2 * This file contains low-level cache management functions
3 * used for sleep and CPU speed changes on Apple machines.
4 * (In fact the only thing that is Apple-specific is that we assume
5 * that we can read from ROM at physical address 0xfff00000.)
7 * Copyright (C) 2004 Paul Mackerras (paulus@samba.org) and
8 * Benjamin Herrenschmidt (benh@kernel.crashing.org)
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
17 #include <asm/processor.h>
18 #include <asm/ppc_asm.h>
19 #include <asm/cputable.h>
22 * Flush and disable all data caches (dL1, L2, L3). This is used
23 * when going to sleep, when doing a PMU based cpufreq transition,
24 * or when "offlining" a CPU on SMP machines. This code is over
25 * paranoid, but I've had enough issues with various CPU revs and
26 * bugs that I decided it was worth beeing over cautious
29 _GLOBAL(flush_disable_caches)
35 END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
38 END_FTR_SECTION_IFSET(CPU_FTR_L2CR)
41 /* This is the code for G3 and 74[01]0 */
45 /* Turn off EE and DR in MSR */
47 rlwinm r0,r11,0,~MSR_EE
48 rlwinm r0,r0,0,~MSR_DR
53 /* Stop DST streams */
57 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
60 mfspr r8,SPRN_HID0 /* Save SPRN_HID0 in r8 */
61 rlwinm r4,r8,0,12,10 /* Turn off HID0[DPM] */
63 mtspr SPRN_HID0,r4 /* Disable DPM */
67 /* ROM base by default */
73 /* RAM base on 750FX */
83 /* Disable / invalidate / enable L1 data */
85 rlwinm r3,r3,0,~(HID0_DCE | HID0_ICE)
89 ori r3,r3,(HID0_DCE|HID0_DCI|HID0_ICE|HID0_ICFI)
93 xori r3,r3,(HID0_DCI|HID0_ICFI)
97 /* Get the current enable bit of the L2CR into r4 */
99 /* Set to data-only (pre-745x bit) */
100 oris r3,r5,L2CR_L2DO@h
102 /* When disabling L2, code must be in L1 */
104 1: mtspr SPRN_L2CR,r3
112 1: /* disp-flush L2. The interesting thing here is that the L2 can be
113 * up to 2Mb ... so using the ROM, we'll end up wrapping back to memory
114 * but that is probbaly fine. We disp-flush over 4Mb to be safe
134 rlwinm r5,r5,0,~L2CR_L2E
136 /* When disabling L2, code must be in L1 */
138 1: mtspr SPRN_L2CR,r5
148 /* Invalidate L2. This is pre-745x, we clear the L2I bit ourselves */
149 oris r4,r5,L2CR_L2I@h
154 /* Wait for the invalidation to complete */
155 1: mfspr r3,SPRN_L2CR
156 rlwinm. r0,r3,0,31,31
160 xoris r4,r4,L2CR_L2I@h
165 /* now disable the L1 data cache */
167 rlwinm r0,r0,0,~(HID0_DCE|HID0_ICE)
172 /* Restore HID0[DPM] to whatever it was before */
175 rlwimi r0,r8,0,11,11 /* Turn back HID0[DPM] */
179 /* restore DR and EE */
187 /* This code is for 745x processors */
189 /* Turn off EE and DR in MSR */
191 rlwinm r0,r11,0,~MSR_EE
192 rlwinm r0,r0,0,~MSR_DR
197 /* Stop prefetch streams */
201 /* Disable L2 prefetching */
217 /* Due to a bug with the HW flush on some CPU revs, we occasionally
218 * experience data corruption. I'm adding a displacement flush along
219 * with a dcbf loop over a few Mb to "help". The problem isn't totally
220 * fixed by this in theory, but at least, in practice, I couldn't reproduce
221 * it even with a big hammer...
229 addi r4,r4,32 /* Go to start of next cache line */
233 /* Now, flush the first 4MB of memory */
240 addi r4,r4,32 /* Go to start of next cache line */
243 /* Flush and disable the L1 data cache */
245 lis r3,0xfff0 /* read from ROM for displacement flush */
246 li r4,0xfe /* start with only way 0 unlocked */
247 li r5,128 /* 128 lines in each way */
253 2: lwz r0,0(r3) /* touch each cache line */
256 rlwinm r4,r4,1,24,30 /* move on to the next way */
258 cmpwi r4,0xff /* all done? */
260 /* now unlock the L1 data cache */
268 /* Flush the L2 cache using the hardware assist */
270 cmpwi r3,0 /* check if it is enabled first */
272 oris r0,r3,(L2CR_L2IO_745x|L2CR_L2DO_745x)@h
274 /* When disabling/locking L2, code must be in L1 */
276 1: mtspr SPRN_L2CR,r0 /* lock the L2 cache */
286 ori r0,r3,L2CR_L2HWF_745x
288 mtspr SPRN_L2CR,r0 /* set the hardware flush bit */
289 3: mfspr r0,SPRN_L2CR /* wait for it to go to 0 */
290 andi. r0,r0,L2CR_L2HWF_745x
293 rlwinm r3,r3,0,~L2CR_L2E
295 /* When disabling L2, code must be in L1 */
297 1: mtspr SPRN_L2CR,r3 /* disable the L2 cache */
307 oris r4,r3,L2CR_L2I@h
311 1: mfspr r4,SPRN_L2CR
312 andis. r0,r4,L2CR_L2I@h
317 /* Flush the L3 cache using the hardware assist */
318 4: mfspr r3,SPRN_L3CR
319 cmpwi r3,0 /* check if it is enabled */
321 oris r0,r3,L3CR_L3IO@h
324 mtspr SPRN_L3CR,r0 /* lock the L3 cache */
329 mtspr SPRN_L3CR,r0 /* set the hardware flush bit */
330 5: mfspr r0,SPRN_L3CR /* wait for it to go to zero */
331 andi. r0,r0,L3CR_L3HWF
333 rlwinm r3,r3,0,~L3CR_L3E
335 mtspr SPRN_L3CR,r3 /* disable the L3 cache */
339 1: mfspr r4,SPRN_L3CR
343 END_FTR_SECTION_IFSET(CPU_FTR_L3CR)
345 6: mfspr r0,SPRN_HID0 /* now disable the L1 data cache */
346 rlwinm r0,r0,0,~HID0_DCE
350 mtmsr r11 /* restore DR and EE */
353 #endif /* CONFIG_6xx */