v4.19.13 snapshot.
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
new file mode 100644
index 0000000..37e4a7c
--- /dev/null
+++ b/arch/powerpc/kernel/head_44x.S
@@ -0,0 +1,1278 @@
+/*
+ * Kernel execution entry point code.
+ *
+ * Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org>
+ * Initial PowerPC version.
+ * Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu>
+ * Rewritten for PReP
+ * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
+ * Low-level exception handers, MMU support, and rewrite.
+ * Copyright (c) 1997 Dan Malek <dmalek@jlc.net>
+ * PowerPC 8xx modifications.
+ * Copyright (c) 1998-1999 TiVo, Inc.
+ * PowerPC 403GCX modifications.
+ * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
+ * PowerPC 403GCX/405GP modifications.
+ * Copyright 2000 MontaVista Software Inc.
+ * PPC405 modifications
+ * PowerPC 403GCX/405GP modifications.
+ * Author: MontaVista Software, Inc.
+ * frank_rowand@mvista.com or source@mvista.com
+ * debbie_chu@mvista.com
+ * Copyright 2002-2005 MontaVista Software, Inc.
+ * PowerPC 44x support, Matt Porter <mporter@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/init.h>
+#include <asm/processor.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/cputable.h>
+#include <asm/thread_info.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/ptrace.h>
+#include <asm/synch.h>
+#include <asm/export.h>
+#include "head_booke.h"
+
+
+/* As with the other PowerPC ports, it is expected that when code
+ * execution begins here, the following registers contain valid, yet
+ * optional, information:
+ *
+ * r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.)
+ * r4 - Starting address of the init RAM disk
+ * r5 - Ending address of the init RAM disk
+ * r6 - Start of kernel command line string (e.g. "mem=128")
+ * r7 - End of kernel command line string
+ *
+ */
+ __HEAD
+_ENTRY(_stext);
+_ENTRY(_start);
+ /*
+ * Reserve a word at a fixed location to store the address
+ * of abatron_pteptrs
+ */
+ nop
+ mr r31,r3 /* save device tree ptr */
+ li r24,0 /* CPU number */
+
+#ifdef CONFIG_RELOCATABLE
+/*
+ * Relocate ourselves to the current runtime address.
+ * This is called only by the Boot CPU.
+ * "relocate" is called with our current runtime virutal
+ * address.
+ * r21 will be loaded with the physical runtime address of _stext
+ */
+ bl 0f /* Get our runtime address */
+0: mflr r21 /* Make it accessible */
+ addis r21,r21,(_stext - 0b)@ha
+ addi r21,r21,(_stext - 0b)@l /* Get our current runtime base */
+
+ /*
+ * We have the runtime (virutal) address of our base.
+ * We calculate our shift of offset from a 256M page.
+ * We could map the 256M page we belong to at PAGE_OFFSET and
+ * get going from there.
+ */
+ lis r4,KERNELBASE@h
+ ori r4,r4,KERNELBASE@l
+ rlwinm r6,r21,0,4,31 /* r6 = PHYS_START % 256M */
+ rlwinm r5,r4,0,4,31 /* r5 = KERNELBASE % 256M */
+ subf r3,r5,r6 /* r3 = r6 - r5 */
+ add r3,r4,r3 /* Required Virutal Address */
+
+ bl relocate
+#endif
+
+ bl init_cpu_state
+
+ /*
+ * This is where the main kernel code starts.
+ */
+
+ /* ptr to current */
+ lis r2,init_task@h
+ ori r2,r2,init_task@l
+
+ /* ptr to current thread */
+ addi r4,r2,THREAD /* init task's THREAD */
+ mtspr SPRN_SPRG_THREAD,r4
+
+ /* stack */
+ lis r1,init_thread_union@h
+ ori r1,r1,init_thread_union@l
+ li r0,0
+ stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
+
+ bl early_init
+
+#ifdef CONFIG_RELOCATABLE
+ /*
+ * Relocatable kernel support based on processing of dynamic
+ * relocation entries.
+ *
+ * r25 will contain RPN/ERPN for the start address of memory
+ * r21 will contain the current offset of _stext
+ */
+ lis r3,kernstart_addr@ha
+ la r3,kernstart_addr@l(r3)
+
+ /*
+ * Compute the kernstart_addr.
+ * kernstart_addr => (r6,r8)
+ * kernstart_addr & ~0xfffffff => (r6,r7)
+ */
+ rlwinm r6,r25,0,28,31 /* ERPN. Bits 32-35 of Address */
+ rlwinm r7,r25,0,0,3 /* RPN - assuming 256 MB page size */
+ rlwinm r8,r21,0,4,31 /* r8 = (_stext & 0xfffffff) */
+ or r8,r7,r8 /* Compute the lower 32bit of kernstart_addr */
+
+ /* Store kernstart_addr */
+ stw r6,0(r3) /* higher 32bit */
+ stw r8,4(r3) /* lower 32bit */
+
+ /*
+ * Compute the virt_phys_offset :
+ * virt_phys_offset = stext.run - kernstart_addr
+ *
+ * stext.run = (KERNELBASE & ~0xfffffff) + (kernstart_addr & 0xfffffff)
+ * When we relocate, we have :
+ *
+ * (kernstart_addr & 0xfffffff) = (stext.run & 0xfffffff)
+ *
+ * hence:
+ * virt_phys_offset = (KERNELBASE & ~0xfffffff) - (kernstart_addr & ~0xfffffff)
+ *
+ */
+
+ /* KERNELBASE&~0xfffffff => (r4,r5) */
+ li r4, 0 /* higer 32bit */
+ lis r5,KERNELBASE@h
+ rlwinm r5,r5,0,0,3 /* Align to 256M, lower 32bit */
+
+ /*
+ * 64bit subtraction.
