/[gxemul]/trunk/src/cpus/memory_sh.c
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
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Annotation of /trunk/src/cpus/memory_sh.c

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Revision 38 - (hide annotations)
Mon Oct 8 16:21:53 2007 UTC (16 years, 6 months ago) by dpavlin
File MIME type: text/plain
File size: 8353 byte(s)
++ trunk/HISTORY	(local)
$Id: HISTORY,v 1.1515 2007/04/14 05:39:46 debug Exp $
20070324	Adding a "--debug" option to the configure script, to disable
		optimizations in unstable development builds.
		Moving out SCSI-specific stuff from diskimage.c into a new
		diskimage_scsicmd.c.
		Applying Hĺvard Eidnes' patch for SCSICDROM_READ_DISKINFO and
		SCSICDROM_READ_TRACKINFO. (Not really tested yet.)
		Implementing disk image "overlays" (to allow simple roll-back
		to previous disk state). Adding a 'V' disk flag for this, and
		updating the man page and misc.html.
20070325	Stability fix to cpu_dyntrans.c, when multiple physical pages
		share the same initial table entry. (The ppp == NULL check
		should be physpage_ofs == 0.) Bug found by analysing GXemul
		against a version patched for Godson.
		Fixing a second occurance of the same problem (also in
		cpu_dyntrans.c).
		Fixing a MAJOR physical page leak in cpu_dyntrans.c; pages
		weren't _added_ to the set of translated pages, they _replaced_
		all previous pages. It's amazing that this bug has been able
		to live for this long. (Triggered when emulating >128MB RAM.)
20070326	Removing the GDB debugging stub support; it was too hackish
		and ugly.
20070328	Moving around some native code generation skeleton code.
20070329	The -lm check in the configure script now also checks for sin()
		in addition to sqrt(). (Thanks to Nigel Horne for noticing that
		sqrt was not enough on Fedora Core 6.) (Not verified yet.)
20070330	Fixing an indexing bug in dev_sh4.c, found by using gcc version
		4.3.0 20070323.
20070331	Some more experimentation with native code generation.
20070404	Attempting to fix some more SH4 SCIF interrupt bugs; rewriting
		the SH interrupt assertion/deassertion code somewhat.
20070410	Splitting src/file.c into separate files in src/file/.
		Cleanup: Removing the dummy TS7200, Walnut, PB1000, and
		Meshcube emulation modes, and dev_epcom and dev_au1x00.
		Removing the experimental CHIP8/RCA180x code; it wasn't really
		working much lately, anyway. It was fun while it lasted.
		Also removing the experimental Transputer CPU support.
20070412	Moving the section about how the dynamic translation system
		works from intro.html to a separate translation.html file.
		Minor SH fixes; attempting to get OpenBSD/landisk to run
		without randomly bugging out, but no success yet.
20070413	SH SCI (serial bit interface) should now work together with a
		(new) RS5C313 clock device (for Landisk emulation).
20070414	Moving Redhat/MIPS down from supported to experimental, in
		guestoses.html.
		Preparing for a new release; doing some regression testing etc.

==============  RELEASE 0.4.5  ==============


1 dpavlin 30 /*
2 dpavlin 34 * Copyright (C) 2006-2007 Anders Gavare. All rights reserved.
3 dpavlin 30 *
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 dpavlin 38 * $Id: memory_sh.c,v 1.18 2007/04/13 07:06:31 debug Exp $
29 dpavlin 30 */
30    
31     #include <stdio.h>
32     #include <stdlib.h>
33     #include <string.h>
34    
35     #include "cpu.h"
36     #include "machine.h"
37     #include "memory.h"
38     #include "misc.h"
39    
40 dpavlin 32 #include "sh4_exception.h"
41     #include "sh4_mmu.h"
42 dpavlin 30
43 dpavlin 32
44 dpavlin 30 /*
45 dpavlin 32 * translate_via_mmu():
46     *
47     * Scan the UTLB for a matching virtual address. If a match was found, then
48     * check permission bits etc. If everything was ok, then return the physical
49     * page address, otherwise cause an exception.
50     *
51     * The implementation should (hopefully) be quite complete, except for lack
52     * of "Multiple matching entries" detection. (On a real CPU, these would
53     * cause exceptions.)
54     *
55     * Same return values as sh_translate_v2p().
