src/cpus/memory_rw.c

/*
 *  Copyright (C) 2003-2007  Anders Gavare.  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *
 *
 *  $Id: memory_rw.c,v 1.1 2007/06/19 02:11:46 debug Exp $
 *
 *  Generic memory_rw(), with special hacks for specific CPU families.
 *
 *  Example for inclusion from memory_mips.c:
 *
 *      MEMORY_RW should be mips_memory_rw
 *      MEM_MIPS should be defined
 *
 *
 *  TODO: Cleanup the "ok" variable usage!
 */


/*
 *  memory_rw():
 *
 *  Read or write data from/to memory.
 *
 *      cpu             the cpu doing the read/write
 *      mem             the memory object to use
 *      vaddr           the virtual address
 *      data            a pointer to the data to be written to memory, or
 *                      a placeholder for data when reading from memory
 *      len             the length of the 'data' buffer
 *      writeflag       set to MEM_READ or MEM_WRITE
 *      misc_flags      CACHE_{NONE,DATA,INSTRUCTION} | other flags
 *
 *  If the address indicates access to a memory mapped device, that device'
 *  read/write access function is called.
 *
 *  This function should not be called with cpu == NULL.
 *
 *  Returns one of the following:
 *      MEMORY_ACCESS_FAILED
 *      MEMORY_ACCESS_OK
 *
 *  (MEMORY_ACCESS_FAILED is 0.)
 */
int MEMORY_RW(struct cpu *cpu, struct memory *mem, uint64_t vaddr,
        unsigned char *data, size_t len, int writeflag, int misc_flags)
{
#ifdef MEM_ALPHA
        const int offset_mask = 0x1fff;
#else
        const int offset_mask = 0xfff;
#endif

#ifndef MEM_USERLAND
        int ok = 2;
#endif
        uint64_t paddr;
        int cache, no_exceptions, offset;
        unsigned char *memblock;
        int dyntrans_device_danger = 0;

        no_exceptions = misc_flags & NO_EXCEPTIONS;
        cache = misc_flags & CACHE_FLAGS_MASK;


#ifdef MEM_USERLAND
#ifdef MEM_ALPHA
        paddr = vaddr;
#else
        paddr = vaddr & 0x7fffffff;
#endif
#else   /*  !MEM_USERLAND  */
        if (misc_flags & PHYSICAL || cpu->translate_v2p == NULL) {
                paddr = vaddr;
        } else {
                ok = cpu->translate_v2p(cpu, vaddr, &paddr,
                    (writeflag? FLAG_WRITEFLAG : 0) +
                    (no_exceptions? FLAG_NOEXCEPTIONS : 0)
                    + (misc_flags & MEMORY_USER_ACCESS)
                    + (cache==CACHE_INSTRUCTION? FLAG_INSTR : 0));

                /*
                 *  If the translation caused an exception, or was invalid in
                 *  some way, then simply return without doing the memory
                 *  access:
                 */
                if (!ok)
                        return MEMORY_ACCESS_FAILED;
        }

#endif  /*  !MEM_USERLAND  */


#ifndef MEM_USERLAND
        /*
         *  Memory mapped device?
         *
         *  TODO: if paddr < base, but len enough, then the device should
         *  still be written to!
         */
        if (paddr >= mem->mmap_dev_minaddr && paddr < mem->mmap_dev_maxaddr) {
                uint64_t orig_paddr = paddr;
                int i, start, end, res;

#if 0

TODO: The correct solution for this is to add RAM devices _around_ the
dangerous device. The solution below incurs a slowdown for _everything_,
not just the device in question.

