diff options
Diffstat (limited to 'arch/ppc/kernel/l2cr.S')
| -rw-r--r-- | arch/ppc/kernel/l2cr.S | 442 |
1 files changed, 442 insertions, 0 deletions
diff --git a/arch/ppc/kernel/l2cr.S b/arch/ppc/kernel/l2cr.S new file mode 100644 index 00000000000..c3944104826 --- /dev/null +++ b/arch/ppc/kernel/l2cr.S @@ -0,0 +1,442 @@ +/* + L2CR functions + Copyright © 1997-1998 by PowerLogix R & D, Inc. + + 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. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ +/* + Thur, Dec. 12, 1998. + - First public release, contributed by PowerLogix. + *********** + Sat, Aug. 7, 1999. + - Terry: Made sure code disabled interrupts before running. (Previously + it was assumed interrupts were already disabled). + - Terry: Updated for tentative G4 support. 4MB of memory is now flushed + instead of 2MB. (Prob. only 3 is necessary). + - Terry: Updated for workaround to HID0[DPM] processor bug + during global invalidates. + *********** + Thu, July 13, 2000. + - Terry: Added isync to correct for an errata. + + 22 August 2001. + - DanM: Finally added the 7450 patch I've had for the past + several months. The L2CR is similar, but I'm going + to assume the user of this functions knows what they + are doing. + + Author: Terry Greeniaus (tgree@phys.ualberta.ca) + Please e-mail updates to this file to me, thanks! +*/ +#include <linux/config.h> +#include <asm/processor.h> +#include <asm/cputable.h> +#include <asm/ppc_asm.h> +#include <asm/cache.h> +#include <asm/page.h> + +/* Usage: + + When setting the L2CR register, you must do a few special + things. If you are enabling the cache, you must perform a + global invalidate. If you are disabling the cache, you must + flush the cache contents first. This routine takes care of + doing these things. When first enabling the cache, make sure + you pass in the L2CR you want, as well as passing in the + global invalidate bit set. A global invalidate will only be + performed if the L2I bit is set in applyThis. When enabling + the cache, you should also set the L2E bit in applyThis. If + you want to modify the L2CR contents after the cache has been + enabled, the recommended procedure is to first call + __setL2CR(0) to disable the cache and then call it again with + the new values for L2CR. Examples: + + _setL2CR(0) - disables the cache + _setL2CR(0xB3A04000) - enables my G3 upgrade card: + - L2E set to turn on the cache + - L2SIZ set to 1MB + - L2CLK set to 1:1 + - L2RAM set to pipelined synchronous late-write + - L2I set to perform a global invalidation + - L2OH set to 0.5 nS + - L2DF set because this upgrade card + requires it + + A similar call should work for your card. You need to know + the correct setting for your card and then place them in the + fields I have outlined above. Other fields support optional + features, such as L2DO which caches only data, or L2TS which + causes cache pushes from the L1 cache to go to the L2 cache + instead of to main memory. + +IMPORTANT: + Starting with the 7450, the bits in this register have moved + or behave differently. The Enable, Parity Enable, Size, + and L2 Invalidate are the only bits that have not moved. + The size is read-only for these processors with internal L2 + cache, and the invalidate is a control as well as status. + -- Dan + +*/ +/* + * Summary: this procedure ignores the L2I bit in the value passed in, + * flushes the cache if it was already enabled, always invalidates the + * cache, then enables the cache if the L2E bit is set in the value + * passed in. + * -- paulus. + */ +_GLOBAL(_set_L2CR) + /* Make sure this is a 750 or 7400 chip */ +BEGIN_FTR_SECTION + li r3,-1 + blr +END_FTR_SECTION_IFCLR(CPU_FTR_L2CR) + + mflr r9 + + /* Stop DST streams */ +BEGIN_FTR_SECTION + DSSALL + sync +END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) + + /* Turn off interrupts and data relocation. */ + mfmsr r7 /* Save MSR in r7 */ + rlwinm r4,r7,0,17,15 + rlwinm r4,r4,0,28,26 /* Turn off DR bit */ + sync + mtmsr r4 + isync + + /* Before we perform the global invalidation, we must disable dynamic + * power management via HID0[DPM] to work around a processor bug where + * DPM can possibly interfere with the state machine in the processor + * that invalidates the L2 cache tags. + */ + mfspr r8,SPRN_HID0 /* Save HID0 in r8 */ + rlwinm r4,r8,0,12,10 /* Turn off HID0[DPM] */ + sync + mtspr SPRN_HID0,r4 /* Disable DPM */ + sync + + /* Get the current enable bit of the L2CR into r4 */ + mfspr r4,SPRN_L2CR + + /* Tweak some bits */ + rlwinm r5,r3,0,0,0 /* r5 contains the new enable bit */ + rlwinm r3,r3,0,11,9 /* Turn off the invalidate bit */ + rlwinm r3,r3,0,1,31 /* Turn off the enable bit */ + + /* Check to see if we need to flush */ + rlwinm. r4,r4,0,0,0 + beq 2f + + /* Flush the cache. First, read the first 4MB of memory (physical) to + * put new data in the cache. (Actually we only need + * the size of the L2 cache plus the size of the L1 cache, but 4MB will + * cover everything just to be safe). + */ + + /**** Might be a good idea to set L2DO here - to prevent instructions + from getting into the cache. But since we invalidate + the next time we enable the cache it doesn't really matter. + Don't do this unless you accomodate all processor variations. + The bit moved on the 7450..... + ****/ + + /* TODO: use HW flush assist when available */ + + lis r4,0x0002 + mtctr r4 + li r4,0 +1: + lwzx r0,r0,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 + +2: + /* Set up the L2CR configuration bits (and switch L2 off) */ + /* CPU errata: Make sure the mtspr below is already in the + * L1 icache + */ + b 20f + .balign L1_CACHE_LINE_SIZE +22: + sync + mtspr SPRN_L2CR,r3 + sync + b 23f +20: + b 21f +21: sync + isync + b 22b + +23: + /* Perform a global invalidation */ + oris r3,r3,0x0020 + sync + mtspr SPRN_L2CR,r3 + sync + isync /* For errata */ + +BEGIN_FTR_SECTION + /* On the 7450, we wait for the L2I bit to clear...... + */ +10: mfspr r3,SPRN_L2CR + andis. r4,r3,0x0020 + bne 10b + b 11f +END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450) + + /* Wait for the invalidation to complete */ +3: mfspr r3,SPRN_L2CR + rlwinm. r4,r3,0,31,31 + bne 3b + +11: rlwinm r3,r3,0,11,9 /* Turn off the L2I bit */ + sync + mtspr SPRN_L2CR,r3 + sync + + /* See if we need to enable the cache */ + cmplwi r5,0 + beq 4f + + /* Enable the cache */ + oris r3,r3,0x8000 + mtspr SPRN_L2CR,r3 + sync + +4: + + /* Restore HID0[DPM] to whatever it was before */ + sync + mtspr 1008,r8 + sync + + /* Restore MSR (restores EE and DR bits to original state) */ + SYNC + mtmsr r7 + isync + + mtlr r9 + blr + +_GLOBAL(_get_L2CR) + /* Return the L2CR contents */ + li r3,0 +BEGIN_FTR_SECTION + mfspr r3,SPRN_L2CR +END_FTR_SECTION_IFSET(CPU_FTR_L2CR) + blr + + +/* + * Here is a similar routine for dealing with the L3 cache + * on the 745x family of chips + */ + +_GLOBAL(_set_L3CR) + /* Make sure this is a 745x