+ */
+ subfc r5,r7,r5
+ subfe r4,r6,r4
+
+ /* Store virt_phys_offset */
+ lis r3,virt_phys_offset@ha
+ la r3,virt_phys_offset@l(r3)
+
+ stw r4,0(r3)
+ stw r5,4(r3)
+
+#elif defined(CONFIG_DYNAMIC_MEMSTART)
+ /*
+ * Mapping based, page aligned dynamic kernel loading.
+ *
+ * r25 will contain RPN/ERPN for the start address of memory
+ *
+ * Add the difference between KERNELBASE and PAGE_OFFSET to the
+ * start of physical memory to get kernstart_addr.
+ */
+ lis r3,kernstart_addr@ha
+ la r3,kernstart_addr@l(r3)
+
+ lis r4,KERNELBASE@h
+ ori r4,r4,KERNELBASE@l
+ lis r5,PAGE_OFFSET@h
+ ori r5,r5,PAGE_OFFSET@l
+ subf r4,r5,r4
+
+ rlwinm r6,r25,0,28,31 /* ERPN */
+ rlwinm r7,r25,0,0,3 /* RPN - assuming 256 MB page size */
+ add r7,r7,r4
+
+ stw r6,0(r3)
+ stw r7,4(r3)
+#endif
+
+/*
+ * Decide what sort of machine this is and initialize the MMU.
+ */
+ li r3,0
+ mr r4,r31
+ bl machine_init
+ bl MMU_init
+
+ /* Setup PTE pointers for the Abatron bdiGDB */
+ lis r6, swapper_pg_dir@h
+ ori r6, r6, swapper_pg_dir@l
+ lis r5, abatron_pteptrs@h
+ ori r5, r5, abatron_pteptrs@l
+ lis r4, KERNELBASE@h
+ ori r4, r4, KERNELBASE@l
+ stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */
+ stw r6, 0(r5)
+
+ /* Clear the Machine Check Syndrome Register */
+ li r0,0
+ mtspr SPRN_MCSR,r0
+
+ /* Let's move on */
+ lis r4,start_kernel@h
+ ori r4,r4,start_kernel@l
+ lis r3,MSR_KERNEL@h
+ ori r3,r3,MSR_KERNEL@l
+ mtspr SPRN_SRR0,r4
+ mtspr SPRN_SRR1,r3
+ rfi /* change context and jump to start_kernel */
+
+/*
+ * Interrupt vector entry code
+ *
+ * The Book E MMUs are always on so we don't need to handle
+ * interrupts in real mode as with previous PPC processors. In
+ * this case we handle interrupts in the kernel virtual address
+ * space.
+ *
+ * Interrupt vectors are dynamically placed relative to the
+ * interrupt prefix as determined by the address of interrupt_base.
+ * The interrupt vectors offsets are programmed using the labels
+ * for each interrupt vector entry.
+ *
+ * Interrupt vectors must be aligned on a 16 byte boundary.
+ * We align on a 32 byte cache line boundary for good measure.
+ */
+
+interrupt_base:
+ /* Critical Input Interrupt */
+ CRITICAL_EXCEPTION(0x0100, CRITICAL, CriticalInput, unknown_exception)
+
+ /* Machine Check Interrupt */
+ CRITICAL_EXCEPTION(0x0200, MACHINE_CHECK, MachineCheck, \
+ machine_check_exception)
+ MCHECK_EXCEPTION(0x0210, MachineCheckA, machine_check_exception)
+
+ /* Data Storage Interrupt */
+ DATA_STORAGE_EXCEPTION
+
+ /* Instruction Storage Interrupt */
+ INSTRUCTION_STORAGE_EXCEPTION
+
+ /* External Input Interrupt */
+ EXCEPTION(0x0500, BOOKE_INTERRUPT_EXTERNAL, ExternalInput, \
+ do_IRQ, EXC_XFER_LITE)
+
+ /* Alignment Interrupt */
+ ALIGNMENT_EXCEPTION
+
+ /* Program Interrupt */
+ PROGRAM_EXCEPTION
+
+ /* Floating Point Unavailable Interrupt */
+#ifdef CONFIG_PPC_FPU
+ FP_UNAVAILABLE_EXCEPTION
+#else
+ EXCEPTION(0x2010, BOOKE_INTERRUPT_FP_UNAVAIL, \
+ FloatingPointUnavailable, unknown_exception, EXC_XFER_EE)
+#endif
+ /* System Call Interrupt */
+ START_EXCEPTION(SystemCall)
+ NORMAL_EXCEPTION_PROLOG(BOOKE_INTERRUPT_SYSCALL)
+ EXC_XFER_EE_LITE(0x0c00, DoSyscall)
+
+ /* Auxiliary Processor Unavailable Interrupt */
+ EXCEPTION(0x2020, BOOKE_INTERRUPT_AP_UNAVAIL, \
+ AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE)
+
+ /* Decrementer Interrupt */
+ DECREMENTER_EXCEPTION
+
+ /* Fixed Internal Timer Interrupt */
+ /* TODO: Add FIT support */
+ EXCEPTION(0x1010, BOOKE_INTERRUPT_FIT, FixedIntervalTimer, \
+ unknown_exception, EXC_XFER_EE)
+
+ /* Watchdog Timer Interrupt */
+ /* TODO: Add watchdog support */
+#ifdef CONFIG_BOOKE_WDT
+ CRITICAL_EXCEPTION(0x1020, WATCHDOG, WatchdogTimer, WatchdogException)
+#else
+ CRITICAL_EXCEPTION(0x1020, WATCHDOG, WatchdogTimer, unknown_exception)
+#endif
+
+ /* Data TLB Error Interrupt */
+ START_EXCEPTION(DataTLBError44x)
+ mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */
+ mtspr SPRN_SPRG_WSCRATCH1, r11
+ mtspr SPRN_SPRG_WSCRATCH2, r12
+ mtspr SPRN_SPRG_WSCRATCH3, r13
+ mfcr r11
+ mtspr SPRN_SPRG_WSCRATCH4, r11
+ mfspr r10, SPRN_DEAR /* Get faulting address */
+
+ /* If we are faulting a kernel address, we have to use the
+ * kernel page tables.
