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Release 4.14 arch/unicore32/mm/alignment.c

/*
 * linux/arch/unicore32/mm/alignment.c
 *
 * Code specific to PKUnity SoC and UniCore ISA
 *
 * Copyright (C) 2001-2010 GUAN Xue-tao
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
/*
 * TODO:
 *  FPU ldm/stm not handling
 */
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/sched/debug.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/uaccess.h>

#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/unaligned.h>

#include "mm.h"


#define CODING_BITS(i)	(i & 0xe0000120)


#define LDST_P_BIT(i)	(i & (1 << 28))	
/* Preindex             */

#define LDST_U_BIT(i)	(i & (1 << 27))	
/* Add offset           */

#define LDST_W_BIT(i)	(i & (1 << 25))	
/* Writeback            */

#define LDST_L_BIT(i)	(i & (1 << 24))	
/* Load                 */


#define LDST_P_EQ_U(i)	((((i) ^ ((i) >> 1)) & (1 << 27)) == 0)


#define LDSTH_I_BIT(i)	(i & (1 << 26))	
/* half-word immed      */

#define LDM_S_BIT(i)	(i & (1 << 26))	
/* write ASR from BSR */

#define LDM_H_BIT(i)	(i & (1 << 6))	
/* select r0-r15 or r16-r31 */


#define RN_BITS(i)	((i >> 19) & 31)	
/* Rn                   */

#define RD_BITS(i)	((i >> 14) & 31)	
/* Rd                   */

#define RM_BITS(i)	(i & 31)	
/* Rm                   */


#define REGMASK_BITS(i)	(((i & 0x7fe00) >> 3) | (i & 0x3f))

#define OFFSET_BITS(i)	(i & 0x03fff)


#define SHIFT_BITS(i)	((i >> 9) & 0x1f)

#define SHIFT_TYPE(i)	(i & 0xc0)

#define SHIFT_LSL	0x00

#define SHIFT_LSR	0x40

#define SHIFT_ASR	0x80

#define SHIFT_RORRRX	0xc0


union offset_union {
	
unsigned long un;
	
signed long sn;
};


#define TYPE_ERROR	0

#define TYPE_FAULT	1

#define TYPE_LDST	2

#define TYPE_DONE	3

#define TYPE_SWAP  4

#define TYPE_COLS  5		
/* Coprocessor load/store */


#define get8_unaligned_check(val, addr, err)		\
	__asm__(                                        \
        "1:     ldb.u   %1, [%2], #1\n"                 \
        "2:\n"                                          \
        "       .pushsection .fixup,\"ax\"\n"           \
        "       .align  2\n"                            \
        "3:     mov     %0, #1\n"                       \
        "       b       2b\n"                           \
        "       .popsection\n"                          \
        "       .pushsection __ex_table,\"a\"\n"                \
        "       .align  3\n"                            \
        "       .long   1b, 3b\n"                       \
        "       .popsection\n"                          \
        : "=r" (err), "=&r" (val), "=r" (addr)          \
        : "0" (err), "2" (addr))


#define get8t_unaligned_check(val, addr, err)		\
	__asm__(                                        \
        "1:     ldb.u   %1, [%2], #1\n"                 \
        "2:\n"                                          \
        "       .pushsection .fixup,\"ax\"\n"           \
        "       .align  2\n"                            \
        "3:     mov     %0, #1\n"                       \
        "       b       2b\n"                           \
        "       .popsection\n"                          \
        "       .pushsection __ex_table,\"a\"\n"                \
        "       .align  3\n"                            \
        "       .long   1b, 3b\n"                       \
        "       .popsection\n"                          \
        : "=r" (err), "=&r" (val), "=r" (addr)          \
        : "0" (err), "2" (addr))


#define get16_unaligned_check(val, addr)			\
	do {                                                    \
                unsigned int err = 0, v, a = addr;              \
                get8_unaligned_check(val, a, err);              \
                get8_unaligned_check(v, a, err);                \
                val |= v << 8;                                  \
                if (err)                                        \
                        goto fault;                             \
        } while (0)


