--- /dev/null
+/*
+ * arch/powerpc/kernel/misc64.S
+ *
+ * This file contains miscellaneous low-level functions.
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
+ * and Paul Mackerras.
+ * Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
+ * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
+ *
+ * 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/config.h>
+#include <linux/sys.h>
+#include <asm/unistd.h>
+#include <asm/errno.h>
+#include <asm/processor.h>
+#include <asm/page.h>
+#include <asm/cache.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/cputable.h>
+#include <asm/thread_info.h>
+
+ .text
+
+/*
+ * Returns (address we are running at) - (address we were linked at)
+ * for use before the text and data are mapped to KERNELBASE.
+ */
+
+_GLOBAL(reloc_offset)
+ mflr r0
+ bl 1f
+1: mflr r3
+ LOAD_REG_IMMEDIATE(r4,1b)
+ subf r3,r4,r3
+ mtlr r0
+ blr
+
+/*
+ * add_reloc_offset(x) returns x + reloc_offset().
+ */
+_GLOBAL(add_reloc_offset)
+ mflr r0
+ bl 1f
+1: mflr r5
+ LOAD_REG_IMMEDIATE(r4,1b)
+ subf r5,r4,r5
+ add r3,r3,r5
+ mtlr r0
+ blr
+
+_GLOBAL(get_msr)
+ mfmsr r3
+ blr
+
+_GLOBAL(get_dar)
+ mfdar r3
+ blr
+
+_GLOBAL(get_srr0)
+ mfsrr0 r3
+ blr
+
+_GLOBAL(get_srr1)
+ mfsrr1 r3
+ blr
+
+_GLOBAL(get_sp)
+ mr r3,r1
+ blr
+
+#ifdef CONFIG_IRQSTACKS
+_GLOBAL(call_do_softirq)
+ mflr r0
+ std r0,16(r1)
+ stdu r1,THREAD_SIZE-112(r3)
+ mr r1,r3
+ bl .__do_softirq
+ ld r1,0(r1)
+ ld r0,16(r1)
+ mtlr r0
+ blr
+
+_GLOBAL(call___do_IRQ)
+ mflr r0
+ std r0,16(r1)
+ stdu r1,THREAD_SIZE-112(r5)
+ mr r1,r5
+ bl .__do_IRQ
+ ld r1,0(r1)
+ ld r0,16(r1)
+ mtlr r0
+ blr
+#endif /* CONFIG_IRQSTACKS */
+
+ /*
+ * To be called by C code which needs to do some operations with MMU
+ * disabled. Note that interrupts have to be disabled by the caller
+ * prior to calling us. The code called _MUST_ be in the RMO of course
+ * and part of the linear mapping as we don't attempt to translate the
+ * stack pointer at all. The function is called with the stack switched
+ * to this CPU emergency stack
+ *
+ * prototype is void *call_with_mmu_off(void *func, void *data);
+ *
+ * the called function is expected to be of the form
+ *
+ * void *called(void *data);
+ */
+_GLOBAL(call_with_mmu_off)
+ mflr r0 /* get link, save it on stackframe */
+ std r0,16(r1)
+ mr r1,r5 /* save old stack ptr */
+ ld r1,PACAEMERGSP(r13) /* get emerg. stack */
+ subi r1,r1,STACK_FRAME_OVERHEAD
+ std r0,16(r1) /* save link on emerg. stack */
+ std r5,0(r1) /* save old stack ptr in backchain */
+ ld r3,0(r3) /* get to real function ptr (assume same TOC) */
+ bl 2f /* we need LR to return, continue at label 2 */
+
+ ld r0,16(r1) /* we return here from the call, get LR and */
+ ld r1,0(r1) /* .. old stack ptr */
+ mtspr SPRN_SRR0,r0 /* and get back to virtual mode with these */
+ mfmsr r4
+ ori r4,r4,MSR_IR|MSR_DR
+ mtspr SPRN_SRR1,r4
+ rfid
+
+2: mtspr SPRN_SRR0,r3 /* coming from above, enter real mode */
+ mr r3,r4 /* get parameter */
+ mfmsr r0
+ ori r0,r0,MSR_IR|MSR_DR
+ xori r0,r0,MSR_IR|MSR_DR
+ mtspr SPRN_SRR1,r0
+ rfid
+
+
+ .section ".toc","aw"
+PPC64_CACHES:
+ .tc ppc64_caches[TC],ppc64_caches
+ .section ".text"
+
+/*
+ * Write any modified data cache blocks out to memory
+ * and invalidate the corresponding instruction cache blocks.
