/[gxemul]/trunk/src/cpus/memory_mips_v2p.c
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Annotation of /trunk/src/cpus/memory_mips_v2p.c

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Revision 42 - (hide annotations)
Mon Oct 8 16:22:32 2007 UTC (16 years, 6 months ago) by dpavlin
File MIME type: text/plain
File size: 13917 byte(s)
++ trunk/HISTORY	(local)
$Id: HISTORY,v 1.1613 2007/06/15 20:11:26 debug Exp $
20070501	Continuing a little on m88k disassembly (control registers,
		more instructions).
		Adding a dummy mvme88k machine mode.
20070502	Re-adding MIPS load/store alignment exceptions.
20070503	Implementing more of the M88K disassembly code.
20070504	Adding disassembly of some more M88K load/store instructions.
		Implementing some relatively simple M88K instructions (br.n,
		xor[.u] imm, and[.u] imm).
20070505	Implementing M88K three-register and, or, xor, and jmp[.n],
		bsr[.n] including function call trace stuff.
		Applying a patch from Bruce M. Simpson which implements the
		SYSCON_BOARD_CPU_CLOCK_FREQ_ID object of the syscon call in
		the yamon PROM emulation.
20070506	Implementing M88K bb0[.n] and bb1[.n], and skeletons for
		ldcr and stcr (although no control regs are implemented yet).
20070509	Found and fixed the bug which caused Linux for QEMU_MIPS to
		stop working in 0.4.5.1: It was a faulty change to the MIPS
		'sc' and 'scd' instructions I made while going through gcc -W
		warnings on 20070428.
20070510	Updating the Linux/QEMU_MIPS section in guestoses.html to
		use mips-test-0.2.tar.gz instead of 0.1.
		A big thank you to Miod Vallat for sending me M88K manuals.
		Implementing more M88K instructions (addu, subu, div[u], mulu,
		ext[u], clr, set, cmp).
20070511	Fixing bugs in the M88K "and" and "and.u" instructions (found
		by comparing against the manual).
		Implementing more M88K instructions (mask[.u], mak, bcnd (auto-
		generated)) and some more control register details.
		Cleanup: Removing the experimental AVR emulation mode and
		corresponding devices; AVR emulation wasn't really meaningful.
		Implementing autogeneration of most M88K loads/stores. The
		rectangle drawing demo (with -O0) for M88K runs :-)
		Beginning on M88K exception handling.
		More M88K instructions: tb0, tb1, rte, sub, jsr[.n].
		Adding some skeleton MVME PROM ("BUG") emulation.
20070512	Fixing a bug in the M88K cmp instruction.
		Adding the M88K lda (scaled register) instruction.
		Fixing bugs in 64-bit (32-bit pairs) M88K loads/stores.
		Removing the unused tick_hz stuff from the machine struct.
		Implementing the M88K xmem instruction. OpenBSD/mvme88k gets
		far enough to display the Copyright banner :-)
		Implementing subu.co (guess), addu.co, addu.ci, ff0, and ff1.
		Adding a dev_mvme187, for MVME187-specific devices/registers.
		OpenBSD/mvme88k prints more boot messages. :)
20070515	Continuing on MVME187 emulation (adding more devices, beginning
		on the CMMUs, etc).
		Adding the M88K and.c, xor.c, and or.c instructions, and making
		sure that mul, div, etc cause exceptions if executed when SFD1
		is disabled.
20070517	Continuing on M88K and MVME187 emulation in general; moving
		the CMMU registers to the CPU struct, separating dev_pcc2 from
		dev_mvme187, and beginning on memory_m88k.c (BATC and PATC).
		Fixing a bug in 64-bit (32-bit pairs) M88K fast stores.
		Implementing the clock part of dev_mk48txx.
		Implementing the M88K fstcr and xcr instructions.
		Implementing m88k_cpu_tlbdump().
		Beginning on the implementation of a separate address space
		for M88K .usr loads/stores.
20070520	Removing the non-working (skeleton) Sandpoint, SonyNEWS, SHARK
		Dnard, and Zaurus machine modes.
		Experimenting with dyntrans to_be_translated read-ahead. It
		seems to give a very small performance increase for MIPS
		emulation, but a large performance degradation for SuperH. Hm.
