0fff);
    150  1.1  joerg 		__asm volatile("iflush %0+4" : : "r" (where));
    151  1.1  joerg 		__asm volatile("iflush %0+8" : : "r" (where));
    152  1.1  joerg 		__asm volatile("iflush %0+12" : : "r" (where));
    153  1.1  joerg 		__asm volatile("iflush %0+16" : : "r" (where));
    154  1.1  joerg 		where[0] = SETHI | HIVAL(neg, 10);
    155  1.1  joerg 		__asm volatile("iflush %0+0" : : "r" (where));
    156  1.1  joerg 		return;
    157  1.1  joerg 	}
    158  1.1  joerg 
    159  1.1  joerg 	/*
    160  1.1  joerg 	 * The general case of a 64bit address is encoded as:
    161  1.1  joerg 	 *	sethi	%hh(addr), %g1
    162  1.1  joerg 	 *	sethi	%lm(addr), %g5
    163  1.1  joerg 	 *	or	%g1, %hm(addr), %g1
    164  1.1  joerg 	 *	sllx	%g1, 32, %g1
    165  1.1  joerg 	 *	or	%g1, %g5, %g1
    166  1.1  joerg 	 *	jmp	%g1+%lo(addr)
    167  1.1  joerg 	 */
    168  1.1  joerg 	where[1] = SETHIG5 | HIVAL(value, 10);
    169  1.1  joerg 	where[2] = OR      | LOVAL(value, 32);
    170  1.1  joerg 	where[3] = SLLX    | 32;
    171  1.1  joerg 	where[4] = ORG5;
    172  1.1  joerg 	where[5] = JMP     | LOVAL(value, 0);
    173  1.1  joerg 	__asm volatile("iflush %0+4" : : "r" (where));
    174  1.1  joerg 	__asm volatile("iflush %0+8" : : "r" (where));
    175  1.1  joerg 	__asm volatile("iflush %0+12" : : "r" (where));
    176  1.1  joerg 	__asm volatile("iflush %0+16" : : "r" (where));
    177  1.1  joerg 	__asm volatile("iflush %0+20" : : "r" (where));
    178  1.1  joerg 	where[0] = SETHI   | HIVAL(value, 42);
    179  1.1  joerg 	__asm volatile("iflush %0+0" : : "r" (where));
    180  1.1  joerg #undef	HIVAL
    181  1.1  joerg #undef	LOVAL
    182  1.1  joerg }
    183  1.1  joerg #else
    184  1.1  joerg #include <sparc/elf_support.h>
    185  1.1  joerg #endif
    186  1.1  joerg #endif
    187