+ *
+ * flush_icache_range(unsigned long start, unsigned long stop)
+ *
+ * flush all bytes from start through stop-1 inclusive
+ */
+
+_KPROBE(__flush_icache_range)
+
+/*
+ * Flush the data cache to memory
+ *
+ * Different systems have different cache line sizes
+ * and in some cases i-cache and d-cache line sizes differ from
+ * each other.
+ */
+ ld r10,PPC64_CACHES@toc(r2)
+ lwz r7,DCACHEL1LINESIZE(r10)/* Get cache line size */
+ addi r5,r7,-1
+ andc r6,r3,r5 /* round low to line bdy */
+ subf r8,r6,r4 /* compute length */
+ add r8,r8,r5 /* ensure we get enough */
+ lwz r9,DCACHEL1LOGLINESIZE(r10) /* Get log-2 of cache line size */
+ srw. r8,r8,r9 /* compute line count */
+ beqlr /* nothing to do? */
+ mtctr r8
+1: dcbst 0,r6
+ add r6,r6,r7
+ bdnz 1b
+ sync
+
+/* Now invalidate the instruction cache */
+
+ lwz r7,ICACHEL1LINESIZE(r10) /* Get Icache line size */
+ addi r5,r7,-1
+ andc r6,r3,r5 /* round low to line bdy */
+ subf r8,r6,r4 /* compute length */
+ add r8,r8,r5
+ lwz r9,ICACHEL1LOGLINESIZE(r10) /* Get log-2 of Icache line size */
+ srw. r8,r8,r9 /* compute line count */
+ beqlr /* nothing to do? */
+ mtctr r8
+2: icbi 0,r6
+ add r6,r6,r7
+ bdnz 2b
+ isync
+ blr
+ .previous .text
+/*
+ * Like above, but only do the D-cache.
+ *
+ * flush_dcache_range(unsigned long start, unsigned long stop)
+ *
+ * flush all bytes from start to stop-1 inclusive
+ */
+_GLOBAL(flush_dcache_range)
+
+/*
+ * Flush the data cache to memory
+ *
+ * Different systems have different cache line sizes
+ */
+ ld r10,PPC64_CACHES@toc(r2)
+ lwz r7,DCACHEL1LINESIZE(r10) /* Get dcache line size */
+ addi r5,r7,-1
+ andc r6,r3,r5 /* round low to line bdy */
+ subf r8,r6,r4 /* compute length */
+ add r8,r8,r5 /* ensure we get enough */
+ lwz r9,DCACHEL1LOGLINESIZE(r10) /* Get log-2 of dcache line size */
+ srw. r8,r8,r9 /* compute line count */
+ beqlr /* nothing to do? */
+ mtctr r8
+0: dcbst 0,r6
+ add r6,r6,r7
+ bdnz 0b
+ sync
+ blr
+
+/*
+ * Like above, but works on non-mapped physical addresses.
