3 Copyright © 1997-1998 by PowerLogix R & D, Inc.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 #include <asm/processor.h>
20 #include <asm/cputable.h>
21 #include <asm/ppc_asm.h>
22 #include <asm/cache.h>
27 When setting the L2CR register, you must do a few special
28 things. If you are enabling the cache, you must perform a
29 global invalidate. If you are disabling the cache, you must
30 flush the cache contents first. This routine takes care of
31 doing these things. When first enabling the cache, make sure
32 you pass in the L2CR you want, as well as passing in the
33 global invalidate bit set. A global invalidate will only be
34 performed if the L2I bit is set in applyThis. When enabling
35 the cache, you should also set the L2E bit in applyThis. If
36 you want to modify the L2CR contents after the cache has been
37 enabled, the recommended procedure is to first call
38 __setL2CR(0) to disable the cache and then call it again with
39 the new values for L2CR. Examples:
41 _setL2CR(0) - disables the cache
42 _setL2CR(0xB3A04000) - enables my G3 upgrade card:
43 - L2E set to turn on the cache
46 - L2RAM set to pipelined synchronous late-write
47 - L2I set to perform a global invalidation
49 - L2DF set because this upgrade card
52 A similar call should work for your card. You need to know
53 the correct setting for your card and then place them in the
54 fields I have outlined above. Other fields support optional
55 features, such as L2DO which caches only data, or L2TS which
56 causes cache pushes from the L1 cache to go to the L2 cache
57 instead of to main memory.
60 Starting with the 7450, the bits in this register have moved
61 or behave differently. The Enable, Parity Enable, Size,
62 and L2 Invalidate are the only bits that have not moved.
63 The size is read-only for these processors with internal L2
64 cache, and the invalidate is a control as well as status.
69 * Summary: this procedure ignores the L2I bit in the value passed in,
70 * flushes the cache if it was already enabled, always invalidates the
71 * cache, then enables the cache if the L2E bit is set in the value
76 /* Make sure this is a 750 or 7400 chip */
80 END_FTR_SECTION_IFCLR(CPU_FTR_L2CR)
84 /* Stop DST streams */
88 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
90 /* Turn off interrupts and data relocation. */
91 mfmsr r7 /* Save MSR in r7 */
93 rlwinm r4,r4,0,28,26 /* Turn off DR bit */
98 mfspr r8,SPRN_HID0 /* Save HID0 in r8 */
99 rlwinm r4,r8,0,12,10 /* Turn off HID0[DPM] */
101 mtspr SPRN_HID0,r4 /* Disable DPM */
104 /* Get the current enable bit of the L2CR into r4 */
107 /* Tweak some bits */
108 rlwinm r5,r3,0,0,0 /* r5 contains the new enable bit */
109 rlwinm r3,r3,0,11,9 /* Turn off the invalidate bit */
110 rlwinm r3,r3,0,1,31 /* Turn off the enable bit */
112 /* Check to see if we need to flush */
116 /* Flush the cache. First, read the first 4MB of memory (physical) to
117 * put new data in the cache. (Actually we only need
118 * the size of the L2 cache plus the size of the L1 cache, but 4MB will
119 * cover everything just to be safe).
122 /**** Might be a good idea to set L2DO here - to prevent instructions
123 from getting into the cache. But since we invalidate
124 the next time we enable the cache it doesn't really matter.
125 Don't do this unless you accomodate all processor variations.
126 The bit moved on the 7450.....
130 /* Disable L2 prefetch on some 745x and try to ensure
131 * L2 prefetch engines are idle. As explained by errata
132 * text, we can't be sure they are, we just hope very hard
133 * that well be enough (sic !). At least I noticed Apple
134 * doesn't even bother doing the dcbf's here...
147 END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
149 /* TODO: use HW flush assist when available */
156 addi r4,r4,32 /* Go to start of next cache line */
160 /* Now, flush the first 4MB of memory */
167 addi r4,r4,32 /* Go to start of next cache line */
171 /* Set up the L2CR configuration bits (and switch L2 off) */
172 /* CPU errata: Make sure the mtspr below is already in the
176 .balign L1_CACHE_BYTES
189 /* Perform a global invalidation */
194 isync /* For errata */
197 /* On the 7450, we wait for the L2I bit to clear......