#define put16_unaligned_check(val, addr)			\
	do {                                                    \
                unsigned int err = 0, v = val, a = addr;        \
                __asm__(                                        \
                "1:     stb.u   %1, [%2], #1\n"                 \
                "       mov     %1, %1 >> #8\n"                 \
                "2:     stb.u   %1, [%2]\n"                     \
                "3:\n"                                          \
                "       .pushsection .fixup,\"ax\"\n"           \
                "       .align  2\n"                            \
                "4:     mov     %0, #1\n"                       \
                "       b       3b\n"                           \
                "       .popsection\n"                          \
                "       .pushsection __ex_table,\"a\"\n"                \
                "       .align  3\n"                            \
                "       .long   1b, 4b\n"                       \
                "       .long   2b, 4b\n"                       \
                "       .popsection\n"                          \
                : "=r" (err), "=&r" (v), "=&r" (a)              \
                : "0" (err), "1" (v), "2" (a));                 \
                if (err)                                        \
                        goto fault;                             \
        } while (0)


#define __put32_unaligned_check(ins, val, addr)			\
	do {                                                    \
                unsigned int err = 0, v = val, a = addr;        \
                __asm__(                                        \
                "1:     "ins"   %1, [%2], #1\n"                 \
                "       mov     %1, %1 >> #8\n"                 \
                "2:     "ins"   %1, [%2], #1\n"                 \
                "       mov     %1, %1 >> #8\n"                 \
                "3:     "ins"   %1, [%2], #1\n"                 \
                "       mov     %1, %1 >> #8\n"                 \
                "4:     "ins"   %1, [%2]\n"                     \
                "5:\n"                                          \
                "       .pushsection .fixup,\"ax\"\n"           \
                "       .align  2\n"                            \
                "6:     mov     %0, #1\n"                       \
                "       b       5b\n"                           \
                "       .popsection\n"                          \
                "       .pushsection __ex_table,\"a\"\n"                \
                "       .align  3\n"                            \
                "       .long   1b, 6b\n"                       \
                "       .long   2b, 6b\n"                       \
                "       .long   3b, 6b\n"                       \
                "       .long   4b, 6b\n"                       \
                "       .popsection\n"                          \
                : "=r" (err), "=&r" (v), "=&r" (a)              \
                : "0" (err), "1" (v), "2" (a));                 \
                if (err)                                        \
                        goto fault;                             \
        } while (0)


#define get32_unaligned_check(val, addr)			\
	do {                                                    \
                unsigned int err = 0, v, a = addr;              \
                get8_unaligned_check(val, a, err);              \
                get8_unaligned_check(v, a, err);                \
                val |= v << 8;                                  \
                get8_unaligned_check(v, a, err);                \
                val |= v << 16;                                 \
                get8_unaligned_check(v, a, err);                \
                val |= v << 24;                                 \
                if (err)                                        \
                        goto fault;                             \
        } while (0)


#define put32_unaligned_check(val, addr)			\
	__put32_unaligned_check("stb.u", val, addr)


#define get32t_unaligned_check(val, addr)			\
	do {                                                    \
                unsigned int err = 0, v, a = addr;              \
                get8t_unaligned_check(val, a, err);             \
                get8t_unaligned_check(v, a, err);               \
                val |= v << 8;                                  \
                get8t_unaligned_check(v, a, err);               \
                val |= v << 16;                                 \
                get8t_unaligned_check(v, a, err);               \
                val |= v << 24;                                 \
                if (err)                                        \
                        goto fault;                             \
        } while (0)


#define put32t_unaligned_check(val, addr)			\
	__put32_unaligned_check("stb.u", val, addr)


static void do_alignment_finish_ldst(unsigned long addr, unsigned long instr, struct pt_regs *regs, union offset_union offset) { if (!LDST_U_BIT(instr)) offset.un = -offset.un; if (!LDST_P_BIT(instr)) addr += offset.un; if (!LDST_P_BIT(instr) || LDST_W_BIT(instr)) regs->uregs[RN_BITS(instr)] = addr; }

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static int do_alignment_ldrhstrh(unsigned long addr, unsigned long instr, struct pt_regs *regs) { unsigned int rd = RD_BITS(instr); /* old value 0x40002120, can't judge swap instr correctly */ if ((instr & 0x4b003fe0) == 0x40000120) goto swp; if (LDST_L_BIT(instr)) { unsigned long val; get16_unaligned_check(val, addr); /* signed half-word? */ if (instr & 0x80) val = (signed long)((signed short)val); regs->uregs[rd] = val; } else put16_unaligned_check(regs->uregs[rd], addr); return TYPE_LDST; swp: /* only handle swap word * for swap byte should not active this alignment exception */ get32_unaligned_check(regs->uregs[RD_BITS(instr)], addr); put32_unaligned_check(regs->uregs[RM_BITS(instr)], addr); return TYPE_SWAP; fault: return TYPE_FAULT; }