+ * Use only for non-LPAR setups ! It also assumes real mode
+ * is cacheable. Used for flushing out the DART before using
+ * it as uncacheable memory
+ *
+ * flush_dcache_phys_range(unsigned long start, unsigned long stop)
+ *
+ * flush all bytes from start to stop-1 inclusive
+ */
+_GLOBAL(flush_dcache_phys_range)
+ ld r10,PPC64_CACHES@toc(r2)
+ lwz r7,DCACHEL1LINESIZE(r10) /* Get dcache line size */
+ addi r5,r7,-1
+ andc r6,r3,r5 /* round low to line bdy */
+ subf r8,r6,r4 /* compute length */
+ add r8,r8,r5 /* ensure we get enough */
+ lwz r9,DCACHEL1LOGLINESIZE(r10) /* Get log-2 of dcache line size */
+ srw. r8,r8,r9 /* compute line count */
+ beqlr /* nothing to do? */
+ mfmsr r5 /* Disable MMU Data Relocation */
+ ori r0,r5,MSR_DR
+ xori r0,r0,MSR_DR
+ sync
+ mtmsr r0
+ sync
+ isync
+ mtctr r8
+0: dcbst 0,r6
+ add r6,r6,r7
+ bdnz 0b
+ sync
+ isync
+ mtmsr r5 /* Re-enable MMU Data Relocation */
+ sync
+ isync
+ blr
+
+_GLOBAL(flush_inval_dcache_range)
+ ld r10,PPC64_CACHES@toc(r2)
+ lwz r7,DCACHEL1LINESIZE(r10) /* Get dcache line size */
+ addi r5,r7,-1
+ andc r6,r3,r5 /* round low to line bdy */
+ subf r8,r6,r4 /* compute length */
+ add r8,r8,r5 /* ensure we get enough */
+ lwz r9,DCACHEL1LOGLINESIZE(r10)/* Get log-2 of dcache line size */
+ srw. r8,r8,r9 /* compute line count */
+ beqlr /* nothing to do? */
+ sync
+ isync
+ mtctr r8
+0: dcbf 0,r6
+ add r6,r6,r7
+ bdnz 0b
+ sync
+ isync
+ blr
+
+
+/*
+ * Flush a particular page from the data cache to RAM.
+ * Note: this is necessary because the instruction cache does *not*
+ * snoop from the data cache.
+ *
+ * void __flush_dcache_icache(void *page)
+ */
+_GLOBAL(__flush_dcache_icache)
+/*
+ * Flush the data cache to memory
+ *
+ * Different systems have different cache line sizes
+ */
+
+/* Flush the dcache */
+ ld r7,PPC64_CACHES@toc(r2)
+ clrrdi r3,r3,PAGE_SHIFT /* Page align */
+ lwz r4,DCACHEL1LINESPERPAGE(r7) /* Get # dcache lines per page */
+ lwz r5,DCACHEL1LINESIZE(r7) /* Get dcache line size */
+ mr r6,r3
+ mtctr r4
+0: dcbst 0,r6
+ add r6,r6,r5
+ bdnz 0b
+ sync
+
+/* Now invalidate the icache */
+
+ lwz r4,ICACHEL1LINESPERPAGE(r7) /* Get # icache lines per page */
+ lwz r5,ICACHEL1LINESIZE(r7) /* Get icache line size */
+ mtctr r4
+1: icbi 0,r3
+ add r3,r3,r5
+ bdnz 1b
+ isync
+ blr
+
+/*
+ * I/O string operations
+ *
+ * insb(port, buf, len)
+ * outsb(port, buf, len)
+ * insw(port, buf, len)
+ * outsw(port, buf, len)
+ * insl(port, buf, len)
+ * outsl(port, buf, len)
+ * insw_ns(port, buf, len)
+ * outsw_ns(port, buf, len)
+ * insl_ns(port, buf, len)
+ * outsl_ns(port, buf, len)
+ *
+ * The *_ns versions don't do byte-swapping.
