--- /dev/null
+/*
+ * This file contains low-level cache management functions
+ * used for sleep and CPU speed changes on Apple machines.
+ * (In fact the only thing that is Apple-specific is that we assume
+ * that we can read from ROM at physical address 0xfff00000.)
+ *
+ * Copyright (C) 2004 Paul Mackerras (paulus@samba.org) and
+ * Benjamin Herrenschmidt (benh@kernel.crashing.org)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/config.h>
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/cputable.h>
+
+/*
+ * Flush and disable all data caches (dL1, L2, L3). This is used
+ * when going to sleep, when doing a PMU based cpufreq transition,
+ * or when "offlining" a CPU on SMP machines. This code is over
+ * paranoid, but I've had enough issues with various CPU revs and
+ * bugs that I decided it was worth beeing over cautious
+ */
+
+_GLOBAL(flush_disable_caches)
+#ifndef CONFIG_6xx
+ blr
+#else
+BEGIN_FTR_SECTION
+ b flush_disable_745x
+END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
+BEGIN_FTR_SECTION
+ b flush_disable_75x
+END_FTR_SECTION_IFSET(CPU_FTR_L2CR)
+ b __flush_disable_L1
+
+/* This is the code for G3 and 74[01]0 */
+flush_disable_75x:
+ mflr r10
+
+ /* Turn off EE and DR in MSR */
+ mfmsr r11
+ rlwinm r0,r11,0,~MSR_EE
+ rlwinm r0,r0,0,~MSR_DR
+ sync
+ mtmsr r0
+ isync
+
+ /* Stop DST streams */
+BEGIN_FTR_SECTION
+ DSSALL
+ sync
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+
+ /* Stop DPM */
+ mfspr r8,SPRN_HID0 /* Save SPRN_HID0 in r8 */
+ rlwinm r4,r8,0,12,10 /* Turn off HID0[DPM] */
+ sync
+ mtspr SPRN_HID0,r4 /* Disable DPM */
+ sync
+
+ /* Disp-flush L1. We have a weird problem here that I never
+ * totally figured out. On 750FX, using the ROM for the flush
+ * results in a non-working flush. We use that workaround for
+ * now until I finally understand what's going on. --BenH
+ */
+
+ /* ROM base by default */
+ lis r4,0xfff0
+ mfpvr r3
+ srwi r3,r3,16
+ cmplwi cr0,r3,0x7000
+ bne+ 1f
+ /* RAM base on 750FX */
+ li r4,0
+1: li r4,0x4000
+ mtctr r4
+1: lwz r0,0(r4)
+ addi r4,r4,32
+ bdnz 1b
+ sync
+ isync
+
+ /* Disable / invalidate / enable L1 data */
+ mfspr r3,SPRN_HID0
+ rlwinm r3,r3,0,~(HID0_DCE | HID0_ICE)
+ mtspr SPRN_HID0,r3
+ sync
+ isync
+ ori r3,r3,(HID0_DCE|HID0_DCI|HID0_ICE|HID0_ICFI)
+ sync
+ isync
+ mtspr SPRN_HID0,r3
+ xori r3,r3,(HID0_DCI|HID0_ICFI)
+ mtspr SPRN_HID0,r3
+ sync
+
+ /* Get the current enable bit of the L2CR into r4 */
+ mfspr r5,SPRN_L2CR
+ /* Set to data-only (pre-745x bit) */
+ oris r3,r5,L2CR_L2DO@h
+ b 2f
+ /* When disabling L2, code must be in L1 */
+ .balign 32
+1: mtspr SPRN_L2CR,r3
+3: sync
+ isync
+ b 1f
+2: b 3f
+3: sync
+ isync
+ b 1b
+1: /* disp-flush L2. The interesting thing here is that the L2 can be
+ * up to 2Mb ... so using the ROM, we'll end up wrapping back to memory
+ * but that is probbaly fine. We disp-flush over 4Mb to be safe
+ */
+ lis r4,2
+ mtctr r4
+ lis r4,0xfff0
+1: lwz r0,0(r4)
+ addi r4,r4,32
+ bdnz 1b
+ sync
+ isync
+ lis r4,2
+ mtctr r4
+ lis r4,0xfff0
+1: dcbf 0,r4
+ addi r4,r4,32
+ bdnz 1b
+ sync
+ isync
+
+ /* now disable L2 */
+ rlwinm r5,r5,0,~L2CR_L2E
+ b 2f
+ /* When disabling L2, code must be in L1 */
+ .balign 32
+1: mtspr SPRN_L2CR,r5
+3: sync
+ isync
+ b 1f
+2: b 3f
+3: sync
+ isync
+ b 1b
+1: sync
+ isync
+ /* Invalidate L2. This is pre-745x, we clear the L2I bit ourselves */
+ oris r4,r5,L2CR_L2I@h
+ mtspr SPRN_L2CR,r4
+ sync
+ isync
+
+ /* Wait for the invalidation to complete */
+1: mfspr r3,SPRN_L2CR
+ rlwinm. r0,r3,0,31,31
+ bne 1b
+
+ /* Clear L2I */
+ xoris r4,r4,L2CR_L2I@h
+ sync
+ mtspr SPRN_L2CR,r4
+ sync
+
+ /* now disable the L1 data cache */
+ mfspr r0,SPRN_HID0
+ rlwinm r0,r0,0,~(HID0_DCE|HID0_ICE)
+ mtspr SPRN_HID0,r0
+ sync
+ isync
+
+ /* Restore HID0[DPM] to whatever it was before */
+ sync
+ mfspr r0,SPRN_HID0
+ rlwimi r0,r8,0,11,11 /* Turn back HID0[DPM] */
+ mtspr SPRN_HID0,r0
+ sync
+
+ /* restore DR and EE */
+ sync
+ mtmsr r11
+ isync
+
+ mtlr r10
+ blr
+
+/* This code is for 745x processors */
+flush_disable_745x:
+ /* Turn off EE and DR in MSR */
+ mfmsr r11
+ rlwinm r0,r11,0,~MSR_EE
+ rlwinm r0,r0,0,~MSR_DR
+ sync
+ mtmsr r0
+ isync
+
+ /* Stop prefetch streams */
+ DSSALL
+ sync
+
+ /* Disable L2 prefetching */
+ mfspr r0,SPRN_MSSCR0
+ rlwinm r0,r0,0,0,29
+ mtspr SPRN_MSSCR0,r0
+ sync
+ isync
+ lis r4,0
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+
+ /* Due to a bug with the HW flush on some CPU revs, we occasionally
+ * experience data corruption. I'm adding a displacement flush along
+ * with a dcbf loop over a few Mb to "help". The problem isn't totally
+ * fixed by this in theory, but at least, in practice, I couldn't reproduce
+ * it even with a big hammer...