56 dpavlin 30 */
57 dpavlin 32 static int translate_via_mmu(struct cpu *cpu, uint32_t vaddr,
58 dpavlin 30 uint64_t *return_paddr, int flags)
59     {
60 dpavlin 32 int wf = flags & FLAG_WRITEFLAG;
61     int i, urb, urc, require_asid_match, cur_asid, expevt = 0;
62     uint32_t hi, lo = 0, mask = 0;
63     int sh; /* Shared */
64     int d; /* Dirty bit */
65     int v; /* Valid bit */
66     int pr; /* Protection */
67     int i_start;
68 dpavlin 30
69 dpavlin 32 cur_asid = cpu->cd.sh.pteh & SH4_PTEH_ASID_MASK;
70     require_asid_match = !(cpu->cd.sh.mmucr & SH4_MMUCR_SV)
71     || !(cpu->cd.sh.sr & SH_SR_MD);
72    
73     if (!(flags & FLAG_NOEXCEPTIONS)) {
74     /*
75     * Increase URC every time the UTLB is accessed. (Note:
76     * According to the SH4 manual, the URC should not be
77     * increased when running the ldtlb instruction. Perhaps this
78     * is a good place? Perhaps it is better to just set it to a
79     * random value? TODO: Find out.
80     */
81     urb = (cpu->cd.sh.mmucr & SH4_MMUCR_URB_MASK) >>
82     SH4_MMUCR_URB_SHIFT;
83     urc = (cpu->cd.sh.mmucr & SH4_MMUCR_URC_MASK) >>
84     SH4_MMUCR_URC_SHIFT;
85    
86     /* fatal("urc = %i ==> ", urc); */
87     urc ++;
88 dpavlin 36 if (urc >= SH_N_UTLB_ENTRIES || (urb > 0 && urc == urb))
89 dpavlin 32 urc = 0;
90     /* fatal("%i\n", urc); */
91    
92     cpu->cd.sh.mmucr &= ~SH4_MMUCR_URC_MASK;
93     cpu->cd.sh.mmucr |= (urc << SH4_MMUCR_URC_SHIFT);
94     }
95    
96     /*
97     * When doing Instruction lookups, the ITLB should be scanned first.
98     * This is done by using negative i. (Ugly hack, but works.)
99     */
100     if (flags & FLAG_INSTR)
101     i_start = -SH_N_ITLB_ENTRIES;
102     else
103     i_start = 0;
104    
105     for (i=i_start; i<SH_N_UTLB_ENTRIES; i++) {
106     if (i<0) {
107     hi = cpu->cd.sh.itlb_hi[i + SH_N_ITLB_ENTRIES];
108     lo = cpu->cd.sh.itlb_lo[i + SH_N_ITLB_ENTRIES];
109     } else {
110     hi = cpu->cd.sh.utlb_hi[i];
111     lo = cpu->cd.sh.utlb_lo[i];
112     }
113     mask = 0xfff00000;
114    
115     v = lo & SH4_PTEL_V;
116 dpavlin 38 if (!v)
117     continue;
118 dpavlin 32
119     switch (lo & SH4_PTEL_SZ_MASK) {
120     case SH4_PTEL_SZ_1K: mask = 0xfffffc00; break;
121     case SH4_PTEL_SZ_4K: mask = 0xfffff000; break;
122     case SH4_PTEL_SZ_64K: mask = 0xffff0000; break;
123     /* case SH4_PTEL_SZ_1M: mask = 0xfff00000; break; */
124     }
125    
126 dpavlin 38 if ((hi & mask) != (vaddr & mask))
127 dpavlin 32 continue;
128    
129     sh = lo & SH4_PTEL_SH;
130    
131     if (!sh && require_asid_match) {
132     int asid = hi & SH4_PTEH_ASID_MASK;
133     if (asid != cur_asid)
134     continue;
135     }
136    
137     /* Note/TODO: Check for multiple matches is not implemented. */
138    
139     break;
140     }
141    
142     /* Virtual address not found? Then it's a TLB miss. */
143     if (i == SH_N_UTLB_ENTRIES)
144     goto tlb_miss;
145    
146 dpavlin 36 /* Matching address found! Let's see whether it is
147     readable/writable, etc.: */
148     d = lo & SH4_PTEL_D? 1 : 0;
149 dpavlin 32 pr = (lo & SH4_PTEL_PR_MASK) >> SH4_PTEL_PR_SHIFT;
150    
151     *return_paddr = (vaddr & ~mask) | (lo & mask & 0x1fffffff);
152    
153     if (flags & FLAG_INSTR) {
154     /*
155     * Instruction access:
156     *
157     * If a matching entry wasn't found in the ITLB, but in the
158     * UTLB, then copy it to a random place in the ITLB.