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Guan Xuetao149100.00%1100.00%
Total149100.00%1100.00%


static int do_alignment_ldrstr(unsigned long addr, unsigned long instr, struct pt_regs *regs) { unsigned int rd = RD_BITS(instr); if (!LDST_P_BIT(instr) && LDST_W_BIT(instr)) goto trans; if (LDST_L_BIT(instr)) get32_unaligned_check(regs->uregs[rd], addr); else put32_unaligned_check(regs->uregs[rd], addr); return TYPE_LDST; trans: if (LDST_L_BIT(instr)) get32t_unaligned_check(regs->uregs[rd], addr); else put32t_unaligned_check(regs->uregs[rd], addr); return TYPE_LDST; fault: return TYPE_FAULT; }

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Guan Xuetao121100.00%1100.00%
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/* * LDM/STM alignment handler. * * There are 4 variants of this instruction: * * B = rn pointer before instruction, A = rn pointer after instruction * ------ increasing address -----> * | | r0 | r1 | ... | rx | | * PU = 01 B A * PU = 11 B A * PU = 00 A B * PU = 10 A B */
static int do_alignment_ldmstm(unsigned long addr, unsigned long instr, struct pt_regs *regs) { unsigned int rd, rn, pc_correction, reg_correction, nr_regs, regbits; unsigned long eaddr, newaddr; if (LDM_S_BIT(instr)) goto bad; pc_correction = 4; /* processor implementation defined */ /* count the number of registers in the mask to be transferred */ nr_regs = hweight16(REGMASK_BITS(instr)) * 4; rn = RN_BITS(instr); newaddr = eaddr = regs->uregs[rn]; if (!LDST_U_BIT(instr)) nr_regs = -nr_regs; newaddr += nr_regs; if (!LDST_U_BIT(instr)) eaddr = newaddr; if (LDST_P_EQ_U(instr)) /* U = P */ eaddr += 4; /* * This is a "hint" - we already have eaddr worked out by the * processor for us. */ if (addr != eaddr) { printk(KERN_ERR "LDMSTM: PC = %08lx, instr = %08lx, " "addr = %08lx, eaddr = %08lx\n", instruction_pointer(regs), instr, addr, eaddr); show_regs(regs); } if (LDM_H_BIT(instr)) reg_correction = 0x10; else reg_correction = 0x00; for (regbits = REGMASK_BITS(instr), rd = 0; regbits; regbits >>= 1, rd += 1) if (regbits & 1) { if (LDST_L_BIT(instr)) get32_unaligned_check(regs-> uregs[rd + reg_correction], eaddr); else put32_unaligned_check(regs-> uregs[rd + reg_correction], eaddr); eaddr += 4; } if (LDST_W_BIT(instr)) regs->uregs[rn] = newaddr; return TYPE_DONE; fault: regs->UCreg_pc -= pc_correction; return TYPE_FAULT; bad: printk(KERN_ERR "Alignment trap: not handling ldm with s-bit set\n"); return TYPE_ERROR; }

