From patchwork Fri Jan 13 05:28:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Penny Zheng X-Patchwork-Id: 13099774 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 853C2C54EBD for ; Fri, 13 Jan 2023 05:30:10 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.476505.738759 (Exim 4.92) (envelope-from ) id 1pGCde-0007sg-NM; Fri, 13 Jan 2023 05:30:02 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 476505.738759; Fri, 13 Jan 2023 05:30:02 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pGCde-0007s4-Im; Fri, 13 Jan 2023 05:30:02 +0000 Received: by outflank-mailman (input) for mailman id 476505; Fri, 13 Jan 2023 05:30:01 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pGCdd-0005sJ-FF for xen-devel@lists.xenproject.org; Fri, 13 Jan 2023 05:30:01 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-sth1.inumbo.com (Halon) with ESMTP id 517a1b38-9303-11ed-91b6-6bf2151ebd3b; Fri, 13 Jan 2023 06:29:58 +0100 (CET) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B35B1FEC; Thu, 12 Jan 2023 21:30:39 -0800 (PST) Received: from a011292.shanghai.arm.com (a011292.shanghai.arm.com [10.169.190.94]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id F37C33F587; Thu, 12 Jan 2023 21:29:54 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 517a1b38-9303-11ed-91b6-6bf2151ebd3b From: Penny Zheng To: xen-devel@lists.xenproject.org Cc: wei.chen@arm.com, Stefano Stabellini , Julien Grall , Bertrand Marquis , Volodymyr Babchuk , Henry Wang Subject: [PATCH v2 06/40] xen/arm64: move MMU related code from head.S to head_mmu.S Date: Fri, 13 Jan 2023 13:28:39 +0800 Message-Id: <20230113052914.3845596-7-Penny.Zheng@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230113052914.3845596-1-Penny.Zheng@arm.com> References: <20230113052914.3845596-1-Penny.Zheng@arm.com> MIME-Version: 1.0 From: Wei Chen There are lots of MMU specific code in head.S. This code will not be used in MPU systems. If we use #ifdef to gate them, the code will become messy and hard to maintain. So we move MMU related code to head_mmu.S, and keep common code still in head.S. And some assembly macros that will be shared by MMU and MPU later, we move them to macros.h. Signed-off-by: Wei Chen Signed-off-by: Henry Wang --- v1 -> v2: 1. Move macros to macros.h 2. Remove the indention modification 3. Duplicate "fail" instead of exporting it. --- xen/arch/arm/arm64/Makefile | 3 + xen/arch/arm/arm64/head.S | 383 ------------------------ xen/arch/arm/arm64/head_mmu.S | 372 +++++++++++++++++++++++ xen/arch/arm/include/asm/arm64/macros.h | 51 ++++ 4 files changed, 426 insertions(+), 383 deletions(-) create mode 100644 xen/arch/arm/arm64/head_mmu.S diff --git a/xen/arch/arm/arm64/Makefile b/xen/arch/arm/arm64/Makefile index 6d507da0d4..22da2f54b5 100644 --- a/xen/arch/arm/arm64/Makefile +++ b/xen/arch/arm/arm64/Makefile @@ -8,6 +8,9 @@ obj-y += domctl.o obj-y += domain.o obj-y += entry.o obj-y += head.o +ifneq ($(CONFIG_HAS_MPU),y) +obj-y += head_mmu.o +endif obj-y += insn.o obj-$(CONFIG_LIVEPATCH) += livepatch.o obj-y += smc.o diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S index b2214bc5e3..5cfa47279b 100644 --- a/xen/arch/arm/arm64/head.S +++ b/xen/arch/arm/arm64/head.S @@ -28,17 +28,6 @@ #include #endif -#define PT_PT 0xf7f /* nG=1 AF=1 SH=11 AP=01 NS=1 ATTR=111 T=1 P=1 */ -#define PT_MEM 0xf7d /* nG=1 AF=1 SH=11 AP=01 NS=1 ATTR=111 T=0 P=1 */ -#define PT_MEM_L3 0xf7f /* nG=1 AF=1 SH=11 AP=01 NS=1 ATTR=111 T=1 P=1 */ -#define PT_DEV 0xe71 /* nG=1 AF=1 SH=10 AP=01 NS=1 ATTR=100 T=0 P=1 */ -#define PT_DEV_L3 0xe73 /* nG=1 AF=1 SH=10 AP=01 NS=1 ATTR=100 T=1 P=1 */ - -/* Convenience defines to get slot used by Xen mapping. */ -#define XEN_ZEROETH_SLOT zeroeth_table_offset(XEN_VIRT_START) -#define XEN_FIRST_SLOT first_table_offset(XEN_VIRT_START) -#define XEN_SECOND_SLOT second_table_offset(XEN_VIRT_START) - #define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2) #define __HEAD_FLAG_PHYS_BASE 1 @@ -85,57 +74,6 @@ * x30 - lr */ -#ifdef CONFIG_EARLY_PRINTK -/* - * Macro to print a string to the UART, if there is one. - * - * Clobbers x0 - x3 - */ -#define PRINT(_s) \ - mov x3, lr ; \ - adr x0, 98f ; \ - bl puts ; \ - mov lr, x3 ; \ - RODATA_STR(98, _s) - -/* - * Macro to print the value of register \xb - * - * Clobbers x0 - x4 - */ -.macro print_reg xb - mov x0, \xb - mov x4, lr - bl putn - mov lr, x4 -.endm - -#else /* CONFIG_EARLY_PRINTK */ -#define PRINT(s) - -.macro print_reg xb -.endm - -#endif /* !CONFIG_EARLY_PRINTK */ - -/* - * Pseudo-op for PC relative adr , where is - * within the range +/- 4GB of the PC. - * - * @dst: destination register (64 bit wide) - * @sym: name of the symbol - */ -.macro adr_l, dst, sym - adrp \dst, \sym - add \dst, \dst, :lo12:\sym -.endm - -/* Load the physical address of a symbol into xb */ -.macro load_paddr xb, sym - ldr \xb, =\sym - add \xb, \xb, x20 -.endm - .section .text.header, "ax", %progbits /*.aarch64*/ @@ -500,296 +438,6 @@ cpu_init: ret ENDPROC(cpu_init) -/* - * Macro to find the slot number at a given page-table level - * - * slot: slot computed - * virt: virtual address - * lvl: page-table level - */ -.macro get_table_slot, slot, virt, lvl - ubfx \slot, \virt, #XEN_PT_LEVEL_SHIFT(\lvl), #XEN_PT_LPAE_SHIFT -.endm - -/* - * Macro to create a page table entry in \ptbl to \tbl - * - * ptbl: table symbol where the entry will be created - * tbl: table symbol to point to - * virt: virtual address - * lvl: page-table level - * tmp1: scratch register - * tmp2: scratch register - * tmp3: scratch register - * - * Preserves \virt - * Clobbers \tmp1, \tmp2, \tmp3 - * - * Also use x20 for the phys offset. - * - * Note that all parameters using registers should be distinct. - */ -.macro create_table_entry, ptbl, tbl, virt, lvl, tmp1, tmp2, tmp3 - get_table_slot \tmp1, \virt, \lvl /* \tmp1 := slot in \tlb */ - - load_paddr \tmp2, \tbl - mov \tmp3, #PT_PT /* \tmp3 := right for linear PT */ - orr \tmp3, \tmp3, \tmp2 /* + \tlb paddr */ - - adr_l \tmp2, \ptbl - - str \tmp3, [\tmp2, \tmp1, lsl #3] -.endm - -/* - * Macro to create a mapping entry in \tbl to \phys. Only mapping in 3rd - * level table (i.e page granularity) is supported. - * - * ptbl: table symbol where the entry will be created - * virt: virtual address - * phys: physical address (should be page aligned) - * tmp1: scratch register - * tmp2: scratch register - * tmp3: scratch register - * type: mapping type. If not specified it will be normal memory (PT_MEM_L3) - * - * Preserves \virt, \phys - * Clobbers \tmp1, \tmp2, \tmp3 - * - * Note that all parameters using registers should be distinct. - */ -.macro create_mapping_entry, ptbl, virt, phys, tmp1, tmp2, tmp3, type=PT_MEM_L3 - and \tmp3, \phys, #THIRD_MASK /* \tmp3 := PAGE_ALIGNED(phys) */ - - get_table_slot \tmp1, \virt, 3 /* \tmp1 := slot in \tlb */ - - mov \tmp2, #\type /* \tmp2 := right for section PT */ - orr \tmp2, \tmp2, \tmp3 /* + PAGE_ALIGNED(phys) */ - - adr_l \tmp3, \ptbl - - str \tmp2, [\tmp3, \tmp1, lsl #3] -.endm - -/* - * Rebuild the boot pagetable's first-level entries. The structure - * is described in mm.c. - * - * After the CPU enables paging it will add the fixmap mapping - * to these page tables, however this may clash with the 1:1 - * mapping. So each CPU must rebuild the page tables here with - * the 1:1 in place. - * - * Inputs: - * x19: paddr(start) - * x20: phys offset - * - * Clobbers x0 - x4 - */ -ENTRY(create_page_tables) - /* Prepare the page-tables for mapping Xen */ - ldr x0, =XEN_VIRT_START - create_table_entry boot_pgtable, boot_first, x0, 0, x1, x2, x3 - create_table_entry boot_first, boot_second, x0, 1, x1, x2, x3 - create_table_entry boot_second, boot_third, x0, 2, x1, x2, x3 - - /* Map Xen */ - adr_l x4, boot_third - - lsr x2, x19, #THIRD_SHIFT /* Base address for 4K mapping */ - lsl x2, x2, #THIRD_SHIFT - mov x3, #PT_MEM_L3 /* x2 := Section map */ - orr x2, x2, x3 - - /* ... map of vaddr(start) in boot_third */ - mov x1, xzr -1: str x2, [x4, x1] /* Map vaddr(start) */ - add x2, x2, #PAGE_SIZE /* Next page */ - add x1, x1, #8 /* Next slot */ - cmp x1, #(XEN_PT_LPAE_ENTRIES<<3) /* 512 entries per page */ - b.lt 1b - - /* - * If Xen is loaded at exactly XEN_VIRT_START then we don't - * need an additional 1:1 mapping, the virtual mapping will - * suffice. - */ - cmp x19, #XEN_VIRT_START - bne 1f - ret -1: - /* - * Setup the 1:1 mapping so we can turn the MMU on. Note that - * only the first page of Xen will be part of the 1:1 mapping. - */ - - /* - * Find the zeroeth slot used. If the slot is not - * XEN_ZEROETH_SLOT, then the 1:1 mapping will use its own set of - * page-tables from the first level. - */ - get_table_slot x0, x19, 0 /* x0 := zeroeth slot */ - cmp x0, #XEN_ZEROETH_SLOT - beq 1f - create_table_entry boot_pgtable, boot_first_id, x19, 0, x0, x1, x2 - b link_from_first_id - -1: - /* - * Find the first slot used. If the slot is not XEN_FIRST_SLOT, - * then the 1:1 mapping will use its own set of page-tables from - * the second level. - */ - get_table_slot x0, x19, 1 /* x0 := first slot */ - cmp x0, #XEN_FIRST_SLOT - beq 1f - create_table_entry boot_first, boot_second_id, x19, 1, x0, x1, x2 - b link_from_second_id - -1: - /* - * Find the second slot used. If the slot is XEN_SECOND_SLOT, then the - * 1:1 mapping will use its own set of page-tables from the - * third level. For slot XEN_SECOND_SLOT, Xen is not yet able to handle - * it. - */ - get_table_slot x0, x19, 2 /* x0 := second slot */ - cmp x0, #XEN_SECOND_SLOT - beq virtphys_clash - create_table_entry boot_second, boot_third_id, x19, 