20070522	Disabling correct SuperH ITLB emulation; it does not seem to be
		necessary in order to let SH4 guest OSes run, and it slows down
		userspace code.
		Implementing "samepage" branches for SuperH emulation, and some
		other minor speed hacks.
20070525	Continuing on M88K memory-related stuff: exceptions, memory
		transaction register contents, etc.
		Implementing the M88K subu.ci instruction.
		Removing the non-working (skeleton) Iyonix machine mode.
		OpenBSD/mvme88k reaches userland :-), starts executing
		/sbin/init's instructions, and issues a few syscalls, before
		crashing.
20070526	Fixing bugs in dev_mk48txx, so that OpenBSD/mvme88k detects
		the correct time-of-day.
		Implementing a generic IRQ controller for the test machines
		(dev_irqc), similar to a proposed patch from Petr Stepan.
		Experimenting some more with translation read-ahead.
		Adding an "expect" script for automated OpenBSD/landisk
		install regression/performance tests.
20070527	Adding a dummy mmEye (SH3) machine mode skeleton.
		FINALLY found the strange M88K bug I have been hunting: I had
		not emulated the SNIP value for exceptions occurring in
		branch delay slots correctly.
		Implementing correct exceptions for 64-bit M88K loads/stores.
		Address to symbol lookups are now disabled when M88K is
		running in usermode (because usermode addresses don't have
		anything to do with supervisor addresses).
20070531	Removing the mmEye machine mode skeleton.
20070604	Some minor code cleanup.
20070605	Moving src/useremul.c into a subdir (src/useremul/), and
		cleaning up some more legacy constructs.
		Adding -Wstrict-aliasing and -fstrict-aliasing detection to
		the configure script.
20070606	Adding a check for broken GCC on Solaris to the configure
		script. (GCC 3.4.3 on Solaris cannot handle static variables
		which are initialized to 0 or NULL. :-/)
		Removing the old (non-working) ARC emulation modes: NEC RD94,
		R94, R96, and R98, and the last traces of Olivetti M700 and
		Deskstation Tyne.
		Removing the non-working skeleton WDSC device (dev_wdsc).
20070607	Thinking about how to use the host's cc + ld at runtime to
		generate native code. (See experiments/native_cc_ld_test.i
		for an example.)
20070608	Adding a program counter sampling timer, which could be useful
		for native code generation experiments.
		The KN02_CSR_NRMMOD bit in the DECstation 5000/200 (KN02) CSR
		should always be set, to allow a 5000/200 PROM to boot.
20070609	Moving out breakpoint details from the machine struct into
		a helper struct, and removing the limit on max nr of
		breakpoints.
20070610	Moving out tick functions into a helper struct as well (which
		also gets rid of the max limit).
20070612	FINALLY figured out why Debian/DECstation stopped working when
		translation read-ahead was enabled: in src/memory_rw.c, the
		call to invalidate_code_translation was made also if the
		memory access was an instruction load (if the page was mapped
		as writable); it shouldn't be called in that case.
20070613	Implementing some more MIPS32/64 revision 2 instructions: di,
		ei, ext, dext, dextm, dextu, and ins.
20070614	Implementing an instruction combination for the NetBSD/arm
		idle loop (making the host not use any cpu if NetBSD/arm
		inside the emulator is not using any cpu).
		Increasing the nr of ARM VPH entries from 128 to 384.
20070615	Removing the ENABLE_arch stuff from the configure script, so
		that all included architectures are included in both release
		and development builds.
		Moving memory related helper functions from misc.c to memory.c.
		Adding preliminary instructions for netbooting NetBSD/pmppc to
		guestoses.html; it doesn't work yet, there are weird timeouts.
		Beginning a total rewrite of the userland emulation modes
		(removing all emulation modes, beginning from scratch with
		NetBSD/MIPS and FreeBSD/Alpha only).
20070616	After fixing a bug in the DEC21143 NIC (the TDSTAT_OWN bit was
		only cleared for the last segment when transmitting, not all
		segments), NetBSD/pmppc boots with root-on-nfs without the
		timeouts. Updating guestoses.html.
