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/*
* Based on arch/arm/mm/proc.S
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
* Copyright (C) 2012 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
#include <asm/hwcap.h>
#include <asm/pgtable-hwdef.h>
#include <asm/pgtable.h>
#include "proc-macros.S"
#ifndef CONFIG_SMP
/* PTWs cacheable, inner/outer WBWA not shareable */
#define TCR_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA
#else
/* PTWs cacheable, inner/outer WBWA shareable */
#define TCR_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA | TCR_SHARED
#endif
#define MAIR(attr, mt) ((attr) << ((mt) * 8))
/*
* cpu_cache_off()
*
* Turn the CPU D-cache off.
*/
ENTRY(cpu_cache_off)
mrs x0, sctlr_el1
bic x0, x0, #1 << 2 // clear SCTLR.C
msr sctlr_el1, x0
isb
ret
ENDPROC(cpu_cache_off)
/*
* cpu_reset(loc)
*
* Perform a soft reset of the system. Put the CPU into the same state
* as it would be if it had been reset, and branch to what would be the
* reset vector. It must be executed with the flat identity mapping.
*
* - loc - location to jump to for soft reset
*/
.align 5
ENTRY(cpu_reset)
mrs x1, sctlr_el1
bic x1, x1, #1
msr sctlr_el1, x1 // disable the MMU
isb
ret x0
ENDPROC(cpu_reset)
/*
* cpu_do_idle()
*
* Idle the processor (wait for interrupt).
*/
ENTRY(cpu_do_idle)
dsb sy // WFI may enter a low-power mode
wfi
ret
ENDPROC(cpu_do_idle)
/*
* cpu_switch_mm(pgd_phys, tsk)
*
* Set the translation table base pointer to be pgd_phys.
*
* - pgd_phys - physical address of new TTB
*/
ENTRY(cpu_do_switch_mm)
mmid w1, x1 // get mm->context.id
bfi x0, x1, #48, #16 // set the ASID
msr ttbr0_el1, x0 // set TTBR0
isb
ret
ENDPROC(cpu_do_switch_mm)
.section ".text.init", #alloc, #execinstr
/*
* __cpu_setup
*
* Initialise the processor for turning the MMU on. Return in x0 the
* value of the SCTLR_EL1 register.
*/
ENTRY(__cpu_setup)
/*
* Preserve the link register across the function call.
*/
mov x28, lr
bl __flush_dcache_all
mov lr, x28
ic iallu // I+BTB cache invalidate
dsb sy
mov x0, #3 << 20
msr cpacr_el1, x0 // Enable FP/ASIMD
msr mdscr_el1, xzr // Reset mdscr_el1
tlbi vmalle1is // invalidate I + D TLBs
/*
* Memory region attributes for LPAE:
*
* n = AttrIndx[2:0]
* n MAIR
* DEVICE_nGnRnE 000 00000000
* DEVICE_nGnRE 001 00000100
* DEVICE_GRE 010 00001100
* NORMAL_NC 011 01000100
* NORMAL 100 11111111
*/
ldr x5, =MAIR(0x00, MT_DEVICE_nGnRnE) | \
MAIR(0x04, MT_DEVICE_nGnRE) | \
MAIR(0x0c, MT_DEVICE_GRE) | \
MAIR(0x44, MT_NORMAL_NC) | \
MAIR(0xff, MT_NORMAL)
msr mair_el1, x5
/*
* Prepare SCTLR
*/
adr x5, crval
ldp w5, w6, [x5]
mrs x0, sctlr_el1
bic x0, x0, x5 // clear bits
orr x0, x0, x6 // set bits
/*
* Set/prepare TCR and TTBR. We use 512GB (39-bit) address range for
* both user and kernel.
*/
ldr x10, =TCR_TxSZ(VA_BITS) | TCR_FLAGS | TCR_IPS_40BIT | \
TCR_ASID16 | TCR_TBI0 | (1 << 31)
#ifdef CONFIG_ARM64_64K_PAGES
orr x10, x10, TCR_TG0_64K
orr x10, x10, TCR_TG1_64K
#endif
msr tcr_el1, x10
ret // return to head.S
ENDPROC(__cpu_setup)
/*
* n n T
* U E WT T UD US IHBS
* CE0 XWHW CZ ME TEEA S
* .... .IEE .... NEAI TE.I ..AD DEN0 ACAM
* 0011 0... 1101 ..0. ..0. 10.. .... .... < hardware reserved
* .... .1.. .... 01.1 11.1 ..01 0001 1101 < software settings
*/
.type crval, #object
crval:
.word 0x000802e2 // clear
.word 0x0405d11d // set
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