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Diffstat (limited to 'arch/arm64/mm/proc.S')
| -rw-r--r-- | arch/arm64/mm/proc.S | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S new file mode 100644 index 00000000000..f1d8b9bbfda --- /dev/null +++ b/arch/arm64/mm/proc.S @@ -0,0 +1,175 @@ +/* + * 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) + +cpu_name: + .ascii "AArch64 Processor" + .align + + .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 + mov x0, #1 + msr oslar_el1, x0 // Set the debug OS lock + 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 | (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 + * .... .100 .... 01.1 11.1 ..01 0001 1101 < software settings + */ + .type crval, #object +crval: + .word 0x030802e2 // clear + .word 0x0405d11d // set |