		Removing the skeleton PSP (Playstation Portable) mode.
		Moving X11-related stuff in the machine struct into a helper
		struct.
		Cleanup of out-of-memory checks, to use a new CHECK_ALLOCATION
		macro (which prints a meaningful error message).
		Adding a COMMENT to each machine and device (for automagic
		.index comment generation).
		Doing regression testing for the next release.

==============  RELEASE 0.4.6  ==============


1 dpavlin 14 /*
2 dpavlin 34 * Copyright (C) 2003-2007 Anders Gavare. All rights reserved.
3 dpavlin 14 *
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 42 * $Id: memory_mips_v2p.c,v 1.17 2007/05/22 13:05:43 debug Exp $
29 dpavlin 14 */
30    
31    
32     /*
33 dpavlin 26 * translate_v2p():
34 dpavlin 14 *
35 dpavlin 32 * Translate a virtual MIPS address to a physical address, by looking up the
36     * address in the TLB. On failure, an exception is generated (except for the
37     * case when FLAG_NOEXCEPTIONS is used).
38 dpavlin 14 *
39 dpavlin 32 * Note: This function is long and hairy, it is included several times with
40     * various defines set, to produce more or less optimized versions of
41     * the function for different emulated CPU types.
42 dpavlin 14 *
43 dpavlin 32 * V2P_MMU3K Defined for R2000/R3000 emulation. If it is not defined,
44     * R4000+/MIPS32/MIPS64 is presumed.
45     * V2P_MMU10K This enables the use of 44 userspace bits, instead of 40.
46     * V2P_MMU4100 VR41xx processors support 1 KB pages, so their page mask
47     * is slightly different. (The emulator only supports 4 KB
48     * pages, though.)
49     * V2P_MMU8K Not yet. (TODO.)
50     *
51     *
52     * Note: Unfortunately, the variable name vpn2 is poorly choosen for R2K/R3K,
53     * since it actual contains the vpn.
54     *
55 dpavlin 14 * Return values:
56     * 0 Failure
57     * 1 Success, the page is readable only
58     * 2 Success, the page is read/write
59     */
60     int TRANSLATE_ADDRESS(struct cpu *cpu, uint64_t vaddr,
61 dpavlin 26 uint64_t *return_paddr, int flags)
62 dpavlin 14 {
63     int writeflag = flags & FLAG_WRITEFLAG? MEM_WRITE : MEM_READ;
64     int no_exceptions = flags & FLAG_NOEXCEPTIONS;
65     int ksu, use_tlb, status, i;
66     uint64_t vaddr_vpn2=0, vaddr_asid=0;
67     int exccode, tlb_refill;
68     struct mips_coproc *cp0;
69    
70     #ifdef V2P_MMU3K
71     const int x_64 = 0;
72     const int n_tlbs = 64;
73 dpavlin 42 const uint32_t pmask = 0xfff;
74 dpavlin 32 uint64_t xuseg_top; /* Well, useg actually. */
75 dpavlin 14 #else
76     #ifdef V2P_MMU10K
77 dpavlin 32 const uint64_t vpn2_mask = ENTRYHI_R_MASK | ENTRYHI_VPN2_MASK_R10K;
78     uint64_t xuseg_top = ENTRYHI_VPN2_MASK_R10K | 0x1fffULL;
79 dpavlin 14 #else
80     #ifdef V2P_MMU4100
81 dpavlin 32 const uint64_t vpn2_mask = ENTRYHI_R_MASK | ENTRYHI_VPN2_MASK | 0x1800;
82 dpavlin 14 #else
83 dpavlin 32 const uint64_t vpn2_mask = ENTRYHI_R_MASK | ENTRYHI_VPN2_MASK;
84 dpavlin 14 #endif
85 dpavlin 32 uint64_t xuseg_top = ENTRYHI_VPN2_MASK | 0x1fffULL;
86 dpavlin 14 #endif
87     int x_64; /* non-zero for 64-bit address space accesses */
88     int pageshift, n_tlbs;
89 dpavlin 42 uint32_t pmask;
90 dpavlin 14 #ifdef V2P_MMU4100
91     const int pagemask_mask = PAGEMASK_MASK_R4100;
92     const int pagemask_shift = PAGEMASK_SHIFT_R4100;
93     const int pfn_shift = 10;
94     #else
95     const int pagemask_mask = PAGEMASK_MASK;
96     const int pagemask_shift = PAGEMASK_SHIFT;
97     const int pfn_shift = 12;
98     #endif
99     #endif /* !V2P_MMU3K */
100    
101    
102     exccode = -1;
103     tlb_refill = 1;
104    
105     /* Cached values: */
106     cp0 = cpu->cd.mips.coproc[0];
107     status = cp0->reg[COP0_STATUS];
108    
109     /*
110 dpavlin 32 * MIPS R4000+ and MIPS64 Address Translation:
111 dpavlin 14 *
112 dpavlin 32 * An address may be in one of the kernel segments, that are directly
113     * mapped to physical addresses, or the address needs to be looked up
114     * in the TLB entries.