                /*
                 *  Really really slow, but unfortunately necessary. This is
                 *  to avoid the folowing scenario:
                 *
                 *      a) offsets 0x000..0x123 are normal memory
                 *      b) offsets 0x124..0x777 are a device
                 *
                 *      1) a read is done from offset 0x100. the page is
                 *         added to the dyntrans system as a "RAM" page
                 *      2) a dyntranslated read is done from offset 0x200,
                 *         which should access the device, but since the
                 *         entire page is added, it will access non-existant
                 *         RAM instead, without warning.
                 *
                 *  Setting dyntrans_device_danger = 1 on accesses which are
                 *  on _any_ offset on pages that are device mapped avoids
                 *  this problem, but it is probably not very fast.
                 *
                 *  TODO: Convert this into a quick (multi-level, 64-bit)
                 *  address space lookup, to find dangerous pages.
                 */
                for (i=0; i<mem->n_mmapped_devices; i++)
                        if (paddr >= (mem->devices[i].baseaddr & ~offset_mask)&&
                            paddr <= ((mem->devices[i].endaddr-1)|offset_mask)){
                                dyntrans_device_danger = 1;
                                break;
                        }
#endif

                start = 0; end = mem->n_mmapped_devices - 1;
                i = mem->last_accessed_device;

                /*  Scan through all devices:  */
                do {
                        if (paddr >= mem->devices[i].baseaddr &&
                            paddr < mem->devices[i].endaddr) {
                                /*  Found a device, let's access it:  */
                                mem->last_accessed_device = i;

                                paddr -= mem->devices[i].baseaddr;
                                if (paddr + len > mem->devices[i].length)
                                        len = mem->devices[i].length - paddr;

                                if (cpu->update_translation_table != NULL &&
                                    !(ok & MEMORY_NOT_FULL_PAGE) &&
                                    mem->devices[i].flags & DM_DYNTRANS_OK) {
                                        int wf = writeflag == MEM_WRITE? 1 : 0;
                                        unsigned char *host_addr;

                                        if (!(mem->devices[i].flags &
                                            DM_DYNTRANS_WRITE_OK))
                                                wf = 0;

                                        if (writeflag && wf) {
                                                if (paddr < mem->devices[i].
                                                    dyntrans_write_low)
                                                        mem->devices[i].
                                                        dyntrans_write_low =
                                                            paddr &~offset_mask;
                                                if (paddr >= mem->devices[i].
                                                    dyntrans_write_high)
                                                        mem->devices[i].
                                                        dyntrans_write_high =
                                                            paddr | offset_mask;
                                        }

                                        if (mem->devices[i].flags &
                                            DM_EMULATED_RAM) {
                                                /*  MEM_WRITE to force the page
                                                    to be allocated, if it
                                                    wasn't already  */
                                                uint64_t *pp = (uint64_t *)mem->
                                                    devices[i].dyntrans_data;
                                                uint64_t p = orig_paddr - *pp;
                                                host_addr =
                                                    memory_paddr_to_hostaddr(
                                                    mem, p & ~offset_mask,
                                                    MEM_WRITE);
                                        } else {
                                                host_addr = mem->devices[i].
                                                    dyntrans_data +
                                                    (paddr & ~offset_mask);
                                        }

                                        cpu->update_translation_table(cpu,
                                            vaddr & ~offset_mask, host_addr,
                                            wf, orig_paddr & ~offset_mask);
                                }

                                res = 0;
                                if (!no_exceptions || (mem->devices[i].flags &
                                    DM_READS_HAVE_NO_SIDE_EFFECTS))
                                        res = mem->devices[i].f(cpu, mem, paddr,
                                            data, len, writeflag,
                                            mem->devices[i].extra);

                                if (res == 0)
                                        res = -1;

                                /*
                                 *  If accessing the memory mapped device
                                 *  failed, then return with a DBE exception.
                                 */
                                if (res <= 0 && !no_exceptions) {
                                        debug("%s device '%s' addr %08lx "
                                            "failed\n", writeflag?
                                            "writing to" : "reading from",
                                            mem->devices[i].name, (long)paddr);
#ifdef MEM_MIPS
                                        mips_cpu_exception(cpu,
                                            cache == CACHE_INSTRUCTION?
                                            EXCEPTION_IBE : EXCEPTION_DBE,
                                            0, vaddr, 0, 0, 0, 0);
#endif
                                        return MEMORY_ACCESS_FAILED;
                                }
                                goto do_return_ok;
                        }

