diff options
Diffstat (limited to 'arch/powerpc/platforms/powermac/cache.S')
| -rw-r--r-- | arch/powerpc/platforms/powermac/cache.S | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powermac/cache.S b/arch/powerpc/platforms/powermac/cache.S new file mode 100644 index 000000000..b8ae56e9f --- /dev/null +++ b/arch/powerpc/platforms/powermac/cache.S @@ -0,0 +1,356 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * 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) + */ + +#include <asm/processor.h> +#include <asm/ppc_asm.h> +#include <asm/cputable.h> +#include <asm/feature-fixups.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 being over cautious + */ + +_GLOBAL(flush_disable_caches) +#ifndef CONFIG_PPC_BOOK3S_32 + 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 + PPC_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 +_ASM_NOKPROBE_SYMBOL(flush_disable_75x) + +/* 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 */ + PPC_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 +_ASM_NOKPROBE_SYMBOL(flush_disable_745x) +#endif /* CONFIG_PPC_BOOK3S_32 */ |