+ */
+ lis r11, PAGE_OFFSET@h
+ cmplw r10, r11
+ blt+ 3f
+ lis r11, swapper_pg_dir@h
+ ori r11, r11, swapper_pg_dir@l
+
+ mfspr r12,SPRN_MMUCR
+ rlwinm r12,r12,0,0,23 /* Clear TID */
+
+ b 4f
+
+ /* Get the PGD for the current thread */
+3:
+ mfspr r11,SPRN_SPRG_THREAD
+ lwz r11,PGDIR(r11)
+
+ /* Load PID into MMUCR TID */
+ mfspr r12,SPRN_MMUCR
+ mfspr r13,SPRN_PID /* Get PID */
+ rlwimi r12,r13,0,24,31 /* Set TID */
+
+4:
+ mtspr SPRN_MMUCR,r12
+
+ /* Mask of required permission bits. Note that while we
+ * do copy ESR:ST to _PAGE_RW position as trying to write
+ * to an RO page is pretty common, we don't do it with
+ * _PAGE_DIRTY. We could do it, but it's a fairly rare
+ * event so I'd rather take the overhead when it happens
+ * rather than adding an instruction here. We should measure
+ * whether the whole thing is worth it in the first place
+ * as we could avoid loading SPRN_ESR completely in the first
+ * place...
+ *
+ * TODO: Is it worth doing that mfspr & rlwimi in the first
+ * place or can we save a couple of instructions here ?
+ */
+ mfspr r12,SPRN_ESR
+ li r13,_PAGE_PRESENT|_PAGE_ACCESSED
+ rlwimi r13,r12,10,30,30
+
+ /* Load the PTE */
+ /* Compute pgdir/pmd offset */
+ rlwinm r12, r10, PPC44x_PGD_OFF_SHIFT, PPC44x_PGD_OFF_MASK_BIT, 29
+ lwzx r11, r12, r11 /* Get pgd/pmd entry */
+ rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
+ beq 2f /* Bail if no table */
+
+ /* Compute pte address */
+ rlwimi r12, r10, PPC44x_PTE_ADD_SHIFT, PPC44x_PTE_ADD_MASK_BIT, 28
+ lwz r11, 0(r12) /* Get high word of pte entry */
+ lwz r12, 4(r12) /* Get low word of pte entry */
+
+ lis r10,tlb_44x_index@ha
+
+ andc. r13,r13,r12 /* Check permission */
+
+ /* Load the next available TLB index */
+ lwz r13,tlb_44x_index@l(r10)
+
+ bne 2f /* Bail if permission mismach */
+
+ /* Increment, rollover, and store TLB index */
+ addi r13,r13,1
+
+ /* Compare with watermark (instruction gets patched) */
+ .globl tlb_44x_patch_hwater_D
+tlb_44x_patch_hwater_D:
+ cmpwi 0,r13,1 /* reserve entries */
+ ble 5f
+ li r13,0
+5:
+ /* Store the next available TLB index */
+ stw r13,tlb_44x_index@l(r10)
+
+ /* Re-load the faulting address */
+ mfspr r10,SPRN_DEAR
+
+ /* Jump to common tlb load */
+ b finish_tlb_load_44x
+
+2:
+ /* The bailout. Restore registers to pre-exception conditions
+ * and call the heavyweights to help us out.
+ */
+ mfspr r11, SPRN_SPRG_RSCRATCH4
+ mtcr r11
+ mfspr r13, SPRN_SPRG_RSCRATCH3
+ mfspr r12, SPRN_SPRG_RSCRATCH2
+ mfspr r11, SPRN_SPRG_RSCRATCH1
+ mfspr r10, SPRN_SPRG_RSCRATCH0
+ b DataStorage
+
+ /* Instruction TLB Error Interrupt */
+ /*
+ * Nearly the same as above, except we get our
+ * information from different registers and bailout
+ * to a different point.
+ */
+ START_EXCEPTION(InstructionTLBError44x)
+ mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */
+ mtspr SPRN_SPRG_WSCRATCH1, r11
+ mtspr SPRN_SPRG_WSCRATCH2, r12
+ mtspr SPRN_SPRG_WSCRATCH3, r13
+ mfcr r11
+ mtspr SPRN_SPRG_WSCRATCH4, r11
+ mfspr r10, SPRN_SRR0 /* Get faulting address */
+
+ /* If we are faulting a kernel address, we have to use the
+ * kernel page tables.
+ */
+ lis r11, PAGE_OFFSET@h
+ cmplw r10, r11
+ blt+ 3f
+ lis r11, swapper_pg_dir@h
+ ori r11, r11, swapper_pg_dir@l
+
+ mfspr r12,SPRN_MMUCR
+ rlwinm r12,r12,0,0,23 /* Clear TID */
+
+ b 4f
+
+ /* Get the PGD for the current thread */
+3:
+ mfspr r11,SPRN_SPRG_THREAD
+ lwz r11,PGDIR(r11)
+
+ /* Load PID into MMUCR TID */
+ mfspr r12,SPRN_MMUCR
+ mfspr r13,SPRN_PID /* Get PID */
+ rlwimi r12,r13,0,24,31 /* Set TID */
+
+4:
+ mtspr SPRN_MMUCR,r12
+
+ /* Make up the required permissions */
+ li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
+
+ /* Compute pgdir/pmd offset */
+ rlwinm r12, r10, PPC44x_PGD_OFF_SHIFT, PPC44x_PGD_OFF_MASK_BIT, 29
+ lwzx r11, r12, r11 /* Get pgd/pmd entry */
+ rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
+ beq 2f /* Bail if no table */
+
+ /* Compute pte address */
+ rlwimi r12, r10, PPC44x_PTE_ADD_SHIFT, PPC44x_PTE_ADD_MASK_BIT, 28
+ lwz r11, 0(r12) /* Get high word of pte entry */
+ lwz r12, 4(r12) /* Get low word of pte entry */
+
+ lis r10,tlb_44x_index@ha
+
+ andc. r13,r13,r12 /* Check permission */
+
+ /* Load the next available TLB index */
+ lwz r13,tlb_44x_index@l(r10)
+
+ bne 2f /* Bail if permission mismach */
+
+ /* Increment, rollover, and store TLB index */
+ addi r13,r13,1
+
+ /* Compare with watermark (instruction gets patched) */
+ .globl tlb_44x_patch_hwater_I
+tlb_44x_patch_hwater_I:
+ cmpwi 0,r13,1 /* reserve entries */
+ ble 5f
+ li r13,0
+5:
+ /* Store the next available TLB index */
+ stw r13,tlb_44x_index@l(r10)
+
+ /* Re-load the faulting address */
+ mfspr r10,SPRN_SRR0
+
+ /* Jump to common TLB load point */
+ b finish_tlb_load_44x
+
+2:
+ /* The bailout. Restore registers to pre-exception conditions
+ * and call the heavyweights to help us out.