+ */
+_GLOBAL(_insb)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,1
+ blelr-
+00: lbz r5,0(r3)
+ eieio
+ stbu r5,1(r4)
+ bdnz 00b
+ twi 0,r5,0
+ isync
+ blr
+
+_GLOBAL(_outsb)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,1
+ blelr-
+00: lbzu r5,1(r4)
+ stb r5,0(r3)
+ bdnz 00b
+ sync
+ blr
+
+_GLOBAL(_insw)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,2
+ blelr-
+00: lhbrx r5,0,r3
+ eieio
+ sthu r5,2(r4)
+ bdnz 00b
+ twi 0,r5,0
+ isync
+ blr
+
+_GLOBAL(_outsw)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,2
+ blelr-
+00: lhzu r5,2(r4)
+ sthbrx r5,0,r3
+ bdnz 00b
+ sync
+ blr
+
+_GLOBAL(_insl)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,4
+ blelr-
+00: lwbrx r5,0,r3
+ eieio
+ stwu r5,4(r4)
+ bdnz 00b
+ twi 0,r5,0
+ isync
+ blr
+
+_GLOBAL(_outsl)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,4
+ blelr-
+00: lwzu r5,4(r4)
+ stwbrx r5,0,r3
+ bdnz 00b
+ sync
+ blr
+
+/* _GLOBAL(ide_insw) now in drivers/ide/ide-iops.c */
+_GLOBAL(_insw_ns)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,2
+ blelr-
+00: lhz r5,0(r3)
+ eieio
+ sthu r5,2(r4)
+ bdnz 00b
+ twi 0,r5,0
+ isync
+ blr
+
+/* _GLOBAL(ide_outsw) now in drivers/ide/ide-iops.c */
+_GLOBAL(_outsw_ns)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,2
+ blelr-
+00: lhzu r5,2(r4)
+ sth r5,0(r3)
+ bdnz 00b
+ sync
+ blr
+
+_GLOBAL(_insl_ns)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,4
+ blelr-
+00: lwz r5,0(r3)
+ eieio
+ stwu r5,4(r4)
+ bdnz 00b
+ twi 0,r5,0
+ isync
+ blr
+
+_GLOBAL(_outsl_ns)
+ cmpwi 0,r5,0
+ mtctr r5
+ subi r4,r4,4
+ blelr-
+00: lwzu r5,4(r4)
+ stw r5,0(r3)
+ bdnz 00b
+ sync
+ blr
+
+/*
+ * identify_cpu and calls setup_cpu
+ * In: r3 = base of the cpu_specs array
+ * r4 = address of cur_cpu_spec
+ * r5 = relocation offset
+ */
+_GLOBAL(identify_cpu)
+ mfpvr r7
+1:
+ lwz r8,CPU_SPEC_PVR_MASK(r3)
+ and r8,r8,r7
+ lwz r9,CPU_SPEC_PVR_VALUE(r3)
+ cmplw 0,r9,r8
+ beq 1f
+ addi r3,r3,CPU_SPEC_ENTRY_SIZE
+ b 1b
+1:
+ sub r0,r3,r5
+ std r0,0(r4)
+ ld r4,CPU_SPEC_SETUP(r3)
+ add r4,r4,r5
+ ld r4,0(r4)
+ add r4,r4,r5
+ mtctr r4
+ /* Calling convention for cpu setup is r3=offset, r4=cur_cpu_spec */
+ mr r4,r3
+ mr r3,r5
+ bctr
+
+/*
+ * do_cpu_ftr_fixups - goes through the list of CPU feature fixups
+ * and writes nop's over sections of code that don't apply for this cpu.
+ * r3 = data offset (not changed)
+ */
+_GLOBAL(do_cpu_ftr_fixups)
+ /* Get CPU 0 features */
+ LOAD_REG_IMMEDIATE(r6,cur_cpu_spec)
+ sub r6,r6,r3
+ ld r4,0(r6)
+ sub r4,r4,r3
+ ld r4,CPU_SPEC_FEATURES(r4)
+ /* Get the fixup table */
+ LOAD_REG_IMMEDIATE(r6,__start___ftr_fixup)
+ sub r6,r6,r3
+ LOAD_REG_IMMEDIATE(r7,__stop___ftr_fixup)
+ sub r7,r7,r3
+ /* Do the fixup */
+1: cmpld r6,r7
+ bgelr
+ addi r6,r6,32
+ ld r8,-32(r6) /* mask */
+ and r8,r8,r4
+ ld r9,-24(r6) /* value */
+ cmpld r8,r9
+ beq 1b
+ ld r8,-16(r6) /* section begin */
+ ld r9,-8(r6) /* section end */
+ subf. r9,r8,r9
+ beq 1b
+ /* write nops over the section of code */
+ /* todo: if large section, add a branch at the start of it */
+ srwi r9,r9,2
+ mtctr r9
+ sub r8,r8,r3
+ lis r0,0x60000000@h /* nop */
+3: stw r0,0(r8)
+ andi. r10,r4,CPU_FTR_SPLIT_ID_CACHE@l
+ beq 2f
+ dcbst 0,r8 /* suboptimal, but simpler */
+ sync
