linux/arch/powerpc/kernel/cpu_setup_power.S
Jordan Niethe 13c7bb3c57 powerpc/64s: Set reserved PCR bits
Currently the reserved bits of the Processor Compatibility
Register (PCR) are cleared as per the Programming Note in Section
1.3.3 of version 3.0B of the Power ISA. This causes all new
architecture features to be made available when running on newer
processors with new architecture features added to the PCR as bits
must be set to disable a given feature.

For example to disable new features added as part of Version 2.07 of
the ISA the corresponding bit in the PCR needs to be set.

As new processor features generally require explicit kernel support
they should be disabled until such support is implemented. Therefore
kernels should set all unknown/reserved bits in the PCR such that any
new architecture features which the kernel does not currently know
about get disabled.

An update is planned to the ISA to clarify that the PCR is an
exception to the Programming Note on reserved bits in Section 1.3.3.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190917004605.22471-2-alistair@popple.id.au
2019-09-21 08:36:53 +10:00

220 lines
4.2 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* This file contains low level CPU setup functions.
* Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org)
*/
#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>
#include <asm/book3s/64/mmu-hash.h>
/* Entry: r3 = crap, r4 = ptr to cputable entry
*
* Note that we can be called twice for pseudo-PVRs
*/
_GLOBAL(__setup_cpu_power7)
mflr r11
bl __init_hvmode_206
mtlr r11
beqlr
li r0,0
mtspr SPRN_LPID,r0
LOAD_REG_IMMEDIATE(r0, PCR_MASK)
mtspr SPRN_PCR,r0
mfspr r3,SPRN_LPCR
li r4,(LPCR_LPES1 >> LPCR_LPES_SH)
bl __init_LPCR_ISA206
mtlr r11
blr
_GLOBAL(__restore_cpu_power7)
mflr r11
mfmsr r3
rldicl. r0,r3,4,63
beqlr
li r0,0
mtspr SPRN_LPID,r0
LOAD_REG_IMMEDIATE(r0, PCR_MASK)
mtspr SPRN_PCR,r0
mfspr r3,SPRN_LPCR
li r4,(LPCR_LPES1 >> LPCR_LPES_SH)
bl __init_LPCR_ISA206
mtlr r11
blr
_GLOBAL(__setup_cpu_power8)
mflr r11
bl __init_FSCR
bl __init_PMU
bl __init_PMU_ISA207
bl __init_hvmode_206
mtlr r11
beqlr
li r0,0
mtspr SPRN_LPID,r0
LOAD_REG_IMMEDIATE(r0, PCR_MASK)
mtspr SPRN_PCR,r0
mfspr r3,SPRN_LPCR
ori r3, r3, LPCR_PECEDH
li r4,0 /* LPES = 0 */
bl __init_LPCR_ISA206
bl __init_HFSCR
bl __init_PMU_HV
bl __init_PMU_HV_ISA207
mtlr r11
blr
_GLOBAL(__restore_cpu_power8)
mflr r11
bl __init_FSCR
bl __init_PMU
bl __init_PMU_ISA207
mfmsr r3
rldicl. r0,r3,4,63
mtlr r11
beqlr
li r0,0
mtspr SPRN_LPID,r0
LOAD_REG_IMMEDIATE(r0, PCR_MASK)
mtspr SPRN_PCR,r0
