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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ L2CR functions
+ Copyright © 1997-1998 by PowerLogix R & D, Inc.
+
+*/
+/*
+ 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 <asm/processor.h>
+#include <asm/cputable.h>
+#include <asm/ppc_asm.h>
+#include <asm/cache.h>
+#include <asm/page.h>
+#include <asm/feature-fixups.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
+ PPC_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 accommodate all processor variations.
+ The bit moved on the 7450.....
+ ****/
+
+BEGIN_FTR_SECTION
+ /* Disable L2 prefetch on some 745x and try to ensure
+ * L2 prefetch engines are idle. As explained by errata
+ * text, we can't be sure they are, we just hope very hard
+ * that well be enough (sic !). At least I noticed Apple
+ * doesn't even bother doing the dcbf's here...
+ */
+ mfspr r4,SPRN_MSSCR0
+ rlwinm r4,r4,0,0,29
+ sync
+ mtspr SPRN_MSSCR0,r4
+ sync
+ isync
+ lis r4,KERNELBASE@h
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
+
+ /* TODO: use HW flush assist when available */
+
+ lis r4,0x0002
+ mtctr r4
+ li r4,0
+1:
+ lwzx 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
+
+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_BYTES
+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
+
+ /* Enable L2 HW prefetch on 744x/745x */
+BEGIN_FTR_SECTION
+ mfspr r3,SPRN_MSSCR0
+ ori r3,r3,3
+ sync
+ mtspr SPRN_MSSCR0,r3
+ sync
+ isync
+END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
+4:
+
+ /* Restore HID0[DPM] to whatever it was before */
+ sync
+ mtspr 1008,r8
+ sync
+
+ /* Restore MSR (restores EE and DR bits to original state) */
+ 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 */
+ PPC_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 r0,0,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:
+ 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
+ PPC_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
+_ASM_NOKPROBE_SYMBOL(__inval_enable_L1)
+
+