linux_dsm_epyc7002/arch/powerpc/kernel/cpu_setup_ppc970.S
Paul Mackerras e31aa453bb powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit
Using LOAD_REG_IMMEDIATE to get the address of kernel symbols
generates 5 instructions where LOAD_REG_ADDR can do it in one,
and will generate R_PPC64_ADDR16_* relocations in the output when
we get to making the kernel as a position-independent executable,
which we'd rather not have to handle.  This changes various bits
of assembly code to use LOAD_REG_ADDR when we need to get the
address of a symbol, or to use suitable position-independent code
for cases where we can't access the TOC for various reasons, or
if we're not running at the address we were linked at.

It also cleans up a few minor things; there's no reason to save and
restore SRR0/1 around RTAS calls, __mmu_off can get the return
address from LR more conveniently than the caller can supply it in
R4 (and we already assume elsewhere that EA == RA if the MMU is on
in early boot), and enable_64b_mode was using 5 instructions where
2 would do.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-09-15 11:08:35 -07:00

193 lines
3.6 KiB
ArmAsm

/*
* This file contains low level CPU setup functions.
* Copyright (C) 2003 Benjamin Herrenschmidt (benh@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 <asm/processor.h>
#include <asm/page.h>
#include <asm/cputable.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/cache.h>
_GLOBAL(__cpu_preinit_ppc970)
/* Do nothing if not running in HV mode */
mfmsr r0
rldicl. r0,r0,4,63
beqlr
/* Make sure HID4:rm_ci is off before MMU is turned off, that large
* pages are enabled with HID4:61 and clear HID5:DCBZ_size and
* HID5:DCBZ32_ill
*/
li r0,0
mfspr r3,SPRN_HID4
rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */
rldimi r3,r0,2,61 /* clear bit 61 (lg_pg_en) */
sync
mtspr SPRN_HID4,r3
isync
sync
mfspr r3,SPRN_HID5
rldimi r3,r0,6,56 /* clear bits 56 & 57 (DCBZ*) */
sync
mtspr SPRN_HID5,r3
isync
sync
/* Setup some basic HID1 features */
mfspr r0,SPRN_HID1
li r3,0x1200 /* enable i-fetch cacheability */
sldi r3,r3,44 /* and prefetch */
or r0,r0,r3
mtspr SPRN_HID1,r0
mtspr SPRN_HID1,r0
isync
/* Clear HIOR */
li r0,0
sync
mtspr SPRN_HIOR,0 /* Clear interrupt prefix */
isync
blr
/* Definitions for the table use to save CPU states */
#define CS_HID0 0
#define CS_HID1 8
#define CS_HID4 16
#define CS_HID5 24
#define CS_SIZE 32
.data
.balign L1_CACHE_BYTES,0
cpu_state_storage:
.space CS_SIZE
.balign L1_CACHE_BYTES,0
.text
_GLOBAL(__setup_cpu_ppc970)
/* Do nothing if not running in HV mode */
mfmsr r0
rldicl. r0,r0,4,63
beqlr
mfspr r0,SPRN_HID0
li r11,5 /* clear DOZE and SLEEP */
rldimi r0,r11,52,8 /* set NAP and DPM */
li r11,0
rldimi r0,r11,32,31 /* clear EN_ATTN */
b load_hids /* Jump to shared code */
_GLOBAL(__setup_cpu_ppc970MP)
/* Do nothing if not running in HV mode */
mfmsr r0
rldicl. r0,r0,4,63
beqlr
mfspr r0,SPRN_HID0
li r11,0x15 /* clear DOZE and SLEEP */
rldimi r0,r11,52,6 /* set DEEPNAP, NAP and DPM */
li r11,0
rldimi r0,r11,32,31 /* clear EN_ATTN */
load_hids:
mtspr SPRN_HID0,r0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
sync
isync
/* Save away cpu state */
LOAD_REG_ADDR(r5,cpu_state_storage)
/* Save HID0,1,4 and 5 */
mfspr r3,SPRN_HID0
std r3,CS_HID0(r5)
mfspr r3,SPRN_HID1
std r3,CS_HID1(r5)
mfspr r3,SPRN_HID4
std r3,CS_HID4(r5)
mfspr r3,SPRN_HID5
std r3,CS_HID5(r5)
blr
/* Called with no MMU context (typically MSR:IR/DR off) to
* restore CPU state as backed up by the previous
* function. This does not include cache setting
*/
_GLOBAL(__restore_cpu_ppc970)
/* Do nothing if not running in HV mode */
mfmsr r0
rldicl. r0,r0,4,63
beqlr
LOAD_REG_ADDR(r5,cpu_state_storage)
/* Before accessing memory, we make sure rm_ci is clear */
li r0,0
mfspr r3,SPRN_HID4
rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */
sync
mtspr SPRN_HID4,r3
isync
sync
/* Clear interrupt prefix */
li r0,0
sync
mtspr SPRN_HIOR,0
isync
/* Restore HID0 */
ld r3,CS_HID0(r5)
sync
isync
mtspr SPRN_HID0,r3
mfspr r3,SPRN_HID0
mfspr r3,SPRN_HID0
mfspr r3,SPRN_HID0
mfspr r3,SPRN_HID0
mfspr r3,SPRN_HID0
mfspr r3,SPRN_HID0
sync
isync
/* Restore HID1 */
ld r3,CS_HID1(r5)
sync
isync
mtspr SPRN_HID1,r3
mtspr SPRN_HID1,r3
sync
isync
/* Restore HID4 */
ld r3,CS_HID4(r5)
sync
isync
mtspr SPRN_HID4,r3
sync
isync
/* Restore HID5 */
ld r3,CS_HID5(r5)
sync
isync
mtspr SPRN_HID5,r3
sync
isync
blr