mfspr r3,SPRN_LPCR
ori r3, r3, LPCR_PECEDH
li r4,0 /* LPES = 0 */
bl __init_LPCR_ISA206
bl __init_HFSCR
bl __init_PMU_HV
bl __init_PMU_HV_ISA207
mtlr r11
blr
_GLOBAL(__setup_cpu_power9)
mflr r11
bl __init_FSCR
bl __init_PMU
bl __init_hvmode_206
mtlr r11
beqlr
li r0,0
mtspr SPRN_PSSCR,r0
mtspr SPRN_LPID,r0
mtspr SPRN_PID,r0
LOAD_REG_IMMEDIATE(r0, PCR_MASK)
mtspr SPRN_PCR,r0
mfspr r3,SPRN_LPCR
LOAD_REG_IMMEDIATE(r4, LPCR_PECEDH | LPCR_PECE_HVEE | LPCR_HVICE | LPCR_HEIC)
or r3, r3, r4
LOAD_REG_IMMEDIATE(r4, LPCR_UPRT | LPCR_HR)
andc r3, r3, r4
li r4,0 /* LPES = 0 */
bl __init_LPCR_ISA300
bl __init_HFSCR
bl __init_PMU_HV
mtlr r11
blr
_GLOBAL(__restore_cpu_power9)
mflr r11
bl __init_FSCR
bl __init_PMU
mfmsr r3
rldicl. r0,r3,4,63
mtlr r11
beqlr
li r0,0
mtspr SPRN_PSSCR,r0
mtspr SPRN_LPID,r0
mtspr SPRN_PID,r0
LOAD_REG_IMMEDIATE(r0, PCR_MASK)
mtspr SPRN_PCR,r0
mfspr r3,SPRN_LPCR
LOAD_REG_IMMEDIATE(r4, LPCR_PECEDH | LPCR_PECE_HVEE | LPCR_HVICE | LPCR_HEIC)
or r3, r3, r4
LOAD_REG_IMMEDIATE(r4, LPCR_UPRT | LPCR_HR)
andc r3, r3, r4
li r4,0 /* LPES = 0 */
bl __init_LPCR_ISA300
bl __init_HFSCR
bl __init_PMU_HV
mtlr r11
blr
__init_hvmode_206:
/* Disable CPU_FTR_HVMODE and exit if MSR:HV is not set */
mfmsr r3
rldicl. r0,r3,4,63
bnelr
ld r5,CPU_SPEC_FEATURES(r4)
LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE | CPU_FTR_P9_TM_HV_ASSIST)
andc r5,r5,r6
std r5,CPU_SPEC_FEATURES(r4)
blr
__init_LPCR_ISA206:
/* Setup a sane LPCR:
* Called with initial LPCR in R3 and desired LPES 2-bit value in R4
*
* LPES = 0b01 (HSRR0/1 used for 0x500)
* PECE = 0b111
* DPFD = 4
* HDICE = 0
* VC = 0b100 (VPM0=1, VPM1=0, ISL=0)
* VRMASD = 0b10000 (L=1, LP=00)
*
* Other bits untouched for now
*/
li r5,0x10
rldimi r3,r5, LPCR_VRMASD_SH, 64-LPCR_VRMASD_SH-5
/* POWER9 has no VRMASD */
__init_LPCR_ISA300:
rldimi r3,r4, LPCR_LPES_SH, 64-LPCR_LPES_SH-2
ori r3,r3,(LPCR_PECE0|LPCR_PECE1|LPCR_PECE2)
li r5,4
rldimi r3,r5, LPCR_DPFD_SH, 64-LPCR_DPFD_SH-3
clrrdi r3,r3,1 /* clear HDICE */
li r5,4
rldimi r3,r5, LPCR_VC_SH, 0
mtspr SPRN_LPCR,r3
isync
blr
__init_FSCR:
mfspr r3,SPRN_FSCR
ori r3,r3,FSCR_TAR|FSCR_DSCR|FSCR_EBB
mtspr SPRN_FSCR,r3
blr
__init_HFSCR:
mfspr r3,SPRN_HFSCR
ori r3,r3,HFSCR_TAR|HFSCR_TM|HFSCR_BHRB|HFSCR_PM|\
HFSCR_DSCR|HFSCR_VECVSX|HFSCR_FP|HFSCR_EBB|HFSCR_MSGP
mtspr SPRN_HFSCR,r3
blr
__init_PMU_HV:
li r5,0
mtspr SPRN_MMCRC,r5
blr
__init_PMU_HV_ISA207:
li r5,0
mtspr SPRN_MMCRH,r5
blr
__init_PMU:
li r5,0
mtspr SPRN_MMCRA,r5
mtspr SPRN_MMCR0,r5
mtspr SPRN_MMCR1,r5
mtspr SPRN_MMCR2,r5
blr
__init_PMU_ISA207:
li r5,0
mtspr SPRN_MMCRS,r5
blr