chip */ +BEGIN_FTR_SECTION + li r3,-1 + blr +END_FTR_SECTION_IFCLR(CPU_FTR_L3CR) + + /* Turn off interrupts and data relocation. */ + mfmsr r7 /* Save MSR in r7 */ + rlwinm r4,r7,0,17,15 + rlwinm r4,r4,0,28,26 /* Turn off DR bit */ + sync + mtmsr r4 + isync + + /* Stop DST streams */ + DSSALL + sync + + /* Get the current enable bit of the L3CR into r4 */ + mfspr r4,SPRN_L3CR + + /* Tweak some bits */ + rlwinm r5,r3,0,0,0 /* r5 contains the new enable bit */ + rlwinm r3,r3,0,22,20 /* Turn off the invalidate bit */ + rlwinm r3,r3,0,2,31 /* Turn off the enable & PE bits */ + rlwinm r3,r3,0,5,3 /* Turn off the clken bit */ + /* Check to see if we need to flush */ + rlwinm. r4,r4,0,0,0 + beq 2f + + /* Flush the cache. + */ + + /* TODO: use HW flush assist */ + + lis r4,0x0008 + mtctr r4 + li r4,0 +1: + lwzx r0,r0,r4 + dcbf 0,r4 + addi r4,r4,32 /* Go to start of next cache line */ + bdnz 1b + +2: + /* Set up the L3CR configuration bits (and switch L3 off) */ + sync + mtspr SPRN_L3CR,r3 + sync + + oris r3,r3,L3CR_L3RES@h /* Set reserved bit 5 */ + mtspr SPRN_L3CR,r3 + sync + oris r3,r3,L3CR_L3CLKEN@h /* Set clken */ + mtspr SPRN_L3CR,r3 + sync + + /* Wait for stabilize */ + li r0,256 + mtctr r0 +1: bdnz 1b + + /* Perform a global invalidation */ + ori r3,r3,0x0400 + sync + mtspr SPRN_L3CR,r3 + sync + isync + + /* We wait for the L3I bit to clear...... */ +10: mfspr r3,SPRN_L3CR + andi. r4,r3,0x0400 + bne 10b + + /* Clear CLKEN */ + rlwinm r3,r3,0,5,3 /* Turn off the clken bit */ + mtspr SPRN_L3CR,r3 + sync + + /* Wait for stabilize */ + li r0,256 + mtctr r0 +1: bdnz 1b + + /* See if we need to enable the cache */ + cmplwi r5,0 + beq 4f + + /* Enable the cache */ + oris r3,r3,(L3CR_L3E | L3CR_L3CLKEN)@h + mtspr SPRN_L3CR,r3 + sync + + /* Wait for stabilize */ + li r0,256 + mtctr r0 +1: bdnz 1b + + /* Restore MSR (restores EE and DR bits to original state) */ +4: SYNC + mtmsr r7 + isync + blr + +_GLOBAL(_get_L3CR) + /* Return the L3CR contents */ + li r3,0 +BEGIN_FTR_SECTION + mfspr r3,SPRN_L3CR +END_FTR_SECTION_IFSET(CPU_FTR_L3CR) + blr + +/* --- End of PowerLogix code --- + */ + + +/* flush_disable_L1() - Flush and disable L1 cache + * + * clobbers r0, r3, ctr, cr0 + * Must be called with interrupts disabled and MMU enabled. + */ +_GLOBAL(__flush_disable_L1) + /* Stop pending alitvec streams and memory accesses */ +BEGIN_FTR_SECTION + DSSALL +END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) + sync + + /* Load counter to 0x4000 cache lines (512k) and + * load cache with datas + */ + li r3,0x4000 /* 512kB / 32B */ + mtctr r3 + lis r3,KERNELBASE@h +1: + lwz r0,0(r3) + addi r3,r3,0x0020 /* Go to start of next cache line */ + bdnz 1b + isync + sync + + /* Now flush those cache lines */ + li r3,0x4000 /* 512kB / 32B */ + mtctr r3 + lis r3,KERNELBASE@h +1: + dcbf 0,r3 + addi r3,r3,0x0020 /* Go to start of next cache line */ + bdnz 1b + sync + + /* We can now disable the L1 cache (HID0:DCE, HID0:ICE) */ + mfspr r3,SPRN_HID0 + rlwinm r3,r3,0,18,15 + mtspr SPRN_HID0,r3 + sync + isync + blr + +/* inval_enable_L1 - Invalidate and enable L1 cache + * + * Assumes L1 is already disabled and MSR:EE is off + * + * clobbers r3 + */ +_GLOBAL(__inval_enable_L1) + /* Enable and then Flash inval the instruction & data cache */ + mfspr r3,SPRN_HID0 + ori r3,r3, HID0_ICE|HID0_ICFI|HID0_DCE|HID0_DCI + sync + isync + mtspr SPRN_HID0,r3 + xori r3,r3, HID0_ICFI|HID0_DCI + mtspr SPRN_HID0,r3 + sync + + blr + + |