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static int do_alignment(unsigned long addr, unsigned int error_code, struct pt_regs *regs) { union offset_union offset; unsigned long instr, instrptr; int (*handler) (unsigned long addr, unsigned long instr, struct pt_regs *regs); unsigned int type; instrptr = instruction_pointer(regs); if (instrptr >= PAGE_OFFSET) instr = *(unsigned long *)instrptr; else { __asm__ __volatile__( "ldw.u %0, [%1]\n" : "=&r"(instr) : "r"(instrptr)); } regs->UCreg_pc += 4; switch (CODING_BITS(instr)) { case 0x40000120: /* ldrh or strh */ if (LDSTH_I_BIT(instr)) offset.un = (instr & 0x3e00) >> 4 | (instr & 31); else offset.un = regs->uregs[RM_BITS(instr)]; handler = do_alignment_ldrhstrh; break; case 0x60000000: /* ldr or str immediate */ case 0x60000100: /* ldr or str immediate */ case 0x60000020: /* ldr or str immediate */ case 0x60000120: /* ldr or str immediate */ offset.un = OFFSET_BITS(instr); handler = do_alignment_ldrstr; break; case 0x40000000: /* ldr or str register */ offset.un = regs->uregs[RM_BITS(instr)]; { unsigned int shiftval = SHIFT_BITS(instr); switch (SHIFT_TYPE(instr)) { case SHIFT_LSL: offset.un <<= shiftval; break; case SHIFT_LSR: offset.un >>= shiftval; break; case SHIFT_ASR: offset.sn >>= shiftval; break; case SHIFT_RORRRX: if (shiftval == 0) { offset.un >>= 1; if (regs->UCreg_asr & PSR_C_BIT) offset.un |= 1 << 31; } else offset.un = offset.un >> shiftval | offset.un << (32 - shiftval); break; } } handler = do_alignment_ldrstr; break; case 0x80000000: /* ldm or stm */ case 0x80000020: /* ldm or stm */ handler = do_alignment_ldmstm; break; default: goto bad; } type = handler(addr, instr, regs); if (type == TYPE_ERROR || type == TYPE_FAULT) goto bad_or_fault; if (type == TYPE_LDST) do_alignment_finish_ldst(addr, instr, regs, offset); return 0; bad_or_fault: if (type == TYPE_ERROR) goto bad; regs->UCreg_pc -= 4; /* * We got a fault - fix it up, or die. */ do_bad_area(addr, error_code, regs); return 0; bad: /* * Oops, we didn't handle the instruction. * However, we must handle fpu instr firstly. */ #ifdef CONFIG_UNICORE_FPU_F64 /* handle co.load/store */ #define CODING_COLS 0xc0000000 #define COLS_OFFSET_BITS(i) (i & 0x1FF) #define COLS_L_BITS(i) (i & (1<<24)) #define COLS_FN_BITS(i) ((i>>14) & 31) if ((instr & 0xe0000000) == CODING_COLS) { unsigned int fn = COLS_FN_BITS(instr); unsigned long val = 0; if (COLS_L_BITS(instr)) { get32t_unaligned_check(val, addr); switch (fn) { #define ASM_MTF(n) case n: \ __asm__ __volatile__("MTF %0, F" __stringify(n) \ : : "r"(val)); \ break; ASM_MTF(0); ASM_MTF(1); ASM_MTF(2); ASM_MTF(3); ASM_MTF(4); ASM_MTF(5); ASM_MTF(6); ASM_MTF(7); ASM_MTF(8); ASM_MTF(9); ASM_MTF(10); ASM_MTF(11); ASM_MTF(12); ASM_MTF(13); ASM_MTF(14); ASM_MTF(15); ASM_MTF(16); ASM_MTF(17); ASM_MTF(18); ASM_MTF(19); ASM_MTF(20); ASM_MTF(21); ASM_MTF(22); ASM_MTF(23); ASM_MTF(24); ASM_MTF(25); ASM_MTF(26); ASM_MTF(27); ASM_MTF(28); ASM_MTF(29); ASM_MTF(30); ASM_MTF(31); #undef ASM_MTF } } else { switch (fn) { #define ASM_MFF(n) case n: \ __asm__ __volatile__("MFF %0, F" __stringify(n) \ : : "r"(val)); \ break; ASM_MFF(0); ASM_MFF(1); ASM_MFF(2); ASM_MFF(3); ASM_MFF(4); ASM_MFF(5); ASM_MFF(6); ASM_MFF(7); ASM_MFF(8); ASM_MFF(9); ASM_MFF(10); ASM_MFF(11); ASM_MFF(12); ASM_MFF(13); ASM_MFF(14); ASM_MFF(15); ASM_MFF(16); ASM_MFF(17); ASM_MFF(18); ASM_MFF(19); ASM_MFF(20); ASM_MFF(21); ASM_MFF(22); ASM_MFF(23); ASM_MFF(24); ASM_MFF(25); ASM_MFF(26); ASM_MFF(27); ASM_MFF(28); ASM_MFF(29); ASM_MFF(30); ASM_MFF(31); #undef ASM_MFF } put32t_unaligned_check(val, addr); } return TYPE_COLS; } fault: return TYPE_FAULT; #endif printk(KERN_ERR "Alignment trap: not handling instruction " "%08lx at [<%08lx>]\n", instr, instrptr); return 1; }

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/* * This needs to be done after sysctl_init, otherwise sys/ will be * overwritten. Actually, this shouldn't be in sys/ at all since * it isn't a sysctl, and it doesn't contain sysctl information. */
static int __init alignment_init(void) { hook_fault_code(1, do_alignment, SIGBUS, BUS_ADRALN, "alignment exception"); return 0; }

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fs_initcall(alignment_init);

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Chen Gang S30.16%125.00%
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