| /* |
| * Hibernate low-level support |
| * |
| * Copyright (C) 2016 ARM Ltd. |
| * Author: James Morse <james.morse@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/linkage.h> |
| #include <linux/errno.h> |
| |
| #include <asm/asm-offsets.h> |
| #include <asm/assembler.h> |
| #include <asm/cputype.h> |
| #include <asm/memory.h> |
| #include <asm/page.h> |
| #include <asm/virt.h> |
| |
| /* |
| * To prevent the possibility of old and new partial table walks being visible |
| * in the tlb, switch the ttbr to a zero page when we invalidate the old |
| * records. D4.7.1 'General TLB maintenance requirements' in ARM DDI 0487A.i |
| * Even switching to our copied tables will cause a changed output address at |
| * each stage of the walk. |
| */ |
| .macro break_before_make_ttbr_switch zero_page, page_table |
| msr ttbr1_el1, \zero_page |
| isb |
| tlbi vmalle1 |
| dsb nsh |
| msr ttbr1_el1, \page_table |
| isb |
| .endm |
| |
| |
| /* |
| * Resume from hibernate |
| * |
| * Loads temporary page tables then restores the memory image. |
| * Finally branches to cpu_resume() to restore the state saved by |
| * swsusp_arch_suspend(). |
| * |
| * Because this code has to be copied to a 'safe' page, it can't call out to |
| * other functions by PC-relative address. Also remember that it may be |
| * mid-way through over-writing other functions. For this reason it contains |
| * code from flush_icache_range() and uses the copy_page() macro. |
| * |
| * This 'safe' page is mapped via ttbr0, and executed from there. This function |
| * switches to a copy of the linear map in ttbr1, performs the restore, then |
| * switches ttbr1 to the original kernel's swapper_pg_dir. |
| * |
| * All of memory gets written to, including code. We need to clean the kernel |
| * text to the Point of Coherence (PoC) before secondary cores can be booted. |
| * Because the kernel modules and executable pages mapped to user space are |
| * also written as data, we clean all pages we touch to the Point of |
| * Unification (PoU). |
| * |
| * x0: physical address of temporary page tables |
| * x1: physical address of swapper page tables |
| * x2: address of cpu_resume |
| * x3: linear map address of restore_pblist in the current kernel |
| * x4: physical address of __hyp_stub_vectors, or 0 |
| * x5: physical address of a zero page that remains zero after resume |
| */ |
| .pushsection ".hibernate_exit.text", "ax" |
| ENTRY(swsusp_arch_suspend_exit) |
| /* |
| * We execute from ttbr0, change ttbr1 to our copied linear map tables |
| * with a break-before-make via the zero page |
| */ |
| break_before_make_ttbr_switch x5, x0 |
| |
| mov x21, x1 |
| mov x30, x2 |
| mov x24, x4 |
| mov x25, x5 |
| |
| /* walk the restore_pblist and use copy_page() to over-write memory */ |
| mov x19, x3 |
| |
| 1: ldr x10, [x19, #HIBERN_PBE_ORIG] |
| mov x0, x10 |
| ldr x1, [x19, #HIBERN_PBE_ADDR] |
| |
| copy_page x0, x1, x2, x3, x4, x5, x6, x7, x8, x9 |
| |
| add x1, x10, #PAGE_SIZE |
| /* Clean the copied page to PoU - based on flush_icache_range() */ |
| raw_dcache_line_size x2, x3 |
| sub x3, x2, #1 |
| bic x4, x10, x3 |
| 2: dc cvau, x4 /* clean D line / unified line */ |
| add x4, x4, x2 |
| cmp x4, x1 |
| b.lo 2b |
| |
| ldr x19, [x19, #HIBERN_PBE_NEXT] |
| cbnz x19, 1b |
| dsb ish /* wait for PoU cleaning to finish */ |
| |
| /* switch to the restored kernels page tables */ |
| break_before_make_ttbr_switch x25, x21 |
| |
| ic ialluis |
| dsb ish |
| isb |
| |
| cbz x24, 3f /* Do we need to re-initialise EL2? */ |
| hvc #0 |
| 3: ret |
| |
| .ltorg |
| ENDPROC(swsusp_arch_suspend_exit) |
| |
| /* |
| * Restore the hyp stub. |
| * This must be done before the hibernate page is unmapped by _cpu_resume(), |
| * but happens before any of the hyp-stub's code is cleaned to PoC. |
| * |
| * x24: The physical address of __hyp_stub_vectors |
| */ |
| el1_sync: |
| msr vbar_el2, x24 |
| eret |
| ENDPROC(el1_sync) |
| |
| .macro invalid_vector label |
| \label: |
| b \label |
| ENDPROC(\label) |
| .endm |
| |
| invalid_vector el2_sync_invalid |
| invalid_vector el2_irq_invalid |
| invalid_vector el2_fiq_invalid |
| invalid_vector el2_error_invalid |
| invalid_vector el1_sync_invalid |
| invalid_vector el1_irq_invalid |
| invalid_vector el1_fiq_invalid |
| invalid_vector el1_error_invalid |
| |
| /* el2 vectors - switch el2 here while we restore the memory image. */ |
| .align 11 |
| ENTRY(hibernate_el2_vectors) |
| ventry el2_sync_invalid // Synchronous EL2t |
| ventry el2_irq_invalid // IRQ EL2t |
| ventry el2_fiq_invalid // FIQ EL2t |
| ventry el2_error_invalid // Error EL2t |
| |
| ventry el2_sync_invalid // Synchronous EL2h |
| ventry el2_irq_invalid // IRQ EL2h |
| ventry el2_fiq_invalid // FIQ EL2h |
| ventry el2_error_invalid // Error EL2h |
| |
| ventry el1_sync // Synchronous 64-bit EL1 |
| ventry el1_irq_invalid // IRQ 64-bit EL1 |
| ventry el1_fiq_invalid // FIQ 64-bit EL1 |
| ventry el1_error_invalid // Error 64-bit EL1 |
| |
| ventry el1_sync_invalid // Synchronous 32-bit EL1 |
| ventry el1_irq_invalid // IRQ 32-bit EL1 |
| ventry el1_fiq_invalid // FIQ 32-bit EL1 |
| ventry el1_error_invalid // Error 32-bit EL1 |
| END(hibernate_el2_vectors) |
| |
| .popsection |
