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-rw-r--r--arch/powerpc/kernel/head_8xx.S398
1 files changed, 248 insertions, 150 deletions
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 3c9452d4308..7ee876d2adb 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -19,6 +19,7 @@
*
*/
+#include <linux/init.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/mmu.h>
@@ -28,6 +29,7 @@
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
+#include <asm/ptrace.h>
/* Macro to make the code more readable. */
#ifdef CONFIG_8xx_CPU6
@@ -38,7 +40,7 @@
#else
#define DO_8xx_CPU6(val, reg)
#endif
- .section .text.head, "ax"
+ __HEAD
_ENTRY(_stext);
_ENTRY(_start);
@@ -70,18 +72,11 @@ _ENTRY(_start);
* in the first level table, but that would require many changes to the
* Linux page directory/table functions that I don't want to do right now.
*
- * I used to use SPRG2 for a temporary register in the TLB handler, but it
- * has since been put to other uses. I now use a hack to save a register
- * and the CCR at memory location 0.....Someday I'll fix this.....
* -- Dan
*/
.globl __start
__start:
- mr r31,r3 /* save parameters */
- mr r30,r4
- mr r29,r5
- mr r28,r6
- mr r27,r7
+ mr r31,r3 /* save device tree ptr */
/* We have to turn on the MMU right away so we get cache modes
* set correctly.
@@ -109,8 +104,8 @@ turn_on_mmu:
* task's thread_struct.
*/
#define EXCEPTION_PROLOG \
- mtspr SPRN_SPRG0,r10; \
- mtspr SPRN_SPRG1,r11; \
+ mtspr SPRN_SPRG_SCRATCH0,r10; \
+ mtspr SPRN_SPRG_SCRATCH1,r11; \
mfcr r10; \
EXCEPTION_PROLOG_1; \
EXCEPTION_PROLOG_2
@@ -120,7 +115,7 @@ turn_on_mmu:
andi. r11,r11,MSR_PR; \
tophys(r11,r1); /* use tophys(r1) if kernel */ \
beq 1f; \
- mfspr r11,SPRN_SPRG3; \
+ mfspr r11,SPRN_SPRG_THREAD; \
lwz r11,THREAD_INFO-THREAD(r11); \
addi r11,r11,THREAD_SIZE; \
tophys(r11,r11); \
@@ -132,9 +127,9 @@ turn_on_mmu:
stw r10,_CCR(r11); /* save registers */ \
stw r12,GPR12(r11); \
stw r9,GPR9(r11); \
- mfspr r10,SPRN_SPRG0; \
+ mfspr r10,SPRN_SPRG_SCRATCH0; \
stw r10,GPR10(r11); \
- mfspr r12,SPRN_SPRG1; \
+ mfspr r12,SPRN_SPRG_SCRATCH1; \
stw r12,GPR11(r11); \
mflr r10; \
stw r10,_LINK(r11); \
@@ -205,6 +200,8 @@ MachineCheck:
EXCEPTION_PROLOG
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
+ li r5,0x00f0
+ mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
stw r5,_DSISR(r11)
addi r3,r1,STACK_FRAME_OVERHEAD
@@ -221,7 +218,9 @@ DataAccess:
stw r10,_DSISR(r11)
mr r5,r10
mfspr r4,SPRN_DAR
- EXC_XFER_EE_LITE(0x300, handle_page_fault)
+ li r10,0x00f0
+ mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
+ EXC_XFER_LITE(0x300, handle_page_fault)
/* Instruction access exception.