                        if (paddr < mem->devices[i].baseaddr)
                                end = i - 1;
                        if (paddr >= mem->devices[i].endaddr)
                                start = i + 1;
                        i = (start + end) >> 1;
                } while (start <= end);
        }


#ifdef MEM_MIPS
        /*
         *  Data and instruction cache emulation:
         */

        switch (cpu->cd.mips.cpu_type.mmu_model) {
        case MMU3K:
                /*  if not uncached addess  (TODO: generalize this)  */
                if (!(misc_flags & PHYSICAL) && cache != CACHE_NONE &&
                    !((vaddr & 0xffffffffULL) >= 0xa0000000ULL &&
                      (vaddr & 0xffffffffULL) <= 0xbfffffffULL)) {
                        if (memory_cache_R3000(cpu, cache, paddr,
                            writeflag, len, data))
                                goto do_return_ok;
                }
                break;
        default:
                /*  R4000 etc  */
                /*  TODO  */
                ;
        }
#endif  /*  MEM_MIPS  */


        /*  Outside of physical RAM?  */
        if (paddr >= mem->physical_max) {
#ifdef MEM_MIPS
                if ((paddr & 0xffffc00000ULL) == 0x1fc00000) {
                        /*  Ok, this is PROM stuff  */
                } else if ((paddr & 0xfffff00000ULL) == 0x1ff00000) {
                        /*  Sprite reads from this area of memory...  */
                        /*  TODO: is this still correct?  */
                        if (writeflag == MEM_READ)
                                memset(data, 0, len);
                        goto do_return_ok;
                } else
#endif /* MIPS */
                {
                        if (paddr >= mem->physical_max && !no_exceptions)
                                memory_warn_about_unimplemented_addr
                                    (cpu, mem, writeflag, paddr, data, len);

                        if (writeflag == MEM_READ) {
                                /*  Return all zeroes? (Or 0xff? TODO)  */
                                memset(data, 0, len);

#if 0
/*
 *  NOTE: This code prevents a PROM image from a real 5000/200 from booting.
 *  I think I introduced it because it was how some guest OS (NetBSD?) detected
 *  the amount of RAM on some machine.
 *
 *  TODO: Figure out if it is not needed anymore, and remove it completely.
 */
#ifdef MEM_MIPS
                                /*
                                 *  For real data/instruction accesses, cause
                                 *  an exceptions on an illegal read:
                                 */
                                if (cache != CACHE_NONE && !no_exceptions &&
                                    paddr >= mem->physical_max &&
                                    paddr < mem->physical_max+1048576) {
                                        mips_cpu_exception(cpu,
                                            EXCEPTION_DBE, 0, vaddr, 0,
                                            0, 0, 0);
                                }
#endif  /*  MEM_MIPS  */
#endif
                        }

                        /*  Hm? Shouldn't there be a DBE exception for
                            invalid writes as well?  TODO  */

                        goto do_return_ok;
                }
        }

#endif  /*  ifndef MEM_USERLAND  */


        /*
         *  Uncached access:
         *
         *  1)  Translate the physical address to a host address.
         *
         *  2)  Insert this virtual->physical->host translation into the
         *      fast translation arrays (using update_translation_table()).
         *
         *  3)  If this was a Write, then invalidate any code translations
         *      in that page.
         */
        memblock = memory_paddr_to_hostaddr(mem, paddr & ~offset_mask,
            writeflag);
        if (memblock == NULL) {
                if (writeflag == MEM_READ)
                        memset(data, 0, len);
                goto do_return_ok;
        }

        offset = paddr & offset_mask;

