[qemu.git] / exec.c

/*
 *  virtual page mapping and translated block handling
 * 
 *  Copyright (c) 2003 Fabrice Bellard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <inttypes.h>
#include <sys/mman.h>

#include "cpu-i386.h"

//#define DEBUG_TB_INVALIDATE
#define DEBUG_FLUSH

/* make various TB consistency checks */
//#define DEBUG_TB_CHECK 

/* threshold to flush the translated code buffer */
#define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)

#define CODE_GEN_MAX_BLOCKS    (CODE_GEN_BUFFER_SIZE / 64)

TranslationBlock tbs[CODE_GEN_MAX_BLOCKS];
TranslationBlock *tb_hash[CODE_GEN_HASH_SIZE];
int nb_tbs;

uint8_t code_gen_buffer[CODE_GEN_BUFFER_SIZE];
uint8_t *code_gen_ptr;

/* XXX: pack the flags in the low bits of the pointer ? */
typedef struct PageDesc {
    unsigned long flags;
    TranslationBlock *first_tb;
} PageDesc;

#define L2_BITS 10
#define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS)

#define L1_SIZE (1 << L1_BITS)
#define L2_SIZE (1 << L2_BITS)

static void tb_invalidate_page(unsigned long address);

unsigned long real_host_page_size;
unsigned long host_page_bits;
unsigned long host_page_size;
unsigned long host_page_mask;

static PageDesc *l1_map[L1_SIZE];

void page_init(void)
{
    /* NOTE: we can always suppose that host_page_size >=
       TARGET_PAGE_SIZE */
    real_host_page_size = getpagesize();
    if (host_page_size == 0)
        host_page_size = real_host_page_size;
    if (host_page_size < TARGET_PAGE_SIZE)
        host_page_size = TARGET_PAGE_SIZE;
    host_page_bits = 0;
    while ((1 << host_page_bits) < host_page_size)
        host_page_bits++;
    host_page_mask = ~(host_page_size - 1);
}

/* dump memory mappings */
void page_dump(FILE *f)
{
    unsigned long start, end;
    int i, j, prot, prot1;
    PageDesc *p;

    fprintf(f, "%-8s %-8s %-8s %s\n",
            "start", "end", "size", "prot");
    start = -1;
    end = -1;
    prot = 0;
    for(i = 0; i <= L1_SIZE; i++) {
        if (i < L1_SIZE)
            p = l1_map[i];
        else
            p = NULL;
        for(j = 0;j < L2_SIZE; j++) {
            if (!p)
                prot1 = 0;
            else
                prot1 = p[j].flags;
            if (prot1 != prot) {
                end = (i << (32 - L1_BITS)) | (j << TARGET_PAGE_BITS);
                if (start != -1) {
                    fprintf(f, "%08lx-%08lx %08lx %c%c%c\n",
                            start, end, end - start, 
                            prot & PAGE_READ ? 'r' : '-',
                            prot & PAGE_WRITE ? 'w' : '-',
                            prot & PAGE_EXEC ? 'x' : '-');
                }
                if (prot1 != 0)
                    start = end;
                else
                    start = -1;
                prot = prot1;
            }
            if (!p)
                break;
        }
    }
}

static inline PageDesc *page_find_alloc(unsigned int index)
{
    PageDesc **lp, *p;

    lp = &l1_map[index >> L2_BITS];
    p = *lp;
    if (!p) {
        /* allocate if not found */
        p = malloc(sizeof(PageDesc) * L2_SIZE);
        memset(p, 0, sizeof(PageDesc) * L2_SIZE);
        *lp = p;
    }
    return p + (index & (L2_SIZE - 1));
}

static inline PageDesc *page_find(unsigned int index)
{
    PageDesc *p;

    p = l1_map[index >> L2_BITS];
    if (!p)
        return 0;
    return p + (index & (L2_SIZE - 1));
}

int page_get_flags(unsigned long address)
{
    PageDesc *p;

    p = page_find(address >> TARGET_PAGE_BITS);
    if (!p)
        return 0;
    return p->flags;
}