* This is "never generated" by the MPC8xx. We jump to it for other
@@ -232,7 +231,7 @@ InstructionAccess:
EXCEPTION_PROLOG
mr r4,r12
mr r5,r9
- EXC_XFER_EE_LITE(0x400, handle_page_fault)
+ EXC_XFER_LITE(0x400, handle_page_fault)
/* External interrupt */
EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
@@ -243,6 +242,8 @@ Alignment:
EXCEPTION_PROLOG
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
+ li r5,0x00f0
+ mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
stw r5,_DSISR(r11)
addi r3,r1,STACK_FRAME_OVERHEAD
@@ -295,8 +296,13 @@ InstructionTLBMiss:
DO_8xx_CPU6(0x3f80, r3)
mtspr SPRN_M_TW, r10 /* Save a couple of working registers */
mfcr r10
+#ifdef CONFIG_8xx_CPU6
stw r10, 0(r0)
stw r11, 4(r0)
+#else
+ mtspr SPRN_DAR, r10
+ mtspr SPRN_SPRG2, r11
+#endif
mfspr r10, SPRN_SRR0 /* Get effective address of fault */
#ifdef CONFIG_8xx_CPU15
addi r11, r10, 0x1000
@@ -311,12 +317,16 @@ InstructionTLBMiss:
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
+#ifdef CONFIG_MODULES
+ /* Only modules will cause ITLB Misses as we always
+ * pin the first 8MB of kernel memory */
andi. r11, r10, 0x0800 /* Address >= 0x80000000 */
beq 3f
lis r11, swapper_pg_dir@h
ori r11, r11, swapper_pg_dir@l
rlwimi r10, r11, 0, 2, 19
3:
+#endif
lwz r11, 0(r10) /* Get the level 1 entry */
rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */
beq 2f /* If zero, don't try to find a pte */
@@ -333,37 +343,58 @@ InstructionTLBMiss:
lwz r10, 0(r11) /* Get the pte */
#ifdef CONFIG_SWAP
- /* do not set the _PAGE_ACCESSED bit of a non-present page */
- andi. r11, r10, _PAGE_PRESENT
- beq 4f
- ori r10, r10, _PAGE_ACCESSED
- mfspr r11, SPRN_MD_TWC /* get the pte address again */
- stw r10, 0(r11)
-4:
-#else
- ori r10, r10, _PAGE_ACCESSED
- stw r10, 0(r11)
+ andi. r11, r10, _PAGE_ACCESSED | _PAGE_PRESENT
+ cmpwi cr0, r11, _PAGE_ACCESSED | _PAGE_PRESENT
+ bne- cr0, 2f
#endif
-
/* The Linux PTE won't go exactly into the MMU TLB.
- * Software indicator bits 21, 22 and 28 must be clear.
+ * Software indicator bits 21 and 28 must be clear.
* Software indicator bits 24, 25, 26, and 27 must be
* set. All other Linux PTE bits control the behavior
* of the MMU.
*/
-2: li r11, 0x00f0
- rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */
+ li r11, 0x00f0
+ rlwimi r10, r11, 0, 0x07f8 /* Set 24-27, clear 21-23,28 */
DO_8xx_CPU6(0x2d80, r3)
mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
- mfspr r10, SPRN_M_TW /* Restore registers */
+ /* Restore registers */
+#ifndef CONFIG_8xx_CPU6
+ mfspr r10, SPRN_DAR
+ mtcr r10
+ mtspr SPRN_DAR, r11 /* Tag DAR */
+ mfspr r11, SPRN_SPRG2
+#else
lwz r11, 0(r0)
mtcr r11
lwz r11, 4(r0)
-#ifdef CONFIG_8xx_CPU6
lwz r3, 8(r0)
#endif
+ mfspr r10, SPRN_M_TW
rfi
+2:
+ mfspr r11, SPRN_SRR1
+ /* clear all error bits as TLB Miss
+ * sets a few unconditionally
+ */
+ rlwinm r11, r11, 0, 0xffff
+ mtspr SPRN_SRR1, r11
+
+ /* Restore registers */
+#ifndef CONFIG_8xx_CPU6
+ mfspr r10, SPRN_DAR
+ mtcr r10
+ li r11, 0x00f0
+ mtspr SPRN_DAR, r11 /* Tag DAR */
+ mfspr r11, SPRN_SPRG2
+#else
+ lwz r11, 0(r0)
+ mtcr r11
+ lwz r11, 4(r0)
+ lwz r3, 8(r0)
+#endif
+ mfspr r10, SPRN_M_TW
+ b InstructionAccess
. = 0x1200
DataStoreTLBMiss:
@@ -373,8 +404,13 @@ DataStoreTLBMiss:
DO_8xx_CPU6(0x3f80, r3)
mtspr SPRN_M_TW, r10 /* Save a couple of working registers */
mfcr r10
+#ifdef CONFIG_8xx_CPU6
stw r10, 0(r0)
stw r11, 4(r0)
+#else
+ mtspr SPRN_DAR, r10
+ mtspr SPRN_SPRG2, r11
+#endif
mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */
/* If we are faulting a kernel address, we have to use the
@@ -405,24 +441,38 @@ DataStoreTLBMiss:
* above.