2, x0, x1, x2 - b link_from_third_id - -link_from_first_id: - create_table_entry boot_first_id, boot_second_id, x19, 1, x0, x1, x2 -link_from_second_id: - create_table_entry boot_second_id, boot_third_id, x19, 2, x0, x1, x2 -link_from_third_id: - create_mapping_entry boot_third_id, x19, x19, x0, x1, x2 - ret - -virtphys_clash: - /* Identity map clashes with boot_third, which we cannot handle yet */ - PRINT("- Unable to build boot page tables - virt and phys addresses clash. -\r\n") - b fail -ENDPROC(create_page_tables) - -/* - * Turn on the Data Cache and the MMU. The function will return on the 1:1 - * mapping. In other word, the caller is responsible to switch to the runtime - * mapping. - * - * Clobbers x0 - x3 - */ -ENTRY(enable_mmu) - PRINT("- Turning on paging -\r\n") - - /* - * The state of the TLBs is unknown before turning on the MMU. - * Flush them to avoid stale one. - */ - tlbi alle2 /* Flush hypervisor TLBs */ - dsb nsh - - /* Write Xen's PT's paddr into TTBR0_EL2 */ - load_paddr x0, boot_pgtable - msr TTBR0_EL2, x0 - isb - - mrs x0, SCTLR_EL2 - orr x0, x0, #SCTLR_Axx_ELx_M /* Enable MMU */ - orr x0, x0, #SCTLR_Axx_ELx_C /* Enable D-cache */ - dsb sy /* Flush PTE writes and finish reads */ - msr SCTLR_EL2, x0 /* now paging is enabled */ - isb /* Now, flush the icache */ - ret -ENDPROC(enable_mmu) - -/* - * Remove the 1:1 map from the page-tables. It is not easy to keep track - * where the 1:1 map was mapped, so we will look for the top-level entry - * exclusive to the 1:1 map and remove it. - * - * Inputs: - * x19: paddr(start) - * - * Clobbers x0 - x1 - */ -ENTRY(remove_identity_mapping) - /* - * Find the zeroeth slot used. Remove the entry from zeroeth - * table if the slot is not XEN_ZEROETH_SLOT. - */ - get_table_slot x1, x19, 0 /* x1 := zeroeth slot */ - cmp x1, #XEN_ZEROETH_SLOT - beq 1f - /* It is not in slot XEN_ZEROETH_SLOT, remove the entry. */ - ldr x0, =boot_pgtable /* x0 := root table */ - str xzr, [x0, x1, lsl #3] - b identity_mapping_removed - -1: - /* - * Find the first slot used. Remove the entry for the first - * table if the slot is not XEN_FIRST_SLOT. - */ - get_table_slot x1, x19, 1 /* x1 := first slot */ - cmp x1, #XEN_FIRST_SLOT - beq 1f - /* It is not in slot XEN_FIRST_SLOT, remove the entry. */ - ldr x0, =boot_first /* x0 := first table */ - str xzr, [x0, x1, lsl #3] - b identity_mapping_removed - -1: - /* - * Find the second slot used. Remove the entry for the first - * table if the slot is not XEN_SECOND_SLOT. - */ - get_table_slot x1, x19, 2 /* x1 := second slot */ - cmp x1, #XEN_SECOND_SLOT - beq identity_mapping_removed - /* It is not in slot 1, remove the entry */ - ldr x0, =boot_second /* x0 := second table */ - str xzr, [x0, x1, lsl #3] - -identity_mapping_removed: - /* See asm/arm64/flushtlb.h for the explanation of the sequence. */ - dsb nshst - tlbi alle2 - dsb nsh - isb - - ret -ENDPROC(remove_identity_mapping) - -/* - * Map the UART in the fixmap (when earlyprintk is used) and hook the - * fixmap table in the page tables. - * - * The fixmap cannot be mapped in create_page_tables because it may - * clash with the 1:1 mapping. - * - * Inputs: - * x20: Physical offset - * x23: Early