/* modify the flags of a page and invalidate the code if
   necessary. The flag PAGE_WRITE_ORG is positionned automatically
   depending on PAGE_WRITE */
void page_set_flags(unsigned long start, unsigned long end, int flags)
{
    PageDesc *p;
    unsigned long addr;

    start = start & TARGET_PAGE_MASK;
    end = TARGET_PAGE_ALIGN(end);
    if (flags & PAGE_WRITE)
        flags |= PAGE_WRITE_ORG;
    for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
        p = page_find_alloc(addr >> TARGET_PAGE_BITS);
        /* if the write protection is set, then we invalidate the code
           inside */
        if (!(p->flags & PAGE_WRITE) && 
            (flags & PAGE_WRITE) &&
            p->first_tb) {
            tb_invalidate_page(addr);
        }
        p->flags = flags;
    }
}

void cpu_x86_tblocks_init(void)
{
    if (!code_gen_ptr) {
        code_gen_ptr = code_gen_buffer;
    }
}

/* set to NULL all the 'first_tb' fields in all PageDescs */
static void page_flush_tb(void)
{
    int i, j;
    PageDesc *p;

    for(i = 0; i < L1_SIZE; i++) {
        p = l1_map[i];
        if (p) {
            for(j = 0; j < L2_SIZE; j++)
                p[j].first_tb = NULL;
        }
    }
}

/* flush all the translation blocks */
void tb_flush(void)
{
    int i;
#ifdef DEBUG_FLUSH
    printf("qemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n", 
           code_gen_ptr - code_gen_buffer, 
           nb_tbs, 
           (code_gen_ptr - code_gen_buffer) / nb_tbs);
#endif
    nb_tbs = 0;
    for(i = 0;i < CODE_GEN_HASH_SIZE; i++)
        tb_hash[i] = NULL;
    page_flush_tb();
    code_gen_ptr = code_gen_buffer;
    /* XXX: flush processor icache at this point */
}

#ifdef DEBUG_TB_CHECK

static void tb_invalidate_check(unsigned long address)
{
    TranslationBlock *tb;
    int i;
    address &= TARGET_PAGE_MASK;
    for(i = 0;i < CODE_GEN_HASH_SIZE; i++) {
        for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) {
            if (!(address + TARGET_PAGE_SIZE <= tb->pc ||
                  address >= tb->pc + tb->size)) {
                printf("ERROR invalidate: address=%08lx PC=%08lx size=%04x\n",
                       address, tb->pc, tb->size);
            }
        }
    }
}

/* verify that all the pages have correct rights for code */
static void tb_page_check(void)
{
    TranslationBlock *tb;
    int i, flags1, flags2;
    
    for(i = 0;i < CODE_GEN_HASH_SIZE; i++) {
        for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) {
            flags1 = page_get_flags(tb->pc);
            flags2 = page_get_flags(tb->pc + tb->size - 1);
            if ((flags1 & PAGE_WRITE) || (flags2 & PAGE_WRITE)) {
                printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
                       tb->pc, tb->size, flags1, flags2);
            }
        }
    }
}

#endif

/* invalidate one TB */
static inline void tb_remove(TranslationBlock **ptb, TranslationBlock *tb,
                             int next_offset)
{
    TranslationBlock *tb1;
    for(;;) {
        tb1 = *ptb;
        if (tb1 == tb) {
            *ptb = *(TranslationBlock **)((char *)tb1 + next_offset);
            break;
        }
        ptb = (TranslationBlock **)((char *)tb1 + next_offset);
    }
}

static inline void tb_invalidate(TranslationBlock *tb, int parity)
{
    PageDesc *p;
    unsigned int page_index1, page_index2;
    unsigned int h;

    /* remove the TB from the hash list */
    h = tb_hash_func(tb->pc);
    tb_remove(&tb_hash[h], tb, 
              offsetof(TranslationBlock, hash_next));
    /* remove the TB from the page list */
    page_index1 = tb->pc >> TARGET_PAGE_BITS;
    if ((page_index1 & 1) == parity) {
        p = page_find(page_index1);
        tb_remove(&p->first_tb, tb, 
                  offsetof(TranslationBlock, page_next[page_index1 & 1]));
    }
    page_index2 = (tb->pc + tb->size - 1) >> TARGET_PAGE_BITS;
    if ((page_index2 & 1) == parity) {
        p = page_find(page_index2);
        tb_remove(&p->first_tb, tb, 
                  offsetof(TranslationBlock, page_next[page_index2 & 1]));
    }
}