+ icbi 0,r8
+2: addi r8,r8,4
+ bdnz 3b
+ sync /* additional sync needed on g4 */
+ isync
+ b 1b
+
+#if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE)
+/*
+ * Do an IO access in real mode
+ */
+_GLOBAL(real_readb)
+ mfmsr r7
+ ori r0,r7,MSR_DR
+ xori r0,r0,MSR_DR
+ sync
+ mtmsrd r0
+ sync
+ isync
+ mfspr r6,SPRN_HID4
+ rldicl r5,r6,32,0
+ ori r5,r5,0x100
+ rldicl r5,r5,32,0
+ sync
+ mtspr SPRN_HID4,r5
+ isync
+ slbia
+ isync
+ lbz r3,0(r3)
+ sync
+ mtspr SPRN_HID4,r6
+ isync
+ slbia
+ isync
+ mtmsrd r7
+ sync
+ isync
+ blr
+
+ /*
+ * Do an IO access in real mode
+ */
+_GLOBAL(real_writeb)
+ mfmsr r7
+ ori r0,r7,MSR_DR
+ xori r0,r0,MSR_DR
+ sync
+ mtmsrd r0
+ sync
+ isync
+ mfspr r6,SPRN_HID4
+ rldicl r5,r6,32,0
+ ori r5,r5,0x100
+ rldicl r5,r5,32,0
+ sync
+ mtspr SPRN_HID4,r5
+ isync
+ slbia
+ isync
+ stb r3,0(r4)
+ sync
+ mtspr SPRN_HID4,r6
+ isync
+ slbia
+ isync
+ mtmsrd r7
+ sync
+ isync
+ blr
+#endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE) */
+
+/*
+ * SCOM access functions for 970 (FX only for now)
+ *
+ * unsigned long scom970_read(unsigned int address);
+ * void scom970_write(unsigned int address, unsigned long value);
+ *
+ * The address passed in is the 24 bits register address. This code
+ * is 970 specific and will not check the status bits, so you should
+ * know what you are doing.
+ */
+_GLOBAL(scom970_read)
+ /* interrupts off */
+ mfmsr r4
+ ori r0,r4,MSR_EE
+ xori r0,r0,MSR_EE
+ mtmsrd r0,1
+
+ /* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
+ * (including parity). On current CPUs they must be 0'd,
+ * and finally or in RW bit
+ */
+ rlwinm r3,r3,8,0,15
+ ori r3,r3,0x8000
+
+ /* do the actual scom read */
+ sync
+ mtspr SPRN_SCOMC,r3
+ isync
+ mfspr r3,SPRN_SCOMD
+ isync
+ mfspr r0,SPRN_SCOMC
+ isync
+
+ /* XXX: fixup result on some buggy 970's (ouch ! we lost a bit, bah
+ * that's the best we can do). Not implemented yet as we don't use
+ * the scom on any of the bogus CPUs yet, but may have to be done
+ * ultimately
+ */
+
+ /* restore interrupts */
+ mtmsrd r4,1
+ blr
+
+
+_GLOBAL(scom970_write)
+ /* interrupts off */
+ mfmsr r5
+ ori r0,r5,MSR_EE
+ xori r0,r0,MSR_EE
+ mtmsrd r0,1
+
+ /* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
+ * (including parity). On current CPUs they must be 0'd.
+ */
+
+ rlwinm r3,r3,8,0,15
+
+ sync
+ mtspr SPRN_SCOMD,r4 /* write data */
+ isync
+ mtspr SPRN_SCOMC,r3 /* write command */
+ isync
+ mfspr 3,SPRN_SCOMC
+ isync
+
+ /* restore interrupts */
+ mtmsrd r5,1
+ blr
+
+
+/*
+ * Create a kernel thread
+ * kernel_thread(fn, arg, flags)
+ */
+_GLOBAL(kernel_thread)
+ std r29,-24(r1)
+ std r30,-16(r1)
+ stdu r1,-STACK_FRAME_OVERHEAD(r1)
+ mr r29,r3
+ mr r30,r4
+ ori r3,r5,CLONE_VM /* flags */
+ oris r3,r3,(CLONE_UNTRACED>>16)
+ li r4,0 /* new sp (unused) */
+ li r0,__NR_clone
+ sc
+ cmpdi 0,r3,0 /* parent or child? */
+ bne 1f /* return if parent */
+ li r0,0
+ stdu r0,-STACK_FRAME_OVERHEAD(r1)
+ ld r2,8(r29)
+ ld r29,0(r29)
+ mtlr r29 /* fn addr in lr */
+ mr r3,r30 /* load arg and call fn */
+ blrl
+ li r0,__NR_exit /* exit after child exits */
+ li r3,0
+ sc
+1: addi r1,r1,STACK_FRAME_OVERHEAD
+ ld r29,-24(r1)
+ ld r30,-16(r1)
+ blr
+
+/*
+ * disable_kernel_fp()
+ * Disable the FPU.
