|  | /* | 
|  | * 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 "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, CriticalInput, unknown_exception) | 
|  |  | 
|  | /* Machine Check Interrupt */ | 
|  | CRITICAL_EXCEPTION(0x0200, 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, 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, FloatingPointUnavailable, unknown_exception, EXC_XFER_EE) | 
|  | #endif | 
|  | /* System Call Interrupt */ | 
|  | START_EXCEPTION(SystemCall) | 
|  | NORMAL_EXCEPTION_PROLOG | 
|  | EXC_XFER_EE_LITE(0x0c00, DoSyscall) | 
|  |  | 
|  | /* Auxiliary Processor Unavailable Interrupt */ | 
|  | EXCEPTION(0x2020, AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE) | 
|  |  | 
|  | /* Decrementer Interrupt */ | 
|  | DECREMENTER_EXCEPTION | 
|  |  | 
|  | /* Fixed Internal Timer Interrupt */ | 
|  | /* TODO: Add FIT support */ | 
|  | EXCEPTION(0x1010, FixedIntervalTimer, unknown_exception, EXC_XFER_EE) | 
|  |  | 
|  | /* Watchdog Timer Interrupt */ | 
|  | /* TODO: Add watchdog support */ | 
|  | #ifdef CONFIG_BOOKE_WDT | 
|  | CRITICAL_EXCEPTION(0x1020, WatchdogTimer, WatchdogException) | 
|  | #else | 
|  | CRITICAL_EXCEPTION(0x1020, 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 | 
|  |  | 
|  | /* | 
|  | * Global functions | 
|  | */ | 
|  |  | 
|  | /* | 
|  | * Adjust the machine check IVOR on 440A cores | 
|  | */ | 
|  | _GLOBAL(__fixup_440A_mcheck) | 
|  | li	r3,MachineCheckA@l | 
|  | mtspr	SPRN_IVOR1,r3 | 
|  | sync | 
|  | blr | 
|  |  | 
|  | /* | 
|  | * extern void giveup_altivec(struct task_struct *prev) | 
|  | * | 
|  | * The 44x core does not have an AltiVec unit. | 
|  | */ | 
|  | _GLOBAL(giveup_altivec) | 
|  | blr | 
|  |  | 
|  | /* | 
|  | * extern void giveup_fpu(struct task_struct *prev) | 
|  | * | 
|  | * The 44x core does not have an FPU. | 
|  | */ | 
|  | #ifndef CONFIG_PPC_FPU | 
|  | _GLOBAL(giveup_fpu) | 
|  | blr | 
|  | #endif | 
|  |  | 
|  | _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 differenciate 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 | 
|  | */ | 
|  | mfspr	r3,SPRN_CCR0 | 
|  | oris	r3,r3,0x0020 | 
|  | 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 | 
|  |  | 
|  | /* | 
|  | * 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 */ |