freebsd-nq/sys/powerpc/aim/locore64.S
Nathan Whitehorn a891d21aac Make sure the first instruction of the low-memory spinloop is in the
cacheline being invalidated.

MFC after:	1 month
2017-12-31 05:38:19 +00:00

186 lines
4.4 KiB
ArmAsm

/* $FreeBSD$ */
/*-
* Copyright (C) 2010-2016 Nathan Whitehorn
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include "assym.s"
#include <sys/syscall.h>
#include <machine/trap.h>
#include <machine/param.h>
#include <machine/spr.h>
#include <machine/asm.h>
#ifdef _CALL_ELF
.abiversion _CALL_ELF
#endif
/* Glue for linker script */
.globl kernbase
.set kernbase, KERNBASE
/*
* Globals
*/
.data
.align 3
GLOBAL(__startkernel)
.llong begin
GLOBAL(__endkernel)
.llong end
.align 4
#define TMPSTKSZ 16384 /* 16K temporary stack */
GLOBAL(tmpstk)
.space TMPSTKSZ
TOC_ENTRY(tmpstk)
/*
* Entry point for bootloaders that do not fully implement ELF and start
* at the beginning of the image (kexec, notably). In its own section so
* that it ends up before any linker-generated call stubs and actually at
* the beginning of the image. kexec on some systems also enters at
* (start of image) + 0x60, so put a spin loop there.
*/
.section ".text.kboot", "x", @progbits
kbootentry:
b __start
. = kbootentry + 0x40 /* Magic address used in platform layer */
.global smp_spin_sem
ap_kexec_spin_sem:
.long -1
. = kbootentry + 0x60 /* Entry point for kexec APs */
ap_kexec_start: /* At 0x60 past start, copied to 0x60 by kexec */
/* r3 set to CPU ID by kexec */
/* Invalidate icache for low-memory copy and jump there */
li %r0,0x80
dcbst 0,%r0
sync
icbi 0,%r0
isync
ba 0x80 /* Absolute branch to next inst */
. = kbootentry + 0x80 /* Aligned to cache line */
1: or 31,31,31 /* yield */
sync
lwz %r1,0x40(0) /* Spin on ap_kexec_spin_sem */
cmpw %r1,%r3 /* Until it equals our CPU ID */
bne 1b
/* Released */
or 2,2,2 /* unyield */
ba EXC_RST
/*
* Now start the real text section
*/
.text
.globl btext
btext:
/*
* Main kernel entry point.
*
* Calling convention:
* r3: Flattened Device Tree pointer (or zero)
* r4: ignored
* r5: OF client interface pointer (or zero)
* r6: Loader metadata pointer (or zero)
* r7: Magic cookie (0xfb5d104d) to indicate that r6 has loader metadata
*/
.text
ASENTRY_NOPROF(__start)
/* Set 64-bit mode if not yet set before branching to C */
mfmsr %r20
li %r21,1
insrdi %r20,%r21,1,0
mtmsrd %r20
isync
nop /* Make this block a multiple of 8 bytes */
/* Set up the TOC pointer */
b 0f
.align 3
0: nop
bl 1f
.llong __tocbase + 0x8000 - .
1: mflr %r2
ld %r1,0(%r2)
add %r2,%r1,%r2
/* Get load offset */
ld %r31,-0x8000(%r2) /* First TOC entry is TOC base */
subf %r31,%r31,%r2 /* Subtract from real TOC base to get base */
/* Set up the stack pointer */
ld %r1,TOC_REF(tmpstk)(%r2)
addi %r1,%r1,TMPSTKSZ-96
add %r1,%r1,%r31
/* Relocate kernel */
std %r3,48(%r1)
std %r4,56(%r1)
std %r5,64(%r1)
std %r6,72(%r1)
std %r7,80(%r1)
bl 1f
.llong _DYNAMIC-.
1: mflr %r3
ld %r4,0(%r3)
add %r3,%r4,%r3
mr %r4,%r31
bl elf_reloc_self
nop
ld %r3,48(%r1)
ld %r4,56(%r1)
ld %r5,64(%r1)
ld %r6,72(%r1)
ld %r7,80(%r1)
/* Begin CPU init */
mr %r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */
bl powerpc_init
nop
/* Set stack pointer to new value and branch to mi_startup */
mr %r1, %r3
li %r3, 0
std %r3, 0(%r1)
bl mi_startup
nop
/* Unreachable */
b .
#include <powerpc/aim/trap_subr64.S>