UART base physical address - * - * Clobbers x0 - x3 - */ -ENTRY(setup_fixmap) -#ifdef CONFIG_EARLY_PRINTK - /* Add UART to the fixmap table */ - ldr x0, =EARLY_UART_VIRTUAL_ADDRESS - create_mapping_entry xen_fixmap, x0, x23, x1, x2, x3, type=PT_DEV_L3 -#endif - /* Map fixmap into boot_second */ - ldr x0, =FIXMAP_ADDR(0) - create_table_entry boot_second, xen_fixmap, x0, 2, x1, x2, x3 - /* Ensure any page table updates made above have occurred. */ - dsb nshst - - ret -ENDPROC(setup_fixmap) - /* * Setup the initial stack and jump to the C world * @@ -818,37 +466,6 @@ fail: PRINT("- Boot failed -\r\n") b 1b ENDPROC(fail) -GLOBAL(_end_boot) - -/* - * Switch TTBR - * - * x0 ttbr - * - * TODO: This code does not comply with break-before-make. - */ -ENTRY(switch_ttbr) - dsb sy /* Ensure the flushes happen before - * continuing */ - isb /* Ensure synchronization with previous - * changes to text */ - tlbi alle2 /* Flush hypervisor TLB */ - ic iallu /* Flush I-cache */ - dsb sy /* Ensure completion of TLB flush */ - isb - - msr TTBR0_EL2, x0 - - isb /* Ensure synchronization with previous - * changes to text */ - tlbi alle2 /* Flush hypervisor TLB */ - ic iallu /* Flush I-cache */ - dsb sy /* Ensure completion of TLB flush */ - isb - - ret -ENDPROC(switch_ttbr) - #ifdef CONFIG_EARLY_PRINTK /* * Initialize the UART. Should only be called on the boot CPU. diff --git a/xen/arch/arm/arm64/head_mmu.S b/xen/arch/arm/arm64/head_mmu.S new file mode 100644 index 0000000000..e2c8f07140 --- /dev/null +++ b/xen/arch/arm/arm64/head_mmu.S @@ -0,0 +1,372 @@ +/* + * xen/arch/arm/head_mmu.S + * + * Start-of-day code for an ARMv8-A. + * + * Ian Campbell + * Copyright (c) 2012 Citrix Systems. + * + * Based on ARMv7-A head.S by + * Tim Deegan + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + */ + +#include +#include + +#define PT_PT 0xf7f /* nG=1 AF=1 SH=11 AP=01 NS=1 ATTR=111 T=1 P=1 */ +#define PT_MEM 0xf7d /* nG=1 AF=1 SH=11 AP=01 NS=1 ATTR=111 T=0 P=1 */ +#define PT_MEM_L3 0xf7f /* nG=1 AF=1 SH=11 AP=01 NS=1 ATTR=111 T=1 P=1 */ +#define PT_DEV 0xe71 /* nG=1 AF=1 SH=10 AP=01 NS=1 ATTR=100 T=0 P=1 */ +#define PT_DEV_L3 0xe73 /* nG=1 AF=1 SH=10 AP=01 NS=1 ATTR=100 T=1 P=1 */ + +/* Convenience defines to get slot used by Xen mapping. */ +#define XEN_ZEROETH_SLOT zeroeth_table_offset(XEN_VIRT_START) +#define XEN_FIRST_SLOT first_table_offset(XEN_VIRT_START) +#define XEN_SECOND_SLOT second_table_offset(XEN_VIRT_START) + +/* + * Macro to find the slot number at a given page-table level + * + * slot: slot computed + * virt: virtual address + * lvl: page-table level + */ +.macro get_table_slot, slot, virt, lvl + ubfx \slot, \virt, #XEN_PT_LEVEL_SHIFT(\lvl), #XEN_PT_LPAE_SHIFT +.endm + +/* + * Macro to create a page table entry in \ptbl to \tbl + * + * ptbl: table symbol where the entry will be created + * tbl: table symbol to point to + * virt: virtual address + * lvl: page-table level + * tmp1: scratch register + * tmp2: scratch register + * tmp3: scratch register + * + * Preserves \virt + * Clobbers \tmp1, \tmp2, \tmp3 + * + * Also use x20 for the phys offset. + * + * Note that all parameters using registers should be distinct. + */ +.macro