*/
rlwimi r11, r10, 0, 27, 27
+ /* Insert the WriteThru flag into the TWC from the Linux PTE.
+ * It is bit 25 in the Linux PTE and bit 30 in the TWC
+ */
+ rlwimi r11, r10, 32-5, 30, 30
DO_8xx_CPU6(0x3b80, r3)
mtspr SPRN_MD_TWC, r11
+ /* Both _PAGE_ACCESSED and _PAGE_PRESENT has to be set.
+ * We also need to know if the insn is a load/store, so:
+ * Clear _PAGE_PRESENT and load that which will
+ * trap into DTLB Error with store bit set accordinly.
+ */
+ /* PRESENT=0x1, ACCESSED=0x20
+ * r11 = ((r10 & PRESENT) & ((r10 & ACCESSED) >> 5));
+ * r10 = (r10 & ~PRESENT) | r11;
+ */
#ifdef CONFIG_SWAP
- /* do not set the _PAGE_ACCESSED bit of a non-present page */
- andi. r11, r10, _PAGE_PRESENT
- beq 4f
- ori r10, r10, _PAGE_ACCESSED
-4:
- /* and update pte in table */
-#else
- ori r10, r10, _PAGE_ACCESSED
+ rlwinm r11, r10, 32-5, _PAGE_PRESENT
+ and r11, r11, r10
+ rlwimi r10, r11, 0, _PAGE_PRESENT
#endif
- mfspr r11, SPRN_MD_TWC /* get the pte address again */
- stw r10, 0(r11)
+ /* Honour kernel RO, User NA */
+ /* 0x200 == Extended encoding, bit 22 */
+ rlwimi r10, r10, 32-2, 0x200 /* Copy USER to bit 22, 0x200 */
+ /* r11 = (r10 & _PAGE_RW) >> 1 */
+ rlwinm r11, r10, 32-1, 0x200
+ or r10, r11, r10
+ /* invert RW and 0x200 bits */
+ xori r10, r10, _PAGE_RW | 0x200
/* The Linux PTE won't go exactly into the MMU TLB.
- * Software indicator bits 21, 22 and 28 must be clear.
+ * Software indicator bits 22 and 28 must be clear.
* Software indicator bits 24, 25, 26, and 27 must be
* set. All other Linux PTE bits control the behavior
* of the MMU.
@@ -432,13 +482,20 @@ DataStoreTLBMiss:
DO_8xx_CPU6(0x3d80, r3)
mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
- mfspr r10, SPRN_M_TW /* Restore registers */
+ /* Restore registers */
+#ifndef CONFIG_8xx_CPU6
+ mfspr r10, SPRN_DAR
+ mtcr r10
+ mtspr SPRN_DAR, r11 /* Tag DAR */
+ mfspr r11, SPRN_SPRG2
+#else
+ mtspr SPRN_DAR, r11 /* Tag DAR */
lwz r11, 0(r0)
mtcr r11
lwz r11, 4(r0)
-#ifdef CONFIG_8xx_CPU6
lwz r3, 8(r0)
#endif
+ mfspr r10, SPRN_M_TW
rfi
/* This is an instruction TLB error on the MPC8xx. This could be due
@@ -468,97 +525,10 @@ DataTLBError:
stw r10, 0(r0)
stw r11, 4(r0)
- /* First, make sure this was a store operation.