+ */
+ mfspr r11, SPRN_SPRG_RSCRATCH4
+ mtcr r11
+ mfspr r13, SPRN_SPRG_RSCRATCH3
+ mfspr r12, SPRN_SPRG_RSCRATCH2
+ mfspr r11, SPRN_SPRG_RSCRATCH1
+ mfspr r10, SPRN_SPRG_RSCRATCH0
+ b InstructionStorage
+
+/*
+ * Both the instruction and data TLB miss get to this
+ * point to load the TLB.
+ * r10 - EA of fault
+ * r11 - PTE high word value
+ * r12 - PTE low word value
+ * r13 - TLB index
+ * MMUCR - loaded with proper value when we get here
+ * Upon exit, we reload everything and RFI.
+ */
+finish_tlb_load_44x:
+ /* Combine RPN & ERPN an write WS 0 */
+ rlwimi r11,r12,0,0,31-PAGE_SHIFT
+ tlbwe r11,r13,PPC44x_TLB_XLAT
+
+ /*
+ * Create WS1. This is the faulting address (EPN),
+ * page size, and valid flag.
+ */
+ li r11,PPC44x_TLB_VALID | PPC44x_TLBE_SIZE
+ /* Insert valid and page size */
+ rlwimi r10,r11,0,PPC44x_PTE_ADD_MASK_BIT,31
+ tlbwe r10,r13,PPC44x_TLB_PAGEID /* Write PAGEID */
+
+ /* And WS 2 */
+ li r10,0xf85 /* Mask to apply from PTE */
+ rlwimi r10,r12,29,30,30 /* DIRTY -> SW position */
+ and r11,r12,r10 /* Mask PTE bits to keep */
+ andi. r10,r12,_PAGE_USER /* User page ? */
+ beq 1f /* nope, leave U bits empty */
+ rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */
+1: tlbwe r11,r13,PPC44x_TLB_ATTRIB /* Write ATTRIB */
+
+ /* Done...restore registers and get out of here.
+ */
+ mfspr r11, SPRN_SPRG_RSCRATCH4
+ mtcr r11
+ mfspr r13, SPRN_SPRG_RSCRATCH3
+ mfspr r12, SPRN_SPRG_RSCRATCH2
+ mfspr r11, SPRN_SPRG_RSCRATCH1
+ mfspr r10, SPRN_SPRG_RSCRATCH0
+ rfi /* Force context change */
+
+/* TLB error interrupts for 476
+ */
+#ifdef CONFIG_PPC_47x
+ START_EXCEPTION(DataTLBError47x)
+ mtspr SPRN_SPRG_WSCRATCH0,r10 /* Save some working registers */
+ mtspr SPRN_SPRG_WSCRATCH1,r11
+ mtspr SPRN_SPRG_WSCRATCH2,r12
+ mtspr SPRN_SPRG_WSCRATCH3,r13
+ mfcr r11
+ mtspr SPRN_SPRG_WSCRATCH4,r11
+ mfspr r10,SPRN_DEAR /* Get faulting address */
+
+ /* If we are faulting a kernel address, we have to use the
+ * kernel page tables.
+ */
+ lis r11,PAGE_OFFSET@h
+ cmplw cr0,r10,r11
+ blt+ 3f
+ lis r11,swapper_pg_dir@h
+ ori r11,r11, swapper_pg_dir@l
+ li r12,0 /* MMUCR = 0 */
+ b 4f
+
+ /* Get the PGD for the current thread and setup MMUCR */
+3: mfspr r11,SPRN_SPRG3
+ lwz r11,PGDIR(r11)
+ mfspr r12,SPRN_PID /* Get PID */
+4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */
+
+ /* Mask of required permission bits. Note that while we
+ * do copy ESR:ST to _PAGE_RW position as trying to write
+ * to an RO page is pretty common, we don't do it with
+ * _PAGE_DIRTY. We could do it, but it's a fairly rare
+ * event so I'd rather take the overhead when it happens
+ * rather than adding an instruction here. We should measure
+ * whether the whole thing is worth it in the first place
+ * as we could avoid loading SPRN_ESR completely in the first
+ * place...
+ *
+ * TODO: Is it worth doing that mfspr & rlwimi in the first
+ * place or can we save a couple of instructions here ?