159     */
160     if (i >= 0) {
161     int r = random() % SH_N_ITLB_ENTRIES;
162 dpavlin 34
163     /* NOTE: Make sure that the old mapping for
164     that itlb entry is invalidated: */
165     cpu->invalidate_translation_caches(cpu,
166     cpu->cd.sh.itlb_hi[r] & ~0xfff, INVALIDATE_VADDR);
167    
168     cpu->invalidate_code_translation(cpu,
169     cpu->cd.sh.utlb_lo[i] & ~0xfff, INVALIDATE_PADDR);
170    
171 dpavlin 32 cpu->cd.sh.itlb_hi[r] = cpu->cd.sh.utlb_hi[i];
172     cpu->cd.sh.itlb_lo[r] = cpu->cd.sh.utlb_lo[i];
173     }
174    
175     /* Permission checks: */
176     if (cpu->cd.sh.sr & SH_SR_MD)
177     return 1;
178     if (!(pr & 2))
179     goto protection_violation;
180    
181     return 1;
182     }
183    
184     /* Data access: */
185     if (cpu->cd.sh.sr & SH_SR_MD) {
186     /* Kernel access: */
187     switch (pr) {
188     case 0:
189     case 2: if (wf)
190     goto protection_violation;
191     return 1;
192     case 1:
193     case 3: if (wf && !d)
194     goto initial_write_exception;
195 dpavlin 36 return 1 + d;
196 dpavlin 32 }
197     }
198    
199     /* User access */
200     switch (pr) {
201     case 0:
202     case 1: goto protection_violation;
203     case 2: if (wf)
204     goto protection_violation;
205     return 1;
206     case 3: if (wf && !d)
207     goto initial_write_exception;
208 dpavlin 36 return 1 + d;
209 dpavlin 32 }
210    
211    
212     tlb_miss:
213     expevt = wf? EXPEVT_TLB_MISS_ST : EXPEVT_TLB_MISS_LD;
214     goto exception;
215    
216     protection_violation:
217     expevt = wf? EXPEVT_TLB_PROT_ST : EXPEVT_TLB_PROT_LD;
218     goto exception;
219    
220     initial_write_exception:
221     expevt = EXPEVT_TLB_MOD;
222    
223    
224     exception:
225     if (flags & FLAG_NOEXCEPTIONS) {
226     *return_paddr = 0;
227     return 2;
228     }
229    
230     sh_exception(cpu, expevt, 0, vaddr);
231    
232     return 0;
233 dpavlin 30 }
234    
235 dpavlin 32
236     /*
237     * sh_translate_v2p():
238     *
239     * Return values:
240     *
241     * 0 No access to the virtual address.
242     * 1 return_paddr contains the physical address, the page is
243     * available as read-only.
244     * 2 Same as 1, but the page is available as read/write.
245     */
246     int sh_translate_v2p(struct cpu *cpu, uint64_t vaddr, uint64_t *return_paddr,
247     int flags)
248     {
249     int user = cpu->cd.sh.sr & SH_SR_MD? 0 : 1;
250    
251     vaddr = (uint32_t)vaddr;
252    
253     /* U0/P0: Userspace addresses, or P3: Kernel virtual memory. */
254     if (!(vaddr & 0x80000000) ||
255     (vaddr >= 0xc0000000 && vaddr < 0xe0000000)) {
256     /* Address translation turned off? */
257     if (!(cpu->cd.sh.mmucr & SH4_MMUCR_AT)) {
258     /* Then return raw physical address: */
259     *return_paddr = vaddr & 0x1fffffff;
260     return 2;
261     }
262    
263     /* Perform translation via the MMU: */
264     return translate_via_mmu(cpu, vaddr, return_paddr, flags);
265     }
266    
267     /* Store queue region: */
268     if (vaddr >= 0xe0000000 && vaddr < 0xe4000000) {
269     /* Note/TODO: Take SH4_MMUCR_SQMD into account. */
270     *return_paddr = vaddr;
271     return 2;
272     }
273    
274     if (user) {
275     if (flags & FLAG_NOEXCEPTIONS) {
276     *return_paddr = 0;
277     return 2;
278     }
279    
280     fatal("Userspace tried to access non-user space memory."
281     " TODO: cause exception! (vaddr=0x%08"PRIx32"\n",
282     (uint32_t) vaddr);
283     exit(1);
284     }
285    
286     /* P1,P2: Direct-mapped physical memory. */
287     if (vaddr >= 0x80000000 && vaddr < 0xc0000000) {
288     *return_paddr = vaddr & 0x1fffffff;
289     return 2;
290     }
291    
292     if (flags & FLAG_INSTR) {
293     fatal("TODO: instr at 0x%08"PRIx32"\n", (uint32_t)vaddr);
294     exit(1);
295     }
296    
297     /* P4: Special registers mapped at 0xf0000000 .. 0xffffffff: */
298     if ((vaddr & 0xf0000000) == 0xf0000000) {
299     *return_paddr = vaddr;
300     return 2;
301     }
302    
303     if (flags & FLAG_NOEXCEPTIONS) {
304     *return_paddr = 0;
305     return 2;
306     }
307    
308     /* TODO */
309     fatal("Unimplemented SH vaddr 0x%08"PRIx32"\n", (uint32_t)vaddr);
310     exit(1);
311 dpavlin 38
312     return 0;
313 dpavlin 32 }
314    

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