create_table_entry, ptbl, tbl, virt, lvl, tmp1, tmp2, tmp3 + get_table_slot \tmp1, \virt, \lvl /* \tmp1 := slot in \tlb */ + + load_paddr \tmp2, \tbl + mov \tmp3, #PT_PT /* \tmp3 := right for linear PT */ + orr \tmp3, \tmp3, \tmp2 /* + \tlb paddr */ + + adr_l \tmp2, \ptbl + + str \tmp3, [\tmp2, \tmp1, lsl #3] +.endm + +/* + * Macro to create a mapping entry in \tbl to \phys. Only mapping in 3rd + * level table (i.e page granularity) is supported. + * + * ptbl: table symbol where the entry will be created + * virt: virtual address + * phys: physical address (should be page aligned) + * tmp1: scratch register + * tmp2: scratch register + * tmp3: scratch register + * type: mapping type. If not specified it will be normal memory (PT_MEM_L3) + * + * Preserves \virt, \phys + * Clobbers \tmp1, \tmp2, \tmp3 + * + * Note that all parameters using registers should be distinct. + */ +.macro create_mapping_entry, ptbl, virt, phys, tmp1, tmp2, tmp3, type=PT_MEM_L3 + and \tmp3, \phys, #THIRD_MASK /* \tmp3 := PAGE_ALIGNED(phys) */ + + get_table_slot \tmp1, \virt, 3 /* \tmp1 := slot in \tlb */ + + mov \tmp2, #\type /* \tmp2 := right for section PT */ + orr \tmp2, \tmp2, \tmp3 /* + PAGE_ALIGNED(phys) */ + + adr_l \tmp3, \ptbl + + str \tmp2, [\tmp3, \tmp1, lsl #3] +.endm + +.section .text.header, "ax", %progbits +/*.aarch64*/ + +/* + * Rebuild the boot pagetable's first-level entries. The structure + * is described in mm.c. + * + * After the CPU enables paging it will add the fixmap mapping + * to these page tables, however this may clash with the 1:1 + * mapping. So each CPU must rebuild the page tables here with + * the 1:1 in place. + * + * Inputs: + * x19: paddr(start) + * x20: phys offset + * + * Clobbers x0 - x4 + */ +ENTRY(create_page_tables) + /* Prepare the page-tables for mapping Xen */ + ldr x0, =XEN_VIRT_START + create_table_entry boot_pgtable, boot_first, x0, 0, x1, x2, x3 + create_table_entry boot_first, boot_second, x0, 1, x1, x2, x3 + create_table_entry boot_second, boot_third, x0, 2, x1, x2, x3 + + /* Map Xen */ + adr_l x4, boot_third + + lsr x2, x19, #THIRD_SHIFT /* Base address for 4K mapping */ + lsl x2, x2, #THIRD_SHIFT + mov x3, #PT_MEM_L3 /* x2 := Section map */ + orr x2, x2, x3 + + /* ... map of vaddr(start) in boot_third */ + mov x1, xzr +1: str x2, [x4, x1] /* Map vaddr(start) */ + add x2, x2, #PAGE_SIZE /* Next page */ + add x1, x1, #8 /* Next slot */ + cmp x1, #(XEN_PT_LPAE_ENTRIES<<3) /* 512 entries per page */ + b.lt 1b + + /* + * If Xen is loaded at exactly XEN_VIRT_START then we don't + * need an additional 1:1 mapping, the virtual mapping will + * suffice. + */ + cmp x19, #XEN_VIRT_START + bne 1f + ret +1: + /* + * Setup the 1:1 mapping so we can turn the MMU on. Note that + * only the first page of Xen will be part of the 1:1 mapping. + */ + + /* + * Find the zeroeth slot used. If the slot is not + * XEN_ZEROETH_SLOT, then the 1:1 mapping will use its own set of + * page-tables from the first level. + */ + get_table_slot x0, x19, 0 /* x0 := zeroeth slot */ + cmp x0, #XEN_ZEROETH_SLOT + beq 1f + create_table_entry boot_pgtable, boot_first_id, x19, 0, x0, x1, x2 + b link_from_first_id + +1: + /* + * Find the first