- */
- mfspr r10, SPRN_DSISR
- andis. r11, r10, 0x0200 /* If set, indicates store op */
- beq 2f
-
- /* The EA of a data TLB miss is automatically stored in the MD_EPN
- * register. The EA of a data TLB error is automatically stored in
- * the DAR, but not the MD_EPN register. We must copy the 20 most
- * significant bits of the EA from the DAR to MD_EPN before we
- * start walking the page tables. We also need to copy the CASID
- * value from the M_CASID register.
- * Addendum: The EA of a data TLB error is _supposed_ to be stored
- * in DAR, but it seems that this doesn't happen in some cases, such
- * as when the error is due to a dcbi instruction to a page with a
- * TLB that doesn't have the changed bit set. In such cases, there
- * does not appear to be any way to recover the EA of the error
- * since it is neither in DAR nor MD_EPN. As a workaround, the
- * _PAGE_HWWRITE bit is set for all kernel data pages when the PTEs
- * are initialized in mapin_ram(). This will avoid the problem,
- * assuming we only use the dcbi instruction on kernel addresses.
- */
mfspr r10, SPRN_DAR
- rlwinm r11, r10, 0, 0, 19
- ori r11, r11, MD_EVALID
- mfspr r10, SPRN_M_CASID
- rlwimi r11, r10, 0, 28, 31
- DO_8xx_CPU6(0x3780, r3)
- mtspr SPRN_MD_EPN, r11
-
- mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */
-
- /* If we are faulting a kernel address, we have to use the
- * kernel page tables.
- */
- andi. r11, r10, 0x0800
- beq 3f
- lis r11, swapper_pg_dir@h
- ori r11, r11, swapper_pg_dir@l
- rlwimi r10, r11, 0, 2, 19
-3:
- lwz r11, 0(r10) /* Get the level 1 entry */
- rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */
- beq 2f /* If zero, bail */
-
- /* We have a pte table, so fetch the pte from the table.
- */
- ori r11, r11, 1 /* Set valid bit in physical L2 page */
- DO_8xx_CPU6(0x3b80, r3)
- mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
- mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
- lwz r10, 0(r11) /* Get the pte */
-
- andi. r11, r10, _PAGE_RW /* Is it writeable? */
- beq 2f /* Bail out if not */
-
- /* Update 'changed', among others.
- */
-#ifdef CONFIG_SWAP
- ori r10, r10, _PAGE_DIRTY|_PAGE_HWWRITE
- /* do not set the _PAGE_ACCESSED bit of a non-present page */
- andi. r11, r10, _PAGE_PRESENT
- beq 4f
- ori r10, r10, _PAGE_ACCESSED
-4:
-#else
- ori r10, r10, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE
-#endif
- mfspr r11, SPRN_MD_TWC /* Get pte address again */
- stw r10, 0(r11) /* and update pte in table */
-
- /* The Linux PTE won't go exactly into the MMU TLB.
- * Software indicator bits 21, 22 and 28 must be clear.
- * Software indicator bits 24, 25, 26, and 27 must be
- * set. All other Linux PTE bits control the behavior
- * of the MMU.
- */
- li r11, 0x00f0
- rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */
- DO_8xx_CPU6(0x3d80, r3)
- mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
-
- mfspr r10, SPRN_M_TW /* Restore registers */
- lwz r11, 0(r0)
- mtcr r11
- lwz r11, 4(r0)
-#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0)
-#endif
- rfi
-2:
+ cmpwi cr0, r10, 0x00f0
+ beq- FixupDAR /* must be a buggy dcbX, icbi insn. */
+DARFixed:/* Return from dcbx instruction bug workaround, r10 holds value of DAR */
mfspr r10, SPRN_M_TW /* Restore registers */
lwz r11, 0(r0)
mtcr r11
@@ -587,9 +557,139 @@ DataTLBError:
. = 0x2000
- .globl giveup_fpu
-giveup_fpu:
- blr
+/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions
+ * by decoding the registers used by the dcbx instruction and adding them.
+ * DAR is set to the calculated address and r10 also holds the EA on exit.