+ */
+ mfspr r12,SPRN_ESR
+ li r13,_PAGE_PRESENT|_PAGE_ACCESSED
+ rlwimi r13,r12,10,30,30
+
+ /* Load the PTE */
+ /* Compute pgdir/pmd offset */
+ rlwinm r12,r10,PPC44x_PGD_OFF_SHIFT,PPC44x_PGD_OFF_MASK_BIT,29
+ lwzx r11,r12,r11 /* Get pgd/pmd entry */
+
+ /* Word 0 is EPN,V,TS,DSIZ */
+ li r12,PPC47x_TLB0_VALID | PPC47x_TLBE_SIZE
+ rlwimi r10,r12,0,32-PAGE_SHIFT,31 /* Insert valid and page size*/
+ li r12,0
+ tlbwe r10,r12,0
+
+ /* XXX can we do better ? Need to make sure tlbwe has established
+ * latch V bit in MMUCR0 before the PTE is loaded further down */
+#ifdef CONFIG_SMP
+ isync
+#endif
+
+ rlwinm. r12,r11,0,0,20 /* Extract pt base address */
+ /* Compute pte address */
+ rlwimi r12,r10,PPC44x_PTE_ADD_SHIFT,PPC44x_PTE_ADD_MASK_BIT,28
+ beq 2f /* Bail if no table */
+ lwz r11,0(r12) /* Get high word of pte entry */
+
+ /* XXX can we do better ? maybe insert a known 0 bit from r11 into the
+ * bottom of r12 to create a data dependency... We can also use r10
+ * as destination nowadays
+ */
+#ifdef CONFIG_SMP
+ lwsync
+#endif
+ lwz r12,4(r12) /* Get low word of pte entry */
+
+ andc. r13,r13,r12 /* Check permission */
+
+ /* Jump to common tlb load */
+ beq finish_tlb_load_47x
+
+2: /* The bailout. Restore registers to pre-exception conditions
+ * and call the heavyweights to help us out.
+ */
+ mfspr r11,SPRN_SPRG_RSCRATCH4
+ mtcr r11
+ mfspr r13,SPRN_SPRG_RSCRATCH3
+ mfspr r12,SPRN_SPRG_RSCRATCH2
+ mfspr r11,SPRN_SPRG_RSCRATCH1
+ mfspr r10,SPRN_SPRG_RSCRATCH0
+ b DataStorage
+
+ /* Instruction TLB Error Interrupt */
+ /*
+ * Nearly the same as above, except we get our
+ * information from different registers and bailout
+ * to a different point.
+ */
+ START_EXCEPTION(InstructionTLBError47x)
+ mtspr SPRN_SPRG_WSCRATCH0,r10 /* Save some working registers */
+ mtspr SPRN_SPRG_WSCRATCH1,r11
+ mtspr SPRN_SPRG_WSCRATCH2,r12
+ mtspr SPRN_SPRG_WSCRATCH3,r13
+ mfcr r11
+ mtspr SPRN_SPRG_WSCRATCH4,r11
+ mfspr r10,SPRN_SRR0 /* Get faulting address */
+
+ /* If we are faulting a kernel address, we have to use the
+ * kernel page tables.
+ */
+ lis r11,PAGE_OFFSET@h
+ cmplw cr0,r10,r11
+ blt+ 3f
+ lis r11,swapper_pg_dir@h
+ ori r11,r11, swapper_pg_dir@l
+ li r12,0 /* MMUCR = 0 */
+ b 4f
+
+ /* Get the PGD for the current thread and setup MMUCR */
+3: mfspr r11,SPRN_SPRG_THREAD
+ lwz r11,PGDIR(r11)
+ mfspr r12,SPRN_PID /* Get PID */
+4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */
+
+ /* Make up the required permissions */
+ li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
+
+ /* Load PTE */
+ /* Compute pgdir/pmd offset */
+ rlwinm r12,r10,PPC44x_PGD_OFF_SHIFT,PPC44x_PGD_OFF_MASK_BIT,29
+ lwzx r11,r12,r11 /* Get pgd/pmd entry */
+
+ /* Word 0 is EPN,V,TS,DSIZ */
+ li r12,PPC47x_TLB0_VALID | PPC47x_TLBE_SIZE
+ rlwimi r10,r12,0,32-PAGE_SHIFT,31 /* Insert valid and page size*/
+ li r12,0
+ tlbwe r10,r12,0
+
+ /* XXX can we do better ? Need to make sure tlbwe has established
+ * latch V bit in MMUCR0 before the PTE is loaded further down */
+#ifdef CONFIG_SMP
+ isync
+#endif
+
+ rlwinm. r12,r11,0,0,20 /* Extract pt base address */
+ /* Compute pte address */
+ rlwimi r12,r10,PPC44x_PTE_ADD_SHIFT,PPC44x_PTE_ADD_MASK_BIT,28
+ beq 2f /* Bail if no table */
+
+ lwz r11,0(r12) /* Get high word of pte entry */
+ /* XXX can we do better ? maybe insert a known 0 bit from r11 into the
+ * bottom of r12 to create a data dependency... We can also use r10
+ * as destination nowadays
+ */
+#ifdef CONFIG_SMP
+ lwsync
+#endif
+ lwz r12,4(r12) /* Get low word of pte entry */
+
+ andc. r13,r13,r12 /* Check permission */
+
+ /* Jump to common TLB load point */
+ beq finish_tlb_load_47x
+
+2: /* The bailout. Restore registers to pre-exception conditions
+ * and call the heavyweights to help us out.
+ */
+ mfspr r11, SPRN_SPRG_RSCRATCH4
+ mtcr r11
+ mfspr r13, SPRN_SPRG_RSCRATCH3
+ mfspr r12, SPRN_SPRG_RSCRATCH2
+ mfspr r11, SPRN_SPRG_RSCRATCH1
+ mfspr r10, SPRN_SPRG_RSCRATCH0
+ b InstructionStorage
+
+/*
+ * Both the instruction and data TLB miss get to this
+ * point to load the TLB.
+ * r10 - free to use
+ * r11 - PTE high word value
+ * r12 - PTE low word value
+ * r13 - free to use
+ * MMUCR - loaded with proper value when we get here
+ * Upon exit, we reload everything and RFI.
+ */
+finish_tlb_load_47x:
+ /* Combine RPN & ERPN an write WS 1 */
+ rlwimi r11,r12,0,0,31-PAGE_SHIFT
+ tlbwe r11,r13,1
+
+ /* And make up word 2 */
+ li r10,0xf85 /* Mask to apply from PTE */
+ rlwimi r10,r12,29,30,30 /* DIRTY -> SW position */
+ and r11,r12,r10 /* Mask PTE bits to keep */
+ andi. r10,r12,_PAGE_USER /* User page ? */
+ beq 1f /* nope, leave U bits empty */
+ rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */
+1: tlbwe r11,r13,2
+
+ /* Done...restore registers and get out of here.