115 dpavlin 14 *
116     * KSU: EXL: ERL: X: Name: Range:
117     * ---- ---- ---- -- ----- ------
118     *
119     * 10 0 0 0 useg 0 - 0x7fffffff (2GB) (via TLB)
120     * 10 0 0 1 xuseg 0 - 0xffffffffff (1TB) (via TLB)
121     *
122     * 01 0 0 0 suseg 0 - 0x7fffffff (2GB via TLB)
123     * 01 0 0 0 ssseg 0xc0000000 - 0xdfffffff (0.5 GB via TLB)
124     * 01 0 0 1 xsuseg 0 - 0xffffffffff (1TB) (via TLB)
125     * 01 0 0 1 xsseg 0x4000000000000000 - 0x400000ffffffffff
126     * (1TB) (via TLB)
127     * 01 0 0 1 csseg 0xffffffffc0000000 - 0xffffffffdfffffff
128     * (0.5TB) (via TLB)
129     *
130     * 00 x x 0 kuseg 0 - 0x7fffffff (2GB) (via TLB) (*)
131     * 00 x x 0 kseg0 0x80000000 - 0x9fffffff (0.5GB)
132     * unmapped, cached
133     * 00 x x 0 kseg1 0xa0000000 - 0xbfffffff (0.5GB)
134     * unmapped, uncached
135 dpavlin 32 * 00 x x 0 ksseg 0xc0000000 - 0xdfffffff (0.5GB) (via TLB)
136     * 00 x x 0 kseg3 0xe0000000 - 0xffffffff (0.5GB) (via TLB)
137 dpavlin 14 * 00 x x 1 xksuseg 0 - 0xffffffffff (1TB) (via TLB) (*)
138     * 00 x x 1 xksseg 0x4000000000000000 - 0x400000ffffffffff
139     * (1TB) (via TLB)
140     * 00 x x 1 xkphys 0x8000000000000000 - 0xbfffffffffffffff
141     * 00 x x 1 xkseg 0xc000000000000000 - 0xc00000ff7fffffff
142     * 00 x x 1 ckseg0 0xffffffff80000000 - 0xffffffff9fffffff
143     * 00 x x 1 ckseg1 0xffffffffa0000000 - 0xffffffffbfffffff
144     * 00 x x 1 cksseg 0xffffffffc0000000 - 0xffffffffdfffffff
145     * 00 x x 1 ckseg3 0xffffffffe0000000 - 0xffffffffffffffff
146 dpavlin 32 * like 0x80000000 - 0xffffffff
147 dpavlin 14 *
148     * (*) = if ERL=1 then kuseg is not via TLB, but unmapped,
149     * uncached physical memory.
150     *
151     * (KSU==0 or EXL=1 or ERL=1 is enough to use k*seg*.)
152     *
153     * An invalid address causes an Address Error.
154     *
155     * See chapter 4, page 96, in the R4000 manual for more info!