+ */
+_GLOBAL(disable_kernel_fp)
+ mfmsr r3
+ rldicl r0,r3,(63-MSR_FP_LG),1
+ rldicl r3,r0,(MSR_FP_LG+1),0
+ mtmsrd r3 /* disable use of fpu now */
+ isync
+ blr
+
+#ifdef CONFIG_ALTIVEC
+
+#if 0 /* this has no callers for now */
+/*
+ * disable_kernel_altivec()
+ * Disable the VMX.
+ */
+_GLOBAL(disable_kernel_altivec)
+ mfmsr r3
+ rldicl r0,r3,(63-MSR_VEC_LG),1
+ rldicl r3,r0,(MSR_VEC_LG+1),0
+ mtmsrd r3 /* disable use of VMX now */
+ isync
+ blr
+#endif /* 0 */
+
+/*
+ * giveup_altivec(tsk)
+ * Disable VMX for the task given as the argument,
+ * and save the vector registers in its thread_struct.
+ * Enables the VMX for use in the kernel on return.
+ */
+_GLOBAL(giveup_altivec)
+ mfmsr r5
+ oris r5,r5,MSR_VEC@h
+ mtmsrd r5 /* enable use of VMX now */
+ isync
+ cmpdi 0,r3,0
+ beqlr- /* if no previous owner, done */
+ addi r3,r3,THREAD /* want THREAD of task */
+ ld r5,PT_REGS(r3)
+ cmpdi 0,r5,0
+ SAVE_32VRS(0,r4,r3)
+ mfvscr vr0
+ li r4,THREAD_VSCR
+ stvx vr0,r4,r3
+ beq 1f
+ ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+ lis r3,MSR_VEC@h
+ andc r4,r4,r3 /* disable FP for previous task */
+ std r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#ifndef CONFIG_SMP
+ li r5,0
+ ld r4,last_task_used_altivec@got(r2)
+ std r5,0(r4)
+#endif /* CONFIG_SMP */
+ blr
+
+#endif /* CONFIG_ALTIVEC */
+
+_GLOBAL(__setup_cpu_power3)
+ blr
+
+_GLOBAL(execve)
+ li r0,__NR_execve
+ sc
+ bnslr
+ neg r3,r3
+ blr
+
+/* kexec_wait(phys_cpu)
+ *
+ * wait for the flag to change, indicating this kernel is going away but
+ * the slave code for the next one is at addresses 0 to 100.
+ *
+ * This is used by all slaves.
+ *
+ * Physical (hardware) cpu id should be in r3.
+ */
+_GLOBAL(kexec_wait)
+ bl 1f
+1: mflr r5
+ addi r5,r5,kexec_flag-1b
+
+99: HMT_LOW
+#ifdef CONFIG_KEXEC /* use no memory without kexec */
+ lwz r4,0(r5)
+ cmpwi 0,r4,0
+ bnea 0x60
+#endif
+ b 99b
+
+/* this can be in text because we won't change it until we are
+ * running in real anyways
+ */
+kexec_flag:
+ .long 0
+
+
+#ifdef CONFIG_KEXEC
+
+/* kexec_smp_wait(void)
+ *
+ * call with interrupts off
+ * note: this is a terminal routine, it does not save lr
+ *
+ * get phys id from paca
+ * set paca id to -1 to say we got here
+ * switch to real mode
+ * join other cpus in kexec_wait(phys_id)
+ */
+_GLOBAL(kexec_smp_wait)
+ lhz r3,PACAHWCPUID(r13)
+ li r4,-1
+ sth r4,PACAHWCPUID(r13) /* let others know we left */
+ bl real_mode
+ b .kexec_wait
+
+/*
+ * switch to real mode (turn mmu off)
+ * we use the early kernel trick that the hardware ignores bits
+ * 0 and 1 (big endian) of the effective address in real mode
+ *
+ * don't overwrite r3 here, it is live for kexec_wait above.