+ */
+ mfspr r11, SPRN_SPRG_RSCRATCH4
+ mtcr r11
+ mfspr r13, SPRN_SPRG_RSCRATCH3
+ mfspr r12, SPRN_SPRG_RSCRATCH2
+ mfspr r11, SPRN_SPRG_RSCRATCH1
+ mfspr r10, SPRN_SPRG_RSCRATCH0
+ rfi
+
+#endif /* CONFIG_PPC_47x */
+
+ /* Debug Interrupt */
+ /*
+ * This statement needs to exist at the end of the IVPR
+ * definition just in case you end up taking a debug
+ * exception within another exception.
+ */
+ DEBUG_CRIT_EXCEPTION
+
+interrupt_end:
+
+/*
+ * Global functions
+ */
+
+/*
+ * Adjust the machine check IVOR on 440A cores
+ */
+_GLOBAL(__fixup_440A_mcheck)
+ li r3,MachineCheckA@l
+ mtspr SPRN_IVOR1,r3
+ sync
+ blr
+
+_GLOBAL(set_context)
+
+#ifdef CONFIG_BDI_SWITCH
+ /* Context switch the PTE pointer for the Abatron BDI2000.
+ * The PGDIR is the second parameter.
+ */
+ lis r5, abatron_pteptrs@h
+ ori r5, r5, abatron_pteptrs@l
+ stw r4, 0x4(r5)
+#endif
+ mtspr SPRN_PID,r3
+ isync /* Force context change */
+ blr
+
+/*
+ * Init CPU state. This is called at boot time or for secondary CPUs
+ * to setup initial TLB entries, setup IVORs, etc...
+ *
+ */
+_GLOBAL(init_cpu_state)
+ mflr r22
+#ifdef CONFIG_PPC_47x
+ /* We use the PVR to differentiate 44x cores from 476 */
+ mfspr r3,SPRN_PVR
+ srwi r3,r3,16
+ cmplwi cr0,r3,PVR_476FPE@h
+ beq head_start_47x
+ cmplwi cr0,r3,PVR_476@h
+ beq head_start_47x
+ cmplwi cr0,r3,PVR_476_ISS@h
+ beq head_start_47x
+#endif /* CONFIG_PPC_47x */
+
+/*
+ * In case the firmware didn't do it, we apply some workarounds
+ * that are good for all 440 core variants here
+ */
+ mfspr r3,SPRN_CCR0
+ rlwinm r3,r3,0,0,27 /* disable icache prefetch */
+ isync
+ mtspr SPRN_CCR0,r3
+ isync
+ sync
+
+/*
+ * Set up the initial MMU state for 44x
+ *
+ * We are still executing code at the virtual address
+ * mappings set by the firmware for the base of RAM.
+ *
+ * We first invalidate all TLB entries but the one
+ * we are running from. We then load the KERNELBASE
+ * mappings so we can begin to use kernel addresses
+ * natively and so the interrupt vector locations are
+ * permanently pinned (necessary since Book E
+ * implementations always have translation enabled).
+ *
+ * TODO: Use the known TLB entry we are running from to
+ * determine which physical region we are located
+ * in. This can be used to determine where in RAM
+ * (on a shared CPU system) or PCI memory space
+ * (on a DRAMless system) we are located.
+ * For now, we assume a perfect world which means
+ * we are located at the base of DRAM (physical 0).
+ */
+
+/*
+ * Search TLB for entry that we are currently using.
+ * Invalidate all entries but the one we are using.
+ */
+ /* Load our current PID->MMUCR TID and MSR IS->MMUCR STS */
+ mfspr r3,SPRN_PID /* Get PID */
+ mfmsr r4 /* Get MSR */
+ andi. r4,r4,MSR_IS@l /* TS=1? */
+ beq wmmucr /* If not, leave STS=0 */
+ oris r3,r3,PPC44x_MMUCR_STS@h /* Set STS=1 */
+wmmucr: mtspr SPRN_MMUCR,r3 /* Put MMUCR */
+ sync
+
+ bl invstr /* Find our address */
+invstr: mflr r5 /* Make it accessible */
+ tlbsx r23,0,r5 /* Find entry we are in */
+ li r4,0 /* Start at TLB entry 0 */
+ li r3,0 /* Set PAGEID inval value */
+1: cmpw r23,r4 /* Is this our entry? */
+ beq skpinv /* If so, skip the inval */
+ tlbwe r3,r4,PPC44x_TLB_PAGEID /* If not, inval the entry */
+skpinv: addi r4,r4,1 /* Increment */
+ cmpwi r4,64 /* Are we done? */
+ bne 1b /* If not, repeat */
+ isync /* If so, context change */
+
+/*
+ * Configure and load pinned entry into TLB slot 63.
+ */
+#ifdef CONFIG_NONSTATIC_KERNEL
+ /*
+ * In case of a NONSTATIC_KERNEL we reuse the TLB XLAT
+ * entries of the initial mapping set by the boot loader.