156     */
157    
158     #ifdef V2P_MMU3K
159     if (status & MIPS1_SR_KU_CUR)
160     ksu = KSU_USER;
161     else
162     ksu = KSU_KERNEL;
163    
164     /* These are needed later: */
165     vaddr_asid = cp0->reg[COP0_ENTRYHI] & R2K3K_ENTRYHI_ASID_MASK;
166     vaddr_vpn2 = vaddr & R2K3K_ENTRYHI_VPN_MASK;
167     #else
168 dpavlin 32 /* kx,sx,ux = 0 for 32-bit addressing, 1 for 64-bit addressing. */
169 dpavlin 14 ksu = (status & STATUS_KSU_MASK) >> STATUS_KSU_SHIFT;
170     if (status & (STATUS_EXL | STATUS_ERL))
171     ksu = KSU_KERNEL;
172    
173 dpavlin 32 switch (ksu) {
174     case KSU_USER:
175     x_64 = status & STATUS_UX;
176     break;
177     case KSU_KERNEL:
178 dpavlin 14 x_64 = status & STATUS_KX;
179 dpavlin 32 break;
180     case KSU_SUPERVISOR:
181 dpavlin 14 x_64 = status & STATUS_SX;
182 dpavlin 32 /* FALLTHROUGH, since supervisor address spaces are not
183     really implemented yet. */
184     default:fatal("memory_mips_v2p.c: ksu=%i not yet implemented yet\n",
185     ksu);
186     exit(1);
187     }
188 dpavlin 14
189 dpavlin 32 n_tlbs = cpu->cd.mips.cpu_type.nr_of_tlb_entries;
190    
191     /* Having this here suppresses a compiler warning: */
192 dpavlin 14 pageshift = 12;
193    
194 dpavlin 32 /* KUSEG: 0x00000000 - 0x7fffffff if ERL = 1 and KSU = kernel: */
195     if (ksu == KSU_KERNEL && (status & STATUS_ERL) &&
196     vaddr <= 0x7fffffff) {
197     *return_paddr = vaddr & 0x7fffffff;
198     return 2;
199     }
200    
201 dpavlin 14 /*
202 dpavlin 32 * XKPHYS: 0x8000000000000000 - 0xbfffffffffffffff
203 dpavlin 14 *
204 dpavlin 32 * TODO: Is the correct error generated if accessing XKPHYS from
205     * usermode?
206 dpavlin 14 *
207 dpavlin 32 * TODO: Magic on SGI machines... Cache control, NUMA, etc.:
208     * 0x9000000080000000 = disable L2 cache (?)
209     * 0x90000000a0000000 = something on IP30?
210     * 0x92.... and 0x96... = NUMA on IP27
211 dpavlin 14 */
212 dpavlin 32 if (ksu == KSU_KERNEL && (vaddr & ENTRYHI_R_MASK) == ENTRYHI_R_XKPHYS) {
213 dpavlin 26 *return_paddr = vaddr & (((uint64_t)1 << 44) - 1);
214 dpavlin 14 return 2;
215     }
216    
217     /* This is needed later: */
218     vaddr_asid = cp0->reg[COP0_ENTRYHI] & ENTRYHI_ASID;
219     /* vpn2 depends on pagemask, which is not fixed on R4000 */
220     #endif
221    
222 dpavlin 32 /* If 32-bit, truncate address and sign extend: */
223     if (x_64 == 0) {
224     vaddr = (int32_t) vaddr;
225     xuseg_top = 0x7fffffff;
226     /* (Actually useg for R2000/R3000) */
227     }
228 dpavlin 14
229 dpavlin 32 if (vaddr <= xuseg_top) {
230 dpavlin 14 use_tlb = 1;
231 dpavlin 32 } else {
232 dpavlin 14 if (ksu == KSU_KERNEL) {
233     /* kseg0, kseg1: */
234     if (vaddr >= (uint64_t)0xffffffff80000000ULL &&
235     vaddr <= (uint64_t)0xffffffffbfffffffULL) {
236 dpavlin 26 *return_paddr = vaddr & 0x1fffffff;
237 dpavlin 14 return 2;
238     }
239    
240     /* other segments: */
241     use_tlb = 1;
242 dpavlin 32 } else {
243 dpavlin 14 use_tlb = 0;