/* invalidate all TBs which intersect with the target page starting at addr */
static void tb_invalidate_page(unsigned long address)
{
    TranslationBlock *tb_next, *tb;
    unsigned int page_index;
    int parity1, parity2;
    PageDesc *p;
#ifdef DEBUG_TB_INVALIDATE
    printf("tb_invalidate_page: %lx\n", address);
#endif

    page_index = address >> TARGET_PAGE_BITS;
    p = page_find(page_index);
    if (!p)
        return;
    tb = p->first_tb;
    parity1 = page_index & 1;
    parity2 = parity1 ^ 1;
    while (tb != NULL) {
        tb_next = tb->page_next[parity1];
        tb_invalidate(tb, parity2);
        tb = tb_next;
    }
    p->first_tb = NULL;
}

/* add the tb in the target page and protect it if necessary */
static inline void tb_alloc_page(TranslationBlock *tb, unsigned int page_index)
{
    PageDesc *p;
    unsigned long host_start, host_end, addr, page_addr;
    int prot;

    p = page_find_alloc(page_index);
    tb->page_next[page_index & 1] = p->first_tb;
    p->first_tb = tb;
    if (p->flags & PAGE_WRITE) {
        /* force the host page as non writable (writes will have a
           page fault + mprotect overhead) */
        page_addr = (page_index << TARGET_PAGE_BITS);
        host_start = page_addr & host_page_mask;
        host_end = host_start + host_page_size;
        prot = 0;
        for(addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE)
            prot |= page_get_flags(addr);
        mprotect((void *)host_start, host_page_size, 
                 (prot & PAGE_BITS) & ~PAGE_WRITE);
#ifdef DEBUG_TB_INVALIDATE
        printf("protecting code page: 0x%08lx\n", 
               host_start);
#endif
        p->flags &= ~PAGE_WRITE;
#ifdef DEBUG_TB_CHECK
        tb_page_check();
#endif
    }
}

/* Allocate a new translation block. Flush the translation buffer if
   too many translation blocks or too much generated code. */
TranslationBlock *tb_alloc(unsigned long pc, 
                           unsigned long size)
{
    TranslationBlock *tb;
    unsigned int page_index1, page_index2;

    if (nb_tbs >= CODE_GEN_MAX_BLOCKS || 
        (code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE)
        tb_flush();
    tb = &tbs[nb_tbs++];
    tb->pc = pc;
    tb->size = size;

    /* add in the page list */
    page_index1 = pc >> TARGET_PAGE_BITS;
    tb_alloc_page(tb, page_index1);
    page_index2 = (pc + size - 1) >> TARGET_PAGE_BITS;
    if (page_index2 != page_index1) {
        tb_alloc_page(tb, page_index2);
    }
    return tb;
}

/* called from signal handler: invalidate the code and unprotect the
   page. Return TRUE if the fault was succesfully handled. */
int page_unprotect(unsigned long address)
{
    unsigned int page_index, prot;
    PageDesc *p;
    unsigned long host_start, host_end, addr;

    page_index = address >> TARGET_PAGE_BITS;
    p = page_find(page_index);
    if (!p)
        return 0;
    if ((p->flags & (PAGE_WRITE_ORG | PAGE_WRITE)) == PAGE_WRITE_ORG) {
        /* if the page was really writable, then we change its
           protection back to writable */
        host_start = address & host_page_mask;
        host_end = host_start + host_page_size;
        prot = 0;
        for(addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE)
            prot |= page_get_flags(addr);
        mprotect((void *)host_start, host_page_size, 
                 (prot & PAGE_BITS) | PAGE_WRITE);
        p->flags |= PAGE_WRITE;

