/* * 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.h> #include <asm/pgtable-hwdef.h> #include <asm/cpufeature.h> #include <asm/alternative.h> #ifdef CONFIG_ARM64_64K_PAGES #define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K #elif defined(CONFIG_ARM64_16K_PAGES) #define TCR_TG_FLAGS TCR_TG0_16K | TCR_TG1_16K #else /* CONFIG_ARM64_4K_PAGES */ #define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K #endif #define TCR_SMP_FLAGS TCR_SHARED /* PTWs cacheable, inner/outer WBWA */ #define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA #define MAIR(attr, mt) ((attr) << ((mt) * 8)) /* * 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) #ifdef CONFIG_CPU_PM /** * cpu_do_suspend - save CPU registers context * * x0: virtual address of context pointer */ ENTRY(cpu_do_suspend) mrs x2, tpidr_el0 mrs x3, tpidrro_el0 mrs x4, contextidr_el1 mrs x5, cpacr_el1 mrs x6, tcr_el1 mrs x7, vbar_el1 mrs x8, mdscr_el1 mrs x9, oslsr_el1 mrs x10, sctlr_el1 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN mrs x11, tpidr_el1 alternative_else mrs x11, tpidr_el2 alternative_endif mrs x12, sp_el0 stp x2, x3, [x0] stp x4, xzr, [x0, #16] stp x5, x6, [x0, #32] stp x7, x8, [x0, #48] stp x9, x10, [x0, #64] stp x11, x12, [x0, #80] ret ENDPROC(cpu_do_suspend) /** * cpu_do_resume - restore CPU register context * * x0: Address of context pointer */ .pushsection ".idmap.text", "ax" ENTRY(cpu_do_resume) ldp x2, x3, [x0] ldp x4, x5, [x0, #16] ldp x6, x8, [x0, #32] ldp x9, x10, [x0, #48] ldp x11, x12, [x0, #64] ldp x13, x14, [x0, #80] msr tpidr_el0, x2 msr tpidrro_el0, x3 msr contextidr_el1, x4 msr cpacr_el1, x6 /* Don't change t0sz here, mask those bits when restoring */ mrs x5, tcr_el1 bfi x8, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH msr tcr_el1, x8 msr vbar_el1, x9 /* * __cpu_setup() cleared MDSCR_EL1.MDE and friends, before unmasking * debug exceptions. By restoring MDSCR_EL1 here, we may take a debug * exception. Mask them until local_daif_restore() in cpu_suspend() * resets them. */ disable_daif msr mdscr_el1, x10 msr sctlr_el1, x12 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN msr tpidr_el1, x13 alternative_else msr tpidr_el2, x13 alternative_endif msr sp_el0, x14 /* * Restore oslsr_el1 by writing oslar_el1 */ ubfx x11, x11, #1, #1 msr oslar_el1, x11 reset_pmuserenr_el0 x0 // Disable PMU access from EL0 alternative_if ARM64_HAS_RAS_EXTN msr_s SYS_DISR_EL1, xzr alternative_else_nop_endif isb ret ENDPROC(cpu_do_resume) .popsection #endif /* * cpu_do_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) mrs x2, ttbr1_el1 mmid x1, x1 // get mm->context.id phys_to_ttbr x0, x3 #ifdef CONFIG_ARM64_SW_TTBR0_PAN bfi x3, x1, #48, #16 // set the ASID field in TTBR0 #endif bfi x2, x1, #48, #16 // set the ASID msr ttbr1_el1, x2 // in TTBR1 (since TCR.A1 is set) isb msr ttbr0_el1, x3 // now update TTBR0 isb b post_ttbr_update_workaround // Back to C code... ENDPROC(cpu_do_switch_mm) .pushsection ".idmap.text", "ax" /* * void idmap_cpu_replace_ttbr1(phys_addr_t new_pgd) * * This is the low-level counterpart to cpu_replace_ttbr1, and should not be * called by anything else. It can only be executed from a TTBR0 mapping. */ ENTRY(idmap_cpu_replace_ttbr1) save_and_disable_daif flags=x2 adrp x1, empty_zero_page phys_to_ttbr x1, x3 msr ttbr1_el1, x3 isb tlbi vmalle1 dsb nsh isb phys_to_ttbr x0, x3 msr ttbr1_el1, x3 isb restore_daif x2 ret ENDPROC(idmap_cpu_replace_ttbr1) .popsection /* * __cpu_setup * * Initialise the processor for turning the MMU on. Return in x0 the * value of the SCTLR_EL1 register. */ .pushsection ".idmap.text", "ax" ENTRY(__cpu_setup) tlbi vmalle1 // Invalidate local TLB dsb nsh mov x0, #3 << 20 msr cpacr_el1, x0 // Enable FP/ASIMD mov x0, #1 << 12 // Reset mdscr_el1 and disable msr mdscr_el1, x0 // access to the DCC from EL0 isb // Unmask debug exceptions now, enable_dbg // since this is per-cpu reset_pmuserenr_el0 x0 // Disable PMU access from EL0 /* * 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 * NORMAL_WT 101 10111011 */ 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) | \ MAIR(0xbb, MT_NORMAL_WT) msr mair_el1, x5 /* * Prepare SCTLR */ mov_q x0, SCTLR_EL1_SET /* * Set/prepare TCR and TTBR. We use 512GB (39-bit) address range for * both user and kernel. */ ldr x10, =TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \ TCR_TG_FLAGS | TCR_ASID16 | TCR_TBI0 | TCR_A1 tcr_set_idmap_t0sz x10, x9 /* * Set the IPS bits in TCR_EL1. */ tcr_compute_pa_size x10, #TCR_IPS_SHIFT, x5, x6 #ifdef CONFIG_ARM64_HW_AFDBM /* * Hardware update of the Access and Dirty bits. */ mrs x9, ID_AA64MMFR1_EL1 and x9, x9, #0xf cbz x9, 2f cmp x9, #2 b.lt 1f orr x10, x10, #TCR_HD // hardware Dirty flag update 1: orr x10, x10, #TCR_HA // hardware Access flag update 2: #endif /* CONFIG_ARM64_HW_AFDBM */ msr tcr_el1, x10 ret // return to head.S ENDPROC(__cpu_setup)