        if (cpu->update_translation_table != NULL && !dyntrans_device_danger
#ifdef MEM_MIPS
            /*  Ugly hack for R2000/R3000 caches:  */
            && (cpu->cd.mips.cpu_type.mmu_model != MMU3K ||
            !(cpu->cd.mips.coproc[0]->reg[COP0_STATUS] & MIPS1_ISOL_CACHES))
#endif
#ifndef MEM_USERLAND
            && !(ok & MEMORY_NOT_FULL_PAGE)
#endif
            && !no_exceptions)
                cpu->update_translation_table(cpu, vaddr & ~offset_mask,
                    memblock, (misc_flags & MEMORY_USER_ACCESS) |
#if !defined(MEM_USERLAND)
                    (cache == CACHE_INSTRUCTION?
                        (writeflag == MEM_WRITE? 1 : 0) : ok - 1),
#else
                    (writeflag == MEM_WRITE? 1 : 0),
#endif
                    paddr & ~offset_mask);

        /*
         *  If writing, or if mapping a page where writing is ok later on,
         *  then invalidate code translations for the (physical) page address:
         */

        if ((writeflag == MEM_WRITE
#if !defined(MEM_USERLAND)
            || (ok == 2 && cache == CACHE_DATA)
#endif
            ) && cpu->invalidate_code_translation != NULL)
                cpu->invalidate_code_translation(cpu, paddr, INVALIDATE_PADDR);

        if ((paddr&((1<<BITS_PER_MEMBLOCK)-1)) + len > (1<<BITS_PER_MEMBLOCK)) {
                printf("Write over memblock boundary?\n");
                exit(1);
        }

        /*  And finally, read or write the data:  */
        if (writeflag == MEM_WRITE)
                memcpy(memblock + offset, data, len);
        else
                memcpy(data, memblock + offset, len);