slot used. If the slot is not XEN_FIRST_SLOT, + * then the 1:1 mapping will use its own set of page-tables from + * the second level. + */ + get_table_slot x0, x19, 1 /* x0 := first slot */ + cmp x0, #XEN_FIRST_SLOT + beq 1f + create_table_entry boot_first, boot_second_id, x19, 1, x0, x1, x2 + b link_from_second_id + +1: + /* + * Find the second slot used. If the slot is XEN_SECOND_SLOT, then the + * 1:1 mapping will use its own set of page-tables from the + * third level. For slot XEN_SECOND_SLOT, Xen is not yet able to handle + * it. + */ + get_table_slot x0, x19, 2 /* x0 := second slot */ + cmp x0, #XEN_SECOND_SLOT + beq virtphys_clash + create_table_entry boot_second, boot_third_id, x19, 2, x0, x1, x2 + b link_from_third_id + +link_from_first_id: + create_table_entry boot_first_id, boot_second_id, x19, 1, x0, x1, x2 +link_from_second_id: + create_table_entry boot_second_id, boot_third_id, x19, 2, x0, x1, x2 +link_from_third_id: + create_mapping_entry boot_third_id, x19, x19, x0, x1, x2 + ret + +virtphys_clash: + /* Identity map clashes with boot_third, which we cannot handle yet */ + PRINT("- Unable to build boot page tables - virt and phys addresses clash. -\r\n") + b fail +ENDPROC(create_page_tables) + +/* + * Turn on the Data Cache and the MMU. The function will return on the 1:1 + * mapping. In other word, the caller is responsible to switch to the runtime + * mapping. + * + * Clobbers x0 - x3 + */ +ENTRY(enable_mmu) + PRINT("- Turning on paging -\r\n") + + /* + * The state of the TLBs is unknown before turning on the MMU. + * Flush them to avoid stale one. + */ + tlbi alle2 /* Flush hypervisor TLBs */ + dsb nsh + + /* Write Xen's PT's paddr into TTBR0_EL2 */ + load_paddr x0, boot_pgtable + msr TTBR0_EL2, x0 + isb + + mrs x0, SCTLR_EL2 + orr x0, x0, #SCTLR_Axx_ELx_M /* Enable MMU */ + orr x0, x0, #SCTLR_Axx_ELx_C /* Enable D-cache */ + dsb sy /* Flush PTE writes and finish reads */ + msr SCTLR_EL2, x0 /* now paging is enabled */ + isb /* Now, flush the icache */ + ret +ENDPROC(enable_mmu) + +/* + * Remove the 1:1 map from the page-tables. It is not easy to keep track + * where the 1:1 map was mapped, so we will look for the top-level entry + * exclusive to the 1:1 map and remove it. + * + * Inputs: + * x19: paddr(start) + * + * Clobbers x0 - x1 + */ +ENTRY(remove_identity_mapping) + /* + * Find the zeroeth slot used. Remove the entry from zeroeth + * table if the slot is not XEN_ZEROETH_SLOT. + */ + get_table_slot x1, x19, 0 /* x1 := zeroeth slot */ + cmp x1, #XEN_ZEROETH_SLOT + beq 1f + /* It is not in slot XEN_ZEROETH_SLOT, remove the entry. */ + ldr x0, =boot_pgtable /* x0 := root table */ + str xzr, [x0, x1, lsl #3] + b identity_mapping_removed + +1: + /* + * Find the first slot used. Remove the entry for the first + * table if the slot is not XEN_FIRST_SLOT. + */ + get_table_slot x1, x19, 1 /* x1 := first slot */ + cmp x1, #XEN_FIRST_SLOT + beq 1f + /* It is not in slot XEN_FIRST_SLOT, remove the entry. */ + ldr x0, =boot_first /* x0 := first table */ + str xzr, [x0, x1, lsl #3] + b identity_mapping_removed + +1: + /* + * Find the second slot used. Remove the entry for the first + * table if the slot is not