+ */
+
+ lis r4,0x0002
+ mtctr r4
+ li r4,0
+1:
+ lwz r0,0(r4)
+ addi r4,r4,32 /* Go to start of next cache line */
+ bdnz 1b
+ isync
+
+ /* Now, flush the first 4MB of memory */
+ lis r4,0x0002
+ mtctr r4
+ li r4,0
+ sync
+1:
+ dcbf 0,r4
+ addi r4,r4,32 /* Go to start of next cache line */
+ bdnz 1b
+
+ /* Flush and disable the L1 data cache */
+ mfspr r6,SPRN_LDSTCR
+ lis r3,0xfff0 /* read from ROM for displacement flush */
+ li r4,0xfe /* start with only way 0 unlocked */
+ li r5,128 /* 128 lines in each way */
+1: mtctr r5
+ rlwimi r6,r4,0,24,31
+ mtspr SPRN_LDSTCR,r6
+ sync
+ isync
+2: lwz r0,0(r3) /* touch each cache line */
+ addi r3,r3,32
+ bdnz 2b
+ rlwinm r4,r4,1,24,30 /* move on to the next way */
+ ori r4,r4,1
+ cmpwi r4,0xff /* all done? */
+ bne 1b
+ /* now unlock the L1 data cache */
+ li r4,0
+ rlwimi r6,r4,0,24,31
+ sync
+ mtspr SPRN_LDSTCR,r6
+ sync
+ isync
+
+ /* Flush the L2 cache using the hardware assist */
+ mfspr r3,SPRN_L2CR
+ cmpwi r3,0 /* check if it is enabled first */
+ bge 4f
+ oris r0,r3,(L2CR_L2IO_745x|L2CR_L2DO_745x)@h
+ b 2f
+ /* When disabling/locking L2, code must be in L1 */
+ .balign 32
+1: mtspr SPRN_L2CR,r0 /* lock the L2 cache */
+3: sync
+ isync
+ b 1f
+2: b 3f
+3: sync
+ isync
+ b 1b
+1: sync
+ isync
+ ori r0,r3,L2CR_L2HWF_745x
+ sync
+ mtspr SPRN_L2CR,r0 /* set the hardware flush bit */
+3: mfspr r0,SPRN_L2CR /* wait for it to go to 0 */
+ andi. r0,r0,L2CR_L2HWF_745x
+ bne 3b
+ sync
+ rlwinm r3,r3,0,~L2CR_L2E
+ b 2f
+ /* When disabling L2, code must be in L1 */
+ .balign 32
+1: mtspr SPRN_L2CR,r3 /* disable the L2 cache */
+3: sync
+ isync
+ b 1f
+2: b 3f
+3: sync
+ isync
+ b 1b
+1: sync
+ isync
+ oris r4,r3,L2CR_L2I@h
+ mtspr SPRN_L2CR,r4
+ sync
+ isync
+1: mfspr r4,SPRN_L2CR
+ andis. r0,r4,L2CR_L2I@h
+ bne 1b
+ sync
+
+BEGIN_FTR_SECTION
+ /* Flush the L3 cache using the hardware assist */
+4: mfspr r3,SPRN_L3CR
+ cmpwi r3,0 /* check if it is enabled */
+ bge 6f
+ oris r0,r3,L3CR_L3IO@h
+ ori r0,r0,L3CR_L3DO
+ sync
+ mtspr SPRN_L3CR,r0 /* lock the L3 cache */
+ sync
+ isync
+ ori r0,r0,L3CR_L3HWF
+ sync
+ mtspr SPRN_L3CR,r0 /* set the hardware flush bit */
+5: mfspr r0,SPRN_L3CR /* wait for it to go to zero */
+ andi. r0,r0,L3CR_L3HWF
+ bne 5b
+ rlwinm r3,r3,0,~L3CR_L3E
+ sync
+ mtspr SPRN_L3CR,r3 /* disable the L3 cache */
+ sync
+ ori r4,r3,L3CR_L3I
+ mtspr SPRN_L3CR,r4
+1: mfspr r4,SPRN_L3CR
+ andi. r0,r4,L3CR_L3I
+ bne 1b
+ sync
+END_FTR_SECTION_IFSET(CPU_FTR_L3CR)
+
+6: mfspr r0,SPRN_HID0 /* now disable the L1 data cache */
+ rlwinm r0,r0,0,~HID0_DCE
+ mtspr SPRN_HID0,r0
+ sync
+ isync
+ mtmsr r11 /* restore DR and EE */
+ isync
+ blr
+#endif /* CONFIG_6xx */
git://git.onelab.eu / linux-2.6.git / blobdiff