do_return_ok:
        return MEMORY_ACCESS_OK;
}

1	/*
2	* Copyright (C) 2003-2007 Anders Gavare. All rights reserved.
3	*
4	* Redistribution and use in source and binary forms, with or without
5	* modification, are permitted provided that the following conditions are met:
6	*
7	* 1. Redistributions of source code must retain the above copyright
8	* notice, this list of conditions and the following disclaimer.
9	* 2. Redistributions in binary form must reproduce the above copyright
10	* notice, this list of conditions and the following disclaimer in the
11	* documentation and/or other materials provided with the distribution.
12	* 3. The name of the author may not be used to endorse or promote products
13	* derived from this software without specific prior written permission.
14	*
15	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25	* SUCH DAMAGE.
26	*
27	*
28	* $Id: memory_rw.c,v 1.1 2007/06/19 02:11:46 debug Exp $
29	*
30	* Generic memory_rw(), with special hacks for specific CPU families.
31	*
32	* Example for inclusion from memory_mips.c:
33	*
34	* MEMORY_RW should be mips_memory_rw
35	* MEM_MIPS should be defined
36	*
37	*
38	* TODO: Cleanup the "ok" variable usage!
39	*/
40
41
42	/*
43	* memory_rw():
44	*
45	* Read or write data from/to memory.
46	*
47	* cpu the cpu doing the read/write
48	* mem the memory object to use
49	* vaddr the virtual address
50	* data a pointer to the data to be written to memory, or
51	* a placeholder for data when reading from memory
52	* len the length of the 'data' buffer
53	* writeflag set to MEM_READ or MEM_WRITE
54	* misc_flags CACHE_{NONE,DATA,INSTRUCTION} \| other flags
55	*
56	* If the address indicates access to a memory mapped device, that device'
57	* read/write access function is called.
58	*
59	* This function should not be called with cpu == NULL.
60	*
61	* Returns one of the following:
62	* MEMORY_ACCESS_FAILED
63	* MEMORY_ACCESS_OK
64	*
65	* (MEMORY_ACCESS_FAILED is 0.)
66	*/
67	int MEMORY_RW(struct cpu cpu, struct memory mem, uint64_t vaddr,
68	unsigned char *data, size_t len, int writeflag, int misc_flags)
69	{
70	#ifdef MEM_ALPHA
71	const int offset_mask = 0x1fff;
72	#else
73	const int offset_mask = 0xfff;
74	#endif
75
76	#ifndef MEM_USERLAND
77	int ok = 2;
78	#endif
79	uint64_t paddr;
80	int cache, no_exceptions, offset;
81	unsigned char *memblock;
82	int dyntrans_device_danger = 0;
83
84	no_exceptions = misc_flags & NO_EXCEPTIONS;
85	cache = misc_flags & CACHE_FLAGS_MASK;
86
87
88	#ifdef MEM_USERLAND
89	#ifdef MEM_ALPHA
90	paddr = vaddr;
91	#else
92	paddr = vaddr & 0x7fffffff;
93	#endif
94	#else /* !MEM_USERLAND */
95	if (misc_flags & PHYSICAL \|\| cpu->translate_v2p == NULL) {
96	paddr = vaddr;
97	} else {
98	ok = cpu->translate_v2p(cpu, vaddr, &paddr,
99	(writeflag? FLAG_WRITEFLAG : 0) +
100	(no_exceptions? FLAG_NOEXCEPTIONS : 0)
101	+ (misc_flags & MEMORY_USER_ACCESS)
102	+ (cache==CACHE_INSTRUCTION? FLAG_INSTR : 0));
103
104	/*
105	* If the translation caused an exception, or was invalid in
106	* some way, then simply return without doing the memory
107	* access:
108	*/
109	if (!ok)
110	return MEMORY_ACCESS_FAILED;
111	}
112
113	#endif /* !MEM_USERLAND */
114
115
116	#ifndef MEM_USERLAND
117	/*
118	* Memory mapped device?
119	*
120	* TODO: if paddr < base, but len enough, then the device should
121	* still be written to!
122	*/
123	if (paddr >= mem->mmap_dev_minaddr && paddr < mem->mmap_dev_maxaddr) {
124	uint64_t orig_paddr = paddr;
125	int i, start, end, res;
126
127	#if 0
128
129	TODO: The correct solution for this is to add RAM devices _around_ the
130	dangerous device. The solution below incurs a slowdown for _everything_,
131	not just the device in question.
132
133	/*
134	* Really really slow, but unfortunately necessary. This is
135	* to avoid the folowing scenario:
136	*
137	* a) offsets 0x000..0x123 are normal memory
138	* b) offsets 0x124..0x777 are a device
139	*
140	* 1) a read is done from offset 0x100. the page is
141	* added to the dyntrans system as a "RAM" page
142	* 2) a dyntranslated read is done from offset 0x200,
143	* which should access the device, but since the
144	* entire page is added, it will access non-existant
145	* RAM instead, without warning.
146	*
147	* Setting dyntrans_device_danger = 1 on accesses which are
148	* on _any_ offset on pages that are device mapped avoids
149	* this problem, but it is probably not very fast.
150	*
151	* TODO: Convert this into a quick (multi-level, 64-bit)
152	* address space lookup, to find dangerous pages.
153	*/
154	for (i=0; i<mem->n_mmapped_devices; i++)
155	if (paddr >= (mem->devices[i].baseaddr & ~offset_mask)&&
156	paddr <= ((mem->devices[i].endaddr-1)\|offset_mask)){
157	dyntrans_device_danger = 1;
158	break;
159	}
160	#endif
161
162	start = 0; end = mem->n_mmapped_devices - 1;
163	i = mem->last_accessed_device;
164
165	/* Scan through all devices: */
166	do {
167	if (paddr >= mem->devices[i].baseaddr &&
168	paddr < mem->devices[i].endaddr) {
169	/* Found a device, let's access it: */
170	mem->last_accessed_device = i;
171
172	paddr -= mem->devices[i].baseaddr;
173	if (paddr + len > mem->devices[i].length)
174	len = mem->devices[i].length - paddr;
175
176	if (cpu->update_translation_table != NULL &&
177	!(ok & MEMORY_NOT_FULL_PAGE) &&
178	mem->devices[i].flags & DM_DYNTRANS_OK) {
179	int wf = writeflag == MEM_WRITE? 1 : 0;
180	unsigned char *host_addr;
181
182	if (!(mem->devices[i].flags &
183	DM_DYNTRANS_WRITE_OK))
184	wf = 0;
185
186	if (writeflag && wf) {
187	if (paddr < mem->devices[i].
188	dyntrans_write_low)
189	mem->devices[i].
190	dyntrans_write_low =
191	paddr &~offset_mask;
192	if (paddr >= mem->devices[i].
193	dyntrans_write_high)
194	mem->devices[i].
195	dyntrans_write_high =
196	paddr \| offset_mask;
197	}
198
199	if (mem->devices[i].flags &
200	DM_EMULATED_RAM) {
201	/* MEM_WRITE to force the page
202	to be allocated, if it
203	wasn't already */
204	uint64_t pp = (uint64_t )mem->
205	devices[i].dyntrans_data;
206	uint64_t p = orig_paddr - *pp;
207	host_addr =
208	memory_paddr_to_hostaddr(
209	mem, p & ~offset_mask,
210	MEM_WRITE);
211	} else {
212	host_addr = mem->devices[i].
213	dyntrans_data +
214	(paddr & ~offset_mask);
215	}
216
217	cpu->update_translation_table(cpu,
218	vaddr & ~offset_mask, host_addr,
219	wf, orig_paddr & ~offset_mask);
220	}
221
222	res = 0;
223	if (!no_exceptions \|\| (mem->devices[i].flags &
224	DM_READS_HAVE_NO_SIDE_EFFECTS))
225	res = mem->devices[i].f(cpu, mem, paddr,
226	data, len, writeflag,
227	mem->devices[i].extra);
228
229	if (res == 0)
230	res = -1;
231
232	/*
233	* If accessing the memory mapped device
234	* failed, then return with a DBE exception.
235	*/
236	if (res <= 0 && !no_exceptions) {
237	debug("%s device '%s' addr %08lx "
238	"failed\n", writeflag?
239	"writing to" : "reading from",
240	mem->devices[i].name, (long)paddr);
241	#ifdef MEM_MIPS
242	mips_cpu_exception(cpu,
243	cache == CACHE_INSTRUCTION?
244	EXCEPTION_IBE : EXCEPTION_DBE,
245	0, vaddr, 0, 0, 0, 0);
246	#endif
247	return MEMORY_ACCESS_FAILED;
248	}
249	goto do_return_ok;
250	}
251
252	if (paddr < mem->devices[i].baseaddr)
253	end = i - 1;
254	if (paddr >= mem->devices[i].endaddr)
255	start = i + 1;
256	i = (start + end) >> 1;
257	} while (start <= end);
258	}
259
260
261	#ifdef MEM_MIPS
262	/*
263	* Data and instruction cache emulation:
264	*/
265
266	switch (cpu->cd.mips.cpu_type.mmu_model) {
267	case MMU3K:
268	/* if not uncached addess (TODO: generalize this) */
269	if (!(misc_flags & PHYSICAL) && cache != CACHE_NONE &&
270	!((vaddr & 0xffffffffULL) >= 0xa0000000ULL &&
271	(vaddr & 0xffffffffULL) <= 0xbfffffffULL)) {