199 10: mfspr r3,SPRN_L2CR
203 END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
205 /* Wait for the invalidation to complete */
206 3: mfspr r3,SPRN_L2CR
207 rlwinm. r4,r3,0,31,31
210 11: rlwinm r3,r3,0,11,9 /* Turn off the L2I bit */
215 /* See if we need to enable the cache */
219 /* Enable the cache */
224 /* Enable L2 HW prefetch on 744x/745x */
232 END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
235 /* Restore HID0[DPM] to whatever it was before */
240 /* Restore MSR (restores EE and DR bits to original state) */
249 /* Return the L2CR contents */
253 END_FTR_SECTION_IFSET(CPU_FTR_L2CR)
258 * Here is a similar routine for dealing with the L3 cache
259 * on the 745x family of chips
263 /* Make sure this is a 745x chip */
267 END_FTR_SECTION_IFCLR(CPU_FTR_L3CR)
269 /* Turn off interrupts and data relocation. */
270 mfmsr r7 /* Save MSR in r7 */
272 rlwinm r4,r4,0,28,26 /* Turn off DR bit */
277 /* Stop DST streams */
281 /* Get the current enable bit of the L3CR into r4 */
284 /* Tweak some bits */
285 rlwinm r5,r3,0,0,0 /* r5 contains the new enable bit */
286 rlwinm r3,r3,0,22,20 /* Turn off the invalidate bit */
287 rlwinm r3,r3,0,2,31 /* Turn off the enable & PE bits */
288 rlwinm r3,r3,0,5,3 /* Turn off the clken bit */
289 /* Check to see if we need to flush */
296 /* TODO: use HW flush assist */
304 addi r4,r4,32 /* Go to start of next cache line */
308 /* Set up the L3CR configuration bits (and switch L3 off) */
313 oris r3,r3,L3CR_L3RES@h /* Set reserved bit 5 */
316 oris r3,r3,L3CR_L3CLKEN@h /* Set clken */
320 /* Wait for stabilize */
325 /* Perform a global invalidation */
332 /* We wait for the L3I bit to clear...... */
333 10: mfspr r3,SPRN_L3CR
338 rlwinm r3,r3,0,5,3 /* Turn off the clken bit */
342 /* Wait for stabilize */
347 /* See if we need to enable the cache */
351 /* Enable the cache */
352 oris r3,r3,(L3CR_L3E | L3CR_L3CLKEN)@h
356 /* Wait for stabilize */
361 /* Restore MSR (restores EE and DR bits to original state) */
368 /* Return the L3CR contents */
372 END_FTR_SECTION_IFSET(CPU_FTR_L3CR)
375 /* --- End of PowerLogix code ---
379 /* flush_disable_L1() - Flush and disable L1 cache
381 * clobbers r0, r3, ctr, cr0
382 * Must be called with interrupts disabled and MMU enabled.
384 _GLOBAL(__flush_disable_L1)
385 /* Stop pending alitvec streams and memory accesses */
388 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
391 /* Load counter to 0x4000 cache lines (512k) and
392 * load cache with datas
394 li r3,0x4000 /* 512kB / 32B */
399 addi r3,r3,0x0020 /* Go to start of next cache line */
404 /* Now flush those cache lines */
405 li r3,0x4000 /* 512kB / 32B */
410 addi r3,r3,0x0020 /* Go to start of next cache line */
414 /* We can now disable the L1 cache (HID0:DCE, HID0:ICE) */
422 /* inval_enable_L1 - Invalidate and enable L1 cache
424 * Assumes L1 is already disabled and MSR:EE is off
428 _GLOBAL(__inval_enable_L1)
429 /* Enable and then Flash inval the instruction & data cache */
431 ori r3,r3, HID0_ICE|HID0_ICFI|HID0_DCE|HID0_DCI
435 xori r3,r3, HID0_ICFI|HID0_DCI