        /* and since the content will be modified, we must invalidate
           the corresponding translated code. */
        tb_invalidate_page(address);
#ifdef DEBUG_TB_CHECK
        tb_invalidate_check(address);
#endif
        return 1;
    } else {
        return 0;
    }
}

/* call this function when system calls directly modify a memory area */
void page_unprotect_range(uint8_t *data, unsigned long data_size)
{
    unsigned long start, end, addr;

    start = (unsigned long)data;
    end = start + data_size;
    start &= TARGET_PAGE_MASK;
    end = TARGET_PAGE_ALIGN(end);
    for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
        page_unprotect(addr);
    }
}
Commit	Line	Data
54936004	1	/*
fd6ce8f6	2	* virtual page mapping and translated block handling
54936004 FB	3	*
	4	* Copyright (c) 2003 Fabrice Bellard
	5	*
	6	* This library is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU Lesser General Public
	8	* License as published by the Free Software Foundation; either
	9	* version 2 of the License, or (at your option) any later version.
	10	*
	11	* This library is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* Lesser General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU Lesser General Public
	17	* License along with this library; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*/
	20	#include <stdlib.h>
	21	#include <stdio.h>
	22	#include <stdarg.h>
	23	#include <string.h>
	24	#include <errno.h>
	25	#include <unistd.h>
	26	#include <inttypes.h>
fd6ce8f6	27	#include <sys/mman.h>
54936004 FB	28
	29	#include "cpu-i386.h"
	30
fd6ce8f6 FB	31	//#define DEBUG_TB_INVALIDATE
	32	#define DEBUG_FLUSH
	33
	34	/* make various TB consistency checks */
	35	//#define DEBUG_TB_CHECK
	36
	37	/* threshold to flush the translated code buffer */
	38	#define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)
	39
	40	#define CODE_GEN_MAX_BLOCKS (CODE_GEN_BUFFER_SIZE / 64)
	41
	42	TranslationBlock tbs[CODE_GEN_MAX_BLOCKS];
	43	TranslationBlock *tb_hash[CODE_GEN_HASH_SIZE];
	44	int nb_tbs;
	45
	46	uint8_t code_gen_buffer[CODE_GEN_BUFFER_SIZE];
	47	uint8_t *code_gen_ptr;
	48
54936004 FB	49	/* XXX: pack the flags in the low bits of the pointer ? */
54936004 FB	50	typedef struct PageDesc {
54936004	51	unsigned long flags;
fd6ce8f6	52	TranslationBlock *first_tb;
54936004 FB	53	} PageDesc;
	54
	55	#define L2_BITS 10
	56	#define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS)
	57
	58	#define L1_SIZE (1 << L1_BITS)
	59	#define L2_SIZE (1 << L2_BITS)
	60
fd6ce8f6 FB	61	static void tb_invalidate_page(unsigned long address);
fd6ce8f6 FB	62
54936004 FB	63	unsigned long real_host_page_size;
	64	unsigned long host_page_bits;
	65	unsigned long host_page_size;
	66	unsigned long host_page_mask;
	67
	68	static PageDesc *l1_map[L1_SIZE];
	69
	70	void page_init(void)
	71	{
	72	/* NOTE: we can always suppose that host_page_size >=
	73	TARGET_PAGE_SIZE */
	74	real_host_page_size = getpagesize();
	75	if (host_page_size == 0)
	76	host_page_size = real_host_page_size;
	77	if (host_page_size < TARGET_PAGE_SIZE)
	78	host_page_size = TARGET_PAGE_SIZE;
	79	host_page_bits = 0;
	80	while ((1 << host_page_bits) < host_page_size)
	81	host_page_bits++;
	82	host_page_mask = ~(host_page_size - 1);
	83	}
	84
	85	/* dump memory mappings */