272	if (memory_cache_R3000(cpu, cache, paddr,
273	writeflag, len, data))
274	goto do_return_ok;
275	}
276	break;
277	default:
278	/* R4000 etc */
279	/* TODO */
280	;
281	}
282	#endif /* MEM_MIPS */
283
284
285	/* Outside of physical RAM? */
286	if (paddr >= mem->physical_max) {
287	#ifdef MEM_MIPS
288	if ((paddr & 0xffffc00000ULL) == 0x1fc00000) {
289	/* Ok, this is PROM stuff */
290	} else if ((paddr & 0xfffff00000ULL) == 0x1ff00000) {
291	/* Sprite reads from this area of memory... */
292	/* TODO: is this still correct? */
293	if (writeflag == MEM_READ)
294	memset(data, 0, len);
295	goto do_return_ok;
296	} else
297	#endif /* MIPS */
298	{
299	if (paddr >= mem->physical_max && !no_exceptions)
300	memory_warn_about_unimplemented_addr
301	(cpu, mem, writeflag, paddr, data, len);
302
303	if (writeflag == MEM_READ) {
304	/* Return all zeroes? (Or 0xff? TODO) */
305	memset(data, 0, len);
306
307	#if 0
308	/*
309	* NOTE: This code prevents a PROM image from a real 5000/200 from booting.
310	* I think I introduced it because it was how some guest OS (NetBSD?) detected
311	* the amount of RAM on some machine.
312	*
313	* TODO: Figure out if it is not needed anymore, and remove it completely.
314	*/
315	#ifdef MEM_MIPS
316	/*
317	* For real data/instruction accesses, cause
318	* an exceptions on an illegal read:
319	*/
320	if (cache != CACHE_NONE && !no_exceptions &&
321	paddr >= mem->physical_max &&
322	paddr < mem->physical_max+1048576) {
323	mips_cpu_exception(cpu,
324	EXCEPTION_DBE, 0, vaddr, 0,
325	0, 0, 0);
326	}
327	#endif /* MEM_MIPS */
328	#endif
329	}
330
331	/* Hm? Shouldn't there be a DBE exception for
332	invalid writes as well? TODO */
333
334	goto do_return_ok;
335	}
336	}
337
338	#endif /* ifndef MEM_USERLAND */
339
340
341	/*
342	* Uncached access:
343	*
344	* 1) Translate the physical address to a host address.
345	*
346	* 2) Insert this virtual->physical->host translation into the
347	* fast translation arrays (using update_translation_table()).
348	*
349	* 3) If this was a Write, then invalidate any code translations
350	* in that page.
351	*/
352	memblock = memory_paddr_to_hostaddr(mem, paddr & ~offset_mask,
353	writeflag);
354	if (memblock == NULL) {
355	if (writeflag == MEM_READ)
356	memset(data, 0, len);
357	goto do_return_ok;
358	}
359
360	offset = paddr & offset_mask;
361
362	if (cpu->update_translation_table != NULL && !dyntrans_device_danger
363	#ifdef MEM_MIPS
364	/* Ugly hack for R2000/R3000 caches: */
365	&& (cpu->cd.mips.cpu_type.mmu_model != MMU3K \|\|
366	!(cpu->cd.mips.coproc[0]->reg[COP0_STATUS] & MIPS1_ISOL_CACHES))
367	#endif
368	#ifndef MEM_USERLAND
369	&& !(ok & MEMORY_NOT_FULL_PAGE)
370	#endif
371	&& !no_exceptions)
372	cpu->update_translation_table(cpu, vaddr & ~offset_mask,
373	memblock, (misc_flags & MEMORY_USER_ACCESS) \|
374	#if !defined(MEM_USERLAND)
375	(cache == CACHE_INSTRUCTION?
376	(writeflag == MEM_WRITE? 1 : 0) : ok - 1),
377	#else
378	(writeflag == MEM_WRITE? 1 : 0),
379	#endif
380	paddr & ~offset_mask);
381
382	/*
383	* If writing, or if mapping a page where writing is ok later on,
384	* then invalidate code translations for the (physical) page address:
385	*/
386
387	if ((writeflag == MEM_WRITE
388	#if !defined(MEM_USERLAND)
389	\|\| (ok == 2 && cache == CACHE_DATA)
390	#endif
391	) && cpu->invalidate_code_translation != NULL)
392	cpu->invalidate_code_translation(cpu, paddr, INVALIDATE_PADDR);
393
394	if ((paddr&((1<<BITS_PER_MEMBLOCK)-1)) + len > (1<<BITS_PER_MEMBLOCK)) {
395	printf("Write over memblock boundary?\n");
396	exit(1);
397	}
398
399	/* And finally, read or write the data: */
400	if (writeflag == MEM_WRITE)
401	memcpy(memblock + offset, data, len);
402	else
403	memcpy(data, memblock + offset, len);
404
405	do_return_ok:
406	return MEMORY_ACCESS_OK;
407	}
408