+ */
+ /* define if you don't want to use self modifying code */
+#define NO_SELF_MODIFYING_CODE
+FixupDAR:/* Entry point for dcbx workaround. */
+ /* fetch instruction from memory. */
+ mfspr r10, SPRN_SRR0
+ andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
+ DO_8xx_CPU6(0x3780, r3)
+ mtspr SPRN_MD_EPN, r10
+ mfspr r11, SPRN_M_TWB /* Get level 1 table entry address */
+ beq- 3f /* Branch if user space */
+ lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
+ ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
+ rlwimi r11, r10, 32-20, 0xffc /* r11 = r11&~0xffc|(r10>>20)&0xffc */
+3: lwz r11, 0(r11) /* Get the level 1 entry */
+ DO_8xx_CPU6(0x3b80, r3)
+ mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
+ mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
+ lwz r11, 0(r11) /* Get the pte */
+ /* concat physical page address(r11) and page offset(r10) */
+ rlwimi r11, r10, 0, 20, 31
+ lwz r11,0(r11)
+/* Check if it really is a dcbx instruction. */
+/* dcbt and dcbtst does not generate DTLB Misses/Errors,
+ * no need to include them here */
+ srwi r10, r11, 26 /* check if major OP code is 31 */
+ cmpwi cr0, r10, 31
+ bne- 141f
+ rlwinm r10, r11, 0, 21, 30
+ cmpwi cr0, r10, 2028 /* Is dcbz? */
+ beq+ 142f
+ cmpwi cr0, r10, 940 /* Is dcbi? */
+ beq+ 142f
+ cmpwi cr0, r10, 108 /* Is dcbst? */
+ beq+ 144f /* Fix up store bit! */
+ cmpwi cr0, r10, 172 /* Is dcbf? */
+ beq+ 142f
+ cmpwi cr0, r10, 1964 /* Is icbi? */
+ beq+ 142f
+141: mfspr r10, SPRN_DAR /* r10 must hold DAR at exit */
+ b DARFixed /* Nope, go back to normal TLB processing */
+
+144: mfspr r10, SPRN_DSISR
+ rlwinm r10, r10,0,7,5 /* Clear store bit for buggy dcbst insn */
+ mtspr SPRN_DSISR, r10
+142: /* continue, it was a dcbx, dcbi instruction. */
+#ifdef CONFIG_8xx_CPU6
+ lwz r3, 8(r0) /* restore r3 from memory */
+#endif
+#ifndef NO_SELF_MODIFYING_CODE
+ andis. r10,r11,0x1f /* test if reg RA is r0 */
+ li r10,modified_instr@l
+ dcbtst r0,r10 /* touch for store */
+ rlwinm r11,r11,0,0,20 /* Zero lower 10 bits */
+ oris r11,r11,640 /* Transform instr. to a "add r10,RA,RB" */
+ ori r11,r11,532
+ stw r11,0(r10) /* store add/and instruction */
+ dcbf 0,r10 /* flush new instr. to memory. */
+ icbi 0,r10 /* invalidate instr. cache line */
+ lwz r11, 4(r0) /* restore r11 from memory */
+ mfspr r10, SPRN_M_TW /* restore r10 from M_TW */
+ isync /* Wait until new instr is loaded from memory */
+modified_instr:
+ .space 4 /* this is where the add instr. is stored */
+ bne+ 143f
+ subf r10,r0,r10 /* r10=r10-r0, only if reg RA is r0 */
+143: mtdar r10 /* store faulting EA in DAR */
+ b DARFixed /* Go back to normal TLB handling */
+#else
+ mfctr r10
+ mtdar r10 /* save ctr reg in DAR */
+ rlwinm r10, r11, 24, 24, 28 /* offset into jump table for reg RB */
+ addi r10, r10, 150f@l /* add start of table */
+ mtctr r10 /* load ctr with jump address */
+ xor r10, r10, r10 /* sum starts at zero */