	86	void page_dump(FILE *f)
	87	{
	88	unsigned long start, end;
	89	int i, j, prot, prot1;
	90	PageDesc *p;
	91
	92	fprintf(f, "%-8s %-8s %-8s %s\n",
	93	"start", "end", "size", "prot");
	94	start = -1;
	95	end = -1;
	96	prot = 0;
	97	for(i = 0; i <= L1_SIZE; i++) {
	98	if (i < L1_SIZE)
	99	p = l1_map[i];
	100	else
	101	p = NULL;
	102	for(j = 0;j < L2_SIZE; j++) {
	103	if (!p)
	104	prot1 = 0;
	105	else
	106	prot1 = p[j].flags;
	107	if (prot1 != prot) {
	108	end = (i << (32 - L1_BITS)) \| (j << TARGET_PAGE_BITS);
	109	if (start != -1) {
	110	fprintf(f, "%08lx-%08lx %08lx %c%c%c\n",
	111	start, end, end - start,
	112	prot & PAGE_READ ? 'r' : '-',
	113	prot & PAGE_WRITE ? 'w' : '-',
	114	prot & PAGE_EXEC ? 'x' : '-');
	115	}
	116	if (prot1 != 0)
	117	start = end;
	118	else
	119	start = -1;
	120	prot = prot1;
	121	}
	122	if (!p)
	123	break;
	124	}
	125	}
	126	}
127
fd6ce8f6	128	static inline PageDesc *page_find_alloc(unsigned int index)
54936004	129	{
54936004 FB	130	PageDesc *lp, p;
54936004 FB	131
54936004 FB	132	lp = &l1_map[index >> L2_BITS];
	133	p = *lp;
	134	if (!p) {
	135	/* allocate if not found */
	136	p = malloc(sizeof(PageDesc) * L2_SIZE);
fd6ce8f6	137	memset(p, 0, sizeof(PageDesc) * L2_SIZE);
54936004 FB	138	*lp = p;
	139	}
	140	return p + (index & (L2_SIZE - 1));
	141	}
	142
fd6ce8f6	143	static inline PageDesc *page_find(unsigned int index)
54936004	144	{
54936004 FB	145	PageDesc *p;
54936004 FB	146
54936004 FB	147	p = l1_map[index >> L2_BITS];
	148	if (!p)
	149	return 0;
fd6ce8f6 FB	150	return p + (index & (L2_SIZE - 1));
	151	}
	152
	153	int page_get_flags(unsigned long address)
	154	{
	155	PageDesc *p;
	156
	157	p = page_find(address >> TARGET_PAGE_BITS);
	158	if (!p)
	159	return 0;
	160	return p->flags;
54936004 FB	161	}
54936004 FB	162
fd6ce8f6 FB	163	/* modify the flags of a page and invalidate the code if
	164	necessary. The flag PAGE_WRITE_ORG is positionned automatically
	165	depending on PAGE_WRITE */
54936004 FB	166	void page_set_flags(unsigned long start, unsigned long end, int flags)
	167	{
	168	PageDesc *p;
	169	unsigned long addr;
	170
	171	start = start & TARGET_PAGE_MASK;
	172	end = TARGET_PAGE_ALIGN(end);
fd6ce8f6 FB	173	if (flags & PAGE_WRITE)
fd6ce8f6 FB	174	flags \|= PAGE_WRITE_ORG;
54936004	175	for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
fd6ce8f6 FB	176	p = page_find_alloc(addr >> TARGET_PAGE_BITS);
	177	/* if the write protection is set, then we invalidate the code
	178	inside */
	179	if (!(p->flags & PAGE_WRITE) &&
	180	(flags & PAGE_WRITE) &&
	181	p->first_tb) {
	182	tb_invalidate_page(addr);
	183	}
54936004 FB	184	p->flags = flags;
	185	}
	186	}
fd6ce8f6 FB	187
	188	void cpu_x86_tblocks_init(void)
	189	{
	190	if (!code_gen_ptr) {
	191	code_gen_ptr = code_gen_buffer;
	192	}
	193	}
	194
	195	/* set to NULL all the 'first_tb' fields in all PageDescs */
	196	static void page_flush_tb(void)
	197	{
	198	int i, j;
	199	PageDesc *p;
	200
	201	for(i = 0; i < L1_SIZE; i++) {
	202	p = l1_map[i];
	203	if (p) {
	204	for(j = 0; j < L2_SIZE; j++)
	205	p[j].first_tb = NULL;
	206	}
	207	}
	208	}
	209
	210	/* flush all the translation blocks */
	211	void tb_flush(void)
	212	{
	213	int i;
	214	#ifdef DEBUG_FLUSH
	215	printf("qemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n",
	216	code_gen_ptr - code_gen_buffer,