+ */
+real_mode: /* assume normal blr return */
+1: li r9,MSR_RI
+ li r10,MSR_DR|MSR_IR
+ mflr r11 /* return address to SRR0 */
+ mfmsr r12
+ andc r9,r12,r9
+ andc r10,r12,r10
+
+ mtmsrd r9,1
+ mtspr SPRN_SRR1,r10
+ mtspr SPRN_SRR0,r11
+ rfid
+
+
+/*
+ * kexec_sequence(newstack, start, image, control, clear_all())
+ *
+ * does the grungy work with stack switching and real mode switches
+ * also does simple calls to other code
+ */
+
+_GLOBAL(kexec_sequence)
+ mflr r0
+ std r0,16(r1)
+
+ /* switch stacks to newstack -- &kexec_stack.stack */
+ stdu r1,THREAD_SIZE-112(r3)
+ mr r1,r3
+
+ li r0,0
+ std r0,16(r1)
+
+ /* save regs for local vars on new stack.
+ * yes, we won't go back, but ...
+ */
+ std r31,-8(r1)
+ std r30,-16(r1)
+ std r29,-24(r1)
+ std r28,-32(r1)
+ std r27,-40(r1)
+ std r26,-48(r1)
+ std r25,-56(r1)
+
+ stdu r1,-112-64(r1)
+
+ /* save args into preserved regs */
+ mr r31,r3 /* newstack (both) */
+ mr r30,r4 /* start (real) */
+ mr r29,r5 /* image (virt) */
+ mr r28,r6 /* control, unused */
+ mr r27,r7 /* clear_all() fn desc */
+ mr r26,r8 /* spare */
+ lhz r25,PACAHWCPUID(r13) /* get our phys cpu from paca */
+
+ /* disable interrupts, we are overwriting kernel data next */
+ mfmsr r3
+ rlwinm r3,r3,0,17,15
+ mtmsrd r3,1
+
+ /* copy dest pages, flush whole dest image */
+ mr r3,r29
+ bl .kexec_copy_flush /* (image) */
+
+ /* turn off mmu */
+ bl real_mode
+
+ /* clear out hardware hash page table and tlb */
+ ld r5,0(r27) /* deref function descriptor */
+ mtctr r5
+ bctrl /* ppc_md.hash_clear_all(void); */
+
+/*
+ * kexec image calling is:
+ * the first 0x100 bytes of the entry point are copied to 0
+ *
+ * all slaves branch to slave = 0x60 (absolute)
+ * slave(phys_cpu_id);
+ *
+ * master goes to start = entry point
+ * start(phys_cpu_id, start, 0);
+ *
+ *
+ * a wrapper is needed to call existing kernels, here is an approximate
+ * description of one method:
+ *
+ * v2: (2.6.10)
+ * start will be near the boot_block (maybe 0x100 bytes before it?)
+ * it will have a 0x60, which will b to boot_block, where it will wait
+ * and 0 will store phys into struct boot-block and load r3 from there,
+ * copy kernel 0-0x100 and tell slaves to back down to 0x60 again
+ *
+ * v1: (2.6.9)
+ * boot block will have all cpus scanning device tree to see if they
+ * are the boot cpu ?????
+ * other device tree differences (prop sizes, va vs pa, etc)...
+ */
+
+ /* copy 0x100 bytes starting at start to 0 */
+ li r3,0
+ mr r4,r30
+ li r5,0x100
+ li r6,0
+ bl .copy_and_flush /* (dest, src, copy limit, start offset) */
+1: /* assume normal blr return */
+
+ /* release other cpus to the new kernel secondary start at 0x60 */
+ mflr r5
+ li r6,1
+ stw r6,kexec_flag-1b(5)
+ mr r3,r25 # my phys cpu
+ mr r4,r30 # start, aka phys mem offset
+ mtlr 4
+ li r5,0
+ blr /* image->start(physid, image->start, 0); */
+#endif /* CONFIG_KEXEC */
git://git.onelab.eu / linux-2.6.git / blobdiff