+ * The XLAT entry is stored in r25
+ */
+
+ /* Read the XLAT entry for our current mapping */
+ tlbre r25,r23,PPC44x_TLB_XLAT
+
+ lis r3,KERNELBASE@h
+ ori r3,r3,KERNELBASE@l
+
+ /* Use our current RPN entry */
+ mr r4,r25
+#else
+
+ lis r3,PAGE_OFFSET@h
+ ori r3,r3,PAGE_OFFSET@l
+
+ /* Kernel is at the base of RAM */
+ li r4, 0 /* Load the kernel physical address */
+#endif
+
+ /* Load the kernel PID = 0 */
+ li r0,0
+ mtspr SPRN_PID,r0
+ sync
+
+ /* Initialize MMUCR */
+ li r5,0
+ mtspr SPRN_MMUCR,r5
+ sync
+
+ /* pageid fields */
+ clrrwi r3,r3,10 /* Mask off the effective page number */
+ ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_256M
+
+ /* xlat fields */
+ clrrwi r4,r4,10 /* Mask off the real page number */
+ /* ERPN is 0 for first 4GB page */
+
+ /* attrib fields */
+ /* Added guarded bit to protect against speculative loads/stores */
+ li r5,0
+ ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G)
+
+ li r0,63 /* TLB slot 63 */
+
+ tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */
+ tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */
+ tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */
+
+ /* Force context change */
+ mfmsr r0
+ mtspr SPRN_SRR1, r0
+ lis r0,3f@h
+ ori r0,r0,3f@l
+ mtspr SPRN_SRR0,r0
+ sync
+ rfi
+
+ /* If necessary, invalidate original entry we used */
+3: cmpwi r23,63
+ beq 4f
+ li r6,0
+ tlbwe r6,r23,PPC44x_TLB_PAGEID
+ isync
+
+4:
+#ifdef CONFIG_PPC_EARLY_DEBUG_44x
+ /* Add UART mapping for early debug. */
+
+ /* pageid fields */
+ lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h
+ ori r3,r3,PPC44x_TLB_VALID|PPC44x_TLB_TS|PPC44x_TLB_64K
+
+ /* xlat fields */
+ lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h
+ ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH
+
+ /* attrib fields */
+ li r5,(PPC44x_TLB_SW|PPC44x_TLB_SR|PPC44x_TLB_I|PPC44x_TLB_G)
+ li r0,62 /* TLB slot 0 */
+
+ tlbwe r3,r0,PPC44x_TLB_PAGEID
+ tlbwe r4,r0,PPC44x_TLB_XLAT
+ tlbwe r5,r0,PPC44x_TLB_ATTRIB
+
+ /* Force context change */
+ isync
+#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
+
+ /* Establish the interrupt vector offsets */
+ SET_IVOR(0, CriticalInput);
+ SET_IVOR(1, MachineCheck);
+ SET_IVOR(2, DataStorage);
+ SET_IVOR(3, InstructionStorage);
+ SET_IVOR(4, ExternalInput);
+ SET_IVOR(5, Alignment);
+ SET_IVOR(6, Program);
+ SET_IVOR(7, FloatingPointUnavailable);
+ SET_IVOR(8, SystemCall);
+ SET_IVOR(9, AuxillaryProcessorUnavailable);
+ SET_IVOR(10, Decrementer);
+ SET_IVOR(11, FixedIntervalTimer);
+ SET_IVOR(12, WatchdogTimer);
+ SET_IVOR(13, DataTLBError44x);
+ SET_IVOR(14, InstructionTLBError44x);
+ SET_IVOR(15, DebugCrit);
+
+ b head_start_common
+
+
+#ifdef CONFIG_PPC_47x
+
+#ifdef CONFIG_SMP
+
+/* Entry point for secondary 47x processors */
+_GLOBAL(start_secondary_47x)
+ mr r24,r3 /* CPU number */
+
+ bl init_cpu_state
+
+ /* Now we need to bolt the rest of kernel memory which
+ * is done in C code. We must be careful because our task
+ * struct or our stack can (and will probably) be out
+ * of reach of the initial 256M TLB entry, so we use a
+ * small temporary stack in .bss for that. This works
+ * because only one CPU at a time can be in this code
+ */
+ lis r1,temp_boot_stack@h
+ ori r1,r1,temp_boot_stack@l
+ addi r1,r1,1024-STACK_FRAME_OVERHEAD
+ li r0,0
+ stw r0,0(r1)
+ bl mmu_init_secondary
+
+ /* Now we can get our task struct and real stack pointer */
+
+ /* Get current_thread_info and current */
+ lis r1,secondary_ti@ha
+ lwz r1,secondary_ti@l(r1)
+ lwz r2,TI_TASK(r1)
+
+ /* Current stack pointer */
+ addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
+ li r0,0
+ stw r0,0(r1)
+
+ /* Kernel stack for exception entry in SPRG3 */
+ addi r4,r2,THREAD /* init task's THREAD */
+ mtspr SPRN_SPRG3,r4
+
+ b start_secondary
+
+#endif /* CONFIG_SMP */
+
+/*
+ * Set up the initial MMU state for 44x
+ *
+ * We are still executing code at the virtual address
+ * mappings set by the firmware for the base of RAM.
+ */
+
+head_start_47x:
+ /* Load our current PID->MMUCR TID and MSR IS->MMUCR STS */
+ mfspr r3,SPRN_PID /* Get PID */
+ mfmsr r4 /* Get MSR */
+ andi. r4,r4,MSR_IS@l /* TS=1? */
+ beq 1f /* If not, leave STS=0 */
+ oris r3,r3,PPC47x_MMUCR_STS@h /* Set STS=1 */
+1: mtspr SPRN_MMUCR,r3 /* Put MMUCR */
+ sync
+
+ /* Find the entry we are running from */
+ bl 1f
+1: mflr r23
+ tlbsx r23,0,r23
+ tlbre r24,r23,0
+ tlbre r25,r23,1
+ tlbre r26,r23,2
+
+/*
+ * Cleanup time
+ */
+
+ /* Initialize MMUCR */
+ li r5,0
+ mtspr SPRN_MMUCR,r5
+ sync
+
+clear_all_utlb_entries:
+
+ #; Set initial values.
+
+ addis r3,0,0x8000
+ addi r4,0,0
+ addi r5,0,0
+ b clear_utlb_entry
+
+ #; Align the loop to speed things up.
+
+ .align 6
+
+clear_utlb_entry:
+
+ tlbwe r4,r3,0
+ tlbwe r5,r3,1
+ tlbwe r5,r3,2
+ addis r3,r3,0x2000
+ cmpwi r3,0
+ bne clear_utlb_entry
+ addis r3,0,0x8000
+ addis r4,r4,0x100
+ cmpwi r4,0
+ bne clear_utlb_entry
+
+ #; Restore original entry.