	217	nb_tbs,
	218	(code_gen_ptr - code_gen_buffer) / nb_tbs);
	219	#endif
	220	nb_tbs = 0;
	221	for(i = 0;i < CODE_GEN_HASH_SIZE; i++)
	222	tb_hash[i] = NULL;
	223	page_flush_tb();
	224	code_gen_ptr = code_gen_buffer;
	225	/* XXX: flush processor icache at this point */
	226	}
	227
	228	#ifdef DEBUG_TB_CHECK
	229
	230	static void tb_invalidate_check(unsigned long address)
	231	{
	232	TranslationBlock *tb;
	233	int i;
	234	address &= TARGET_PAGE_MASK;
	235	for(i = 0;i < CODE_GEN_HASH_SIZE; i++) {
	236	for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) {
	237	if (!(address + TARGET_PAGE_SIZE <= tb->pc \|\|
	238	address >= tb->pc + tb->size)) {
	239	printf("ERROR invalidate: address=%08lx PC=%08lx size=%04x\n",
	240	address, tb->pc, tb->size);
	241	}
	242	}
	243	}
	244	}
	245
	246	/* verify that all the pages have correct rights for code */
	247	static void tb_page_check(void)
	248	{
	249	TranslationBlock *tb;
	250	int i, flags1, flags2;
251
252	for(i = 0;i < CODE_GEN_HASH_SIZE; i++) {
253	for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) {
254	flags1 = page_get_flags(tb->pc);
255	flags2 = page_get_flags(tb->pc + tb->size - 1);
256	if ((flags1 & PAGE_WRITE) \|\| (flags2 & PAGE_WRITE)) {
257	printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
258	tb->pc, tb->size, flags1, flags2);
259	}
260	}
261	}
262	}
263
264	#endif
265
266	/* invalidate one TB */
267	static inline void tb_remove(TranslationBlock *ptb, TranslationBlock tb,
268	int next_offset)
269	{
270	TranslationBlock *tb1;
271	for(;;) {
272	tb1 = *ptb;
273	if (tb1 == tb) {
274	ptb = (TranslationBlock *)((char )tb1 + next_offset);
275	break;
276	}
277	ptb = (TranslationBlock *)((char )tb1 + next_offset);
278	}
279	}
280
281	static inline void tb_invalidate(TranslationBlock *tb, int parity)
282	{
283	PageDesc *p;
284	unsigned int page_index1, page_index2;
285	unsigned int h;
286
287	/* remove the TB from the hash list */
288	h = tb_hash_func(tb->pc);
289	tb_remove(&tb_hash[h], tb,
290	offsetof(TranslationBlock, hash_next));
291	/* remove the TB from the page list */
292	page_index1 = tb->pc >> TARGET_PAGE_BITS;
293	if ((page_index1 & 1) == parity) {
294	p = page_find(page_index1);
295	tb_remove(&p->first_tb, tb,
296	offsetof(TranslationBlock, page_next[page_index1 & 1]));
297	}
298	page_index2 = (tb->pc + tb->size - 1) >> TARGET_PAGE_BITS;
299	if ((page_index2 & 1) == parity) {
300	p = page_find(page_index2);
301	tb_remove(&p->first_tb, tb,
302	offsetof(TranslationBlock, page_next[page_index2 & 1]));
303	}
304	}
305
306	/* invalidate all TBs which intersect with the target page starting at addr */
307	static void tb_invalidate_page(unsigned long address)
308	{
309	TranslationBlock tb_next, tb;
310	unsigned int page_index;
311	int parity1, parity2;
312	PageDesc *p;
313	#ifdef DEBUG_TB_INVALIDATE
314	printf("tb_invalidate_page: %lx\n", address);
315	#endif
316
317	page_index = address >> TARGET_PAGE_BITS;
318	p = page_find(page_index);
319	if (!p)
320	return;
321	tb = p->first_tb;
322	parity1 = page_index & 1;
323	parity2 = parity1 ^ 1;
324	while (tb != NULL) {
325	tb_next = tb->page_next[parity1];
326	tb_invalidate(tb, parity2);
327	tb = tb_next;
328	}
329	p->first_tb = NULL;
330	}
331
332	/* add the tb in the target page and protect it if necessary */
