freebsd-nq/sys/powerpc/aim/locore64.S
Wojciech Macek 6d13fd638c PowerNV: Put processor to power-save state in idle thread
When processor enters power-save state it releases resources shared with other
cpu threads which makes other cores working much faster.

This patch also implements saving and restoring registers that might get
corrupted in power-save state.

Submitted by:          Patryk Duda <pdk@semihalf.com>
Obtained from:         Semihalf
Reviewed by:           jhibbits, nwhitehorn, wma
Sponsored by:          IBM, QCM Technologies
Differential revision: https://reviews.freebsd.org/D14330
2018-02-21 14:28:40 +00:00

193 lines
4.5 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
GLOBAL(can_wakeup)
.llong 0x0
.align 4
#define TMPSTKSZ 16384 /* 16K temporary stack */
GLOBAL(tmpstk)
.space TMPSTKSZ
TOC_ENTRY(tmpstk)
TOC_ENTRY(can_wakeup)
/*
* 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 */
/* Make sure that it will be software reset. Clear SRR1 */
li %r1,0
mtsrr1 %r1
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>