+ bctr /* jump into table */
+150:
+ add r10, r10, r0 ;b 151f
+ add r10, r10, r1 ;b 151f
+ add r10, r10, r2 ;b 151f
+ add r10, r10, r3 ;b 151f
+ add r10, r10, r4 ;b 151f
+ add r10, r10, r5 ;b 151f
+ add r10, r10, r6 ;b 151f
+ add r10, r10, r7 ;b 151f
+ add r10, r10, r8 ;b 151f
+ add r10, r10, r9 ;b 151f
+ mtctr r11 ;b 154f /* r10 needs special handling */
+ mtctr r11 ;b 153f /* r11 needs special handling */
+ add r10, r10, r12 ;b 151f
+ add r10, r10, r13 ;b 151f
+ add r10, r10, r14 ;b 151f
+ add r10, r10, r15 ;b 151f
+ add r10, r10, r16 ;b 151f
+ add r10, r10, r17 ;b 151f
+ add r10, r10, r18 ;b 151f
+ add r10, r10, r19 ;b 151f
+ add r10, r10, r20 ;b 151f
+ add r10, r10, r21 ;b 151f
+ add r10, r10, r22 ;b 151f
+ add r10, r10, r23 ;b 151f
+ add r10, r10, r24 ;b 151f
+ add r10, r10, r25 ;b 151f
+ add r10, r10, r26 ;b 151f
+ add r10, r10, r27 ;b 151f
+ add r10, r10, r28 ;b 151f
+ add r10, r10, r29 ;b 151f
+ add r10, r10, r30 ;b 151f
+ add r10, r10, r31
+151:
+ rlwinm. r11,r11,19,24,28 /* offset into jump table for reg RA */
+ beq 152f /* if reg RA is zero, don't add it */
+ addi r11, r11, 150b@l /* add start of table */
+ mtctr r11 /* load ctr with jump address */
+ rlwinm r11,r11,0,16,10 /* make sure we don't execute this more than once */
+ bctr /* jump into table */
+152:
+ mfdar r11
+ mtctr r11 /* restore ctr reg from DAR */
+ mtdar r10 /* save fault EA to DAR */
+ b DARFixed /* Go back to normal TLB handling */
+
+ /* special handling for r10,r11 since these are modified already */
+153: lwz r11, 4(r0) /* load r11 from memory */
+ b 155f
+154: mfspr r11, SPRN_M_TW /* load r10 from M_TW */
+155: add r10, r10, r11 /* add it */
+ mfctr r11 /* restore r11 */
+ b 151b
+#endif
/*
* This is where the main kernel code starts.
@@ -602,9 +702,7 @@ start_here:
/* ptr to phys current thread */
tophys(r4,r2)
addi r4,r4,THREAD /* init task's THREAD */
- mtspr SPRN_SPRG3,r4
- li r3,0
- mtspr SPRN_SPRG2,r3 /* 0 => r1 has kernel sp */
+ mtspr SPRN_SPRG_THREAD,r4
/* stack */
lis r1,init_thread_union@ha
@@ -617,11 +715,8 @@ start_here:
/*
* Decide what sort of machine this is and initialize the MMU.
*/
- mr r3,r31
- mr r4,r30
- mr r5,r29
- mr r6,r28
- mr r7,r27
+ li r3,0
+ mr r4,r31
bl machine_init
bl MMU_init
@@ -687,12 +782,12 @@ start_here:
*/
initial_mmu:
tlbia /* Invalidate all TLB entries */
-#ifdef CONFIG_PIN_TLB
+/* Always pin the first 8 MB ITLB to prevent ITLB
+ misses while mucking around with SRR0/SRR1 in asm
+*/
lis r8, MI_RSV4I@h
ori r8, r8, 0x1c00
-#else
- li r8, 0
-#endif
+
mtspr SPRN_MI_CTR, r8 /* Set instruction MMU control */
#ifdef CONFIG_PIN_TLB
@@ -763,6 +858,9 @@ initial_mmu:
addis r11, r11, 0x0080 /* Add 8M */
mtspr SPRN_MD_RPN, r11
+ addi r10, r10, 0x0100
+ mtspr SPRN_MD_CTR, r10
+
addis r8, r8, 0x0080 /* Add 8M */
mtspr SPRN_MD_EPN, r8
mtspr SPRN_MD_TWC, r9
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-09 06:20:55 +0000