333	static inline void tb_alloc_page(TranslationBlock *tb, unsigned int page_index)
334	{
335	PageDesc *p;
336	unsigned long host_start, host_end, addr, page_addr;
337	int prot;
338
339	p = page_find_alloc(page_index);
340	tb->page_next[page_index & 1] = p->first_tb;
341	p->first_tb = tb;
342	if (p->flags & PAGE_WRITE) {
343	/* force the host page as non writable (writes will have a
344	page fault + mprotect overhead) */
345	page_addr = (page_index << TARGET_PAGE_BITS);
346	host_start = page_addr & host_page_mask;
347	host_end = host_start + host_page_size;
348	prot = 0;
349	for(addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE)
350	prot \|= page_get_flags(addr);
351	mprotect((void *)host_start, host_page_size,
352	(prot & PAGE_BITS) & ~PAGE_WRITE);
353	#ifdef DEBUG_TB_INVALIDATE
354	printf("protecting code page: 0x%08lx\n",
355	host_start);
356	#endif
357	p->flags &= ~PAGE_WRITE;
358	#ifdef DEBUG_TB_CHECK
359	tb_page_check();
360	#endif
361	}
362	}
363
364	/* Allocate a new translation block. Flush the translation buffer if
365	too many translation blocks or too much generated code. */
366	TranslationBlock *tb_alloc(unsigned long pc,
367	unsigned long size)
368	{
369	TranslationBlock *tb;
370	unsigned int page_index1, page_index2;
371
372	if (nb_tbs >= CODE_GEN_MAX_BLOCKS \|\|
373	(code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE)
374	tb_flush();
375	tb = &tbs[nb_tbs++];
376	tb->pc = pc;
377	tb->size = size;
378
379	/* add in the page list */
380	page_index1 = pc >> TARGET_PAGE_BITS;
381	tb_alloc_page(tb, page_index1);
382	page_index2 = (pc + size - 1) >> TARGET_PAGE_BITS;
383	if (page_index2 != page_index1) {
384	tb_alloc_page(tb, page_index2);
385	}
386	return tb;
387	}
388
389	/* called from signal handler: invalidate the code and unprotect the
390	page. Return TRUE if the fault was succesfully handled. */
391	int page_unprotect(unsigned long address)
392	{
393	unsigned int page_index, prot;
394	PageDesc *p;
395	unsigned long host_start, host_end, addr;
396
397	page_index = address >> TARGET_PAGE_BITS;
398	p = page_find(page_index);
399	if (!p)
400	return 0;
401	if ((p->flags & (PAGE_WRITE_ORG \| PAGE_WRITE)) == PAGE_WRITE_ORG) {
402	/* if the page was really writable, then we change its
403	protection back to writable */
404	host_start = address & host_page_mask;
405	host_end = host_start + host_page_size;
406	prot = 0;
407	for(addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE)
408	prot \|= page_get_flags(addr);
409	mprotect((void *)host_start, host_page_size,
410	(prot & PAGE_BITS) \| PAGE_WRITE);
411	p->flags \|= PAGE_WRITE;
412
413	/* and since the content will be modified, we must invalidate
414	the corresponding translated code. */
415	tb_invalidate_page(address);
416	#ifdef DEBUG_TB_CHECK
417	tb_invalidate_check(address);
418	#endif
419	return 1;
420	} else {
421	return 0;
422	}
423	}
424
425	/* call this function when system calls directly modify a memory area */
426	void page_unprotect_range(uint8_t *data, unsigned long data_size)
427	{
428	unsigned long start, end, addr;
429
430	start = (unsigned long)data;
431	end = start + data_size;
432	start &= TARGET_PAGE_MASK;
433	end = TARGET_PAGE_ALIGN(end);
434	for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
435	page_unprotect(addr);
436	}
437	}