244 dpavlin 32 }
245 dpavlin 14 }
246    
247     if (use_tlb) {
248     #ifndef V2P_MMU3K
249 dpavlin 22 int odd = 0;
250     uint64_t cached_lo1 = 0;
251 dpavlin 14 #endif
252     int g_bit, v_bit, d_bit;
253     uint64_t cached_hi, cached_lo0;
254     uint64_t entry_vpn2 = 0, entry_asid, pfn;
255 dpavlin 32 int i_end;
256 dpavlin 14
257 dpavlin 32 i = cpu->cd.mips.last_written_tlb_index;
258     i_end = i == 0? n_tlbs-1 : i - 1;
259    
260     /* Scan all TLB entries: */
261     for (;;) {
262 dpavlin 14 #ifdef V2P_MMU3K
263     /* R3000 or similar: */
264     cached_hi = cp0->tlbs[i].hi;
265     cached_lo0 = cp0->tlbs[i].lo0;
266    
267     entry_vpn2 = cached_hi & R2K3K_ENTRYHI_VPN_MASK;
268     entry_asid = cached_hi & R2K3K_ENTRYHI_ASID_MASK;
269     g_bit = cached_lo0 & R2K3K_ENTRYLO_G;
270     v_bit = cached_lo0 & R2K3K_ENTRYLO_V;
271     d_bit = cached_lo0 & R2K3K_ENTRYLO_D;
272     #else
273     /* R4000 or similar: */
274     pmask = cp0->tlbs[i].mask & pagemask_mask;
275     cached_hi = cp0->tlbs[i].hi;
276     cached_lo0 = cp0->tlbs[i].lo0;
277     cached_lo1 = cp0->tlbs[i].lo1;
278    
279     /* Optimized for minimum page size: */
280     if (pmask == 0) {
281     pageshift = pagemask_shift - 1;
282     entry_vpn2 = (cached_hi & vpn2_mask)
283     >> pagemask_shift;
284     vaddr_vpn2 = (vaddr & vpn2_mask)
285     >> pagemask_shift;
286     pmask = (1 << (pagemask_shift-1)) - 1;
287     odd = (vaddr >> (pagemask_shift-1)) & 1;
288     } else {
289     /* Non-standard page mask: */
290     switch (pmask | ((1 << pagemask_shift) - 1)) {
291     case 0x00007ff: pageshift = 10; break;
292     case 0x0001fff: pageshift = 12; break;
293     case 0x0007fff: pageshift = 14; break;
294     case 0x001ffff: pageshift = 16; break;
295     case 0x007ffff: pageshift = 18; break;
296     case 0x01fffff: pageshift = 20; break;
297     case 0x07fffff: pageshift = 22; break;
298     case 0x1ffffff: pageshift = 24; break;
299     case 0x7ffffff: pageshift = 26; break;
300 dpavlin 42 default:fatal("pmask=%08"PRIx32"\n", pmask);
301 dpavlin 14 exit(1);
302     }
303    
304     entry_vpn2 = (cached_hi &
305     vpn2_mask) >> (pageshift + 1);
306     vaddr_vpn2 = (vaddr & vpn2_mask) >>
307     (pageshift + 1);
308     pmask = (1 << pageshift) - 1;
309     odd = (vaddr >> pageshift) & 1;
310     }
311    
312     /* Assume even virtual page... */
313     v_bit = cached_lo0 & ENTRYLO_V;
314     d_bit = cached_lo0 & ENTRYLO_D;
315    
316     #ifdef V2P_MMU8K
317     /*
318     * TODO: I don't really know anything about the R8000.
319     * http://futuretech.mirror.vuurwerk.net/i2sec7.html
320     * says that it has a three-way associative TLB with
321     * 384 entries, 16KB page size, and some other things.
322     *
323     * It feels like things like the valid bit (ala R4000)
324     * and dirty bit are not implemented the same on R8000.
325     *
326     * http://sgistuff.tastensuppe.de/documents/
327     * R8000_chipset.html
328     * also has some info, but no details.