+
+ oris r23,r23,0x8000 /* specify the way */
+ tlbwe r24,r23,0
+ tlbwe r25,r23,1
+ tlbwe r26,r23,2
+
+/*
+ * Configure and load pinned entry into TLB for the kernel core
+ */
+
+ lis r3,PAGE_OFFSET@h
+ ori r3,r3,PAGE_OFFSET@l
+
+ /* Load the kernel PID = 0 */
+ li r0,0
+ mtspr SPRN_PID,r0
+ sync
+
+ /* Word 0 */
+ clrrwi r3,r3,12 /* Mask off the effective page number */
+ ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_256M
+
+ /* Word 1 - use r25. RPN is the same as the original entry */
+
+ /* Word 2 */
+ li r5,0
+ ori r5,r5,PPC47x_TLB2_S_RWX
+#ifdef CONFIG_SMP
+ ori r5,r5,PPC47x_TLB2_M
+#endif
+
+ /* We write to way 0 and bolted 0 */
+ lis r0,0x8800
+ tlbwe r3,r0,0
+ tlbwe r25,r0,1
+ tlbwe r5,r0,2
+
+/*
+ * Configure SSPCR, ISPCR and USPCR for now to search everything, we can fix
+ * them up later
+ */
+ LOAD_REG_IMMEDIATE(r3, 0x9abcdef0)
+ mtspr SPRN_SSPCR,r3
+ mtspr SPRN_USPCR,r3
+ LOAD_REG_IMMEDIATE(r3, 0x12345670)
+ mtspr SPRN_ISPCR,r3
+
+ /* Force context change */
+ mfmsr r0
+ mtspr SPRN_SRR1, r0
+ lis r0,3f@h
+ ori r0,r0,3f@l
+ mtspr SPRN_SRR0,r0
+ sync
+ rfi
+
+ /* Invalidate original entry we used */
+3:
+ rlwinm r24,r24,0,21,19 /* clear the "valid" bit */
+ tlbwe r24,r23,0
+ addi r24,0,0
+ tlbwe r24,r23,1
+ tlbwe r24,r23,2
+ isync /* Clear out the shadow TLB entries */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_44x
+ /* Add UART mapping for early debug. */
+
+ /* Word 0 */
+ lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h
+ ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_TS | PPC47x_TLB0_1M
+
+ /* Word 1 */
+ lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h
+ ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH
+
+ /* Word 2 */
+ li r5,(PPC47x_TLB2_S_RW | PPC47x_TLB2_IMG)
+
+ /* Bolted in way 0, bolt slot 5, we -hope- we don't hit the same
+ * congruence class as the kernel, we need to make sure of it at
+ * some point
+ */
+ lis r0,0x8d00
+ tlbwe r3,r0,0
+ tlbwe r4,r0,1
+ tlbwe r5,r0,2
+
+ /* Force context change */
+ isync
+#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
+
+ /* Establish the interrupt vector offsets */
+ SET_IVOR(0, CriticalInput);
+ SET_IVOR(1, MachineCheckA);
+ SET_IVOR(2, DataStorage);
+ SET_IVOR(3, InstructionStorage);
+ SET_IVOR(4, ExternalInput);
+ SET_IVOR(5, Alignment);
+ SET_IVOR(6, Program);
+ SET_IVOR(7, FloatingPointUnavailable);
+ SET_IVOR(8, SystemCall);
+ SET_IVOR(9, AuxillaryProcessorUnavailable);
+ SET_IVOR(10, Decrementer);
+ SET_IVOR(11, FixedIntervalTimer);
+ SET_IVOR(12, WatchdogTimer);
+ SET_IVOR(13, DataTLBError47x);
+ SET_IVOR(14, InstructionTLBError47x);
+ SET_IVOR(15, DebugCrit);
+
+ /* We configure icbi to invalidate 128 bytes at a time since the
+ * current 32-bit kernel code isn't too happy with icache != dcache
+ * block size. We also disable the BTAC as this can cause errors
+ * in some circumstances (see IBM Erratum 47).
+ */
+ mfspr r3,SPRN_CCR0
+ oris r3,r3,0x0020
+ ori r3,r3,0x0040
+ mtspr SPRN_CCR0,r3
+ isync
+
+#endif /* CONFIG_PPC_47x */
+
+/*
+ * Here we are back to code that is common between 44x and 47x
+ *
+ * We proceed to further kernel initialization and return to the
+ * main kernel entry
+ */
+head_start_common:
+ /* Establish the interrupt vector base */
+ lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */
+ mtspr SPRN_IVPR,r4
+
+ /*
+ * If the kernel was loaded at a non-zero 256 MB page, we need to
+ * mask off the most significant 4 bits to get the relative address
+ * from the start of physical memory
+ */
+ rlwinm r22,r22,0,4,31
+ addis r22,r22,PAGE_OFFSET@h
+ mtlr r22
+ isync
+ blr
+
+/*
+ * We put a few things here that have to be page-aligned. This stuff
+ * goes at the beginning of the data segment, which is page-aligned.
+ */
+ .data
+ .align PAGE_SHIFT
+ .globl sdata
+sdata:
+ .globl empty_zero_page
+empty_zero_page:
+ .space PAGE_SIZE
+EXPORT_SYMBOL(empty_zero_page)
+
+/*
+ * To support >32-bit physical addresses, we use an 8KB pgdir.
+ */
+ .globl swapper_pg_dir
+swapper_pg_dir:
+ .space PGD_TABLE_SIZE
+
+/*
+ * Room for two PTE pointers, usually the kernel and current user pointers
+ * to their respective root page table.
+ */
+abatron_pteptrs:
+ .space 8
+
+#ifdef CONFIG_SMP
+ .align 12
+temp_boot_stack:
+ .space 1024
+#endif /* CONFIG_SMP */