XEN_SECOND_SLOT. + */ + get_table_slot x1, x19, 2 /* x1 := second slot */ + cmp x1, #XEN_SECOND_SLOT + beq identity_mapping_removed + /* It is not in slot 1, remove the entry */ + ldr x0, =boot_second /* x0 := second table */ + str xzr, [x0, x1, lsl #3] + +identity_mapping_removed: + /* See asm/arm64/flushtlb.h for the explanation of the sequence. */ + dsb nshst + tlbi alle2 + dsb nsh + isb + + ret +ENDPROC(remove_identity_mapping) + +/* + * Map the UART in the fixmap (when earlyprintk is used) and hook the + * fixmap table in the page tables. + * + * The fixmap cannot be mapped in create_page_tables because it may + * clash with the 1:1 mapping. + * + * Inputs: + * x20: Physical offset + * x23: Early UART base physical address + * + * Clobbers x0 - x3 + */ +ENTRY(setup_fixmap) +#ifdef CONFIG_EARLY_PRINTK + /* Add UART to the fixmap table */ + ldr x0, =EARLY_UART_VIRTUAL_ADDRESS + create_mapping_entry xen_fixmap, x0, x23, x1, x2, x3, type=PT_DEV_L3 +#endif + /* Map fixmap into boot_second */ + ldr x0, =FIXMAP_ADDR(0) + create_table_entry boot_second, xen_fixmap, x0, 2, x1, x2, x3 + /* Ensure any page table updates made above have occurred. */ + dsb nshst + + ret +ENDPROC(setup_fixmap) + +/* Fail-stop */ +fail: PRINT("- Boot failed -\r\n") +1: wfe + b 1b +ENDPROC(fail) + +GLOBAL(_end_boot) + +/* + * Switch TTBR + * + * x0 ttbr + * + * TODO: This code does not comply with break-before-make. + */ +ENTRY(switch_ttbr) + dsb sy /* Ensure the flushes happen before + * continuing */ + isb /* Ensure synchronization with previous + * changes to text */ + tlbi alle2 /* Flush hypervisor TLB */ + ic iallu /* Flush I-cache */ + dsb sy /* Ensure completion of TLB flush */ + isb + + msr TTBR0_EL2, x0 + + isb /* Ensure synchronization with previous + * changes to text */ + tlbi alle2 /* Flush hypervisor TLB */ + ic iallu /* Flush I-cache */ + dsb sy /* Ensure completion of TLB flush */ + isb + + ret +ENDPROC(switch_ttbr) + +/* + * Local variables: + * mode: ASM + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/arch/arm/include/asm/arm64/macros.h b/xen/arch/arm/include/asm/arm64/macros.h index 140e223b4c..f28c124e66 100644 --- a/xen/arch/arm/include/asm/arm64/macros.h +++ b/xen/arch/arm/include/asm/arm64/macros.h @@ -32,6 +32,57 @@ hint #22 .endm +#ifdef CONFIG_EARLY_PRINTK +/* + * Macro to print a string to the UART, if there is one. + * + * Clobbers x0 - x3 + */ +#define PRINT(_s) \ + mov x3, lr ; \ + adr x0, 98f ; \ + bl puts ; \ + mov lr, x3 ; \ + RODATA_STR(98, _s) + +/* + * Macro to print the value of register \xb + * + * Clobbers x0 - x4 + */ +.macro print_reg xb + mov x0, \xb + mov x4, lr + bl putn + mov lr, x4 +.endm + +#else /* CONFIG_EARLY_PRINTK */ +#define PRINT(s) + +.macro print_reg xb +.endm + +#endif /* !CONFIG_EARLY_PRINTK */ + +/* + * Pseudo-op for PC relative adr , where is + * within the range +/- 4GB of the PC. + * + * @dst: destination register (64 bit wide) + * @sym: name of the symbol + */ +.macro adr_l, dst, sym + adrp \dst, \sym + add \dst, \dst, :lo12:\sym +.endm + +/* Load the physical address of a symbol into xb */ +.macro load_paddr xb, sym + ldr \xb, =\sym + add \xb, \xb, x20 +.endm + /* * Register aliases. */