329     */
330     v_bit = 1; /* Big TODO */
331     d_bit = 1;
332     #endif
333    
334     entry_asid = cached_hi & ENTRYHI_ASID;
335    
336     /* ... reload pfn, v_bit, d_bit if
337     it was the odd virtual page: */
338     if (odd) {
339     v_bit = cached_lo1 & ENTRYLO_V;
340     d_bit = cached_lo1 & ENTRYLO_D;
341     }
342     #ifdef V2P_MMU4100
343     g_bit = cached_lo1 & cached_lo0 & ENTRYLO_G;
344     #else
345     g_bit = cached_hi & TLB_G;
346     #endif
347    
348     #endif
349    
350     /* Is there a VPN and ASID match? */
351     if (entry_vpn2 == vaddr_vpn2 &&
352     (entry_asid == vaddr_asid || g_bit)) {
353 dpavlin 24 /* debug("OK MAP 1, i=%i { vaddr=%016"PRIx64" "
354     "==> paddr %016"PRIx64" v=%i d=%i "
355     "asid=0x%02x }\n", i, (uint64_t) vaddr,
356 dpavlin 26 (uint64_t) *return_paddr, v_bit?1:0,
357 dpavlin 14 d_bit?1:0, vaddr_asid); */
358     if (v_bit) {
359     if (d_bit || (!d_bit &&
360     writeflag == MEM_READ)) {
361     uint64_t paddr;
362     /* debug("OK MAP 2!!! { w=%i "
363 dpavlin 24 "vaddr=%016"PRIx64" ==> "
364     "d=%i v=%i paddr %016"
365     PRIx64" ",
366     writeflag, (uint64_t)vaddr,
367 dpavlin 14 d_bit?1:0, v_bit?1:0,
368 dpavlin 26 (uint64_t) *return_paddr);
369 dpavlin 14 debug(", tlb entry %2i: ma"
370 dpavlin 24 "sk=%016"PRIx64" hi=%016"
371     PRIx64" lo0=%016"PRIx64
372     " lo1=%016"PRIx64"\n",
373 dpavlin 14 i, cp0->tlbs[i].mask, cp0->
374     tlbs[i].hi, cp0->tlbs[i].
375     lo0, cp0->tlbs[i].lo1);
376     */
377     #ifdef V2P_MMU3K
378     pfn = cached_lo0 &
379     R2K3K_ENTRYLO_PFN_MASK;
380     paddr = pfn | (vaddr & pmask);
381     #else
382     pfn = ((odd? cached_lo1 :
383     cached_lo0)
384     & ENTRYLO_PFN_MASK)
385     >> ENTRYLO_PFN_SHIFT;
386 dpavlin 40 paddr = ((pfn << pfn_shift) &
387     ~pmask) | (vaddr & pmask);
388 dpavlin 14 #endif
389    
390 dpavlin 26 *return_paddr = paddr;
391 dpavlin 14 return d_bit? 2 : 1;
392     } else {
393     /* TLB modif. exception */
394     tlb_refill = 0;
395     exccode = EXCEPTION_MOD;
396     goto exception;
397     }
398     } else {
399     /* TLB invalid exception */
400     tlb_refill = 0;
401     goto exception;
402     }
403     }
404 dpavlin 32
405     if (i == i_end)
406     break;
407    
408     /* Go to the next TLB entry: */
409     i ++;
410     if (i == n_tlbs)
411     i = 0;
412 dpavlin 14 }
413     }
414    
415     /*
416     * We are here if for example userland code tried to access
417     * kernel memory, OR if there was a TLB refill.
418     */
419    
420     if (!use_tlb) {
421     tlb_refill = 0;
422     if (writeflag == MEM_WRITE)
423     exccode = EXCEPTION_ADES;
424     else
425     exccode = EXCEPTION_ADEL;
426     }
427    
428     exception:
429     if (no_exceptions)
430     return 0;
431    
432     /* TLB Load or Store exception: */
433     if (exccode == -1) {
434     if (writeflag == MEM_WRITE)
435     exccode = EXCEPTION_TLBS;
436     else
437     exccode = EXCEPTION_TLBL;
438     }
439    
440     #ifdef V2P_MMU3K
441     vaddr_asid >>= R2K3K_ENTRYHI_ASID_SHIFT;
442     vaddr_vpn2 >>= 12;
443     #endif
444    
445     mips_cpu_exception(cpu, exccode, tlb_refill, vaddr,
446     0, vaddr_vpn2, vaddr_asid, x_64);
447    
448     /* Return failure: */
449     return 0;
450     }
451    

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